maximios

West coast whale entanglements are hitting historical highs, prompting government agencies, fishermen, researchers, and NGOs to collaborate in finding ways to reduce them. Werner and McCarron shared their perspectives through invited talks and discussions during the March 29-20, 2017 workshop in Portland, Oregon, organized by the Pacific States Marine Fisheries Commission. A list of workshop […]

Do circle hooks reduce bycatch?…It depends. Last week, NOAA hosted over 160 marine scientists, fisheries managers, gear experts, and commercial and recreational fishermen, from 20 countries, in Coral Gables, FL, for the first international symposium on circle hooks in research, management and conservation.  While we all came away more informed about circle hooks, we left with more […]

Two captive harbor porpoises were exposed to three sound types (frequency from 100 kHz to 140 kHz, 200 ms long, and presented once per 4 s). Each session consisted of a 10 min period persound, a 5 min period of sound, and a 10 min period after the sound. Behavior was recorded on video and […]

Pelagic longline hooks equipped with magnets were tested for their ability to repel blue sharks.  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 […]

A review of recently published articles dealing with the effects of magnetic fields on elasmobranchs and potential use in bycatch avoidance was conducted. The authors suggest these papers ignore that teleosts may also demonstrate magnetite based magnetoreception and that electroreception is present in many teleosts. Based on this, the possibility of induction based indirect magenetoreception […]

Citations for studies that pertain to bycatch reduction approaches. Summaries of the findings for each study. Descriptions of bycatch reduction techniques. Descriptions of fishing methods. Links to studies and study authors, where available. Users can search the database by fishing gear, bycatch reduction technique, or non-target wildlife group singly or in combination. This is achieved […]

This study investigated the efficiency of a sieve‐panel to separate bycatch species from Norway lobster (Nephrops norvegicus) in trawl gear via mechanical and behavioral means. Four different designs of varying panel mesh size or inclination were tested. The sieving efficiency for Nephrops increased from ~17% to ~71% as mesh size increased, and decreased with increasing carapace length, but […]

Average annual seabird bycatch has declined by 73% in the last 5 years (2002-2006) compared to bycatch from the late 1990s. Despite the recent reductions resulting from mandatory mitigation requirements, seabirds continue to be caught at higher rates than would be expected given results of controlled studies that demonstrated bycatch reductions of nearly 100% with […]

White Dukane pingers with a fundamental frequency of 10kHz and harmonies of up to 160 kHz, elicited the strongest response from Hector’s dolphins, compared to the black Pice and red Dukane pingers. More than half (62.5%) of the dolphins exhibited avoidance when exposed to the white pinger. However, no significant differences between pingers were found […]

A study was conducted on observed interactions between a Portuguese purse-seine fishery and cetaceans. Cetaceans, primarily common dolphins (Delphinus delphis), were present during 16.9% of fishing events. The majority of these occurrences happened during the summer and early fall, and during the night. The presence of cetaceans was significantly linked to sardine catches, effort and […]

Pingers have been used on shark nets set along Queensland’s beaches since 1992. Due to an increase in whale entanglements in 2009, new pingers (Fumunda F3 whale pingers and F10 dolphin pingers) were deployed between July and August 2010. Subsequently updated research on the use of these pingers was needed. For this study, the acoustic […]

Four commercially available pingers (AIRMAR, Aquamark 100, Fumunda, Save Wave Saver) were tested on vessels operating in Cornwall targeting hake with gillnets. Pingers were tested for their effectiveness at reducing incidental interactions between the gillnets and porpoises. Only one of the four tested pingers, AIRMAR, performed ‘satisfactorily’. 

A study was conducted with humpback whales to test their response to recordings of conspecific social sounds and an artificially generated tone stimulus. Experiments were conducted during humpback whales southward migration along the east coast of Australia. A total of 13 tone experiments, 15 social sound experiments and 3 silent controls were conducted during two […]

Six different acoustic pingers and signals were tested at sea to determine their impact on dolphin behavior. Two prototype devices from the Board Iascaigh Mhara (BIM) were tested. One was a continuous pinger (CP) and the second a responsive pinger (RP). These were tested on five occasions. A third modified RP was also tested on […]