Unanswered Forum Topics

Effectiveness of northern shrimp trawls designed to reduce megafauna bycatch

Study Type
Field study in the wild
Location
Gulf of St. Lawrence, Canada
Target catch
Northern shrimp (Pandalus borealis)
Effect on bycatch species
Unknown. No Greenland sharks were observed during the study.
Effect on target catch
No difference in catch rates vs. traditional gear, but a slight reduction in catch of larger shrimp. However, when escape openings were located before the Nordmore grid, rather than at the grid, catch decreased by 18%.
Bycatch species
Reduction technique
Fishing Gear

Evidence for a fisher-designed solution to manta and devil ray bycatch in tuna fisheries

Study Type
Field study in the wild
Location
Pacific Ocean
Target catch
skipjack tuna (Katsuwonus pelamis), yellowfin tuna (Thunnus albacares), bigeye tuna (Thunnus obesus)
Effect on bycatch species
Of the 21 individuals released during the study, use of sorting grid allowed fishers to release larger mobuilids without increasing handling time.
Effect on target catch
None. Sorting grids in study were implemented post-capture at the hopper.
Bycatch species
Reduction technique
Fishing Gear

Evidence for a fisher-designed solution to manta and devil ray bycatch in tuna fisheries

Study Type
Field study in the wild
Location
Pacific Ocean
Target catch
skipjack tuna (Katsuwonus pelamis), yellowfin tuna (Thunnus albacares), bigeye tuna (Thunnus obesus)
Effect on bycatch species
Of the 21 individuals released during the study, use of sorting grid allowed fishers to release larger mobuilids without increasing handling time.
Effect on target catch
None. Sorting grids in study were implemented post-capture at the hopper.
Bycatch species
Reduction technique
Fishing Gear

Evidence for a fisher-designed solution to manta and devil ray bycatch in tuna fisheries

Study Type
Field study in the wild
Location
Pacific Ocean
Target catch
skipjack tuna (Katsuwonus pelamis), yellowfin tuna (Thunnus albacares), bigeye tuna (Thunnus obesus)
Effect on bycatch species
Of the 21 individuals released during the study, use of sorting grid allowed fishers to release larger mobuilids without increasing handling time.
Effect on target catch
None. Sorting grids in study were implemented post-capture at the hopper.
Bycatch species
Reduction technique
Fishing Gear

Disentangling pinniped incidental mortality in a bottom-trawl fishery with seal exclusion devices

Study Type
Field study in the wild
Location
Falkland Islands
Target catch
Patagonian squid (Doryteuthis gahi)
Effect on bycatch species
0.91% of seals over 12 fishing seasons were caught in trawls with SEDs, with a survival rate of 89.5%. SED mortalities were attributed to drowning from blockages in the SED or entanglement in the trawl. Faster hauling speeds may also increase bycatch.
Effect on target catch
Not studied.
Bycatch species
Reduction technique
Fishing Gear