Conservation Evidence: Evidence Data

Collected Evidence: Collected Evidence: Use circle hooks instead of J-hooks Eleven studies evaluated the effects of using circle hooks instead of J-hooks on reptile populations. Five studies were in the Atlantic, three were in the Pacific and one study was in each of the Mediterranean, the Atlantic and North Pacific and the western North Atlantic, Azores, Gulf of Mexico and Ecuador. COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (3 STUDIES) Survival (3 studies): Two studies (including one replicated, controlled, paired study) off the coast of Hawaii and in the north-east Atlantic Ocean found that survival of loggerhead and leatherback turtles and leatherback and hard-shell sea turtles caught by circle hooks or J-hooks was similar. One review of studies in five pelagic longline fisheries found that fewer sea turtles died when circle hooks were used compared to J-hooks in four of five fisheries. Condition (3 studies): Two replicated, controlled studies in the Mediterranean Sea and south-western Atlantic Ocean found that fewer immature loggerhead turtles and loggerhead turtles swallowed circle hooks compared to J-hooks. One before-and-after study off the coast of Hawaii found that a lower percentage of loggerhead and leatherback turtles were deeply hooked by circle hooks compared to J-hooks. BEHAVIOUR (0 STUDIES) OTHER (11 STUDIES) Unwanted catch (11 studies): Seven of 10 studies (including six replicated, controlled studies) in the Pacific, Atlantic, Atlantic and North Pacific and Mediterranean and one review of studies in five pelagic longline fisheries found that circle hooks or circle hooks and tuna hooks caught fewer sea turtles than J-hooks, or that non-offset G-style circle hooks caught fewer leatherback and hard-shell sea turtles that offset J-Hooks. One of these studies also found that circle hooks caught slightly larger loggerhead turtles than J-hooks, and one also found that offset Gt-style circle hooks caught a similar number of leatherback and hard-shell sea turtles compared to offset J-hooks. One study found that circle hooks caught a similar number of leatherback, green and olive ridley turtles compared to J-hooks. One study found that fish-baited circle hooks caught fewer loggerhead and leatherback turtles than squid-baited J-hooks. The review found mixed effects of using circle hooks compared to J-hooks on unwanted catch of sea turtles depending on the fishery. The other study found mixed effects of using circle hooks or J-hooks in combination with squid or fish bait on the number of loggerhead and leatherback turtles that were caught. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3559https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3559Wed, 08 Dec 2021 14:21:43 +0000Collected Evidence: Collected Evidence: Use non-offset hooks Two studies evaluated the effects of using non-offset hooks on reptile populations. One study was off the Pacific coast of Costa Rica and one was in the north-east Atlantic. COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (1 STUDY) Survival (1 study): One replicated, controlled, paired study in the north-east Atlantic Ocean found that mortality of leatherback turtles was similar when caught with non-offset hooks or offset hooks. BEHAVIOUR (0 STUDIES) OTHER (2 STUDIES) Unwanted catch (2 studies): One of two replicated, paired studies (including one controlled study) off the Pacific coast of Costa Rica and in the north-east Atlantic found that non-offset circle hooks caught a similar number of olive ridley and green turtles compared to offset circle hooks in a shallow-set longline fishery. The other study found that non-offset G-style circle hooks caught fewer leatherback and hard-shell turtles compared to offset Gt-style circle hooks or offset J-hooks in a longline swordfish fishery. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3571https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3571Wed, 08 Dec 2021 15:13:12 +0000Collected Evidence: Collected Evidence: Use a different bait type: Sea turtles Nine studies evaluated the effects of using a different bait type on sea turtle populations. Three studies were in each of the Atlantic and Pacific, and one was in each of the Atlantic and north Pacific, the Gulf of Garbes (Tunisia) and Italy. COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (2 STUDIES) Survival (2 studies): Two studies (including one replicated, controlled study) off the coast of Hawaii and in the Southern Atlantic found that the percentage of loggerhead and leatherback turtles that survived being caught by fish-baited or squid-baited hooks or fish-baited circle hooks and squid-baited J-hooks was similar. Condition (1 study): One before-and-after study off the coast of Hawaii found that fish-baited circle hooks deeply hooked fewer leatherback and hard-shell turtles compared to squid-baited J-hooks. BEHAVIOUR (1 STUDY) Use (1 study): One controlled study in Italy found that loggerhead turtles in a captive setting were less likely to bite at fish bait than squid bait. The study also found that smaller turtles were more likely to bite at mackerel bait and larger turtles at squid bait. OTHER (8 STUDIES) Unwanted catch (8 studies): Four of five studies (including one replicated, paired, controlled study) in the North Pacific, Eastern Pacific, Atlantic and Atlantic and North Pacific found that fish-baited hooks caught fewer sea turtles or were swallowed by fewer olive ridley turtles than squid baited hooks. One study also found that fish bait in combination with larger circle hooks lead to the highest percentage of external hookings. The other study found mixed effects of using fish or squid-baited hooks on the unwanted catch of hard-shell and leatherback turtles. One replicated, controlled study in the north-western Atlantic Ocean found that fish-baited J-hooks caught fewer sea turtles compared to squid-baited hooks. The study also found that unwanted catch was more similar for fish-baited and squid-baited circle hooks. One before-and-after study off the coast of Hawaii found that fish-baited circle hooks caught fewer loggerhead and leatherback turtles compared to compared to squid-baited J-hooks. One replicated study in the Gulf of Garbes found that hooks baited with stingray caught fewer loggerhead turtles compared to fish-baited hooks. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3612https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3612Thu, 09 Dec 2021 12:02:07 +0000