Disturbed, hungry and lost - The impact of climate change on whales

[Guest guest]

WWF News - May 2007WWF News

 

Disturbed, hungry and lost - The impact of climate change on whales

 

Whales, dolphins and porpoises are facing increasing threats from global

warming including changes in sea temperature, rises in sea level and the

decline in the populations of krill - a tiny shrimp-like animal that is the

main source of food for many of the great whales.

Our climate is now changing at such a fast pace that it is unclear to what

extent whales and dolphins will be able to adjust.

Find out more about the impact of climate change on whales

http://www.panda.org/news_facts/newsroom/index.cfm?uNewsID=102980

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GREY WHALES ARE STARVING

[from http://www.seashepherd.org/news/media_070521_1.html]

 

Gray whale numbers have declined to 18,000 and the individual whales are

leaner than they should be.

 

" I went down to Mexico this winter, and my colleagues and I were finding

whales that were starving, " says Dr. William Megill, a leading whale expert.

" You can tell because the fat has disappeared from the back of their heads.

There are these big divots. "

 

And the whales are not breeding normally. Conception usually occurs between

November and January. Gray whale females usually are pregnant over a

two-year cycle, producing a single calf every other year. " It's pretty

obvious when whales are breeding. The penis of a grey whale is about 9-feet

long and bright pink. You can't miss it. Usually when tourists come ashore

in Mexico they are talking about having seen them. This year there was no

talk of it, really. We have a feeling that the animals are looking for

food, " says Dr. Megill.

 

Lack of food is killing thousands of gray whales. Between 1998 and 1999, an

El Niño weather pattern reduced the population from around 25,000 to 18,000.

It warmed up the water, which reduced oxygen levels, resulting in less of

the tiny crustaceans that whales eat. " The result was that we had a lot of

starving whales and it was a big enough crash in the population to have a

lot of people worried, " he says.

 

Eastern Pacific gray whales eat small shrimp called amphipods, which live at

the bottom of the Bering Sea. In recent years, however, they appear to have

vanished. " Now, when you look there is no mud or amphipods – there's just

rock. Our whole ecosystem has disappeared from that part of the Bering Sea.

We don't know why the amphipod beds disappeared. It might be to do with

global warming or overfishing. “

 

The gray whales have begun to feed on mysids, a small type of shrimp that

live in kelp beds along the shore, but which are a poorer food source.

" These mysids may be able to tide them over for a while, but it may not be

enough to keep the population indefinitely at its current level, " he warned.

" Some people are getting really worked up about it. Some whales will starve

and some will die and we have to make sure there is enough resilience in the

resource of the food they eat that it can recover and thereby the whales

also recover. "

 

This summer, Dr. Megill will return to Mexico to monitor the mysids and the

whale population. There are currently around 20 groups researching gray

whales around the Pacific Rim. " All of us have the same concern in mind, " he

says. " All we can do is monitor it. Once we have figured out what is going

on, if it is a man-made thing we can slow it down.

" We have really big threats in the Bering Sea in the form of oil

exploration. Before they even do any drilling, they do seismic testing. They

want to do that this summer, right in the middle of the grey whales' feeding

time. And there are some real conflicts coming up in terms of the fisheries.

 

" Whether or not the grey whale numbers are linked to global warming, I

couldn't make that claim. But there are a whole series of issues that we

really seriously need to understand, so we can make these long-term

management plans to make sure we don't lose the species. If I go up this

summer and find mysids then I'll heave a sigh of relief. If I don't find any

and no whales either, then I'm going to start rattling a lot of cages. "

 

Steven Swartz, an expert in gray whales who monitors them in Baja California

in Mexico with the Autonomous University of Baja California Sur, is another

scientist who is concerned about the starving creatures. " It could be the

early signs of something serious; we're not sure yet. We were able to

photograph animals this year that appear to be either malnourished or

suffering from disease or a combination of factors and we don't know what is

contributing to it, " said Dr Swartz, who also works for the fisheries

service of America's National Oceanic & Atmospheric Administration.

 

" We know that the primary feeding ground is in the Bering Sea, north of the

Gulf of Alaska. We know that has been going through some severe changes

associated with climate change, warming of the water and changing of the

oceanography. Where the whales used to congregate in large numbers to feed,

they don't any more. They may be suffering from not enough food, or they may

have become vulnerable to parasites or diseases from having to switch to

different food sources. They can survive this for a period of time, but not

for ever. The biggest concern is if they are nutrition-stressed, the females

may not be able to bring their calves to term or give birth to those that

are hardy enough to survive. "

 

The counts of gray whales, especially female-calf pairs, residing within

Laguna San Ignacio in Baja California Sur in Mexico, during the past winter

season were noticeably lower than in any previous year since 1978. According

to Dr Swartz, the falling numbers could either be a reflection of the

overall decline in the grey whale population since its peak in 1997-1998, or

they have moved elsewhere. Certainly, the plight of the skinny whales needs

to be watched closely. " It could be the early signs of something serious, "

says Dr Swartz.

 

Considering this situation, the IWC should ban the hunting of all gray

whales and the United States should re-list the California gray as

endangered once again.

The signs are very clear that the gray whale is in serious trouble and it is

imperative that measures be taken to both investigate and address this

crisis.

 

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Disturbed, hungry and lost – climate change impacts on whales

22 May 2007

Gland, Switzerland – Whales, dolphins and porpoises are facing increasing

threats from climate change, according to a new report published by WWF and

the Whale and Dolphin Conservation Society (WDCS) ahead of the 59th meeting

of the International Whaling Commission.

 

The report — Whales in hot water? — highlights the growing impacts of

climate change on cetaceans. They range from changes in sea temperature and

the freshening of the seawater because of melting ice and increased

rainfalls, to sea level rise, loss of icy polar habitats and the decline of

krill populations in key areas.

 

Krill — a tiny shrimp-like animal that is dependent on sea ice — is the main

source of food for many of the great whales.

 

Accelerating climate change adds significantly to disturbances from other

human activities, such as chemical and noise pollution, collisions with

ships and entanglement in fishing nets, which kills some 1,000 cetaceans

every day.

 

“Whales, dolphins and porpoises have some capacity to adapt to their

changing environment,†said Mark Simmonds, International Director of Science

at WCDS, “but the climate is now changing at such a fast pace that it is

unclear to what extent whales and dolphins will be able to adjust, and we

believe many populations to be very vulnerable to predicted changes.â€

 

Climate change impacts are currently greatest in the Arctic and the

Antarctic. According to the report, cetaceans that rely on polar, icy waters

for their habitat and food resources, such as belugas, narwhals and bowhead

whales, are likely to be dramatically affected by the reduction of sea ice

cover.

 

And as sea ice cover decreases, there will be more human activities, such as

commercial shipping, oil, gas and mining exploration and development as well

as military activities, in previously untouched areas of the Arctic.

 

“This will result in much greater risks from oil and chemical spills, worse

acoustic disturbance and more collisions between whales and ships,†said the

lead author of the report, Wendy Elliott of WWF’s Global Species Programme.

 

Other projected impacts of climate change listed in the report include:

reduction of available habitat for several cetacean species unable to move

into colder waters (e.g. river dolphins); the acidification of the oceans as

they absorb growing quantities of CO2; an increased susceptibility of

cetaceans to diseases; and reduced reproductive success, body condition and

survival rates.

 

Climate change could also be the nail in the coffin for the last 300 or so

endangered North Atlantic right whales, as the survival of their calves has

been directly related to the effects of climate variability on prey

abundance.

 

WWF and WCDS and are urging governments to cut CO2 global emissions by at

least 50 per cent by the middle of this century. The latest report of the

Intergovernmental Panel on Climate Change showed it was possible to stop

global warming if the world’s emissions start to decline before 2015.

 

The two conservation organizations further call on the International Whaling

Commission to facilitate research on future impacts of climate change on

cetaceans, including by supporting a special climate change workshop in the

coming year; elaborate conservation and management plans in light of the

climate change threat; and increase efforts and resources to fight all the

other threats to cetaceans.