Kites and eye-patterned buoys reduce auk bycatch in Cornwall trial
The story at a glance
A field trial in a UK fishery found lower odds of auk bycatch in gillnet sets using bird-of-prey kites or spinning buoys marked with eye patterns, compared with control sets.1
The results suggest the devices could help reduce seabird bycatch in the fishery tested. They do not establish that the approach will work equally well elsewhere or deliver lasting population-level benefits.134
The story in brief
What you need to know
- Researchers monitored 1,057 gillnet sets. Compared with control sets, the odds of auk bycatch were 71% lower when kites were used and 59% lower with looming-eye buoys.1
- The Cornwall project tested whether devices positioned above the water could reduce seabird bycatch during operational set-net fishing. The project was designed to test a practical mitigation approach, rather than simply whether fewer birds gathered near nets.34
- The trial also recorded 191 non-fish animals caught in nets: 153 birds, 25 seals and 13 cetaceans. Reporting notes a possible increase in seal catches in nets using buoys, but says this needs further testing.1
- The results are not a guarantee of effectiveness in other fisheries. An earlier trial of looming-eye buoys in Iceland’s lumpfish fishery did not find a reduction in seabird bycatch.1
- A Danish study found that looming-eye buoys temporarily reduced fish-eating birds at pound nets, with the effect fading over about a month. That different gear and setting raises a question about habituation, but does not directly test the Cornwall result. Mongabay’s report describes both studies.12
Conservation context
Why this matters
Accidental capture in fishing nets is a conservation concern, and this trial offers evidence that above-water deterrents can reduce auk bycatch in an operational fishery. The findings are a practical step, but the available reporting does not show whether the reduction benefits seabird populations over time.134
The developing story
What happens next
Further trials would need to establish whether the devices remain effective over longer periods and in different fisheries, seasons and operating conditions. Larger tests could also investigate whether buoy nets are associated with higher seal catches. The sources do not report a specific next trial or a confirmed plan for wider deployment.12
Established evidence
What we know
- The Cornwall trial monitored 1,057 gillnet sets and reported lower odds of auk bycatch with both tested deterrents than with controls.1
- The devices tested were bird-of-prey kites and spinning buoys with eye patterns. The project focused on their use in operational set-net fishing.134
- The trial recorded birds, seals and cetaceans caught in nets, and the reported possibility of increased seal catches in buoy nets remains a question for further testing.1
Open questions
What we don't know
- The available sources do not establish whether deterrent performance lasts across longer periods or different seasons, gear types and fisheries.12
- It is not yet clear whether buoy use increases seal bycatch. The reported possibility has not been confirmed by further testing in the supplied evidence.1
- The sources do not show whether fishers will adopt the devices at targeted locations and times, or whether the trial’s bycatch reduction will produce measurable population-level benefits for seabirds.1
Source coverage
