Bycatch of Northern fulmars in Norwegian longline fisheries

A new study sheds light on the extent of bycatch of Northern fulmars (Fulmarus glacialis) in the Norwegian pelagic longline fishery. The results, which are based on data collected over a 10-year period, show that fulmars are especially exposed to being bycaught in the breeding period, and the risk is highest in the southern Norwegian Sea.

Highest risk near the colonies

For this study, which was published in the journal Global Ecology and Conservation, the researchers used data from the Norwegian pelagic reference fleet, led by the Institute of Marine Research (IMR). The data set includes observations from three of the fishing vessels in this fleet over the period from 2012 to 2021. The results show an average bycatch of 0,01 Northern fulmar per 1000 hooks. This corresponds to a total of between 51 and 16 242 (95% CI) fulmars bycaught annually in the Norwegian longline fishery, when accounting for the uncertainty related to the data set. The highest risk of bycatch was identified within the breeding season in areas with high fishing activity around the largest colonies of breeding fulmars in the northeastern Atlantic Ocean.

Valuable for management

The researchers also compared bycatch estimates with overlap in distribution between Northern fulmars and fishing activity, and they found a strong correlation between estimated bycatch rate and areas with both high fulmar abundance and simultaneous high fishing activity. This shows that indexes for overlap between fulmars and fisheries may be useful tools for assessing which areas may have an increased risk of bycatch. This provides valuable insight for managers who need to take measures based on spatially and temporally identified risk zones.

Need for more data

The large data set collected by the IMR’s reference fleet was combined with information from SEATRACK, and the study is thus an example of the importance of both long data series and collaboration between research institutions. It also underlines the need for more precise data in order to assess population effects of bycatch on fulmars. With fulmar populations in decline in large parts of their distribution area, it is crucial to understand the cumulative pressure being imposed on these birds through bycatch.

Read the article:

• Bycatch of northern fulmar (Fulmarus glacialis) in Norwegian longline fisheries: Assessing spatiotemporal variations in scale and risk to improve management