CONTENTS 



Page 



CONVERSION FACTORS, U.S. CUSTOMARY TO METRIC (SI) 9 



GLOSSARY OF BIOLOGICAL TERMS 10 



I INTRODUCTION 11 



II MARINE SEDIMENTARY COMMUNITIES 12 



1. Physical-Chemical Factors 13 



2. Biological Factors 15 



3. The Importance of Life-History Information 15 



4. Diversity 16 



5. Southern California and Imperial Beach Sediments. . . 17 



6. Southern California and Imperial Beach Infauna. ... 17 



7. Sampling Design Considerations 18 



III MATERIALS AND METHODS 20 



Beach Replenishment 27 



IV PHYSICAL AND CHEMICAL RESULTS 28 



1. Beach Topography 28 



2. Grain-Size Analysis 30 



3. Organic Carbon 38 



4 . Temperature 44 



5. Wave Data and Seasonal Storms 44 



V BIOLOGICAL RESULTS 47 



1. Sampling Design Effectiveness 47 



2. Biological Impacts of Dredge Disposal 51 



3. Major Species 83 



VI CONCLUSIONS 99 



LITERATURE CITED 101 



APPENDIX 



A IMPERIAL BEACH DREDGING/DISPOSAL OPERATION SCHEDULE. ... Ill 



B TAXA FOUND IN CORE SAMPLES DURING THE FIVE SURVEY 



PERIODS AT IMPERIAL BEACH, CALIFORNIA 116 



TABLES 



1 Sampling dates for Imperial Beach study 23 



2 Total number and type of core samples taken at each station 



for Imperial Beach 26 



