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A mechanical separating bycatch reduction device was tested in the Spencer Gulf king prawn trawl fishery to reduce the incidental capture of giant cuttlefish (Sepia apama) and blue swimmer crabs (Portunus armatus). Different sizes of Nordmore grids were tested. Two Nordmore grids were inserted into the posterior extension sections and triangular escape exits were cut out. One grid was located in the extension with an angle of -45 degrees (small grid) and the second large grid was set at a 30 degree angle in the extension. The large Nordmore grid significantly reduced bycatch of cuttlefish and blue swimmer crabs by 30-50%. Catches of king prawn were not impacted by the use of Nordmore grids.

Estimates of post-release mortality (PRM) rates for discarded bycatch are largely unknown across marine fisheries and represent a substantial source of uncertainty when estimating total fishery mortality. One way to predict PRM is through the use of reflex action mortality predictors (RAMP), whereby the presence or absence of target reflexes and known post-release fate are used to create a delayed mortality model. The researchers employed reflex impairment assessments in concert with post-capture caging and video monitoring to predict 5-d PRM rates for the deep-sea giant isopod Bathynomus giganteus, a common bycatch species in numerous deepwater fisheries worldwide, and also considered the factors contributing to mortality. Mortality rates 5 days post-capture ranged from 50 to 100% and both RAMP scores and time at the surface were significant predictors of mortality, although conclusions regarding the effect of surface time are limited. In-cage video documented little movement within the 24-h monitoring period following capture, and it appeared that surviving individuals often fed within the holding period after cage deployment. Results suggest that PRM in B. giganteus is common and that this unaccounted source of mortality should be quantified for other deep-sea crustaceans captured as bycatch.

The selectivity of the Skagerrak standard trawls were compared with a trawl differing only in the belly length, being 37% shorter. 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. Bycatch of Norway pout (Trispterus esmarkii) was slightly reduced in the shorter trawl, unrelated to fish length.

 Data was collected on the relative performance of single and multiple round, rectangular, and square escape gaps across three fishing operations. Compared to control traps, those with escape gaps maintained catches of legal-sized P. pelagicus, but caught 51–100% fewer undersized individuals. Generally, rectangular escape gaps and especially multiple configurations were the most effective. Escape gaps represent a low-cost option for minimizing interactions with unwanted catches throughout the fishery.

The individual and cumulative effects of increasing mesh size and installing three escape gaps (36 × 120 mm) in collapsible‐netted round traps were assessed to address concerns associated with excessive discarding in an Australian portunid fishery. Compared to conventional traps of 56‐mm mesh throughout, those with the same mesh size and escape gaps caught significantly fewer (by 54%) undersized blue swimmer crabs, Portunus armatus, and yellowfin bream, Acanthopagrus australis (by 64%). Irrespective of escape gaps, simply increasing the mesh size to 75 mm did not significantly affect catches of undersized P. armatus, although 87% fewer A. australis were retained. Traps with both 75‐mm mesh and escape gaps maintained reductions of A. australis, but had a clear cumulative effect on P. armatus selection, retaining 84% fewer undersized individuals across a larger size at retention. The results support using escape gaps in existing conventional traps, but illustrate the need to configure the minimum legal mesh size to approach the desired target size of P. armatus as a precursor to maximizing trap selectivity. 

In 2015, NPF Industry Pty Ltd launched the Northern Prawn Fishery’s Bycatch Strategy 2015-2018 with the vision to reduce small bycatch by 30% in three years. A key component of the strategy was industry innovation and through this process the Kon’s Covered Fisheyes Bycatch Reduction Device (BRD) was developed.In 2016, at-sea testing of the Kon’s Covered Fisheyes Bycatch Reduction Device (BRD) was conducted in the Gulf of Carpentaria to determine its effectiveness in reducing small bycatch in the tiger prawn fishery compared to a currently legislated device. The device was found to significantly reduce small bycatch by approximately 36.7%, with commercial prawn catch increasing by an average of 0.5%. The device proved to be easy and safe for crew to use and due to the significant reduction in bycatch, the time taken for crew to process the catch was reduced.

This study tests the impact of skids placed on scallop dredges in various habitats to reduce seabed impact; skids raise the scallop collecting bag 10-11cm off the seabed. The modified skid dredge caught more marketable scallops per unit area, but also retained more bycatch overall and more undersize scallops. Results were habitat specific.

Through on-board fishing vessel observations and Autonomous Underwater Vehicle (AUV) transects, this study explored the impact of trammel nets on cold-water gorgonian (soft coral) populations in the Northwestern Mediterranean Sea. High bycatch of gorgonians, especially larger colonies with greater than average height, was observed in the majority of assessed nets at an average rate of 2.4 ± 0.8 colonies or fragments per 200m of net. Impact was higher in specific areas below 80m depth and where wave heights were greater than 1m. Trammel nets mostly caught large colonies with greater height than average. Impact could be significantly mitigated by measures such as avoiding fishing at 80-90m depth during adverse weather conditions.

This study examined the effectiveness of various sizes of guarding nets to reduce bycatch (specifically crustaceans) in cuttlefish trammel net fisheries. All nets did siginificantly reduce crustacean capture, notably spider crabs, but only the smaller mesh guarding net (20mm instead of 40mm) had no significant impact on target cuttlefish catch. However, guardnets may benefit fishers overall by avoiding later delays in disentangling bycatch and damage to gear. 

This summary study analyzes unintended horsehoe crab (Tachypleus tridentatus) bycatch in trawl and gillnet fisheries in the Letzhou Gulf, China. Estimates show at least 9120 ± 315 horseshoe crabs are caught annually. Bycatch rates increase in spring and autumn, and are higher in gillnet fisheries compared to trawl fisheries. The study also highlights several zones/areas of the Letzhou Gulf with "abundant shoal resources" and higher bycatch rates.