In Iceland, an estimated 8,000 seabirds are thought to be accidentally killed as bycatch in the Lumpfish fisheries. In today’s blog Yann Rouxel, Bycatch Programme Manager, gives an update on a new piece of technology created to help.
Marine biodiversity is facing enormous pressure from a wide range of human activities. And a huge part of the problem is seabird ‘bycatch’, with an estimated 200,000 seabirds accidentally caught and killed by commercial fishing hooks and nets each year in Europe alone.
From Newfoundland (Canada) in the west, to the Barents Sea in the East and Denmark in the South, gillnet fisheries targeting Lumpfish occur in the North Atlantic. Among the nations involved in this fishing activity, Iceland and Greenland account for the vast majority of the landings, with fishing fleets consisting of small coastal vessels using large-mesh bottom set gillnets. This fishery is largely targeting gravid females for their valued eggs which are considered inexpensive caviar.
But Lumpfish fisheries have been identified as important bycatch hotspots, posing a significant threat to several populations of diving seabirds and of marine mammals. Each year, in Iceland alone, over 8,000 seabirds are estimated to be killed in this fishery.
This unusual looking fish is highly sought after for its caviar (Jielbeaumadier – Wikimedia Commons: CC BY-SA 3.0)
Common Eiders, Black Guillemots, Common Guillemots, Great Cormorants, European Shags, and Long-tailed Ducks are the most reported bycaught seabird species in Lumpfish fisheries. In Iceland, most of these species are listed as Endangered or Vulnerable on the Icelandic Red List for Birds.
In 2020, the fishery was re-certified under MSC with four conditions raised in relation to seabird bycatch. However, there were no proven technical solutions to prevent seabirds from being caught in gillnets, which is a major barrier to resolve this important conservation issue.
Mitigating bycatch in Lumpfish fisheries
Therefore, with the support of the fishery, a project started in October 2021 to test a new type of mitigation measure called the “looming-eyes buoy”, which had shown promising results in a pilot study in Estonia. Deployed alongside a gillnet, this device aims at reducing seabird bycatch by reducing the probability for seabirds to dive into nets.
Fishermen putting out the buoy
The buoy is a three-dimensional device, with the opposite face of each panel exhibiting an eye pattern of different sizes, to create the ‘looming' effect when the panels rotate. The main goal was to examine the efficacy of this device in reducing seabird bycatch while maintaining fish catch.
A total of 7 boats in the North of Iceland participated in this project and were asked to use one of their set of nets as “experimental” (with looming-eyes buoys (LEBs) deployed across its length) and other sets as normal sets (“control”). 84 fishing trips were carried under this project and over 930 set-of-nets were deployed, including 61 “experimental” sets. During this period, several seabirds (mainly Common Eider, Common Guillemot and Black Guillemot) and marine mammals were bycaught.
Unfortunately, the looming-eyes buoy did not achieve the level of bycatch mitigation initially expected in light of the pilot trials conducted in the Baltic Sea. When accounting for fishing effort and environmental variables, the differences in bycatch rate between unmodified and experimental nets were not statistically significant for Eider Ducks or guillemot species.
A new discovery
However, fishing depths were observed to have an important effect on seabird bycatch rates, with bycatch in shallower waters being much higher than in deeper waters. Up to >90% lower bird bycatch rates, depending on the depths considered. In the meantime, Lumpfish catch did not seem to be affected when fishing at the depths considered.
If applied to the estimated total seabird bycatch across the Icelandic lumpfish fishery, depth-based fishing restrictions might have the potential to save thousands of birds each year in this fishery. Such a measure would need to account for fishing practicality and needs to be discussed with the industry.
Overall, this project allowed to collect a fairly large database for the area and provided several important lessons that would prove very valuable for future bycatch mitigation efforts. Mitigation measures for bycatch are not a “one size fits all” solution, therefore it is important to continue testing and funding different projects to reduce this threat to seabirds.
One perfect example is the Albatross Task Force that helped reduce seabird deaths by 99% in South Africa thanks to an active collaboration with fishers, and the use of mitigation measures such as bird scaring lines, night settings, and line weighting.
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