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Solutions to mitigate cetacean bycatch have targeted specific fisheries and gears, however, these targeted mechanisms can be effective if interactions occur only between a particular population and gear type or fishery. Most dolphin and whale populations face incidental capture from multiple fisheries and gears. Accordingly, broad-scale spatial approaches to mitigation are needed to address bycatch across multiple species at the scale at which the species occur. This study applied decision-theoretic bio-economic techniques to inform the reduction of cetacean bycatch in a case study of Australian fisheries. Spatial mapping highlighted substantial variation in the location of optimal cost-effective management strategies. Although trawl-net modifications were the cheapest strategy overall, there were many locations where spatial closures were the  most cost-effective solution (despite their high costs to fisheries) due to their effectiveness in reducing all fisheries interactions. 

Several designs of seal exclusion devices (SEDs) were tested to reduce bycatch of Australian fur seals (Arctocephalus pusillus doriferus) in the winter blue grenadier (Macruronus novaezelandiae) trawl fishery. A 'top-hatch' SED, or one with a top-mounted escape hatch, resulted in the lowest occurrence of seal bycatch than any other SED design or than nets without a SED. The SED prevented entry into the net codend where drownings occurred. SEDs also successfully expelled seals and limited access into the net via the escape hatch. Cameras are needed to verify the results.

Gillnets with three difference mesh sizes (2 7/8", 3" and 4") were modified to use 200 lbs/200 yard lead line and 11 oz buoyancy floats (versus 50lbs/200 yard lead line and 3 oz floats) to increase the tension in the net. Catch rates of Atlantic sharpnose (Rhizoprionodon terraenovae) and bonnethead (Sphyrna tiburo) sharks were significantly lower in the 4" modified net. The proportion of hammer-wrapped bonnethead sharks was significantly higher in the 4" unmodified net and significantly less blacktip sharks (Carcharhinus limbatus) were wrapped in the 3" modified net. Selectivity of blacknose sharks (Carcharhinus acronotus) varied between the modified and unmodified nets. Catch rates of targeted Spanish mackerel and spot were not significantly different between modified and unmodified nets.

The potential of modifying gillnets to reduce shark bycatch was investigated in the US Spanish mackerel (Scomberomorus maculatus)  and spot (Leiostomus xanthurus) gillnet fisheries. The modified net had larger floats on the head-rope and increased weight on the lead-line to increase the tension of the net. Results showed that the catch rate of some shark species was significantly reduced in the modified gillnets. Target catch rates of Spanish mackerel did not differ significantly between control and modified nets of the same mesh size.

At-sea and on-shore trials were conducted to test the safety and effectiveness of an alternative line weight for pelagic longlines called the Safe Lead.  This new line weight is designed to reduce danger to the crew in the event of a bite-off by sliding down or off the line.  At-sea trials were conducted in South Africa and indicated that dangerous fly-backs, a result of a bite-off, were reduced when the Safe Lead was used. During these trials, only 4.2% of Safe Lead fly-backs reached the fishing vessel, compared to 73.3% with traditional leaded swivels.  On-shore trials indicated that the degree of slippage of the Safe Lead off the line was dependent on the distance from the Safe Lead to the hook and the tension on the line. When the Safe Lead was placed within 2m of the hook, it slid off the line under all four tension treatments. Safe Leads appear to be both a cost effective and operationally simple alternative to traditional leaded swivels.

Tests were conducted aboard Canadian longline vessels targeting swordfish (Xiphias gladius) to determine if there were differences in the catch rates and size composition of swordfish and bycatch species caught by monofilament and multifilament nylon gangions.  No significant differences in the mean lengths of swordfish were found between the two nylon gangions but catch rates did differ significantly, with more swordfish caught on the monofilament gangions. There was also a significant difference in catch rates between the two gangions for blue sharks (Prionace glauca) and pelagic stingrays (Dasyatis violacea), with more animals caught on monofilament gangions. There was no significant difference in catch rates between gangions for mako sharks (Isurus oxyrinchus), white marlin (Tetrapturus albidus) or loggerhead sea turtles (Caretta caretta).

In May 2025, a ten-day gear trial using FloMo's "Modular Harvesting System" was conducted in the western Irish Sea Nephrops norvegicus fishery to assess the gear's effectiveness in reducing bycatch while maintaining catch retention. Across 22 tows, FloMo gear significantly reduced bycatch of undersized whiting (Merlangius merlangus) compared to a control trawl fitted with a 300mm square mesh panel. Retention of whole Nephrops was similar between gears, however, the quantity of retained smaller Nephrops suitable for the scampi market was significantly lower when using FloMo. Operationally, the FloMo gear did not present any major difficulties during the trial, however, most vessels in the Northern Ireland Nephrops fleet have a different net drum configuration with less clear deck space than the vessel used in the trial, which may limit adoption.

Neodymium-iron-boron (Nd2Fe14B) permanent magnets were used to test behavioral responses in spotted catsharks (Scyliorhinus canicula) and thornback skates (Raja clavata). Both species significantly avoided the Nd2Fe14B magnets more often in comparison to the control and procedural control and they fed significantly more from the control and procedural control in comparison to the magnets. The study also demonstrated a correlation between avoidance speed and distance with water temperature. 

An experimental leader design was tested on pound nets in the Chesapeake Bay, United States, in 2004 and 2005 to determine their effectiveness in reducing the incidental catches of sea turtles (Lepidochelys kempi and Caretta caretta). The experimental design consisted of replacing the top two thirds of the traditional mesh panel leader with vertical ropes spaced 61 cm apart. During the study, 21 sea turtles interacted with the control net, while only 1 interaction with the experimental net occurred. In addition, there was no significant differences in the harvest weight or size selectivity of finfish between the two net types, although these results were not considered very robust. 

Four types of tori-lines (long streamer, light streamer, hybrid streamer and modified light streamer) were tested for their ability to reduce seabird bycatch on commercial longline fishing vessels in the north Pacific Ocean.  Two experiments were undertaken 1) determine the frequency of bycatch of Laysan albatross (Phoebastria immutabilis) for each tori-line and 2) determine mean rate of attacks for tori-lines.  In experiment 1, the mean number of seabirds appearing and the catch per unit effort (for seabirds) was not statistically different between the four tori-lines.  In experiment 2, seabird attack rates (Laysan albatross and shearwater) were not statistically different nor were bycatch rates of Laysan albatross among the four tori-line types.