Up to 320,000 seabirds are being killed each year after being caught up in fishing lines, according to a new study.
The study, published in the journal Endangered Species Research and being presented today at the World Conference on Marine Biodiversity, reports that some seabird species are being pushed towards extinction as many fishing fleets fail to implement simple measures to prevent bycatch.
Seabirds heading towards extinction
The most frequently caught species are albatrosses, petrels and shearwaters, with the total number of seabird deaths estimated at 160,000 to 320,000 a year. Of particular concern are the Spanish longline fleet in the Gran Sol fishing grounds off southwest Ireland, which may kill over 50,000 birds a year, as well as the Japanese tuna fleet, which may kill 20,000 birds a year.
The study only looked at longline fisheries and did not take into account seabird deaths associated with trawl and gillnet fisheries. These may also be making a significant contribution to seabird mortality.
According to Orea Anderson, the lead author of the study, “It is little wonder that so many of the affected seabird species are threatened with extinction – their slow rate of reproduction is simply incapable of compensating for losses on the scale this study has demonstrated.”
Substantial improvement in some fisheries
There has, however, been significant success in reducing seabird bycatch in some fisheries. This is partly down to decreased fishing effort and partly to the implementation of simple but effective mitigation measures.
These measures include setting longlines at night when birds are less active, dying fish bait blue to make it less visible to birds, controlling fish discards, using bird-scaring devices, and setting lines deeper underwater. Around South Georgia in the southern Atlantic Ocean, tough measures have brought about an impressive 99% reduction in seabird deaths, while South Africa achieved an 85% decrease in its foreign-licensed fleet in 2008.
Another of the authors of the study, Cleo Small, said, “Using simple bird-scaring lines and weighting of hooks as they enter the water could dramatically reduce the number of seabirds being killed.”
More to be done
Unfortunately, seabird deaths are still a problem in other fishing fleets, with many failing to take these simple measures to reduce bycatch. There is also a lack of good data on seabird deaths in many regions, including around Iceland, the Faroe Islands and Norway, the Mediterranean, and some Asian fishing grounds.
The authors of the study say that minimum standards of data collection and reporting of bycatch are necessary to properly monitor the problem.
As simple and inexpensive measures have been shown to quickly and substantially reduce seabird deaths, they recommend that these should be implemented across all fisheries, to reduce bycatch to levels that no longer pose a significant threat to seabird populations.
Find out more about seabird conservation at the Albatross Task Force.
Read more on this story at the Guardian – Fishing boats ‘killing up to 320,000 seabirds a year’.
Liz Shaw, ARKive Species Text Author