Penguins and their chicks’ responses to local fish numbers informs marine conservation

SOUTH AFRICA – How adult penguins fish and the body condition of their chicks are directly linked to local fish abundance, and could potentially inform fishery management, a new study has found.

African penguin adult at the edge of the colony
on Robben Island, South Africa.
Photo credit: R.B. Sherley

The researchers studied an endangered African penguin colony during a rare three-year closure of commercial fisheries around Robben Island, South Africa, and their findings were published in the Journal of Applied Ecology.

Fishing is often considered to be one of the biggest drivers of biodiversity loss in the ocean. It is so widespread that we lack an understanding of the ‘natural’ relationships between marine predators and their prey, and thus the extent to which predators are disrupted by competition from fisheries.

This is a critical knowledge gap since many marine predators such as penguins are considered indicator species: a species whose success indicates the condition of their habitat.

No-fishing zones help endangered penguins

SOUTH AFRICA – Small no-fishing zones around colonies of African penguins can help this struggling species, new research shows.

African penguins. Photo credit: Richard Sherley

Working with the South African government, researchers from the University of Exeter and University of Cape Town tested bans on catching "forage fish" such as sardines and anchovies – key prey for the endangered penguins – from 20 km around their breeding islands.

The body condition and survival of chicks improved when the no-fishing zones were in place.

More research is needed, but the scientists say the fishing closures should continue in South Africa and should be considered elsewhere.

Fishing nets major threat to penguins

AUSTRALIA – The results of the first global review of penguin bycatch are in – and they highlight the serious risks that fishing nets pose to the survival of many penguin species. The study was published in the journal Endangered Species Research.

Penguins are among the world’s most iconic and loved birds, in spite of the fact most people will never get to see one in the wild. And opportunities to do so are diminishing, with 10 of the 18 penguin species threatened with extinction. After albatrosses, penguins are the most threatened group of seabirds. And this global review shows that, as it is for albatrosses, bycatch is a serious threat to some penguin species.

Hundreds of penguin deaths go unreported by the NZ fishing industry

NEW ZEALAND – Hundreds of penguins, including endangered yellow-eyed penguins, are dying in fishing set nets each year, according to conservation organisation Forest & Bird.

Yellow-eyed penguin. Photo credit: Kimberley Collins

Information released under New Zealand's Official Information Act shows that Ministry for Primary Industries (MPI) recorded 14 penguin deaths in the year from October 2015 to October 2016, but Forest & Bird chief executive Kevin Hague said this is likely to be vastly underreported.

“Thirteen of the 14 deaths were reported by MPI observers, who cover only 3 percent of fishing boats,” Mr Hague said.

“The real number of penguin deaths is likely to be in the hundreds, since the 97% of the fishing fleet that has no observers has reported only one dead penguin.”

Endangered African penguins are falling into an 'ecological trap'

AFRICA – As the climate changes and fisheries transform the oceans, the world's African penguins are in trouble, according to researchers reporting in Current Biology on 9 February. Young penguins aren't able to take all the changes into account and are finding themselves "trapped" in parts of the sea that can no longer support them even as better options are available.

"Our results show that juvenile African penguins are stuck foraging for food in the wrong places due to fishing and climate change," said Richard Sherley of the University of Exeter and University of Cape Town.

Yellow-eyed penguins feed in straight lines off the Otago coast

NEW ZEALAND - A research team at the University of Otago has discovered that the endangered and endemic yellow-eyed penguin forages in straight lines for several kilometres by following furrows in the seafloor scoured out by fishing trawlers.

Using GPS dive loggers the researchers monitored the penguins’ movements over three years showing the birds use furrows scoured on the seabed by otter boards from trawl nets to find food, particularly blue cod.

Bottom-up research to understand penguin diets

Cawtron Institute senior scientist Jonathan
Banks at work in Antarctica.
Photo credit: Cawthron Institute

ANTARCTICA - What can penguins' poo reveal about how the birds are affected by climate change and commercial fishing?

Cawthron Institute senior scientist Jonathan Banks, a faecal DNA specialist, is applying his unique expertise to an international research project into the impacts of climate change and commercial fishing on penguins, killer whales and seals - Antarctica’s top predators.

Conservationists call for wider set net ban to save yellow-eyed penguins

Yellow-eyed penguin.
Photo credit: Craig Mckenzie

NEW ZEALAND – Forest & Bird has called for an immediate extension to a ban on commercial and recreational set-netting around Otago Peninsula – a move that has angered the area’s commercial fishermen, the Otago Daily Times reported.

Karen Baird, Forest & Bird Seabird Advocate, said that because yellow-eyed penguins feed in the coastal waters that set nets are used in, they are a prime example of a species whose chances of survival would improve with better controls on set nets.

Penguin population shifts due to fishy factors?

ANTARCTICA - There's something fishy going on with the Adelie penguin populations in the Ross Sea region. Ecologist David Ainley, principal investigator for a long-term project trying to understand penguin population response to climate and ecosystem change, told the Antarctic Sun he is concerned that a toothfish fishery that operates in the Ross Sea may skew data collected by climate change researchers.

With the exception of the Cape Royds colony, which suffered a population crash after icebergs carved off the Ross Ice Shelf in 2000 and massively extended the penguins' journeys to the open sea, Adelie penguin colonies in the Ross Sea region have grown tremendously. Cape Crozier, possibly the largest Adelie penguin colony in the world, now has an estimated 230,000 breeding pairs; that's an increase of nearly 50,000 breeding pairs in the last decade. The nearby Beaufort Island colony has expanded from 40,000 to 55,000 breeding pairs.

While population increases like these should be good news, a possible explanation for them is not good: industrial fishing. In the 1996-97 austral summer, an Antarctic toothfish fishery began operating in the region. In less than a decade, scientists who had been successfully capturing and releasing Antarctic toothfish, known to consumers as "Chilean seabass", in McMurdo Sound for research since the 1970s could no longer find any. Research has shown that, at the same time, Ross Sea killer whales, which prey on toothfish, have decreased in occurence frequency. And there have been these increases in the populations of Adelie penguins, which compete with toothfish for food.

Ainley and others have argued that too little is known about toothfish, and Ainley said it was unwise to allow the fishery to operate without learning more about them. He told the Antarctic Sun that he believes the fishery may be taking too big a bite out of the toothfish population, and that although a lot of people would want to discount it, the fishery may be behind the apparent shift in populations of toothfish, penguins and whales.

While there are other environmental factors involved in the penguin population increases, such as the immigration of Cape Royds penguins who abandoned their colony in the "tough iceberg years" to neighbouring colonies, Ainley said immigration from Cape Royds cannot explain the rapid expansion of the other Ross Sea colonies.

"Just as when thousands of food-competing Antarctic minke whales were removed from the wintering area of Ross Sea penguins during the 1970s, Adelies are exhibiting a spurt of colony growth not easily explained by climate change," he told the Antarctic Sun.

Ainley is concerned that researchers like himself who are studying the effects of climate change on the marine ecosystem may have their data skewed by the fishery. He asked, "You're either studying climate change or you’re studying fish depletion, so what are you going to study?"

Source
Population pressures by Peter Rejcek, 18 February 2011, The Antarctic Sun