BirdLife: The Magazine Jan-Mar 2018 - Page 52

MARINE in Argentina and Chile to the non-breeding grounds off Brazil and Uruguay – has not been assessed. With the species listed as Near Threatened, the need to understand the impact of bycatch is pressing. There is a lack of contemporary data on the bycatch of Humboldt Penguins, but historically high bycatch in Peruvian and Chilean gillnets highlights a need to deploy observers on vessels overlapping with penguin distribution in key locations. The size of this fleet (over 10,000 vessels are thought to use gillnets in Peru alone) means this is no small task, but the conservation status of Humboldt penguins – Vulnerable on the Red List – mean action is critical. The bycatch of Yellow-eyed Penguins is of even greater concern. Populations of these stunning but Endangered birds are small and fragile, and while official estimates of bycatch in gillnets are relatively low, at 35 birds per year, this is likely to be an underestimate, owing to limited observer coverage in key Yellow-eyed Penguin feeding areas. Regardless, even this low estimate has the potential to contribute to the species’ demise, given its precarious status and low global population estimate of just 3,400. The recent crash of the important population on predator-free Codfish Island brings the issue into focus: without substantially increased observation of the New Zealand set-net fleet 52 Gillnets being prepared. Photo Katrina Borrow 0 Stellers Eider Polysticta stelleri, a diving sea duck, snared in a fishing net Photo Markus Vetemaa 4 Yellow-eyed Penguin Megadyptes antipodes Photo Eric Woehler 7 populations of yellow-eyed penguins are small, so even low estimates could contribute to their demise and management action, there is a very real risk that bycatch will give Yellow-eyed Penguins a helping hand towards extinction. BirdLife is working to develop technical solutions to the issue of gillnet bycatch. The implementation of such measures in trawl and longline fisheries has proven to be hugely effective in reducing albatross bycatch, partly because they allow fishermen to keep fishing while limiting their impact on non-target species. Identifying these measures for gillnets remains a challenge, but using the inspiration of our Albatross Task Force, we remain optimistic that one day we might follow a similar model to save penguins (and a whole host of other diving birds) from bycatch too. One solution currently being tested is the development of black and white sheets, that are affixed to fishing nets and alert diving birds to their presence (gillnets are otherwise invisible to birds underwater). That said, it is clear from the global review that Humboldt, Magellanic and particularly Yellow-eyed Penguins can’t afford to wait for technical fixes, especially in the face of myriad threats from climate change, invasive predators and habitat loss. In the short-term, efforts must be made improve observation of the fleets that pose a risk to penguins, so that targeted action can be taken to minimise the tragic loss of these charismatic birds. birdlife • Jan-Mar 2018