Chapter 11 CContinued) 



Fecundity 11-15 



Spawning Habits 11-16 



EARLY LIFE HISTORY 11-20 



Larval Populations 11-20 



FOOD AND FEEDING HABITS 11-23 



FACTORS AFFECTING DISTRIBUTION AND ABUNDANCE 11-28 



Water Temperature 11-28 



Salinity 11-29 



Competition 11-29 



Predation and Harvest 11-31 



Diseases and Parasites 11-31 



Dams and Obstructions 11-31 



Water Quality 11-32 



Turbidity 11-33 



Dissolved oxygen 11-33 



Pathogens 11-33 



Toxicants 11-33 



Radioactivity 11-35 



Nutrients 11-35 



pH 11-35 



IMPORTANCE TO HUMANITY 11-36 



MANAGEMENT 11-44 



RESEARCH NEEDS 11-46 



CASE STUDY: SHORTNOSE STURGEON 11-48 



Range and Distribution 11-48 



Reproduction and Growth 11-48 



Food and Feeding Habits 11-49 



Predation 11-50 



Importance to Humanity 11-50 



REFERENCES 11-51 



CHAPTER 12: COMMERCIALLY IMPORTANT INVERTEBRATES 12-1 



SOFT- SHELL CLAM ( My a arenaria ) 12-2 



Distribution and Abundance 12-2 



Life History 12-2 



Habitat Preferences 12-3 



Factors of Abundance 12-3 



Human Impacts 12-4 



Importance to Humanity 12-4 



Management 12-5 



BLUE MUSSEL ( Mytilus edulis ) 12-7 



Distribution and Abundance 12-7 



Life History 12-7 



Habitat Preferences 12-8 



Factors of Abundance 12-8 



Human Impacts 12-9 



Importance to Humanity 12-9 



Management 12-9 



SEA SCALLOP ( Placopecten magellanicus ) 12-10 



Distribution and Abundance 12-10 



Life History 12-11 



10-80 



