97 



ISSUES 



Because of their reliance on nearshore hab- 

 itats (i.e., estuaries, reefs, mangroves, etc.) 

 species in this group are particularly sus- 

 ceptible to habitat loss, pollution, changes 

 in freshwater flows, siltation, and other en- 

 vironmental problems. Pacific striped bass 

 have been hurt by habitat degradation and 

 salinity changes in the San Francisco Bay 

 estuary; Chesapeake Bay species, such as 

 river herrings and hickory shad, have de- 

 clined drastically in recent years; and At- 

 lantic coast and Gulf of Mexico oyster and 

 hard clam harvests have been severely 

 reduced by pollution, disease, salinity 

 changes, and habitat losses. Louisiana 

 alone loses an estimated 35,200 acres of 

 coastal wetlands habitat each year. 



Because many shellfish fisheries are 

 close to large population areas, the likeli- 

 hood of pollution problems is high; Fishing 



closures due to shellfish bed contamina- 

 tion cause large economic losses each 

 year. In addition to direct pollution im- 

 pacts, excessive nutrient loads may in- 

 crease toxic plankton blooms that cause 

 red tides and paralytic shellfish poisoning. 

 Environmental stresses also make fish 

 more susceptible to diseases and para- 

 sites, either killing them outright or making 

 them difficult or impossible to market. 



Overutilization has been at least partially 

 responsible for depleting such species as 

 Pacific razor clams, Pismo clams, abalo- 

 nes, oysters, Pacific shrimp, and snook. 

 Marine mammals also feed on some of 

 these species and may compete with fish- 

 ermen; for example, sea otters on the Pa- 

 cific coast have depleted abalone and sea 

 urchin stocks, particularly in California. 



