Chapter 11 (Continued) 



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 ( Mya 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 



Habitat Preferences 12-11 



Factors of Abundance 12-12 



Human Impacts 12-12 



Importance to Humanity 12-14 



Management 12-14 



AMERICAN LOBSTER ( Homarus americanus ) 12-14 



Distribution and Abundance 12-14 



Life History 12-15 



Habitat Preferences 12-15 



Factors of Abundance 12-16 



Human Impacts 12-16 



Importance to Humanity 12-17 



Management 12-17 



Rock Crab (Cancer irroratus ) and JONAH CRAB (Cancer borealis ) . . 12-18 



Distribution and Abundance 12-18 



Life History 12-19 



iii 



