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The type (circle 18/0 0 degree offset and J-style 9/0 10 degree offset) and position of hooks in the water column were tested to determine the effects on catch rates and mortality of elasmobranchs in pelagic and bottom longline fisheries in Brazil. Tests were conducted aboard pelagic and bottom longline vessels. Catch per unit effort (CPUE)  for blue shark (Prionace glauca), silky shark (Carcharhinus falciformis) and oceanic whitetip sharks (Carcharhinus longimanus) were significantly higher with circle hooks than with J-style hooks. Silky, blue and oceanic whitetip sharks had a significantly higher mortality at haulback with J-style hooks. Significant differences in hooking location between the two hook types was found for night, blue, silky and oceanic whitetip sharks. These sharks were more commonly hooked externally vs internally.  No significant differences between hook types was found for the CPUE of the sharks on bottom longlines.  Significantly more blacknose sharks (Carcharhinus acronotus) were alive at haulback when circle hooks were used on bottom longlines. Bottom longlines were also used to test for differences in CPUE by fishing depth.  Demersal hooks had significantly higher CPUEs than those suspended in the water column for blacknose sharks, nurse sharks (Ginglymostoma cirratum), and southern stingrays (Hypanus americanus).

An excluder grate (grid) was tested in the silver hake (Merluccius bilinearis) trawl fishery in Massachusetts Bay, United States to determine its effectiveness in reducing spiny dogfish (Squalus acanthias) bycatch.  The effects of color (white or black), angle and direction of the 50 mm spaced grids were investigated through video observations and data collection.  The number of spiny dogfish caught in trawls with the excluder grate were greatly reduced for all gear configurations, while the number of target species caught remained within typical commercial quantities.  Over 88% of spiny dogfish were excluded by the grate regardless of color or gear configuration. There were no observed differences in the behavior of spiny dogfish between gear configurations or grate colors.

A study was conducted to determine the impact of removing the 'tickler' from in front of ground gear of trawls. The 'tickler' is a length of chain placed in front of the ground gear of trawl gear, which is supposed to increase catches of sharks and rays. Tests were conducted where the 'tickler' was removed and secondary nets (ground gear bags) were placed behind the ground gear to determine the amount and species of fish that escaped capture. The results indicated that removing the 'tickler' from in front of the ground gear reduced the capture of skates and sharks. Therefore, prohibiting the use of 'tickler' chains in critical habitats for skates and sharks could be a beneficial management tool.

Pelagic longline hooks equipped with magnets were tested for their ability to repel blue sharks (Prionace glauca). Tests were conducted aboard pelagic longliners operating in the Northeast Atlantic Ocean. Two magnets, one large and one small, were tested. Magnets were manually attached to the hooks (polarized so the magnet field was oriented N or S and in parallel with the hook axis). Three test zones, each with 5 hooks with 1 magnet, 11 hooks with 2 magnets and 16 control hooks, were deployed along a longline. The results indicated that blue shark catch rates were not reduced with the use of magnets, and can instead have an increased attractive effect. The attraction was higher with the large magnet.

Experiments were conducted aboard longline vessels operating in the Seychelles targeting swordfish and tuna. Experimental longlines fitted with hook timers and temperature depth recorders were used to identify differences in species composition, quantity and depth of catch between night sets using a shallow basket (swordfish target) and day sets using both shallow and deep baskets (tuna target). The majority of species were caught during day sets (75%). Lancetfish (Alepisaurus sp.) was the main bycatch species during daytime sets. Sharks were the most common nightime bycatch species, with blue (Prionace glauca) and shortfin mako sharks (Isurus oxyrinchus) being the predominant shark species. All marketable species were caught in the 150 m layer, marlins were never caught below 100 m. Sharks were caught below 150 m during both night and day sets. For other bycatch species, all were caught in depths less than 150 m during night sets. Daytime depth captures varied.

A literature review of 30 studies was conducted to determine the  effectiveness of various bycatch reduction devices for elasmobranchs. The risk of capture was 1.2 times higher on circle hooks but haulbaulk mortality as well as deep hooking was reduced. Wire leaders had higher shark catch and haulback mortality rates compared to monofilament. Hooking position is determined by the hook shape and width combined with bait. These characteristics also affect the ability to sever monofilament leaders. Shark catch rates and deep hooking were increased when fish was used for bait compared to squid. Wider hooks resulted in reduced pelagic stingray (Pteroplatytrygon violacea) catch and mortality.

A literature review of 30 studies was conducted to determine the  effectiveness of various bycatch reduction devices for elasmobranchs. The risk of capture was 1.2 times higher on circle hooks but haulbaulk mortality as well as deep hooking was reduced. Wire leaders had higher shark catch and haulback mortality rates compared to monofilament. Hooking position is determined by the hook shape and width combined with bait. These characteristics also affect the ability to sever monofilament leaders. Shark catch rates and deep hooking were increased when fish was used for bait compared to squid. Wider hooks resulted in reduced pelagic stingray (Pteroplatytrygon violacea) catch and mortality.

The elasmobranch assemblage associated with the shrimp trawl fishery operating along the Pacific coast of Costa Rica was assessed. Trawl hauls were conducted between August 2008 and August 2012, resulting in the sampling of 4,564 elasmobranchs from 25 species and 13 families. The most commonly caught species (66% of the elasmobranch abundance) included the Panamic stingray (Urotrygon aspidura), rasptail skate (Rostoraja velezi), brown smoothhound (Mustelus henlei) and witch guitarfish (Zapteryx xyster). Elasmobranch species richness was significantly higher at depths less than 100 m, compared to deeper depths. In addition, size and sex distribution is influenced by depth of fishing. The movement of this fishery into shallower waters could be problematic for elasmobranch bycatch.