sábado, 24 de noviembre de 2007

Anuncian medidas urgentes para la protección de ballenas y delfines en costas chilenas

Viernes 23 de Noviembre de 2007
Fuente :La Segunda Internet

Listado incluye a la ballena azul, tonina overa, delfín chileno, ballena franca austral, ballena jorobada y delfín nariz de botella. Ministra Uriarte reiteró su rechazo al anuncio del gobierno de Japón de reanudar la caza de ballenas en aguas del Santuario Ballenero del Océano Austral, como parte de su programa de cacería científica.

La Ministra de Medio Ambiente, Ana Lya Uriarte, dio a conocer esta mañana una serie de medidas destinadas a proteger y conservar las ballenas a lo largo de nuestras costas.

Para la Secretaria de Estado, “la protección de nuestros ecosistemas y de especies tan emblemáticas como las ballenas y otros cetáceos, es un tema de interés nacional, no sólo para el gobierno, sino que particularmente para toda una sociedad, que entiende que es nuestra obligación proteger este patrimonio natural y buscar los mecanismos para su conservación”.

Por este motivo, sostuvo la autoridad, “es que en el marco del Reglamento de Clasificación de Especies coordinado por Conama -el cual establece un procedimiento transparente, participativo e informado con base en criterios científico técnicos para catalogar en forma oficial y formal las especies silvestres de flora y fauna-, hemos decidido incluir un listado que contiene las siguientes especies de mamíferos marinos: ballena azul, tonina overa, delfín chileno, ballena franca austral, ballena jorobada y delfín nariz de botella”.

Dicha lista, señaló la Ministra Uriarte, “deberá ser sometida al Consejo de Ministros de Conama en el más breve plazo, para dar inicio de esta forma a su proceso de clasificación formal y posterior ratificación por parte de la Presidenta de la República”.

“Junto con lo anterior, Conama ha encargado un estudio que permita recabar antecedentes para la consideración, en futuros procesos de clasificación, de otras especies de mamíferos marinos, entre las que se cuentan la ballena minke, ballena Sei, ballena de aleta, delfín común pelágico, delfín Risso, delfín de Peale, orcas, y cachalotes”, aseguró la autoridad

Respecto a medidas de más largo plazo, la Ministra del Medio Ambiente informó que Conama coordinará un Consejo Directivo de Áreas Marinas y Costeras Protegidas, que deberá entre otros temas, elaborar un Plan de Acción para la conservación de cetáceos en el transcurso del año 2008.

De igual modo, y en el marco de la implementación del área marina costera protegida Francisco Coloane y el parque marino del mismo nombre –ubicados ambos en el Estrecho de Magallanes– se acaba de concluir un Reglamento de Observación de Cetáceos y un plan de investigación para el área, destinado a proteger los sitios de alimentación de la ballena jorobada.

Por último, la Ministra Uriarte reiteró su rechazo al anuncio japonés de reanudar la caza de ballenas en aguas del Santuario Ballenero del Océano Austral, como parte de su programa de cacería científica.

Según la máxima autoridad ambiental del país, “esta medida contraviene el espíritu de la moratoria para la cacería comercial de tales especies, en vigencia desde 1986. Y hacemos un llamado a Japón para que suspenda indefinidamente esta actividad”.

martes, 20 de noviembre de 2007

Japón decide retomar caza de ballenas pese a repudio internacional

19/11/2007

El gobierno australiano ordenó a su embajador en Japón que presente una queja formal por la reanudación del programa de caza de ballenas en el Pacífico Sur.

Sin hacer caso de las duras protestas internacionales, la flota ballenera de Japón reanudó la caza de los cetáceos en la Antártida, informó la agencia Kyodo.

Hasta mediados de abril serán capturados unos 850 rorcuales aliblancos, así como 50 rorcuales comunes y otras tantas ballenas jorobadas o yubarta, "con fines científicos", según señala el gobierno nipón.

La flota está formada por el barco nodriza Nisshin Maru, de 8.044 toneladas, y otras cinco naves, que registrarán datos como el contenido del estómago de los animales y su edad.

A su regreso de la caza, la carne de las ballenas será vendida en los mercados, según la versión de Japón para financiar futuras expediciones.

Pese a la moratoria aprobada en 1986 a la caza comercial de ballenas, Japón evade esta prohibición alegando los "fines científicos" de su flota, pese a las protestas del resto de los países.

"Aunque tenemos que enfrentar perniciosas tácticas de bloqueo de grupos ecologistas, tenemos que seguir con esta tarea en el futuro", declaró el director de la flota en la ceremonia de partida en el puerto de Shimonoseki, sede tradicionalmente de los barcos balleneros.

Según Greenpeace, la flota debía partir el viernes, pero su salida fue retrasada para no incomodar al primer ministro Yasuo Fukuda durante su encuentro ese día con el Presidente estadounidense, George W. Bush.

AUSTRALIA PROTESTA
El gobierno de Australia manifestó hoy su frustración por el inicio temporada de caza de ballenas en Japón.

Un comunicado conjunto firmado por los titulares de Exteriores, Alexander Downer, y Medio Ambiente, Malcolm Turnbull, indicó que el Ejecutivo australiano se opone "implacablemente" a todas las formas de captura de cetáceos y emplazó a las autoridades niponas a que reconsideren su posición respecto a esta "práctica inhumana".

Australia ha ordenado a su embajador en Japón, Murray McLean, que presente una queja formal por la reanudación del programa para la caza de ballenas jorobadas en el Pacífico Sur, poniendo fin de forma unilateral a una moratoria vigente desde 1963.

La Comisión Ballenera Internacional (CBI) solicitó en junio pasado a Japón que detenga su programa de "capturas con fines científicos", tras una resolución no vinculante auspiciada por Australia, uno de los países que con mayor insistencia rechaza el plan.

La CBI ha ratificado la moratoria vigente desde 1986 contra la caza de ballenas con fines comerciales, pese a las presiones niponas para que se levante el veto para la captura a pequeña escala.

Noruega es el único país del mundo que permite la caza comercial de cetáceos, pero Japón e Islandia cazan más de 2.000 ballenas al año con fines "científicos", lo que, según los grupos ecologistas, es una forma encubierta de realizar capturas comerciales.

domingo, 18 de noviembre de 2007

Japón inicia misión de cacería masiva de ballenas protegidas

18 de Noviembre, 2007

Japón desafió a la comunidad internacional e inició el domingo su mayor expedición de caza de ballenas en varias décadas, con la mira en una especie del cetáceo que está protegida.

Una embarcación de activistas de Greenpeace, opuestos a la caza de ballenas, esperaba a la flota japonesa en el mar.

Se trata de la primera expedición masiva de caza de la ballena jorobada desde la década de los años 60.

Tras una ceremonia en el puerto de Shimonoseki, en el sur del país, cuatro barcos se encaminaron hacia las aguas cercanas a la Antártida, reanudando una cacería que debió ser interrumpida por un incendio letal en febrero.

Las autoridades de la expedición dijeron a la multitud que despedía a los barcos que Japón no cederá ante los activistas y preservará su cultura de comer ballenas.

"Son terroristas ambientales violentos", expresó el líder de la misión Hajime Ishikawa en la ceremonia. "Su violencia es imperdonable ... debemos luchar contra su hipocresía y mentiras".

La flotilla planea matar cerca de 50 ballenas jorobadas, en lo que sería la primera cacería de gran escala de la especie casi extinguida desde que una moratoria de 1963 en el océano Pacífico sur colocó bajo protección internacional a estos mamíferos marinos.

La misión busca cazar también cerca de 935 ballenas antárticas y unas 50 rorcuales. Según la Agencia de Pesca de Japón sería la mayor caza de ballena con fines científicos que se haya realizado hasta ahora.

La expedición se extenderá hasta abril.

Japón sostiene que necesita matar a los animales para realizar investigaciones sobre sus comportamientos reproductivos y de alimentación.

La Comisión Ballenera Internacional autoriza la caza de ballenas con fines científicos, pero los críticos consideran que Japón utiliza la ciencia para encubrir una caza comercial.

El grupo Greenpeace dijo que su embarcación, llamada Esperanza, estaba a poca distancia de las aguas territoriales de Japón y perseguirá a la flota japonesa hasta el sur. No se informó el domingo si se había registrado alguna confrontación.

"Vamos a hacer todo lo que podamos para reducir la caza", manifestó en comunicación telefónica con la AP Karli Thomas, líder de la expedición a bordo del Esperanza. "El programa de investigación de Japón es una farsa. Exigimos que el gobierno japonés lo cancele".

La moratoria para la caza comercial de ballenas entró en efecto en 1986, pero desde entonces Japón ha matado cerca de 10.500 ballenas minke y rorcuales de Bryde amparada en permisos científicos. Durante años, Tokio ha instado sin éxito a la comisión ballenera para que deje sin efecto la moratoria.

jueves, 15 de noviembre de 2007

Contaminación acústica en Canarias, Gibraltar y Baleares

03-11-2007

Las aguas de Canarias, Gibraltar y Baleares, las zonas con más contaminación acústica


Los fondos marinos de las Islas Canarias, el Estrecho de Gibraltar y el archipiélago balear son las zonas españolas en las que hay una mayor contaminación acústica submarina, lo que tiene unos efectos nefastos para los cetáceos, muchos de los cuales acaban muriendo a causa de la sordera.


El incesante tráfico marítimo de barcos de pasajeros, yates, mercantes y pesqueros en aguas españolas está teniendo consecuencias irreversibles para el ecosistema marino y, en especial, para las ballenas, los delfines, las orcas y otras especies de cetáceos, que corren riesgo de desaparecer, según ha advertido a Efe el biólogo francés Michel André.

El ruido que producen tanto los barcos como otras fuentes artificiales, como los radares o las prospecciones petroleras, están provocando una pérdida de la capacidad auditiva de estos animales, lo que les impide algo tan esencial para su supervivencia como es el hecho de comunicarse entre ellos.

Esta disminución auditiva tiene otros efectos aún más fatídicos, si cabe, para estas especies, pues la sordera, causada por la exposición continua a ruidos excesivos, provoca que muchos cetáceos sean incapaces de captar los sonidos de baja frecuencia que emiten los buques y no puedan esquivarlos.

Sólo en las aguas de las Islas Canarias, según André, fallecen cada año entre seis y diez cachalotes por el impacto con barcos, una cifra alarmante teniendo en cuenta que en esta zona habitan unos 300 de estos ejemplares, divididos en grupos de diez a quince individuos, que alcanzan la madurez reproductiva sobre los treinta años.

Lo cierto es que esta problemática no afecta sólo a España, pues la actividad del hombre ha perturbado el silencio de todo el fondo marino del planeta, sin excepción. 'No existe ya ningún rincón del mundo donde no haya contaminación acústica', subraya André.

Aunque no existen datos del número de cetáceos que mueren cada año en aguas españolas tras impactar contra barcos, este experto señala que algunas de las zonas 'más calientes', es decir, más ruidosas y más peligrosas, son el archipiélago canario, el Estrecho de Gibraltar y las Islas Baleares.

Hasta el momento el equipo científico de Michel André ha elaborado, por primera vez en todo el mundo, un mapa de contaminación acústica submarina de las Baleares, y ahora hará lo mismo en la costa catalana, gracias a un proyecto financiado por la Fundación La Caixa, cuyos resultados se conocerán a finales de año.

'Este mapa nos dará la oportunidad de conocer la realidad del fondo marino, qué ruidos hay y dónde están los focos, para saber cómo afecta a los cetáceos y qué medidas podemos adoptar', explica el director del Laboratorio de Aplicaciones Bioacústicas de la Universidad Politécnica de Cataluña (UPC).

Lo ideal, según André, sería poder realizar este mapa de contaminación acústica en todo el litoral español, aunque antes, subraya, 'se tiene que lograr la financiación necesaria', que no siempre es fácil.

El investigador considera que el problema de la contaminación acústica es sumamente importante para el equilibrio mundial de los ecosistemas marinos, pese a que no goza de la concienciación necesaria ni entre la ciudadanía ni entre los gobiernos.

En su opinión, en este caso sucederá algo 'similar' a lo que ha ocurrido con el cambio climático, en el sentido de que hace años que los científicos advierten de los peligros del calentamiento global por las emisiones de gases de efecto invernadero, aunque no se ha decidido actuar hasta que los efectos han sido evidentes.

'También en este caso empezamos a tener datos. Hay que concienciar a la sociedad de que es necesario actuar. No dejemos pasar los años, o será demasiado tarde', advierte André.



EFE

Turismo Ballenero

Canarias

Medio Ambiente multará con 300.000 euros a barcos incumplen turismo ballenero


18/10/2007 - El Ministerio de Medio Ambiente multará con hasta 300.000 euros a las embarcaciones que incumplan la normativa que regula el turismo ballenero, dijo hoy Borja Heredia, jefe del Área de Acciones de Conservación, durante su participación en el Encuentro Internacional para la Protección de Cetáceos en la Costa Occidental Africana. Estas sanciones se harán efectivas en noviembre después de que se apruebe un real decreto y serán en función de la "gravedad de cada caso", dijo Heredia. Las multas las podrá notificar el SEPRONA (Servicio de Protección de la Naturaleza) de la Guardia Civil, que actuará en colaboración con otros agentes de vigilancia de las comunidades autónomas.

El responsable de Medio Ambiente en la conferencia "Observaciones de Ballenas en España", reconoció que "no hay suficientes medidas para vigilar el turismo ballenero", aunque "el decreto intentará normalizar la situación por la vía legal ante la complejidad e vigilar el mar".

Las medidas de protección para las embarcaciones de avistamiento de cetáceos prohíben todo contacto físico con estos mamíferos, alimentarlos, emitir ruidos, bañarse o bucear cerca de ellos dentro e unas directrices complementarias que igualmente velan por respetar el desarrollo libre de la navegación.

Borja Heredia está convencido de que el turismo ballenero ofrece "la posibilidad de revelar datos sobre los delfines de interés científico", además de representar una importante fuente de ingresos para las comunidades que practican esta actividad.

Al respecto, Nicola Hodgins, de la Sociedad de Conservación de Ballenas y Delfines, dijo en la ponencia "Nuestra tarea en la observación de las ballenas y delfines" que el negocio del turismo ballenero genera al año 1.500 millones de dólares y que el crecimiento de esta industria es de un 12 por ciento anual.

Hodgins aseguró que la observación de los delfines ha levantado la economía de algunas comunidades o pueblos en lo que denominó "ecoturismo".

Esta actividad es "un ejemplo perfecto para conservar los cetáceos", agregó la miembro de la Sociedad de Conservación de Ballenas y Delfines.

En Canarias, cada año un millón de personas visitan a los delfines en estas embarcaciones, aunque no es una de las actividades que más se promociona en las islas, comentaron técnicos de Medio Ambiente del Ayuntamiento de Adeje.

Fuente: EFE

Iceland turn-around on commercial whaling?

21.09.07


Despite the Fisheries Minister’s announcement to Icelandic media in August that “There is no reason to continue commercial whaling if there is no demand for the product”, more whales are destined to die in Iceland’s controversial commercial hunt. Via an amendment to the regulation - new regulation, number 822 issued on the 14th of September 2007 - the Minister, Einar K. Gudfinnsson has extended the commercial hunting season until 1st November 2007.

“In this bizarre turn around, the Minister has sanctioned the extension of the commercial whaling season into the start of winter, when weather condition for hunting may further reduce the probably of whales being killed humanely. Now 23 minke whales and 2 fin whales which were left untaken from the 2006/07 commercial quota are once again available for the whalers to hunt. The question is what has prompted this u-turn? It seems unlikely that market has miraculously improved overnight. It is unclear what this may mean for the long term future of commercial whaling in Iceland” said Philippa Brakes, WDCS whaling expert.

According to the Minke Whalers Association, the whaling vessel the Halldor Sigurdsson is readying itself and will go out at the first opportunity to continue the commercial minke whale hunt.

How YOU can help:

Please help us make whaling in Iceland history by emailing the Icelandic Foreign Minister, requesting that Iceland makes a binding pledge to never issue any further quotas for whaling.
Go to:

http://www.stopbloodywhaling.org/story_details.php?select=85

lunes, 5 de noviembre de 2007

Heroes Star In Japan Dolphin Cull Clash



By Peter Sharp
Asia correspondent, Japan
Updated:10:29, Thursday November 01, 2007
TV star Hayden Panettiere has been involved in a violent confrontation with Japanese fishermen as she tried to disrupt their annual dolphin slaughter.

Heroes star Hayden in tears

The 18-year-old actress, who stars in TV blockbuster Heroes, paddled out on a surfboard in an attempt to reach a pod of dolphins to stop them being driven into a nearby cove and killed.

But the six surfers, from Australia and the United States, were intercepted by a fishing boat before they could reach the dolphins.

The fishermen used the boat's propellers to block their way and at one point struck out with a boathook.

It was an ugly and potentially life-threatening confrontation that lasted more than 10 minutes before the surfers were forced to return to the beach.
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It is believed that the dolphins were later taken into the cove and killed.

Panettiere, who is a keen surfer and a committed marine conservationist and supporter of the campaign to save the Japan dolphins, said: "It was really frightening.

"Some of us were hit by the boathook. But in the end all we really worried about was the dolphins.

"It was so incredibly sad. We were so close to them and they were sky hopping, jumping out of the water to see us."

Surfers attacked by fishermen


Breaking down in tears, she added: "One little baby dolphin stuck his head out and kinda looked at me and the thought that it's no longer with us is really hard to take."

The surfers drove straight to Osaka airport and left the country to avoid arrest by the Japanese national police.

All would have been charged with trespass, but Panettiere is now back in Los Angeles.

More than 22,000 dolphins are slaughtered by fishermen in Japan every year. The hunt continues despite worldwide condemnation.

In Taijie, more than 2,000 mammals are slaughtered in the season.

Many Japanese believe dolphins should be treated like fish. They have been hunting dolphins for centuries and see any criticism of this as an attack on their culture.

http://news.sky.com/skynews/article/0,,30200-1291049,00.html

Surf and Dolphins

Dolphins' Defenders
Acclaimed professional surfer and dolphin defender Dave Rastovich made a bold declaration against the ongoing commercial slaughter of dolphins in Japan by leading an international crew of surfers, musicians, actors, and activists in a traditional surfing paddle-out ceremony to honor the memory of the thousands of dolphins killed each year at the notorious killing cove in Taiji, Japan. During a second ceremony, the group met with a violent reaction from the local fishermen.go here to see the video http://news.sky.com/skynews/article/0,,30200-1291049,00.html.

Ric O'Barry, director of the Save Japan Dolphins coalition, is in Taiji continuing to lead efforts to educate the Japanese public about the cruelty of the drive fishery and the toxic contamination of dolphin meat being sold in Japan.

viernes, 2 de noviembre de 2007

Conservación Ballenas Jorobadas del Pácifico Sudeste

13/07/2007
Investigador presenta publicación sobre ballenas jorobadas

Como una estrategia e importante herramienta para la conservación y protección de la especie es considerado el libro ““Estrategia para la Conservación de la Ballena Jorobada del Pacífico Sudeste. Lineamientos para un plan de acción regional e iniciativas nacionales” y que forma parte de un trabajo conjunto entre instituciones nacionales y extranjeras que destacan una serie de experiencias conocidas sobre la ballena jorobada. El libro fue presentado por uno de sus autores, el biólogo marino Jorge Gibbons, investigador y académico de la Universidad de Magallanes, el pasado miércoles 5 de junio en el Auditorio Universitario ante la presencia de las autoridades universitarias, la Intendenta regional subrogante, Sra. Ana María Díaz, académicos e investigadores de nuestra casa de estudios.

Edición internacional

Financiado por el Fondo Mundial de la Vida Silvestre y coeditado por la Fundación Yubarta; Fundación Ecuatoriana para el Estudio de Mamíferos Marinos; Instituto de la Patagonia-Universidad de Magallanes; Smithsonian Tropical Research Institute y el Centro Peruano de Estudios Cetológicos, el libro es un documento que tiene el objetivo de reunir antecedentes entre Panamá y Chile sobre la ballena jorobada y ponerlos a disposición de las autoridades y la comunidad en general.

La iniciativa surgió por el interés del Fondo Mundial de la Vida Silvestre, que otorgó el financiamiento, y comenzó a tomar forma hacia el año 2004, efectuando invitaciones directas a investigadores que pudieran entregar aportes significativos sobre la especie. Uno de esos investigadores fue Jorge Gibbons.


La ballena jorobada es una especie que tiene como una de sus poblaciones el pacífico sudeste, que incluye a todos los países con costa al Pacífico, y que, a juicio de Gibbons, la comunidad ha empezado a cambiar su impresión general acerca del ámbito de acción de las ballenas. Así, por ejemplo, han dejado de ser algo excéntrico o extraño y pasaron a convertirse en ejemplares de observación que destacan incluso por su magia y carisma. Además, destacó que el cine y el arte han ayudado a socializar el conocimiento sobre la especie ya sea a través del documentalismo, produciendo un acercamiento con personas lejanas al entorno científico. De acuerdo a la información existente, la ballena jorobada se desplaza entre Panamá, en Centroamérica, y el continente antártico. En la Patagonia y la Antártida puede encontrarse durante la época veraniega. Esta publicación será distribuida a las bibliotecas y centros de investigación.

Fuente:
http://www.umag.cl/noticias/?id=529

Ecuador protege a Delfines y Atunes

Fecha de Publicación: 2007-10-17
Ecuador presenta propuesta para proteger atún patudo

MANTA, ECUADOR.-Ecuador mantiene su posición de establecer algunas normas para normar la captura del atún en el Océano Pacífico oriental.

Una de esas propuestas es que se cierre un área especial, ubicada a unas 400 millas al oeste de Galápagos, para evitar la pesca del atún patudo en esa zona. Según el subsecretario de Recursos Pesqueros, Guillermo Morán, en este lugar se congregan los especimenes juveniles del atún patudo (Thunnus obesus) y el cierre ayudará a proteger la especie.

Además, se ha planteado que se mantenga la veda de 42 días para la flota tipo 6, es decir, para los barcos de mayor capacidad.

Ecuador presentó, junto con España, estos mismos planteamientos en una reunión anterior, realizada este año en Cancún, México.

“La idea es que desde el próximo año las medidas de ordenamiento surtan efecto positivo e impacten lo menos posible en la industria”, señaló Morán.

Mientras, la presidenta de la Asociación de Atuneros del Ecuador, Atunec, Lucía Fernández, añadió que es preciso que los países miembros concuerden en la necesidad de no aumentar el esfuerzo pesquero en el OPO. "Los atuneros ecuatorianos estamos de acuerdo que para hacer una pesquería sustentable es necesario no incrementar el número de embarcaciones".



Los informes científicos de la CIAT indican que el atún se está aprovechando por encima del máximo sostenible.

De los 16 países miembros de la CIAT, Ecuador, con 84 embarcaciones, es la flota más numerosa, según los registro de Atunec.



Conservación de delfines

Un tema importante por tratarse es el Acuerdo sobre el Programa Internacional para la Conservación del Delfín, APICD, que fue creado en 1999 y que tiene como fin proteger a los delfines durante las faenas de captura del atún.



El APICD busca reducir progresivamente la mortalidad incidental de delfines en la pesca de atún con red de cerco. También persigue métodos ambientalmente adecuados para capturar atunes aleta amarilla grandes (Thunnus albacares) no asociados con delfines, asegurando la sostenibilidad de las poblaciones de atún y de los recursos marinos vivos relacionados con la pesquería.



Capacidad de flota

Ecuador mantiene la tesis de que no se debe ampliar la capacidad de la flota atunera en el océano Pacífico oriental, y se mantenga el programa de observadores a bordo de los barcos atuneros.

Fuente: El Diario, Atunec

México y otros países contra los Estados Unidos: “atún-delfines”

La Ley de los Estados Unidos de Protección de los Mamíferos Marinos:

La Ley de los Estados Unidos de Protección de los Mamíferos Marinos prohibía el hostigamiento, la caza, la captura o la matanza de mamíferos marinos, o la tentativa de estos actos, y su importación a los Estados Unidos sin autorización expresa.

En particular, regulaba la captura de mamíferos marinos atrapados incidentalmente en las redes de los pescadores de atún aleta amarilla en el Pacífico tropical oriental, una zona donde se sabe que los delfines nadan por encima de los bancos de atunes.

La ley equivalía a prohibir la importación comercial de pescado o de productos del pescado capturado con técnicas de pesca comercial que provocaban que las muertes y las heridas graves incidentales de mamíferos marinos fueran superiores a las establecidas por las normas estadounidenses.

En particular, se prohibió la importación de atún aleta amarilla pescado con redes cerqueras en el Pacífico tropical oriental (prohibición aplicable a la nación directamente exportadora), salvo si las autoridades estadounidenses competentes establecían lo siguiente:

i) que el gobierno del país pesquero había adoptado un programa de regulación de la captura incidental de mamíferos marinos comparable al de los Estados Unidos; y

ii) que la tasa media de capturas incidentales de las embarcaciones del país pesquero era comparable a la tasa media de las embarcaciones de los Estados Unidos.

La tasa media de las capturas incidentales (es decir, el número de delfines matados incidentalmente cada vez que se echan las redes cerqueras) realizadas por la flota atunera de ese país no debía ser más de 1,25 veces la tasa media de las embarcaciones estadounidenses en ese mismo período. También se prohibieron las importaciones de atún procedentes de países que lo compran a un país sometido a la prohibición aplicable a naciones directamente exportadoras (prohibición aplicable a las naciones intermediarias).
En términos jurídicos:

México sostenía que la prohibición de las importaciones de atún aleta amarilla y de productos del atún era incompatible con los artículos XI, XIII y III del Acuerdo General. Los Estados Unidos pedían que el Grupo Especial constatara que la prohibición aplicable a la nación directamente exportadora era compatible con el artículo III y, en caso alternativo, estaba justificada por los apartados b), d) y g) del artículo XX.

El Grupo Especial constató que la prohibición de las importaciones en ambos casos no era una reglamentación interna en el sentido del artículo III, era contraria a lo dispuesto en el párrafo 1 del artículo XI y no quedaba amparada por las excepciones de los apartados b) y g) del artículo XX. Además, la prohibición aplicable a los países intermediarios no estaba amparada por el apartado d) del artículo XX.

Fuente:

http://www.wto.org/spanish/tratop_s/envir_s/edis04_s.htm

FAO otorga reconocimiento a México por pesca responsable de atún

2005

El Consejo de la Organización de las Naciones Unidas para la Agricultura y la Alimentación (FAO), acordó por unanimidad otorgar la medalla "Margarita Lizárraga" al Acuerdo sobre el Programa Internacional para la Conservación de los Delfines (APICD), del cual la flota atunera mexicana forma parte.

El comisionado nacional de Pesca y Acuacultura, Ramón Corral Avila, explicó que ese reconocimiento es resultado de la aplicación del Código de Conducta para la Pesca Responsable de la FAO, utilizado por las embarcaciones mexicanas para la captura del atún y que ha reducido casi en su totalidad la muerte incidental de delfines.

El funcionario aseguró que la distinción de la FAO se suma al reconocimiento del Parlamento Europeo al APICD como etiqueta ecológicamente responsable.

Recordó que el APICD es un acuerdo internacional cuyo objetivo es reducir progresivamente la mortalidad incidental de delfines durante las actividades de pesca del atún y promueve una pesca sustentable de la especie.

Dicho acuerdo ha permitido reducir la captura incidental de delfines en más de 98 por ciento en los últimos 15 años.

Por ello, consideró que para el sector pesquero mexicano el otorgamiento de la medalla "Margarita Lizárraga" al APICD es un reconocimiento al esfuerzo decidido de la industria atunera nacional desde 1986.

Explicó que en ese año inició el programa de observadores que monitorean las prácticas de pesca dirigidas a la protección de los delfines a bordo de las embarcaciones dedicadas a la pesca del atún.

Actualmente, dijo, la flota atunera mexicana de cerco cuenta en su totalidad con observadores aprobados por el APICD, equipos de monitoreo satelital (VMS) y cumplen con las leyes y normas de pesca responsable más exigentes tanto nacionales como internacionales.

Corral Avila reiteró que la Comisión Interamericana del Atún Tropical es un ejemplo exitoso a nivel mundial, sobre cómo puede lograrse la cooperación internacional para aprovechar los recursos marinos regionales de una manera responsable y sustentable.

Por todo lo anterior, el funcionario confió que la corte de apelaciones de los Estados Unidos, que tiene a su cargo la decisión sobre la introducción de atún etiquetado APICD Dolphin Safe a ese mercado, considere al igual que el Parlamento Europeo y la FAO la validez científica y metodológica de dicha etiqueta.

Fuente:
http://www.ecoceanos.cl/sitio/docs/noticias.php?codNoticia=513

lunes, 29 de octubre de 2007

Orca teaching explained by Dr Ingrid Visser

Orca Teaching

Orca and Dog

Killer Whale Conversations

New Technology Reveals Killer Whale Conversations


April 2, 2004

A new technology is allowing scientists to eavesdrop on the deep conversations of killer whales. For the first time they can not only listen in on a group of whales, but now they can decipher which one is doing the talking.

Killer whales (Orcinus orca) live in stable families. The kids stay with their mother for their entire life. As many as four generations of whales live together in some of these matrilineal groups.

Within these families, members are incredibly vocal. But most research to date has used underwater microphones, called hydrophones, to study the collection of sounds produced by various groups—not individuals.

"This is like using a microphone at a cocktail party—you can't see or hear who said which thing," said Patrick Miller, a marine biologist at the Natural Environment Research Council Sea Mammal Research Unit at the University of St. Andrews in Fife, United Kingdom. Miller led the research that will be published in the journal Animal Behavior.

Not knowing which whale said what makes it difficult to interpret orca, or killer whale, communication and social bonds.

Marine mammals are often very difficult to observe during research, so it is almost impossible to ascribe sounds to individuals in these tight-knit matrilines. Miller and his colleagues developed an instrument and technique that allows researchers to assign calls to individual killer whales. "That's never been done before," Miller said.

Look Who's Talking

As killer whales feast on salmon in the waters of Johnstone Strait—sandwiched between the northeast coast of Vancouver Island and the rugged, snowy peaks of the mainland—they holler back and forth, precisely repeating each others' calls. Many times the same call is echoed over and over as the two individuals continue to call and respond.

Miller and his colleagues dragged a hydrophone array—a string of hydrophones—behind the research vessel, conducting "sound traces" to determine the angle at which certain calls originated. With laser range finders and a compass, Miller matched the calls with visual data to pinpoint a particular animal. The method works well when the animals are separated by greater than about 115 feet (35 meters).

Canadian researchers, led by the late Michael Biggs, laid the groundwork for these studies. They spent the last several decades photographing the fins of killer whales and produced a catalog of the members of groups within the British Columbia/Washington State region. Miller and his colleagues used these catalogs to identify whales based on their unique fin shape and pattern.

"It shows what sophisticated techniques are required to monitor these conversations," said Volker Deecke, a marine biologist at the Marine Mammal Research Unit at the University of British Columbia in Vancouver, Canada. Deecke studies vocal behavior in transient killer whales, which tend to have a larger range and different diet from Millers' resident fish-eating orcas.

Window Into Orca Culture

Killer whales bunch together when they socialize or rest—touching, rubbing, resting, and rolling on the surface. They spread out to find food. But even when they separate they remain in acoustic range.

There are between 7 and 17 calls in the repertoire of the average killer whale matriline. However, during the dialogues that Miller recorded, the call produced by the first individual was copied almost immediately by the responder—a phenomenon that the scientists dubbed "call-matching."

At one point they noted such an exchange between a mother and calf.

But it is not yet clear what these exchanges mean. It could signal that the responder is aware of the first caller and is paying attention, or that the message might simply have been received.

"Call-matching has been found in a number of species, and probably has a variety of meanings," Deecke said.

In primates, call-matching can be used as a sign of reconciliation after a nasty situation or fight. In some songbirds, song-matching signals a "stay away" territorial warning.

"Miller's work is the first step to understanding the function of these calls in the context of killer whale behavior," Deecke said.

The fact that call-matching behavior is seen in other species suggests there might be basic rules of communication, Miller said. He intends to follow the call-matching observations with underwater playback experiments to see how killer whales respond to a range of calls.

The ability to identify individual callers and calls also provides an opportunity to study how vocalizations are passed from one generation to the next, opening a window into killer whale culture. Now the trick is to figure out what these creatures are saying.

Fuente:

National Geographic News
http://news.nationalgeographic.com/news/2004/04/0402_040402_TVkillerwhale.html

Killer whales most toxic mammals in Arctic

Norwegian killer whales most toxic mammals in Arctic


A new WWF-supported report shows that Norwegian killer whales are the most toxic mammals in the Arctic.
© WWF-Canon / William W. Rossiter

12 Dec 2005

Gland, Swtizerland – Initial scientific results show Norwegian killer whales are the most toxic mammals in the Arctic, says WWF, the global conservation organization.

Previous research awarded this dubious honour to the polar bear, but a new study shows that killer whales have even higher levels of PCBs, pesticides and a brominated flame retardant.

The results are based on blubber samples taken from killer whales in Tysfjord, a fjord in arctic Norway. This is the first time the findings of the research, carried out by the Norwegian Polar Institute (NPI), and partly funded by the Norwegian Research Council, have been revealed.

“Killer whales can be regarded as indicators of the health of our marine environment," said Dr Hans Wolkers, a researcher with NPI.

"The high levels of contaminants are very alarming. They clearly show that the arctic seas are not as clean as they should be, which, in particular, affects animals at the top of the food chain.”

Killer whales are found throughout arctic Norway, including Svalbard and the Barents Sea, but congregate in the Tysfjord area to feed on spawning herring during the winter. This offers an excellent opportunity to sample them in an efficient way.

WWF funded Dr Wolkers to carry out new research from this November to further monitor the levels of dangerous contaminants in the killer whales, including another brominated flame retardant called deca-BDE, used in electronic goods and coatings for household products such as carpets. The findings of this research are expected next year.

The appearance of a potentially dangerous brominated flame retardant in killer whales is of particular concern, because – unlike PCBs and the most harmful pesticides – most hazardous brominated flame retardants are not currently banned. Brominated flame retardants can affect the animals' neurological function, behaviour and reproduction.

"This new killer whale research re-confirms that the Arctic is now a toxic sink," said Brettania Walker, a toxics officer with WWF's International Arctic Programme.

"Chemicals in everyday products are contaminating arctic wildlife. The European Council of Ministers, due to vote on REACH on December 13th, must agree to the replacement of all hazardous chemicals with safer alternatives whenever these are available."

"The toxic contamination of killer whales clearly shows the result of an unsustainable use of chemicals internationally," added Helen Bjørnøy, the Norwegian Minister of Environment. "This is one of the greatest global environmental threats. The EU ministers now have the possibility to strengthen the chemicals legislation in Europe, and I urge them to use it. It is imperative that the REACH regulation becomes a tool to stop using the most dangerous chemicals."

END NOTES:

• Killer whales are particularly vulnerable to contaminants because they feed at the top of the food chain and therefore accumulate contaminants from the species they prey on. These contaminants accumulate in their blubber and other fat-rich tissues. Killer whales can live up to 40 years so can have very high contaminant levels in their tissues. Toxin levels increase moving up the food chain (a process called biomagnification) and are highest in top predators, such as polar bears.

• Blubber samples were taken from ten male killer whales from Tysfjord, Norway in November 2002. They were later tested for PCB 153, toxaphene, chlordane, DDE, and PBDE 47. They showed higher levels of these chemicals compared to Svalbard polar bears and harbor seals and beluga whales from Svalbard and the Gulf of St. Lawrence, Canada.

• The PBDE (polybrominated diphenyl ethers) class of brominated flame retardants is structurally similar to PCBs and exponential increases of PBDEs have been documented in wildlife and humans in recent years. PBDEs are used in electrical equipment, construction materials, coatings, textiles and polyurethane foam.

• The PBDE brominated flame retardant detected in the Norwegian killer whales sampling was 2,2',4,4'-tetrabromodiphenyl ether, also called PBDE 47. PBDE 47 is often studied due to its persistence and ability to bioaccumulate. Studies in mice have linked neonatal exposure to PBDE 47 to permanent alterations in spontaneous behavior.

• Many pollutants of concern in the Arctic were not produced or ever used in the Arctic. Instead, chemicals from everyday household products and industrial and agricultural chemicals from other areas of the world travel great distances via air and water currents to finally end up in the Arctic. Long, dark winters and cold temperatures inhibit the breakdown of chemicals in the Arctic.

• REACH (Registration, Evaluation and Authorisation of Chemicals) is the draft EU law that should lead to the identification and phasing out of the most harmful chemicals. If it becomes law it will be enforced in all countries in the European Union. REACH will also lead to changes in chemical regulation and production outside the European Union. The current EU chemical regulatory system, similar to others around the world, considers chemicals "safe until proven otherwise".

Fuente:
http://www.panda.org/about_wwf/where_we_work/europe/what_we_do/arctic/what_we_do/marine/barents/news/index.cfm?uNewsID=53520

Orcas se adaptan a la contaminación acústica

Hay demasiado ruido. Por eso, las orcas de la costa oeste de EE.UU. están extendiendo la duración de las ondas con que se comunican, para que sus compañeras puedan escucharlas por encima del intenso tráfico de botes que hay en la zona.

El hallazgo fue hecho por investigadores británicos y estadounidenses que publicaron las conclusiones de su estudio en la revista Nature.

Los científicos descubrieron que las orcas, o ballenas asesinas, hacen llamados más largos en presencia de botes, en un aparente intento por ser escuchadas por sobre el ruido de los motores.

Pero sólo lo hacen cuando los ruidos alcanzan niveles críticos, dice la investigación.

Los mamíferos estudiados habitan cerca de la costa del estado de Washington, un área que en la última década ha visto crecer sustancialmente su tráfico marítimo.

Asunto vital

El equipo de investigadores comparó grabaciones de orcas hechas en los períodos de 1977-81, 1989-92 y 2001-03, tanto en presencia y en ausencia de botes.

Orcas en el estado de Washington
El número de orcas en las costas del estado de Washington han disminuido en los últimos años.

Aunque entre los dos primeros períodos no encontraron diferencias importantes, notaron que en el de 2001 a 2003 la duración de las ondas aumentó entre un 10% y 15%.

Ésta sería una medida de supervivencia.

Según los científicos, si el exceso de ruido continúa podría afectar la capacidad de las ballenas asesinas para alimentarse.

"Estos animales se llaman en parte para mantenerse comunicados, pero también para coordinar la búsqueda de alimentos", indicó Andrew Foote, uno de los autores del estudio.



Fuente:

http://news.bbc.co.uk/hi/spanish/science/newsid_3668000/3668827.stm

Las orcas, las más contaminadas



Las orcas se han convertido en el mamífero más contaminado del Ártico, indica un nuevo estudio.

Orca
Las orcas son las más contaminadas porque están en la cima de la cadena alimenticia.
Los científicos del Instituto Polar Noruego afirman que ningún otro mamífero en el Ártico ingiere una concentración tan alta de sustancias químicas peligrosas producidas por el hombre.

La investigación descubrió que las orcas, o ballenas asesinas, han superado a los osos polares en el primer lugar de la tabla especies contaminadas.

"El Ártico se ha convertido en un vertedero de sustancias químicas", dijo a BBC Mundo Pilar Marcos, de la organización ecologista Fondo Mundial para la Naturaleza (WWF).

"Este estudio refleja el enorme desconocimiento que tenemos de nuestros mares", afirma.

Vertedero tóxico

El Instituto Polar Noruego analizó muestras de grasa de ballena tomadas de especimenes en Tysfjord, en el Ártico noruego.

Las sustancias químicas que encontraron en los cetáceos incluían pesticidas, sustancias para retardar el fuego y los bifeniles policlorinados, o PCB, que solían utilizarse principalmente en procesos industriales.

Orcas
El estudio pide regulaciones más estrictas para el uso de sustancias tóxicas.
Los investigadores están particularmente preocupados por las sustancias para retardar el fuego, porque a diferencia de muchos otros productos químicos peligrosos, su uso es legal.

Tal como señala Pilar Marcos de WWF, las principales especies afectadas por la contaminación tóxica son las que se encuentran en el primer lugar de la cadena trófica (alimenticia).

"Las ballenas, igual que los osos polares, reflejan la salud del medio ambiente marino", señala.

En el pasado, se ha estudiado mucho a las poblaciones de osos polares en Ártico, porque son más fáciles de investigar.

Pero hasta ahora no se había podido analizar la salud de estos animales.

"Los resultados de este estudio reflejan la urgente necesidad de que se establezcan una legislación más estricta para regular el uso de estas sustancias", afirma Pilar Marcos.

Legislación

Existen regulaciones sobre los PCB desde los años 70, y desde entonces se han investigado alternativas más seguras y más actualizadas con el avance tecnológico.

El Ártico se ha convertido en un vertedero de sustancias químicas
Pilar Marcos, Fondo Mundial para la Naturaleza
"Todas estas sustancias tóxicas pasan de la tierra al mar ya sea por la gravedad o por emisarios submarinos que son tuberías de desechos que van de las costas hasta los mares", explica la funcionaria de WWF.

Y el Océano Ártico, dice la experta, "tiene una dinámica muy peculiar ya que las corrientes mundiales, con todas sus sustancias contaminantes, llegan hasta allí en algún momento de su existencia".

"Es una dinámica muy difícil de entender", agrega, "pero es una realidad".

"Nunca hasta ahora se había reflejado esta realidad en la salud de las orcas, y ahora se sabe que las concentraciones de contaminantes en ellas son mucho más elevadas que en los osos polares", afirma.

La próxima semana deben reunirse los ministros de Medio Ambiente de la Unión Europea para decidir sobre nuevas legislaciones de sustancias químicas.

Basadas en los resultados de este estudio, las organizaciones ecologistas están pidiendo modificar la legislación europea sobre sustancias tóxicas.

"Gracias a esta investigación podemos ahora probar que estos productos, como las sustancias para retardar el fuego, son realmente dañinos para el medio marino y sus especies", afirma Pilar Marcos.

Fuente:

http://news.bbc.co.uk/hi/spanish/science/newsid_4521000/4521172.stm

sábado, 27 de octubre de 2007

Whale Composers

Whale Composers

Humpback whales are "inveterate composers," says Roger Payne of the Ocean Alliance in Lincoln, Mass., after 3 decades of oceanic listening. The most musicianlike of the whales, male humpbacks sing while cruising around their summer breeding grounds or migrating. The loud, wavering songs string together several repeated phrases or themes, and one whale's session of song after song can stretch more than 24 hours.

Males change their songs as the months pass. All the males in the same ocean sing basically the same tunes, even though the current hit takes some time to travel. "There seems to be no limit to what they can come up with. It's just that they get there by modifying existing sounds rather than by creating them de novo, as is our habit," Payne observes.

Whatever the process, humpbacks sing in patterns that Payne calls "strikingly similar" to human musical traditions. He detects rhythms, phrases that last just a few seconds, song lengths ranging between those of human ballads and symphonic movements, and percussive elements as an occasional emphasis in longer strains of pure tones. Even though a whale can woo-oo over at least seven octaves, Payne finds that it combines notes that have wavelength relationships familiar to people's ears.

Most surprising, says Payne, is the discovery that humpbacks use rhymes. "When someone speaks in a language you don't understand, you still know when they are reciting poetry," he argues. Among whales, a particular sound repeats at relatively regular intervals.

These rhymes may be for whales just what moon, spoon, and June do for human crooners, suggest Linda Guinee and Katy Payne of Cornell University. For a long concert during breeding season, the rhymes may help the performer remember what comes next. When Guinee and Payne checked for rhymes in simple and elaborate humpback songs, the complex ones were much more likely to rhyme.

Payne, R. 2000. Whale songs; musicality, or mantra? American Association for the Advancement of Science Annual Meeting and Science Exposition. Feb. 20. Washington, D.C.

Katy Payne
Bioacoustic Research Program
Cornell Laboratory of Ornithology
Ithaca, NY 14850

Roger Payne
The Ocean Alliance
191 Weston Road
Lincoln, MA 01773


From Science News, Vol. 157, No. 16, April 15, 2000, p. 252.


Cetacean Seniors

Cetacean Seniors

Whales that give new meaning to longevity

Janet Raloff

Like a stream of massive torpedoes, thousands of blubbery dynamos are making a southwest migration through the icy Arctic Ocean. They're bowhead whales heading toward winter haunts in the Bering Sea, just north of the Aleutian Islands.

a4514_1697.JPG

Because big bowheads can break through deep, solid ice to breathe, many ignore the cracks in pack ice, shown here, where Iñupiat whalers scout for them. Iñupiat also prefer not to eat the bigger, tougher whales. So, whale harvests may miss the population's real old-timers.
Todd Chandler/Cascadia Research Collective

Along the way, Iñupiat Eskimos in Alaska will legally harvest several of these endangered mammals—30-to-60-foot-long behemoths that sometimes tip the scales at 50 tons or more.

Having hunted these whales for centuries, the Iñupiat are keen observers of the bowhead (Balaena mysticetus). Their tales recall whales that hunters had recognized by distinctive scars. In some cases, several generations of storytellers described encountering the same whale, leading to speculation that bowheads might live some 60 years.

Studies now suggest that these whales can actually outlive people—perhaps by a century.

Ancient points

The new research was triggered by hunters finding ancient harpoon points in the foot-thick blubber of newly landed whales. Six points made of stone or ivory have turned up since 1981. None of the Iñupiat subsistence whalers could remember having seen such primitive tools used.

ancient harpoon points

Ancient harpoon points found in modern whales include two of slate, two of stone, a triangular metal blade, and an ivory head bearing a piercing metal blade, which perhaps represents a transitional type. (George and Alaska Eskimo Whaling Commission)

"You have to understand that [the Iñupiat] are technological pickpockets," quips biologist David W. Norton, with a grin of respect. Now working in Fairbanks, he conducted research in Barrow, Alaska, over roughly 3 decades. During that time, he saw Iñupiat hunters in Alaska's northernmost county, the North Slope Borough, quickly embrace any useful technology to which they were exposed. Indeed, history shows that as soon as Iñupiat whalers gained access to metal, around 1870, they swapped it for stone and ivory in their tools.

Against that backdrop, the old harpoon points suggest that at least some contemporary bowheads are survivors of run-ins with whalers 100 years earlier, observes biologist Todd M. O'Hara of the borough's Department of Wildlife Management in Barrow.

To investigate this provocative possibility, O'Hara's colleague J. Craig George began looking for a way to determine the age of elder bowheads. A little research led him to Jeffrey L. Bada of the Scripps Institution of Oceanography in La Jolla, Calif.

A geochemist, Bada has been refining a technique for dating fossils on the basis of changes in their aspartic acid. This amino acid can exist in either of two mirror-image forms. Living things make and use only the left-handed version. However, after death, a body's aspartic acid gradually converts to a 50-50 mix of the two forms. In fossils, that conversion takes about 1 million years.

Bada's team had shown that this change in the ratio also occurs in living animals' body parts that are not undergoing metabolism, such as teeth and the lens of the eye. In such tissues, body heat sets the pace of change in the ratio of left-handed to right-handed aspartic acid.

Indeed, the conversion rate appears to be identical in the lenses of all animals with the same basic body temperature. The scientists have tested more than 20 species, including people and bowhead whales. Bada offered to help calculate the age of North Slope bowheads from that ratio of the two forms of aspartic acid in eye lenses.

George sent tissues from 48 bowhead whales to Bada without letting him know whether each had come from an infant, juvenile, young adult, or mature adult. The chemist's assays accurately dated the relative age of the young whales and indicated that most adults had been 20 to 60 years old at death. However, the lens analyses from five large males suggested that at the time that Iñupiat hunters harpooned them, one was 90, four were between 135 and 180, and one was more than 200 years old.

Recent recruits

O'Hara's group has recently recruited two other research teams to apply other techniques to estimate bowhead ages.

A bowhead breaches off Barrow.

A bowhead breaches off Barrow. (Chandler)

Next month, for instance, Mark Baskaran of Wayne State University in Detroit expects to start measuring radioactive lead in samples of bowhead bone. The lead isotope forms during the decay of radium, a naturally occurring calciumlike radionuclide in seawater. Because both the radium and lead decay at known rates, Baskaran can use their ratio to determine the age of bones more than a year old.

Cheryl Rosa of the University of Alaska, Fairbanks plans to assay pentosidine in samples of whales' skin. Aging leads to a progressive build-up of this chemical in many animals' skin. Rosa envisions eventually using it to determine the ages of living whales. A tethered dart can extract a small chunk of skin from a passing animal. Rosa notes, "The whale doesn't even seem to notice."

Bada points out that these complementary studies are important to confirm the longevity indicated by his work. They might even provide further surprises. Unless whales' eyes are much warmer than people's and therefore have a faster aspartic acid conversion rate, Bada says, "what we have assigned the bowheads are only minimum ages—which is staggering! These are truly aged animals, perhaps the most long-lived mammals."

However, he points out that other members of the whale family may also have the capacity to be centenarians, even if they don't live as long as bowheads. Bada claims to have "a bunch of pretty compelling data" to suggest several other whales can get "quite old."


Letters:

The thought that anyone, Eskimo or otherwise, would willingly kill a member of an endangered species that may have been swimming when George Washington was still alive makes me sick at heart. Honoring one's ancestors could surely be achieved by going out in a whaleboat, engaging in a mock hunt, and showing true reverence for ancestral traditions by not slaughtering an intelligent, magnificent animal that may have eluded those very ancestors.

Gordon J. Louttit
Manhattan Beach, Calif.

References:

George, J.C., J. Bada, et al. 1999. Age and growth estimates of bowhead whales (Balaena mysticetus) via aspartic acid racemization. Canadian Journal of Zoology 77(April):571-580. Abstract .

Further Readings:

Baskaran, M., and T.M. Iliffe. 1993. Age determination of recent cave deposits using excess 210Pb—a new technique. Geophysical Research Letters 20(April 9):603.

George, J.C., et al. 1989. Observations on the ice-breaking and ice navigation behavior of migrating bowhead whales (Balaena mysticetus) near Point Barrow, Alaska, spring 1985. Arctic 42(March):24-30. Abstract.

Information about Iñupiat history, language, and culture is available at http://www.co.north-slope.ak.us/ihlc/.

Shelden, K.E.W., and D.J. Rugh. 1995. The Bowhead Whale, Balena mysticetus: Its historic and current status. Marine Fisheries Review 57(3-4):1-20. Available at http://nmml.afsc.noaa.gov/
CetaceanAssessment/bowhead/bmsos.htm
.

Sources:

Jeffrey Bada
Scripps Institution of Oceanography
University of California, San Diego
San Diego, CA 92093-0236

Mark M. Baskaran
Department of Geology
0224 Old Main Building
Wayne State University
Detroit, MI 48202

Stephen E. Brown
Scripps Institution of Oceanography
University of California, San Diego
San Diego, CA 92093-0236

J. Craig George
Department of Wildlife Management
North Slope Borough
Box 69
Barrow, AK 99723

David W. Norton
Arctic Rim Research
1749 Red Fox Drive
Fairbanks, AK 99709

Todd M. O'Hara
Department of Wildlife Management
North Slope Borough
Box 69
Barrow, AK 99723

Cheryl Rosa
Institute of Arctic Biology
P.O. Box 757000
311 Irving I Building
University of Alaska, Fairbanks
Fairbanks, AK 99775-7000

Laura Scott
Scripps Institution of Oceanography
University of California, San Diego
San Diego, CA 92093-0236

Fuente:
http://www.sciencenews.org/articles/20001014/bob10.asp

From Science News, Vol. 158, No. 16, Oct. 14, 2000, p. 254.

Culture of the Sea

Culture of the Sea

Whales and dolphins strut their social stuff for scientists

Bruce Bower

On a November day 9 years ago, Christophe Guinet and his coworkers stood transfixed on the beach of an isolated island in the southern Indian Ocean. They watched as a killer whale and her 5-to-6-year-old female calf, cruising a short way offshore, abruptly stopped and together turned to face an elephant seal pup moving slowly in shallow water.

a4784_1575.jpg


Guinet, a zoologist at the National Center of Scientific Research in Villiers en Bois, France, trained a video camera on the animals and recorded the ensuing scene.

With a determined flip of the tail, the calf moved toward the young seal. The older whale followed right behind, giving her offspring a push. With deadly precision, the calf clamped her jaws around the startled pup. Meanwhile, the mother moved closer to shore, preventing the youngster from going in too far and stranding herself on the beach.

Prey firmly in mouth, the whale calf laboriously turned around. She arched her back, flapped her flippers, and dragged her belly through the soggy sand. Her attentive mother then gave her a push out to deeper waters.

Over four seasons of field work on the island not far from Antarctica, Guinet had observed the same calf or another young killer whale on numerous occasions almost stranding itself on the beach and struggling back to sea. Their mothers and adult female relatives had kept a close watch on them and swum to their aid when they got stuck. On a few occasions, one or the other of the two calves had also followed as the mother attacked seal pups near the shore.

Finally, however, Guinet felt that he had witnessed a developmental milestone. After extended observation and practice, a calf had nabbed a seal largely on its own.

This confirmed his suspicion that the whales' dangerous practice of intentionally entering shallow water in search of prey reflects neither a blind instinct nor the trial-and-error discoveries of one creature at a time. Instead, female killer whales take their offspring under their fins, so to speak, and spend years showing them how to hunt seals according to local custom.

Prior to Guinet's work, an Argentinian research team published a report describing female killer whales that tutored their offspring in seal hunting.

"I'm convinced that killer whales transfer group knowledge socially through teaching and apprenticeship," Guinet says.

His killer whale observation, published in 1995, and the Argentinian report were among the first in a rapidly growing body of research that supports the existence of cultural traditions among whales and dolphins. These practices include social learning, which researchers define as adopting behaviors from others in the group. This line of research challenges the traditional view of culture as a uniquely human pursuit.

Even if evidence for obvious teaching remains rare, most scientists who study whales and dolphins in the wild agree that these creatures live in social groups that somehow transmit learned behavior from one generation to the next. The same cultural capacity may hold for wild chimpanzees, which live in groups that pass on distinctive forms of tool use and social grooming (SN: 6/19/99, p. 388).

"I think we'll find cultural transmission in many animals that are capable of social learning," says biologist and dolphin researcher Vincent M. Janik of Woods Hole (Mass.) Oceanographic Institution.

Making waves

Whales and dolphins, known collectively with porpoises as cetaceans, have begun to make waves with their penchant for learning from each other. Cetacean researchers presented their latest findings in August at a Chicago symposium on animal social complexity and intelligence. Luke Rendell and Hal Whitehead of Dalhousie University in Halifax, Nova Scotia, will publish a synthesis of cetacean research in an upcoming Behavioral and Brain Sciences.

a4784_2510.jpg

Carrying a harbor seal carcass after a successful hunting foray, a transient killer whale cruises through the Pacific Ocean near Canada.
Robin W. Baird

The Dalhousie biologists portray the four best-studied cetacean species—the bottlenose dolphin, the killer whale, the sperm whale, and the humpback whale—as generators of group-based, cultural systems of communication, feeding, mating, and raising their young.

Still, the concept of culture is a moving target that scientists can't seem to agree on. Broad definitions emphasize the acquisition of behaviors by succeeding generations through social learning of any kind, such as adopting an activity after seeing it performed many times by many different individuals. Strict definitions focus on traditional behaviors cultivated solely through teaching or one animal imitating another.

Cetacean evidence generally meets the broad definition of culture and, in some instances, satisfies the strict criteria, Rendell and Whitehead say. For instance, male humpback whales in breeding populations from Hawaii to Mexico produce nearly identical sequences of vocalizations, or songs, at any given time, and their songs change from year to year. An as-yet-unknown means of learning enables humpback whales to keep singing in unison despite the changes, the researchers argue. The humpbacks' song learning and sharing stand as cultural achievements in the broad sense, the scientists hold.

Innovative feeding methods also spread rapidly within humpback groups. When first studied in 1991, members of a whale population commonly enveloped schools of fish in clouds of bubbles by exhaling underwater; they then gulped down the trapped prey. At the same time, a few individuals took a different approach to wrapping fish in bubbles. Each of these innovators would slam its massive tail flukes onto the water just before diving for a snack.

Over the next 9 years, many other whales in the population, and especially juveniles just coming into their own as independent feeders, adopted the tail-slam maneuver, reported a team led by Mason Weinrich of the Whale Center of New England in Gloucester, Mass.

This trend likely depended on imitation, say Rendell and Whitehead.

Like other cetaceans, fluke-flopping whales appear ill suited for one aspect of human culture: tool use. However, an intriguing example of simple tool use may occur among bottlenose dolphins in Shark Bay, Australia. In a group of more than 60 of these animals, 5 adult females regularly carry sponges in their mouths as they search for food, perhaps to scoop prey out of hiding places on the sea floor, says psychologist Janet Mann of Georgetown University in Washington, D.C.

These devout sponge carriers forage alone, as do several of their juvenile daughters who also carry sponges.

Other female dolphins at Shark Bay only occasionally carry sponges, according to Mann. These females usually forage in groups that don't use sponges.

Male dolphins at Shark Bay haven't been observed carrying sponges. These dolphins generally gather food with one or two compatriots.

Distinct populations

Cultural practices stand out among killer whales that live in the Pacific Ocean around Vancouver Island, off the coast of Canada and Washington State, according to Rendell and Whitehead. There, whales of a single species operate in two culturally distinct populations.

a4784_3607.jpg

A dolphin mother nurses her calf in Shark Bay, Australia. Calves there nurse for 3 to 6 years.
Janet Mann

Resident pods, which each contain 10 to 25 animals, are organized around sets of closely related females. Members of these pods primarily eat salmon and other fish. Over more than 20 years of research, scientists have yet to observe a killer whale moving from one resident pod to another.

In contrast, transient pods of these killer whales each consists of three to six whales. Members of these pods are often not close relatives, and some of the whales occasionally travel with other transient groups. Transients, who appear to be more typical of killer whales in other parts of the world, prefer a diet of seals and other marine mammals.

Vocalizing may provide an important avenue for cultural expression among the resident killer whales. Each of their pods uses its own vocal dialect, according to analyses of underwater recordings directed by biologist John K.B. Ford of the University of British Columbia in Vancouver. A single pod shares a set of between 7 and 17 discrete calls emitted by all of its members, Ford's team reported in 1991. These vocal dialects persist for at least six generations of killer whales.

Some pods share parts of their vocal dialects, thus creating what Ford refers to as vocal clans. Pods in the same vocal clan don't necessarily mingle with each other more than they do with pods from different clans, members of Ford's group reported at the Chicago symposium.

However, vocal clans tend to consist of pods that contain some closely related adult females, the researchers say. Killer whales may minimize inbreeding by avoiding potential mates who use a dialect similar to their own, the researchers theorize.

Sperm whales, like killer whales, display dialects, Whitehead says. Each group of females emits a typical pattern, or coda, of 3 to 12 clicks, which partially overlaps with the codas of neighboring groups.

Researchers have recorded instances in which two female sperm whales from different pods jointly modify their codas into identical click patterns, in a kind of vocal duet. Sperm whales may learn to match codas in this way as a sign of friendliness, Whitehead proposes.

However, definitive experiments confirming that whales learn to imitate codas or other behaviors will probably never be conducted, he notes. Such demonstrations would require raising and studying groups of the huge animals in captivity.

Compelling examples

The most compelling examples of imitation in cetaceans come from research on dolphins. "Captive dolphins are fantastic imitators of human sounds," says biologist Peter L. Tyack of Woods Hole Oceanographic Institution. These animals also accurately reproduce patterns of tones within seconds of hearing them.

a4784_4177.jpg

Like her mother, a 14-year-old female dolphin at Shark Bay carries a sponge, apparently while foraging for food. Researchers have seen her engage in this behavior since she was 1 1/2 years old.
Janet Mann

In the wild, it's now clear that bottlenose dolphins frequently imitate the learned whistles of other members of their particular social group, Woods Hole's Janik reports in the Aug. 25 Science. In underwater settings where the field of vision is typically limited, so-called whistle matching enables dolphins to address each other from a distance, Janik suggests. An individual dolphin might echo another's call as a friendly greeting in some situations and as a hostile warning in others.

Janik used underwater microphones to record the vocalizations of dolphins that periodically gather off the coast of Scotland. During 7 different days, he recorded 39 instances in which the same whistle was emitted by two dolphins within 3 seconds. Whistle matching occurred over distances of up to one-third mile and usually in the presence of 10 or more dolphins.

Whistle matching adds to the impressive mental skills exhibited by bottlenose dolphins, Janik says.

In the Feb. 1999 Animal Learning & Behavior, Louis Herman of the University of Hawaii in Honolulu, who has directed research on these abilities, summarized the evidence on the intellectual feats of captive dolphins. For instance, with training, captive dolphins readily apply learned rules to new situations, grasp abstract concepts, and understand an artificial, grammar-based language.

Still, researchers haven't observed any examples of one dolphin teaching another any behavior, such as whistle matching, Janik remarks. He regards the isolated observations of alleged instruction in seal-hunting techniques among killer whales with skepticism.

"Something fascinating is going on with killer whales, but I don't know if it's teaching," comments psychologist Bennett G. Galef of McMaster University in Hamilton, Ont., who has long criticized reports of cultural behavior in chimps.

Rendell and Whitehead, in contrast, accept Guinet's conclusion that female killer whales teach their young how to hunt seals.

Cultural lives

Researchers have described 17 cetacean behaviors that may be cultural, according to Rendell and Whitehead's tally. The four best-studied cetacean species possess biological attributes that prime them for cultural lives, the researchers propose. These traits include long life spans (60 to 90 years), advanced mental abilities, and prolonged periods of rearing young.

What's more, these animals operate in underwater environments that often undergo rapid and substantial changes, Rendell and Whitehead say. Cultural learning may increase the chances of a species' survival in changeable settings.

Whitehead further argues that the spread of cultural traits in some whale species has altered their genetic evolution. Mitochondrial DNA samples from killer and sperm whales contain far fewer random changes and rearrangements than comparable genetic samples from many other cetacean species, he reported 2 years ago.

Killer and sperm whales live in groups headed by related females who possess distinctive cultural traits, Whitehead argues. Offspring who adopt their mothers' cultural traits survive and reproduce better than those who don't, leading to reduced genetic diversity, in his view.

There are other explanations for the genetic finding, however. For example, extensive human hunting of some killer whale populations may largely account for the animals' low genetic diversity, according to Mann.

"Still, social learning clearly seems to be important in many cetacean species," Mann says.

Chimp researcher Frans B.M. de Waal of Emory University in Atlanta agrees. De Waal listened with great interest to presentations by cetacean researchers at the recent Chicago symposium.

"It was a real eye-opener to see what cetaceans are capable of," he remarks. "Some scientists might argue about whether the word culture applies here, but cetaceans are clearly investing their intellectual energy in social knowledge and its transmission."

References:

Herman, L.M., and R.K. Ukeyama. 1999. The dolphin's grammatical competency: Comments on Kako (1999). Animal Learning and Behavior 27(February):18.

Janik, V.M. 2000. Whistle matching in wild bottlenose dolphins (Tursiops truncatus). Science 289(Aug. 25):1355-1357. Available at http://www.sciencemag.org/cgi/content/full/289/5483/1355.

Rendell, L., and A. Whitehead. 2001. Culture in whales and dolphins. Behavioral and Brain Sciences 24(April):309-324. Abstract . Preprint available at http://www.bbsonline.org/documents/
a/00/00/04/91/bbs00000491-00/bbs.rendell.html
.

Tyack, P.L. 2000. Dolphins whistle a signature tune. Science 289(Aug. 25):1310-1311. Summary available at http://www.sciencemag.org/cgi/content/summary/289/5483/1310.

Further Readings:

Bower, B. 1999. Chimps employ culture to branch out. Science News 155(June 19):388. References and sources available at http://www.sciencenews.org/pages/sn_arc99/6_19_99/fob1ref.htm.

Connor, R.C., J. Mann, et al. 1998. Social evolution in toothed whales. Trends in Ecology and Evolution 13(June 1):228-232. Abstract available at http://dx.doi.org/10.1016/S0169-5347(98)01326-3.

Sources:

Louis M. Herman
Kewalo Basin Marine Mammal Laboratory
1129 Ala Moana Boulevard
Honolulu, HI 96814

Vincent M. Janik
Biology Department
Woods Hole Oceanographic Institution
Woods Hole, MA 02543

Luke Rendell
Department of Biology
Dalhousie University
Halifax, Nova Scotia B3H 4J1
Canada

Peter L. Tyack
Biology Department
Woods Hole Oceanographic Institution
Woods Hole, MA 02543

Fuente:

http://www.sciencenews.org/articles/20001028/bob10.as

From Science News, Vol. 158, No. 18, Oct. 28, 2000, p. 284.

Sleeples Dolphins

Sleepless in SeaWorld: Some newborns and moms forgo slumber

Naila Moreira

Orca-whale and dolphin mothers and their newborns appear not to sleep for a month after the pups' birth, researchers report. Neither parent nor offspring shows any ill effects from the long waking stint, and the animals don't later compensate with extra sleep.

a6302_1551.jpg

UP WITH THE BABY. An orca-whale mother and her newborn pup may forgo sleep for several weeks before adopting a normal pattern. Dolphins also exhibit this behavior.
SeaWorld, San Diego

No previously studied mammal stays awake for so long, says Jerry Siegel of the University of California, Los Angeles (UCLA), an investigator in the study.

In the months following their wakeful period, baby whales and dolphins—and their mothers—ramped up slowly to sleep amounts typical of normal adults, Siegel and his colleagues report. The infants' sleep pattern contrasts with that of other mammals, which need extra sleep during infancy and gradually sleep less as they age.

Oleg Lyamin, also of UCLA, started observing an orca mother and her baby just after it was born at SeaWorld, San Diego. Orcas usually snooze for 5 to 8 hours a night, closing both eyes and floating motionlessly.

The SeaWorld orca mother and baby, Lyamin found, neither shut their eyes nor remained motionless. Instead, the animals were constantly active, with the infant surfacing for a breath every 30 seconds. The researchers made similar observations of another SeaWorld orca mom and baby.

The team also watched dolphins at the Utrish Dolphinarium in Moscow. Dolphins sleep with one-half of the brain at a time, closing one eye while floating or swimming about. The team observed no sleeping behavior in the first month after birth among four dolphin mom-baby pairs.

The findings, reported in the June 30 Nature, challenge prevailing notions of the purpose of sleep, some researchers say. "We're under the belief that if you don't get sleep, you can't perform, and you're at risk for developing all sorts of disorders," says Paul Shaw of Washington University in St. Louis. For instance, rats die after being deprived of sleep for just 2 weeks.

The UCLA data are "the beginning of a change in the way we view sleep," says Shaw.

Scientists have commonly hypothesized that people and other animals require sleep for brain development and learning (SN: 6/1/02, p. 341: http://www.sciencenews.org/articles/20020601/fob6.asp). "Here we have a developing [whale or dolphin] youngster with no evidence of sleep," says Irene Tobler of ETH-Zurich in Switzerland. "It will revolutionize many people's ways of thinking."

Siegel argues that sleep is not required for brain development in these and other young animals and instead plays some role as yet unknown.

Alternatively, whales and dolphins may have evolved unusual compensatory mechanisms that permit them to develop without sleep, while other animals still require sleep for brain development, Tobler says.

Robert Stickgold of Harvard University suggests that mother and baby whales and dolphins may have evolved an unusual form of sleeping. "A sleepwalker makes it down the stairs, into the kitchen, into the refrigerator quite well while a [brain wave] recording says they're in deep sleep," he notes.

Stickgold says that such recordings from the animals could help determine whether the orcas and dolphins are awake.

Siegel speculates that mothers and babies of both species need constant activity to survive. The mother pushes the baby to the surface to breathe at regular intervals. Also, the baby must stay warm in cold water while it develops its blubber coat.

"The mystery is that they're ... dispensing with sleep behavior when so many sleep researchers have assumed that sleep has a vital function," Siegel says.


Letters:

Why should the whale study lead scientists to "change the way we view sleep"? Among whales, the priority is that babies not drown in the first weeks of life. Maturational processes thought to occur during sleep, such as brain development, might have to be put on hold while this critical lesson is learned. Our neonatal sleeping pattern, 4-to-6-hour periods interspersed with bouts of feeding, is dictated by a critical need for rapid, overall physical development to achieve mobility. To live, the already mobile baby whale must first learn to breathe.

Brenda Marion Gray
Glen Burnie, Md.

References:

2005. No sleep in the deep: Unlike other mammals, newborn dolphins and killer whales stay active 24/7 during first months of development. University of California, Los Angeles press release. June 29. Available at http://www.newsroom.ucla.edu/page.asp?RelNum=6274.

Lyamin, O. . . . and J. Siegel. 2005. Animal behaviour: Continuous activity in cetaceans after birth. Nature 435(June 30):1177. Abstract available at http://dx.doi.org/10.1038/4351177a.

Further Readings:

Bower, B. 2002. Snooze power: Midday nap may awaken learning potential. Science News 161(June 1):341. Available at http://www.sciencenews.org/articles/20020601/fob6.asp.

Brownlee, C. 2005. Losing sleep: Mutant flies need less shut-eye. Science News 167(April 30):275. Available at http://www.sciencenews.org/articles/20050430/fob2.asp.

Hesman, T. 2000. Fly naps inspire dreams of sleep genetics. Science News 157(Feb. 19):117. Available at http://www.sciencenews.org/articles/20000219/fob4.asp.

Milius, S. 2004. Sparrows cheat on sleep: Migratory birds are up at night but still stay sharp. Science News 166(July 17):38. Available at http://www.sciencenews.org/articles/20040717/fob7.asp.

A version of this article written for younger readers is available at Science News for Kids.

Sources:

Paul Shaw
Anatomy and Neurobiology
Washington University School of Medicine
660 S. Euclid Avenue
Campus Box 8108
St. Louis, MO 63110

Jerry Siegel
Psychiatry and Biobehavioral Sciences
Center for Sleep Research
Neurobiology Research 151A3
VA GLAHS Sepulveda
16111 Plummer Street
North Hills, CA 91343

Robert Stickgold
Center for Sleep and Cognition
Harvard Medical School
Beth Israel Deaconess Medical Center E/FD861
330 Brookline Avenue
Boston, MA 02115

Irene Tobler
Institute of Pharmacology and Toxicology
University of Zurich
Winterthurerstrasse 190
CH-8057 Zurich
Switzerland

Fuente:
http://www.sciencenews.org/articles/20050702/fob1.asp


From Science News, Vol. 168, No. 1, July 2, 2005, p. 3.

Whale watchers noise

Din among the Orcas: Are whale watchers making too much noise?

Susan Milius

Whale-watcher boats may be making so much noise that killer whales off the coast of Washington have to change their calls to communicate over the racket.

a4847_1822.jpg

WATCH OUT. Whale watching has become so popular that 22 tourist boats, on average, attend a pod of killer whales off the Washington coast.
F. Felleman

Recordings made during the past 3 years, after a boom in whale watching in Washington State, show that killer whales lengthen a characteristic call by about 15 percent when boats cluster around them, reports Andrew D. Foote of the University of Durham in England.

Recordings from earlier eras, when there were fewer whale watchers, showed no link between call length and the presence of boats, say Foote and his colleagues in the April 29 Nature. They suggest that boats following the whales may not interfere with animal communication until some critical number of churning engines makes the noise just too loud.

That change "is certainly a red flag," contends coauthor Rus Hoelzel, also of Durham. "Maybe we ought to think about fewer boats."

People naturally adjust their voices to make themselves understood over background noise, and research suggests that animals do the same. Humpback whales lengthen their calls during playback of low-frequency active sonar, and in the July 17, 2003 Nature, researchers in the Netherlands reported that city birds near heavy traffic tend to sing at higher pitches (SN: 7/19/03, p. 37: http://www.sciencenews.org/articles/20030719/fob5.asp).

The killer whale–research team analyzed recordings from three pods, or maternally related whale groups. In these pods, which live off the Washington coast, "everybody seems to stay home with Mum," says Hoelzel. "There are males we saw born 30 years ago, and they're still there."

Each pod has its own distinctive primary call, which accounts for more than half the vocalizations and may coordinate foraging. Foote describes the three pods' calls, respectively, as sounding like a train whistle, a kitten mewing, and a slide whistle. The researchers compared the length of these calls, with and without boats present, in recordings from 1977 to 1981, 1989 to 1992, and 2001 to 2003.

The only difference in call length turned up in the last period. During the 1990s, the average number of vessels clustering around a pod of whales increased roughly fivefold, and it now averages about 22. This whale population has been declining since 1996, but biologists aren't sure why.

"One thing I want to make clear is that I think whale watching is a good thing," says Hoelzel. It just may need tighter regulation, he explains.

Roger Gentry, who directs acoustics studies of marine mammals for the U.S. National Oceanographic and Atmospheric Administration, says he certainly finds it plausible that killer whales would compensate for underwater clamor. However, the meaning for the whales of the increase in call length isn't yet clear. "We have to keep watching," he says.


Letters:

In this article Rus Hoelzel states, "One thing I want to make clear is that I think whale watching is a good thing." He then states that the activity may just need "tighter regulations." I feel that this argument isn't valid. If whale watching is causing danger to the species, then it's not good. Whales should have the right to live in peace. If people want to whale watch they should find a safer way to do it, perhaps from shore.

Erica Hodge
San Ramon, Calif.

If the engines of whale-watching boats are disturbing the Orcas, why not switch the boats to sail power? Surely, this means of locomotion would also provide a better experience for the whale watchers.

Lorien Davy
Santa Barbara, Calif.

References:

Foote, A.D., R.W. Osborne, and A.R. Hoezel. 2004. Whale-call response to masking boat noise. Nature 428(April 29):910. Abstract available at http://dx.doi.org/10.1038/428910a.

Further Readings:

Milius, S. 2003. Bad bubbles: Could sonar give whales the bends? Science News 164(Oct. 11):228. Available to subscribers at http://www.sciencenews.org/articles/20031011/fob3.asp.

______. 2003. City song: Birds sing higher near urban traffic. Science News 164(July 19):27. Available at http://www.sciencenews.org/articles/20030719/fob5.asp.

Miller, P.J., et al. 2000. Whale songs lengthen in response to sonar. Nature 405(June 22):903. Abstract available at http://dx.doi.org/10.1038/35016148.

For further information on killer whales, go to http://nmml.afsc.noaa.gov/education/cetaceans/killer2.htm.

Sources:

Andrew D. Foote
School of Biological and Biomedical Sciences
University of Durham
Durham DH1 3LE
United Kingdom

Roger Gentry
NOAA Office of Protected Resources
1315 East-West Highway
Silver Spring, MD 20910

A. Rus Hoelzel
School of Biological and Biomedical Sciences
University of Durham
Durham DH1 3LE
United Kingdom

Fuente:

http://www.sciencenews.org/articles/20040501/fob2.asp

From Science News, Vol. 165, No. 18, May 1, 2004, p. 275.