MSC 111 Lecture Notes - Lecture 18: Orange Roughy, Pelagic Fish, Chilean Sea

• School: University of Miami
• Department: Marine Science
• Course: MSC 111
• Professor: Peterson Larry

Document Summary

Decline since- debate between scientists and fishermen. Today: population is believed to be 1% of that in 1977. Catching adult fish faster than the population can reproduce. 350 tons/day- stores 7000 tons as frozen fish. Cannot reproduce fast enough to replenish population. Avoid some species due to concerns about mercury/other contaminants (higher trophic level organisms) Chilean sea bass, orange roughy (harvested intensely) Bycatch injured/dead fish or other marine animals unintentionally caught by fishermen then thrown overboard. Endangered species- whales, sharks, dead/injured nontarget fish. Nets: 40ft high, 100ft long, trawl doors. Rollers on bottom line- sweep everything on the seafloor into the net. Cone shaped net- towed at midwater to bottom. Accidentally kills thousands of endangered sea turtles an seabirds each year. One of the largest percent of bycatch of fishing. Fine mesh material- catches fish by the gills an marine mammals. Gill nets banned- clam farming increases to compensate for jobs lost. Kills all fish in 10-20 m radius.