Conservation Evidence: Evidence Data

Collected Evidence: Collected Evidence: Use baited lines instead of nets for shark control Two studies evaluated the effects on marine mammals of using baited lines instead of nets for shark control. One study was in the Indian Ocean (South Africa) and one in the South Pacific Ocean (Australia). COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (1 STUDY) Survival (1 study): One site comparison study in the South Pacific Ocean found that using baited lines instead of nets increased the survival of entangled common and bottlenose dolphins. BEHAVIOUR (0 STUDIES) OTHER (2 STUDIES) Reduction in entanglements/unwanted catch (2 studies): Two site comparison studies in the Indian Ocean and South Pacific Ocean found that baited lines used for shark control had fewer entanglements of dolphins, whales and dugongs than nets. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2856https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2856Mon, 08 Feb 2021 11:13:28 +0000Collected Evidence: Collected Evidence: Use ‘soft start’ procedures to deter marine and freshwater mammals to reduce noise exposure Three studies evaluated the effects of using ‘soft start’ procedures to deter marine and freshwater mammals to reduce noise exposure. One study was in each of the South Atlantic Ocean (Gabon), the South Pacific Ocean (Australia) and various water bodies (UK). COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (0 STUDIES) BEHAVIOUR (3 STUDIES) Behaviour change (3 studies): One study in various water bodies around the UK found that a greater proportion of cetaceans (including whales, dolphins and porpoise) avoided or moved away from vessels during ‘soft start’ procedures with seismic airguns compared to when airguns were not firing. One study in the South Atlantic Ocean found that during ‘soft start’ procedures using seismic airguns, a pod of short-finned whales initially moved away but remained within 900 m of the vessel as it passed by. One study in the South Pacific Ocean found that during ‘soft-start’ procedures with a small experimental airgun array, migrating humpback whales slowed their speed towards the vessel but did not significantly alter their course. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2897https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2897Mon, 08 Feb 2021 12:12:04 +0000Collected Evidence: Collected Evidence: Rescue and release stranded or trapped marine and freshwater mammals Eleven studies evaluated the effects of rescuing and releasing stranded or trapped marine and freshwater mammals. Five studies were in the North Atlantic Ocean (USA), two studies were in the Indian Ocean (Tasmania, South Africa), and one study was in each of the South Atlantic Ocean (Brazil), the Cachoeira River estuary (Brazil), the North Pacific Ocean (USA) and the Shannon Estuary (Ireland). COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (11 STUDIES) Reproductive success (2 studies): One review in the North Pacific Ocean found that after rescuing and releasing stranded or trapped Hawaiian monk seals, along with at least seven other interventions to enhance survival, more than a quarter of the seals reproduced. One study in the Shannon Estuary found that a stranded common bottlenose dolphin that was rescued and released was observed with a calf a year later. Survival (11 studies): Seven studies (including one review) in the North Atlantic Ocean, Indian Ocean and the Shannon Estuary found that 17–100% of rescued and released Atlantic white-sided dolphins, short-beaked common dolphins, common bottlenose dolphins, long-finned pilot whales, short-finned pilot whales, and Cape fur seals survived during post-release monitoring periods, which ranged in length from three weeks to three years. Three studies in the South Atlantic Ocean, the Cachoeira estuary and the Indian Ocean found that a trapped rough-toothed dolphin, two stranded tucuxi dolphins and seven stranded sperm whales were successfully rescued and released, although long-term survival was not reported. One review in the North Pacific Ocean found that rescuing and releasing stranded or trapped Hawaiian monk seals, along with at least seven other interventions to enhance survival, resulted in more than a quarter of the seals surviving. BEHAVIOUR (0 STUDIES)Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2924https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2924Mon, 08 Feb 2021 16:51:49 +0000