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11 December 2017

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.

The international penguin scientific community produced the review lead by Dr Ursula Ellenberg, who has a joint affiliation with Australia's La Trobe University and New Zealand's University of Otago. The penguin community is using the review to call for all governments with penguins in their jurisdictions to act urgently to improve the chances of survival of penguins around the world.

Of the world’s 18 penguin species, 14 have been recorded as bycatch in fishing gear. Three penguin species are of particular concern: yellow-eyed (endangered), Humboldt (vulnerable) and Magellanic penguins (near-threatened).

Dr Ellenberg said the research identifies set nets (otherwise known as gillnets) as the fishing gear causing most penguin deaths.

“Set nets – walls of fine nylon mesh used to catch fish by the gills – are the main problem when it comes penguin deaths,” she said.

“In Tasmania around 10,000 gillnets are registered, with many more unregistered, and in New Zealand waters around 330 commercial boats use gillnets, in addition to many recreational users.

“Diving birds like penguins are unable to see the fine mesh underwater, and become entangled and drown.”

Forest & Bird’s seabird advocate Karen Baird, who contributed to the review, said yellow-eyed penguin numbers have dramatically declined in recent years, with only 246 breeding pairs left on New Zealand’s South Island in 2015–16. They face a number of threats, including fishing nets, climate change, predation and habitat degradation.

“The deaths of penguins in set nets is one threat that could be easily avoided,” Ms Baird said.

Little penguins in Australia are also affected by gillnetting, particularly in Tasmania. While spatial closures have been implemented around some penguin colonies in Tasmania , there remain many colonies exposed without such protection.

Dr Eric Woehler, a co-author from Tasmania and Convenor of BirdLife Tasmania, provided detailed evidence of widespread penguin entanglement and drowning around Tasmania.

“For almost 20 years the evidence has been mounting of little penguins drowned en mass in gillnets, yet virtually nothing has been done,” he said.

“We will never know the true, horrific scale of penguins drowning as fisherfolk never report these incidents.”

Dr Ellenberg said the review recommends a number of actions to tackle the problem, including the presence of fisheries observers or video monitoring on vessels to monitor bycatch, and managing set net fisheries in important penguin foraging areas to reduce bycatch deaths.

The review found that little penguins were at ‘moderate’ risk of bycatch in fisheries.

However, Dr Woehler noted that action now – prohibition of gillnets – would ensure that the conservation status of little penguins would not deteriorate.

“Proactive measures now – banning gillnetting – would decrease the need for more stringent reactive measures in the future,” he said.

"The aim of such management is to make sure that nets are not set in areas that are important foraging hotspots for threatened penguins," said Dr Ellenberg.

"Setting the net at night can considerably reduce the bycatch of penguins since these are visual hunters and mostly forage during daylight hours. We need to act urgently and work with the fishing industry to tackle this problem."

Source
Fishing nets major threat to penguins [media release], 1 December 2017, La Trobe University

Journal citation
Crawford, R., Ellenberg, U., Frere, E., Hagen, C., Baird, K., Brewin, P., ... Small, C. (2017). Tangled and drowned: a global review of penguin bycatch in fisheries. Endangered Species Research, 34, 373-396. https://doi.org/10.3354/esr00869

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