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SeaWeb Ocean Update: July 13, 2000 Whales Are at Risk from Climate Change
Global climate change is having a measurable impact on the Arctic and Antarctic, and among the repercussions may prove to be significant impacts on the region's cetacean populations. So says a new paper published by the Pacific Institute for Studies in Development, Environment, and Security.
According to the Intergovernmental Panel on Climate Change (IPCC), under the so-called "business-as-usual" scenario, atmospheric concentrations of greenhouse gases could reach twice pre-industrial levels by the end of this century. Researchers have predicted that, in the Antarctic, the resultant warming could reduce sea-ice cover by more than 40 per cent; the Pacific Institute study notes that such a reduction "may lead to a decline in the productivity of algae, the primary source of food for the zooplankton species krill during the winter and could deny krill larvae critical protection from predators." As krill are the primary food source for cetacean species in the Antarctic, the study continues, this "could have serious implications for [cetacean] populations in the region."
In the Arctic, sea ice decline could have similar impacts, leading to 'knock-on effects' throughout the Arctic food chain, including declines in the stocks of several key prey species of cetaceans, such as copepods and plankton-feeding fish, including arctic cod. Warming and the attendant ice melt might also result "in greater stratification of the water column and decreased nutrient resupply, limiting the growth of phytoplankton populations that are a critical link in the cetacean food chain in the region." Additionally, projected reductions in sea ice area could also open up the Northwest Passage, potentially exposing cetaceans to increased ship traffic and mineral exploitation.
Although the polar regions may see the earliest, and some of the most extreme, impacts on cetaceans as a result of global warming, there will be changes in other regions of the world also: for example, warming may alter ocean upwelling patterns, fostering increased blooms of toxic phytoplankton. Toxic phytoplankton blooms have resulted in mass mortalities of cetaceans on several occasions in recent years. Additionally, the report continues, "warming may result in an increased incidence of violent weather events, or increased intensity of such events. Increased precipitation associated with such storms could result in more pollutants running off from land into coastal waterways inhabited by whales, as well as the introduction of river-borne contaminants into Arctic waters."
The study notes that the International Whaling Commission has sought to confront the threat to cetaceans from climate change through a research program that began in 1996. However, it observes, "this program is under funded and the prospects for additional funding from the parties are not good. Moreover, even if the research initiatives of the IWC and other organizations improve our understanding of the impact of climate change on cetacean species, these impacts ultimately can be averted only if nations demonstrate the resolve to substantially reduce greenhouse gas emissions. Unfortunately, the parties to the United Nations Framework Convention for Climate Change (UNFCCC) have shown little resolve to meaningfully reduce emissions, and even full implementation of the Kyoto Protocol under the treaty would not substantially reduce projected warming over the next century."
Contact: Wil Burns, Director of Communications/Research Associate, Pacific Institute for Studies in Development, Environment, and Security, 654 13th St., Preservation Park, Oakland, CA 94612. Tel: (510) 251 1600. Fax: (510) 251 2203. Pager: (510) 288 6346. E-mail: wburns@pacinst.org. WWW: http://www.pacinst.org/
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