Mitigating bycatch Cetacean bycatch

1 mitigating bycatch

1.1 acoustic deterrent devices
1.2 barium sulfate
1.3 fishing regulations , management
1.4 temporary closure
1.5 observers on boat

1.5.1 in u.s.


1.6 other ways of mitigating bycatch

mitigating bycatch
acoustic deterrent devices

the use of acoustic alarms mitigate by-catch , protect aquaculture sites has been proposed has advantages , risks associated alarms. acoustic deterrent devices, or pingers, have reduced number of cetaceans caught in gill nets. harbour porpoises have been excluded bottom-set gill nets during many experiments instance in gulf of maine, along olympic peninsula, in bay of fundy, , in north sea. of these studies show 90% decrease in harbour porpoise bycatch. pingers work because produce sound aversive (20; 15). there has been recent re-evaluation of potential of pingers , use in other fisheries due growing success. experiment on california drift gill net fishery demonstrated how acoustic pingers reduce marine mammal bycatch. shown bycatch reduced common dolphins , sea lions. bycatch rates lower other cetacean species northern right whale dolphin, pacific white-sided dolphin, risso’s dolphin , dall s porpoise. agreed upon more pingers on net, less bycatch. there 12-fold decrease in common dolphin entanglement using net 40 pingers. however, widespread use of pingers along coastlines excludes cetaceans such porpoises prime habitat , resources. cetaceans extremely sensitive noise being driven preferred coastal habitats use of acoustic devices. in poorer quality habitat, harbour porpoises subjected increased competition resources. situation recognized range contraction can result of climate change, anthropogenic activity, or population decline. large scale range contractions considered indicative of impending extinction. similar form of deterrent noise pollution originating vessel traffic.

barium sulfate

a promising gillnet effective in reducing bycatch harbor porpoises contains barium sulfate. these nets detected @ greater distance conventional nets because barium sulfate reflects echolocation signal, , renders nets more visible. barium sulfate makes nets stiffer if added @ high concentration. 3 factors: echo reflectivity, stiffness, , visibility may important in reducing bycatch. fish takes in bay of fundy normal, except haddock takes, down 3-5%. advantage of approach is passive , not require batteries, , there no “dinner bell effect. potential advantage of these nets greatest in artisanal fishery. noaa further testing verify effectiveness of nets.

fishing regulations , management

management , regulation lacking in many fisheries today. management measures urgently needed monitor fisheries (and illegal fisheries) protect cetaceans. efforts document bycatch should focus on gill-net fisheries because cetaceans more caught in gill-nets. conservation efforts should directed areas marine mammal bycatch high no infrastructure exists assess impact. there lack of reporting on global scale of cetacean bycatch.

in u.s. marine mammal protection act prohibits use , sale of marine mammals captured fisheries. similar legislation prohibits use , sale of marine mammals in other countries. marine mammal mortality monitoring program commercial fisheries occurs in u.s. “take reduction teams observe extent of bycatch , formulate strategies reduce bycatch , take reduction plans put place.

temporary closure

temporary closure of fisheries during short period of year when cetaceans migrating through area decrease bycatch significantly.

observers on boat

observers on fishing vessels spoting cetaceans in water can avoided.

in u.s.

some programs earth island institute’s dolphin safe label certification claim require certification onboard observers. however, fishery in world independent scientific observers certify whether or not dolphin has been harmed eastern tropical pacific, home aidcp treaty program. other tuna fisheries of world, efficacy of onboard observer certification has come under increasing scrutiny such programs have proven indefensible or unmanageable:

in interview radio australia last year, mark palmer of eii confirmed case eii monitors not go on board of vessels, , organization not have kind of resources put observers on “many thousands of ships out there catching tuna.

additionally, environmental groups have criticized earth island institute’s support of u.s. policies not require independent, on-board observation , instead rely on self-certification fishing captains, , may @ point in future require independent observers, lack of uniformity in tracing , verifying certifications in different countries means non-certified products can become certified if taken right port.

other ways of mitigating bycatch

implement gear technology (changes in fishing gear , practices) documented mitigate cetacean bycatch
buy tuna , other seafood has dolphin safe label.
buy sustainable seafood. find out seafood produced sustainably (i.e. using cetacean friendly gear), refer world wildlife fund global access worldwide sustainable seafood guides
support sustainable seafood companies , restaurants
raise international awareness assess, monitor , mitigate bycatch problems
create legislation on responsible fishing practices.
develop , promote industry adoption of best practice guidelines fishing operations




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