Thirty Years of Sea Ranching Manila Clams (Venerupis philippinarum): Successful Techniques and Lessons Learned

Abstract

Successful intertidal mollusk farming requires a working knowledge of the biology, density, dynamics, and distribution of mollusk populations. Little Skookum Shellfish Growers (LSSG) has operated under economically and environmentally sustainable sea ranching guidelines for Manila clams (Venerupis philippinarum) since 1977 in Little Skookum Inlet near Shelton, Washington, USA. LSSG's system of benthic surveys and seeding offers a rational approach for establishing and monitoring standing stocks and biomass dynamics of infaunal mollusk populations, allowing LSSG to sea ranch Manila clams in excess of 60,000 kg/ha/y in sustainable yield. Until successful acoustical methods for infaunal biomass analysis are established, this approach may be the only cost effective way of achieving economical and sustainable results with a full working knowledge of the impacts involved in either intertidal sea ranching or stock enhancement for infaunal mollusks.

Keywords:

• aquaculture
• Manila clams
• Venerupis phillipanarum
• management
• sea ranching

ACKNOWLEDGEMENTS

Many people participated in the time series of surveys that support our conclusions on the sustainability of LSSG and its production system. The authors would like to thank the key people who have helped keep the process going and contributed materially to the surveys for the last 30 years: Michael Kyte, James P Glock, Erik Hurlburt, Daniel P. Cheney, Greg Bonacker, Elaine A. Bishop, Andrew Surbier and the students of The Evergreen State College, The Lakeside School, Seattle, and North Mason High School. We also would like to acknowledge the long-time interest, advice, encouragement, as well as the thoughtful review of this paper from Dr. Kenneth Chew. Finally, the authors also wish to thank the anonymous reviewers who contributed significantly to the clarity and readability of the paper.