Non-target benthic invertebrates are caught as bycatch in huge volumes, but precise numbers are not available.
| Location | Gear | Technique | Species | Results | Catch | Effect on Target Catch | Type | Reference | |
|---|---|---|---|---|---|---|---|---|---|
| North Coast, Australia | Trawls | Excluder devices | Invertebrates | Reduced bycatch if small individuals by 37.6% | Prawns: White Banana (Fenneropenaeus merguiensis), Red-legged Banana (F. indicus), Brown Tiger (Penaeus esculentus), Grooved Tiger (P. semisulcatus), Blue Endeavour (Metapenaeus endeavouri), and Red Endeavour (M. ensis) | Increased by .05% | Field study in the wild | Kon's Covered Fisheyes BRD Trial Report | |
| Southeastern Australia | Traps | Trap-net modification | Bony Fishes, Invertebrates | 87% reduction in yellowfin bream, 84% reduction in undersized crab | Blue swimmer crab (P. armatus) | No effect | Field study in the wild | Cumulative selectivity benefits of increasing mesh size and using escape gaps in Australian Portunus armatus traps | |
| Southeastern Australia | Traps | Trap-net modification | Invertebrates | 51-100% reduction of juvenile crab | Blue swimmer crab (P. pelagicus) | No effect | Field study in the wild | Performance of industry-developed escape gaps in Australian Portunus pelagicus traps | |
| Skagerrak, Norway | Trawls | Modified ground gear (mobile) | Invertebrates | Bycatch of Norway pout was slightly reduced in the shorter trawl. | Northern shrimp (Pandalus borealis) | The trawls fished shrimp above 19 mm carapace length equally, while catch rates of shrimp below 15.5–16 mm carapace length in the shorter trawl were more than halved. | Field study in the wild | Shorter trawls improve size selection of northern shrimp | |
| Electromagnetic deterrents | Invertebrates | N/A | Shrimp tended to do a tail flip in response to some electric pulses and ragworm showed a squirming response independent of the frequency. | N/A | Study in the lab | Determining the safety range of electrical pulses for two benthic invertebrates: brown shrimp (Crangon crangon L.) and ragworm (Alitta virens S.) | |||
| Spencer Gulf | Trawls | Excluder devices | Invertebrates | Reduced capture of giant cuttlefish and blue swimmer crabs by 30-50% | King prawn | Catch of target species was not affected | Field study in the wild | Mitigating the bycatch of giant cuttlefish Sepia apama and blue swimmer crabs Portunus armatus in an Australian penaeid-trawl fishery | |
| Spencer Gulf | Trawls | Excluder devices | Invertebrates | Small and large grids reduced number and weight of cuttlefish and crabs | Prawn | Small grid caught less prawns compared to large grid and control nets | Field study in the wild | Bycatch reduction devices (BRDs) to reduce the incidental catch of cuttlefish in the Spencer Gulf prawn fishery | |
| Lake Maracaibo, Venezuela | Gillnets | Deep sets, Sub-surface sets (gillnets) | Sharks, Skates/Rays, Bony Fishes, Elasmobranchs, Invertebrates | None, reduced bycach capture rate | shrimp | None | Field study in the wild | ||
| Venezuela | Trawls | Modified ground gear (mobile) | Sharks, Skates/Rays, Bony Fishes, Elasmobranchs, Invertebrates | Decrease of 26-32% | shrimp | Maintained or increased | Field study in the wild | The use of devices to reduce bycatch in Venezuelan shrimp fisheries and the FAO Code of Conduct for Responsible Fishing | |
| North Sea | Trawls | Modified ground gear (mobile) | Bony Fishes, Invertebrates | Significantly fewer invertebrates; no difference in undersized plaice; significantly fewer undersized sole | Plaice and sole | Significantly fewer plaice and sole | Field study in the wild | Performance of pulse trawling compared to conventional beam trawling | |
| Isle of Man | Trawls | Modified ground gear (mobile) | Invertebrates | There was no significant difference in the abundance of bycatch between the traditional and new "Newhaven" dredge design. | Queen scallop | The new "Newhaven" dredge caught significantly more queen scallops than the traditional dredge. | Field study in the wild | Efficiency and environmental impacts of three different queen scallop fishing gears | |
| Izmir Bay, Turkey | Gillnets | Sub-surface sets (gillnets) | Invertebrates | Trial 1, experimental net caught 44% fewer crabs and mantis shrimp and 49% fewer murex than control net. Trial 2, experimental net 1 caught 66% fewer crabs, 27% fewer mantis shrimp and 32% fewer murex, while experiemnetal net 2 caught 51% fewer crabs, | Prawns | Trial 1, experimental net 1 caught 17% fewer prawns than the control net. Trial 2, experimental net 2 caught 2% fewer prawns than the control net. | Field study in the wild | Bycatch reduction in trammel net fishery for prawn (Melicertus kerathurus) by using guarding net in Izmir Bay on Aegean Coast of Turkey | |
| Northern Australia | Trawls | Excluder devices | Elasmobranchs, Invertebrates, Sea Turtles | Little effect | Prawns | Little effect | Field study in the wild | The impact of turtle excluder devices and bycatch reduction devices on diverse tropical marine communities in Australia's northern prawn trawl fishery | |
| Northern Australia | Trawls | Excluder devices | Invertebrates | Downward facing TEDs reduced large sponge catches by 95.9% | Prawns | Reduced the proportion of soft and damaged prawns by 63.2% and reduced catches of tiger prawns by 6.3% | Field study in the wild | The impact of turtle excluder devices and bycatch reduction devices on diverse tropical marine communities in Australia's northern prawn trawl fishery | |
| Northern Australia | Trawls | Excluder devices | Invertebrates | Upward facing TED's reduced large sponge catches by 81.6% | Prawns | Reduced the proportion of soft and damaged prawns by 35.8% and reduced catches of tiger prawns by 6.3% | Field study in the wild | The impact of turtle excluder devices and bycatch reduction devices on diverse tropical marine communities in Australia's northern prawn trawl fishery | |
| Northern Australia | Trawls | Excluder devices | Invertebrates | Reduced large sponge catches by 85.3% | Prawns | Reduced the proportion of soft and damaged prawns by 41.6% and reduced catches of tiger prawns by 6.5% | Field study in the wild | The impact of turtle excluder devices and bycatch reduction devices on diverse tropical marine communities in Australia's northern prawn trawl fishery | |
| United Kingdom | Dredge | Excluder devices | Invertebrates | Reduced likelihood of mortality | Scallops | Decreased for deep-dwelling scallops, increased for surface-dwelling species | Field study in the wild | Hydrodredge: Reducing the negative impacts of scallop dredging | |
| North Sea | Trawls | Electromagnetic deterrents | Invertebrates | Reduced bycatch | shrimp | Negligible effect | Field study in the wild | On electrical fishing for brown shrimp (Crangon crangon) II. Sea trials | |
| North Sea | Trawls | Modified ground gear (mobile), Raised footropes | Invertebrates | Reduced bycatch | shrimp | Negligible effect | Field study in the wild | On electrical fishing for brown shrimp (Crangon crangon) II. Sea trials | |
| Australia | Trawls | Invertebrates | Reduced bycatch | Shrimp and scallop | Reduced catch by about 10% | Field study in the wild | Design and assessment of two gear modifications to reduce the benthic impact and fuel intensity of prawn trawling in Australia | ||
| Australia | Trawls | Invertebrates | Reduced bycatch of starfish but increased bycatch of nektobenthic species | Shrimp and scallop | Decreased shrimp catch, increased scallop catch | Field study in the wild | Design and assessment of two gear modifications to reduce the benthic impact and fuel intensity of prawn trawling in Australia | ||
| Australia | Trawls | Excluder devices | Invertebrates | Reduced bycatch | Shrimp and scallop | Did not affect target catch | Field study in the wild | Benefits of square mesh codends in Queenslands scallop and prawn trawl fisheries |
