Lecture 31- Unsustainable Fishing Practices Flashcards
(39 cards)
bottom trawling
- fishing method used to collect organisms on or near the seafloor
- bottom of net heavily weighted and dragged across seafloor
- most damaging
surface long-line fishing
- used to catch pelagic predators such as tuna, and swordfish
- uses more than 100km of fishing line and thousands of baited hooks
fish aggregating devices (FADS)
- large school of fish around the devices and ships come back with net
- also end up getting unintended fish as well
— of the world’s tuna is caught using FADs
50%
purse seine net
used in conjunction with FADs or with dolphin associated tuna schools
overfishing is primary the result of a dramatic shift to
industrialized fishing operations that are run by large corporate companies who don’t care about conservation
—% decline in top predator fish abundance in the world’s oceans between 1995 and 2000
90%
overall wild captured biomass has — since the 1990s
leveled off since the 1990s at about 80 million tons
—% of the major world fisheries are either maximally exploited or overfished
93
one of the most striking trends of the past 3 decades has been the rise of
aquaculture
aquaculture provides about
47% of global fish production
overfished fisheries grew from 10% to
33% of all fisheries in 2015
what is directly driving overfishing and associated environmental degradation
subsidies
without the fuel subsidy
trawling the bottom of the ocean would almost stop certainly
harmful subsidies remain partly due to
lobbying by vested interest groups
as much as — of sea life scraped up by the trawlers is undesirable and discarded back into the ocean, most often as dead animals
70%
each year, trawling affects an area — times greater than global area of forest that is cleared
150 times greater
what do bottom trawling leave behind?
sediment trails
main problem of FADs?
they don’t just attract target species (skipjack tuna), they also attract other non-target animals
FADs increase bycatch by between
500 and 1000% when compared to nets set on free-swimming schools
between 15-20% of the total catch of a FAD associated skipjack seine is actually
juvenile yellowfin and bigeye which are threatened species
the plastic netting and other synthetic materials wash up on benches and snag on coral reefs and generally
add to the marine debris problems across the oceans
— FADs are abandoned every year
tens of thousands
problem with longline fishing
unintentionally catches seabirds (they swoop down to the fish), turtles, and sharks