Gillnet bycatch of seabirds in Southwest Greenland, 2003 - 2008. Technical Report No. 85

Previous studies (2000/2001) in Southwest Greenland, limited to the 
Nuuk area, showed that bycatch in gillnets, especially lumpsucker 
(Cyclopterus lumpus) gillnets, was of conservation concern for the 
common eider (Somateria mollissima). From 2002 it became mandatory to 
report the bycatch as part of the annual hunting statistics and here I 
present the data reported for 2003 – 2008, with the purpose of describing 
the relative magnitude of the problem within Greenland. Landing 
statistics representing gillnet catches of lumpsucker, cod (Gadus morhua) 
and ringed seal (Phoca hispida) were analysed to identify sources of the 
bycatch.

The data show that bycatch of seabirds in Greenland is largely limited to 
Southwest Greenland and concerns almost exclusively the common eider 
and to a smaller extent also the king eider (Somateria spectabilis). Murres 
(Uria spp.) were also consistently reported as bycatch, 307 - 1,911 birds 
annually. However, these numbers appear to be strongly biased by reporting errors. No relationship was found between the various gillnet 
catches in Southwest Greenland and the reported bycatch, but a significant proportion (52%) of the bycatch variation was explained by the 
hunting records for murres, indicating that some hunters incorrectly reported hunted birds as bycatch. Probably, the true number of murres 
caught as bycatch in gillnets is negligible. Five other seabird species were 
reported as bycatch, but also in negligible numbers.

For the eiders, the data confirm that the bycatch in Southwest Greenland 
to a large extent is caused by the gillnetting of lumpsucker in March, 
April and May, and especially the regions of Nuuk and Maniitsoq appear to be high-risk areas for eider bycatch. The lumpsucker landings 
explained 40% of variation in eider bycatch, but also the gillnet catches of 
ringed seal contributed significantly to the bycatch. Combined, the two 
variables explained 68% of the bycatch variation. In contrast to previous 
observations from Nuuk, the cod fishery was not detectable as a factor 
influencing the level of eider bycatch, however, this may be due to the 
available statistics on cod landings, which does not discriminate between 
gillnet fishery and other fisheries. In months with no records of lumpsucker landings only the hunting records for eiders could explain a significant proportion of the eider bycatch (56%), indicating that errors due 
to misalignment also occur when hunted eiders are reported. The total 
number of eiders reported as bycatch ranged between 1,000 and 5,930 
birds annually in 2003 - 2008, but an alternative estimate indicates that 
the actual level of eider bycatch, from lumpsucker gillnets alone, was between 6,000 and 20,000 birds.

The fastest and most effective solution to reduce the bycatch of eiders 
would be to manage the lumpsucker fishery according to abundancebased fishery openings, which would imply a postponement of the 
lumpsucker fishery until May. This may be implemented throughout 
Southwest Greenland, or limited to the fishing areas with the highest 
bycatch risk. The latter would, however, require more detailed 
information about the exact locations of the bycatch and the circumstances.