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| Edited By: |Source: ANI |Updated: Mar 11, 2018, 03:24 AM IST
Ten of the planet's 18 penguin species have experienced further serious population decline, warn Penguin biologists from around the world.
Among the major factors contributing to the decline are, climate change, over fishing, chronic oil pollution and predation by introduced mammals.
More than 180 penguin biologists, government officials, conservation advocates, and zoo and aquarium professionals from 22 nations have convened in Boston for the five day International Penguin Conference, which is being hosted this year by the New England Aquarium.
The effect of climate change on different penguin species has been the topic of many of the scientists' papers and presentations. Many penguin species are highly dependent on small schooling fish for food.
These masses of anchovies, sardines and other small finfish are seasonally brought to many penguin habitats by cold-water currents.
In years with El Nino events in the Pacific, there has been a dramatic warming of sea surface temperatures, which effectively blocked cold-water currents coming up the western coast of South America.
Sea ice also creates an important nursery cover for juvenile krill, which feed on ice algae. Krill is the primary fuel at the base the Antarctic food chain.
Reduced sea ice cover has led to a dramatic decline in krill and will likely lead to a decline in many wildlife populations further up the food chain that relies on krill as its foundation food source.
For penguins living in harsh conditions, the ability to properly time when to migrate, nest, mate and seek food are critical decisions often with a very small margin for error, both for both individual animals and entire species.
As fishing efforts around the globe have multiplied several fold over the last few decades, penguins are now competing with people for enough food.
The large scale harvesting of anchovy and sardine stocks have directly reduced the prey available to many penguin species including Macaroni and Chinstrap penguins in the South Atlantic.
Combined with the effects of climate change on the locations of fish stocks, reduced food availability leads to higher starvation rates, increased vulnerability to disease and lower breeding success.
Thousands of penguins are also killed annually when caught in fixed fishing nets.
Large-scale oil spills make worldwide headlines, but chronic petroleum pollution has killed thousands of penguins particularly off the coasts of South America and South Africa.
The most common sources are illegal operational dumping from ships, long-term leaks from sunken ships and some land-based discharges.
Better legislation and law enforcement efforts can yield positive results. The incidence of oiling of Magellanic penguins off the coast of Argentina has decline significantly in recent years due to increased public awareness and enforcement.
Many penguin species evolved in extremely remote settings devoid of any mammal predators. Prior to the arrival of humans, New Zealand's only mammals were bats.
Now, introduced weasels have had a large impact on the small populations of Yellow-Eyed and Fiordland penguins. In Australia and Argentina, the arrival of foxes has had impacts while feral cats in the Galapagos have reduced penguin populations there.
