Marine Biology - Fish and Fishing

counter shading
dark on top, light on bottom, helps reduce the visibility of epipelagic fish
disruptive coloration
a banding pattern of contrasting colors (opposites on the color wheel) that helps coral reef fish disrupt their silhouettes and camouflage
swim bladder
an air filled chamber that allows bony fish to adjust their buoyancy
a limit to the total number of pounds any permitted fishermen can take
Limited Entry
a limit to the number of boats that can participate in a fishery
maximum sustainable yield
the most fish that can be removed from a population without sacrificing the long term health and sustainability of the fish population
the most successful defensive strategy for fish (both large and small) in the ocean
marine protected areas
A region of the ocean set aside to shelter fishes and other organisms to spawn and mature, but may be open to other human activities
class agnatha
jawless fishes such as hagfishes and lampreys
bottom trawling
a fishing technique in which the ocean floor is literally scraped by heavy nets that smash everything in their path. This is very detrimental to the ecosystem.
purse seine
a fishing method capable of harvesting large quantities of surface-schooling pelagic fish by surrounding the school with a net, used in Alaska for pink salmon and herring
epipelagic long lining
a long line with baited hooks. it targets a variety of pelagic species , best known for tuna swordfish and marlins. disadvantages: by-catch, catches endangered species
bottom long lining
a long line with baited hooks, used in Alaska to target halibut and sable fish
set net
gill net that hangs, anchored, in a fixed location, used in Alaska primarily to catch sockeye salmon
manta ray
large plankton eating chondrichthyes with dramatically expanded pectoral fins and no dorsal fin
an organ serves to metabolize toxins and produce lipids, it is especially large in sharks because it also serves keep them afloat
bill fish
sailfish, swordfish, marlin, they possess large bills that they use to slash at and disable potential prey
pectoral fins
fins on the lateral or ventral side, they provide lift in sharks
dorsal fins
located on the dorsal side of the fish, it allows swimming fish to stay straight, the movie Jaws gave it a notorious reputation
over fishing of sharks in coral reefs
When shark numbers are reduced, there are increasing numbers of mid-level predators such as snappers and a reduction in the number of herbivores such as parrotfishes. The parrotfishes are very important to coral reef health because they eat the algae that would otherwise overwhelm young corals.
Ampulae of Lorenzini
sensory vesicles that respond to changes in temperature, water pressure, weak electrical fields, and salinity.
Lateral Line
system of sensory pits along the side of a fish that detects changes in water pressure
salmon shark
a close relative of the great white shark, this shark is the only pelagic shark commonly found in Alaskan waters
whale shark
largest fish in the ocean, this shark eats mostly plankton
fish with calcified bones, including pike, trout, and a few thousand other species
lunate caudal fin
found on bluefin tuna, aides in efficient high speed swimming
truncated caudal fin
found on rainbow trout, allows for a balance between speed and manuverability
heterocercal caudal fin
larger on top, smaller on bottom, found on most sharks, largest on the thresher sharks
organs that exchange oxygen and carbon dioxide with water