Information about the rapid depletion of the penguin population has been found in reports in the past week. Penguin numbers appear to be reducing rapidly both in Cape Town as well as internationally.
The China Post reported that the African Penguin numbers have been reducing by 60% in the last seven years, with only 26000 pairs left, the lowest count ever. At the beginning of this century 2 million penguins were counted. Last year the African Penguins, the species found locally, were classified as an endangered species. It is understood that a shortage of food due to changing fish patterns and greater commercial fishing of sardines and anchovies are the reasons for the declining penguin numbers. The South African Department of Environmental Affairs has found that the migration path of sardines has moved by 600 km, too far a distance for penguins to get to.
National Geographic News reported earlier this month that the Chinstrap and Adélie penguin populations in the West Antarctic Peninsula and Scotia Sea have reduced by 50% in the past thirty years. Fisheries biologists studying the penguin population have found that a shortage of krill, which is the major food eaten by penguins, is to blame, the young penguins being unable to survive their first winter due to a shortage of finding krill. Since 1970 the number of penguin chicks surviving has dropped from 50% to only 10%. The quantity of krill has declined by 80 % in the past twenty years, a direct correlation with the decline in penguin numbers.
Krill production itself has been affected by climate change, with warmer water temperature by 5-6°C, affecting the supply of phytoplankton, required for krill to survive. Krill is also the mainstay of the diet of whales, and whale numbers have increased due to greater controls over whaling by bodies such as the Sea Shepherd Conservation Society. This has exacerbated the reduction in krill.
It would appear that penguins used to eat fish before they started eating krill. Given the shortage of krill, Wayne Z. Trivelpiece of the National Marine Fisheries Service in La Jolla, California, has expressed surprise that penguins have not reverted back to eating fish in the face of the krill shortage.
The declining penguin population is of concern, in that scientists use penguin numbers as a predictor for problems in the oceans. It is hoped that nature will find a way to help the penguins find food, to regrow the penguin populations, before they become extinct. Birdlife International has called for greater research into climate change and its effect on penguin populations, as well as the declaration of no-fishing zones around penguin island colonies. “It’s bigger than the penguins. It’s about the health of our marine ecosystem. A lot of focus is on the penguins but at the end of the day it’s about the ecosystem. The marine ecosystem is taking strain and the penguins are just really telling a part of the story”, said Venessa Strauss of the Southern African Foundation for the Conservation of Coastal Birds.
The penguin population at Boulder’s Beach in Simonstown is an important tourist attraction for Cape Town. The declining penguin population could have a negative impact on the future of an important Cape Town tourism asset.
Chris von Ulmenstein, Whale Cottage Portfolio: www.whalecottage.com Twitter: @WhaleCottage
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