EAS 1540 Lecture Notes - Lecture 17: Pelagic Fish, Trawling, Predatory Fish
27 Jun 2016
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Bottom trawling: collects organisms on or near the seafloor with a heavy chain scraping the bottom into a net. Mid-water trawling: large net pulled through the middle of a water column. Purse seine net: used to collect mostly shallow fish. Surface long-line fishing: 100km lines with thousands of baited hooks to catch pelagic fish. Kills many birds (every species of albatross is no endangered - 10% of wandering albatross killed by these each year) Drift net fishing: floating nets that can be hundreds of kilometers long. Fish aggregating devices (fads): catch 50% of world"s tuna; make fish go to one area before they are taken. Tens of thousands are abandoned each year, leading to increased environmental damage. Caused by a dramatic shift to industrialized fishing operations that are run by large corporations with little concern for conservation. 90% decline in the top predator fish abundance between 1955-2000.
