Distribution and Ecology (and fishing gear):

Distribution and Ecology:
Habitat:
- Blue crabs are bottom-dwellers in every type of habitat.
- from the saltiest water of the gulf to the almost fresh water of the back bays and estuaries.
- from the low tide line to water 120 feet deep.

Distribution:
- the range of the blue crab is from Nova Scotia, down the east coast of North America, throughout the Gulf Of Mexico and the Caribbean Sea, and down down the east coast of South America to Northern Argentina.
- the blue crab has been introduced, probably via ship ballasts into Europe, north Africa, and southwest Aisa.

Environment:
Water temperature:
- from 10°C -15°C.
- water temperature above 33°C is lethal.

Water Salinity:
- salinity is important, but requirements very by life stage.
-generally optimum is 3-15 parts per thousand (ppt).

Water pH:
-tolerance range is pH 6-8.
-less than 6 is lethal.


Fishing Gears:
The most common type of commercial fishing gear is the crab pot which is a cubical wire trap with two or four entrance funnels. The pot has two chambers, a lower chamber which has the entrance funnels and the bait well and an upper chamber that is separated from the lower chamber by a wire partition that has two holes.
The blue crab's natural reaction to confinement is to swim upward. In doing so, they move into the upper chamber, thereby reducing their chances for escape. The crab pot was first introduced in Chesapeake Bay in about 1936, but was not widely used in South Carolina until the late 1950's. Crabs are also caught and sold as part of the bycatch of shrimp trawlers and after the shrimp trawling season is closed, usually in January, trawling for crabs with large mesh trawls is permitted until March 31.

Recreational blue crab fishermen employ several fishing gears and methods. South Carolina law allows individuals to fish two crab pots without a license if they are properly marked with floats bearing the owner's name. Fishing more than two pots requires a commercial crabbing license. Whether fishing from a dock or boat, recreational crab pots should have a marked float and enough line to prevent the float from being submerged at high tide. Recreational crabbers should also be careful not to leave a pot in an area that would expose the pot and crabs at low tide. Pots should be checked daily and catches can often be doubled if the pots are checked twice per day. To remove crabs, pull the wire apart and shake the crabs into a tub or bucket. Some stubborn crabs may have to be dislodged with a stick. Remember that crabs can pinch, so be very careful about putting your hand in a pot.









Drop net Crab Pot (trap) Dip net

Drop nets and collapsible traps, usually baited with herring, can be fished from docks and bridges. Another effective recreational method called "dipping" requires a long-handled dip net, several yards of string and bait. The bait, usually a chicken neck or fish head, is tied to the string and thrown into the water away from the bank. Once a tug is felt, the crabber pulls the bait and crab close enough to be quickly dipped from the water and placed into a waiting bucket. The beginner should be cautious when handling a blue crab since the pinch of the powerful claws can be extremely painful. (The inexperienced crabber should probably wear thick gloves). Always approach from the rear when picking up a crab. An experienced crabber can quickly grab the base of one of its swimming legs while holding the claws down with some object. Should a crab get a hold on a finger, it is usually best not to pull it off. First, try letting it hang; many times the crab will release and drop. If the crab will not release, use the free hand to immobilize the other claw and slowly bend the offending claw backward until the crab releases it.

Crabs can be caught during all twelve months, but become inactive in winter when water temperature falls below 50-55 degrees F. As temperatures rise in March and April, catch rates increase rapidly. The best time of year to harvest large, heavy crabs is usually from October to December. Mature females are typically near the ocean, but large males are most common in the rivers and creeks.