Purse seine fishing
an effective fishing method for species that school near the surface; a large net is encircled around the targeted catch, after which the bottom of the net is drawn tight like the strings of a purse, thus confining the catch in the net. (ch12)
Drift nets
huge fishing nets that scoop up everything in their path, profitable but destructive and most state has banned their use
Long line fishing
puts out lines up to 80 miles long, hung with thousands of baited hooks; the depth of the lines can be adjusted to catch open ocean fish species such as swordfish, tuna, and sharks or bottom fishes such as halibut and cod; long lines also hook endangered
Sonar fishing
commercial fishing vessels rely almost completely on acoustic sonar and sounders to detect fish. Fishermen also use active sonar and echo sounder technology to determine water depth, bottom contour, and bottom composition.
Tragedy of the commons
situation in which people acting individually and in their own interest use up commonly available but limited resources, creating disaster for the entire community
By catch
unwanted marine creatures that are caught in the nets while fishing for another species
Bottom trawling
a fishing technique in which the ocean floor is literally scraped by heavy nets that smash everything in their path
Benthic
relating to the bottom of a lake or sea or the organisms that live there
Pelagic
The area of the ocean past the continental shelf, with areas of open water often reaching to very great depths
How does bottom trawling affect benthic organisms?
It carried along unwanted species of the underground sea including corals, and other species that belong in the bottom of the ocean.
Biomagnification
The accumulation of pollutants at successive levels of the food chain
Bioaccumulation
The accumulation of a substance, such as a toxic chemical, in various tissues of a living organism.
Top predator
The predator within a food chain or food web that has no natural predators. Example: bald eagle
Herbivore
an animal that eats only plants
Carnivore
an animal that eats only other animals
Omnivore
a consumer that eats both plants and animals
CITES
Convention on International Trade in Endangered Species of 1975 it is a step toward worldwide protection of endangered flora and fauna.
Marine Mammal Protection Act
1972 - Federal law that gives responsibility of protecting marine animals to the Department of Commerce and the Department of the Anterior; in 1994 you can't harrass marine mammals; doesn't protect polar bear trophies import/export
Exclusive Economic Zone
area in which resources found up to 200 nautical miles offshore belong exclusively to the geographically bordering country
What is the formula to calculate % change?
Take the new, "current value" and divide it by the old, obsolete value. Subtract 1.00 (or 100%) from the result.