Human Impacts 



Studies on Jonah and rock crabs indicate that commercial harvesting is highly 

 selective, favoring larger crabs, generally males. It is believed that crabs 

 are being harvested at close to the optimum capacity to sustain the population 

 (personal communication from J. Cowger, Maine Department of Marine Resources, 

 Augusta, ME; November 1977). The effects of fishing on these crabs are 

 unknown. 



Other potential impacts include dredging and spoil disposal, oil spills, and 

 other toxic discharges. The effect of these factors on the Jonah and rock 

 crab populations is unknown. 



Importance to Humanity 



In the past, harvest of the rock crab and the Jonah crab has been incidental 

 to the lobster fishery in Maine. Lobstermen commonly find crabs, particularly 

 the rock crab, in their traps and usually discard them; however, as prices 

 continue to rise, fishing intensity will increase and more crabs will be kept 

 and sold by lobstermen. Fishermen who fish specifically for crabs use crab 

 pots that lobsters cannot enter. 



Although landings of crabs in the last 10 years have been variable (see figure 

 12-6) , the value of the crab fishery in the last few years has increased 

 rapidly. The actual harvest may have been significantly greater than what the 

 data indicate, as many crabbers process the meat at home and sell directly to 

 retailers. Almost the entire crab harvest is sold as fresh, handpicked meat 

 within the State (Fisheries Development Corporation 1977). 



Management 



Currently, there are no management regulations on crab resources in Maine. 

 Harvest restrictions on the fishery are the same as those on the lobster 

 fishery. 



NORTHERN SHRIMP ( Pandalus borealis ) 



The northern shrimp is a decapod crustacean that is circumboreal (i.e., found 

 around the world in the boreal zone) in distribution and occurs in both 

 inshore and offshore waters at various stages in its life cycle. The species 

 may reach a size of 6 inches (150 mm) at maturity (TRIGOM 1974) and during its 

 life span usually functions first as a male, for 2.5 to 3.5 years, then as a 

 female. 



In the past, the shrimp fishery of Maine has been erratic. It reached a peak 

 in the late 1960s but since then has been declining. 



Distribution and Abundance 



In New England, the northern shrimp occurs in the Gulf of Maine, especially 

 near Jeffrey's Ledge, southwest of Cashes Ledge, and southeast of Mt. Desert 

 Island, at depths from 30 to 1100 feet (9 to 329 m; Haynes and Wigley 1969). 



12-20 



