Distribution and Abundance of East Coast Bivalve 



Mollusks Based on Specimens in the National Marine 



Fisheries Service Woods Hole Collection 



ROGER B. THEROUX 1 and ROLAND L. WIGLEY 2 

 ABSTRACT 



The distribution and numerical abundance of over 108,000 specimens of bivalve mollusks (81 % of which were 

 alive when captured) collected and maintained by the Benthic Dynamics Investigation at the NMFS Northeast 

 Fisheries Center at Woods Hole, Mass., are presented. They are illustrated in a series of charts, and their 

 bathymetric range and bottom sediment preferences are outlined in tabular form. Taxonomic groups represented 

 include 5 subclasses, 8 orders. 46 families. 99 genera, and 164 species. The specimens are contained in 10,465 lots 

 from 2,767 sampling sites along the east coast continental shelf and slope, and upper continental rise between Nova 

 Scotia and southern Florida. Samples range in depth from to nearly 4,000 m. The collections were obtained by a 

 variety of research vessels and persons using quantitative and qualitative sampling devices (i.e., grabs, dredges, 

 trawls, etc.) over a period of 21 yr. Also included are current vernacular names, zoogeographic data, and a 

 reference to the original description of represented species. 



The data upon which this report is based are stored on magnetic tape and disc files, and the specimens are 

 stored in a Specimen Reference Collection at the Northeast Fisheries Center in Woods Hole, Mass. 



INTRODUCTION 



Bivalves, as a group, are a major component of the U.S. 

 east coast macrobenthic invertebrate fauna accounting for 

 22% of the total number and 70% of the total biomass of 

 invertebrates in the Middle Atlantic Bight (Wigley and The- 

 roux 198 1 ). and for 1 2% of the number and 44% of the biomass 

 of invertebrates in the offshore New England region (Theroux 

 and Wigley 3 ). In addition, several species support important 

 fisheries (e.g., sea scallops, oysters, surf clams, ocean 

 quahogs, and bay scallops), especially in the northeastern 

 sector, which, in 1979, accounted for landings of bivalve 

 meats totaling 151 million lb valued at $205.1 million fPileggi 

 and Thompson 1980). 



Since 1955 the Benthic Dynamics Investigation of the 

 National Marine Fisheries Service's (NMFS) Northeast 

 Fisheries Center (NEFC) at Woods Hole, Mass. (U.S. De- 

 partment of Commerce, NOAA), has been conducting ecolo- 

 gical studies relating to benthic invertebrates and demersal 

 fishes. As a result of intensive sampling for these studies we 

 have accumulated a large collection of invertebrate speci- 

 mens from inshore and offshore locations which are main- 

 tained in a Specimen Reference Collection (SRC). Bivalve 

 specimens make up a significant and diverse portion of the 

 Collection accounting for 225 separate taxa, with representa- 

 tives from estuaries, embayments, the shoreline, the con- 

 tinental shelf, slope, and portions of the upper continental 



'Northeast Fisheries Center Woods Hole Laboratory. National Marine Fisher- 

 ies Service, NOAA, Woods Hole, MA 02543. 



2 Northeast Fisheries Center Woods Hole Laboratory. National Marine Fisher- 

 ies Service. NOAA. Woods Hole, Mass.; present address: 35 Wilson Road, 

 Woods Hole. MA 02543. 



3 Theroux, R. B., and R. L. Wigley. Quantitative composition and distribu- 

 tion of the macrobenthic invertebrate fauna of the New England Region. 

 Manuscr. in prep. Northeast Fisheries Center Woods Hole Laboratory, 

 National Marine Fisheries Service, NOAA, Woods Hole, MA 02543. 



rise. Sampling depths represented range from to nearly 

 4,000 m. 



This report deals with the geographic and bathymetric dis- 

 tribution and occurrence, and relationship to bottom sedi- 

 ments of all taxonomic groups of bivalves in our collection. 

 Geographic distribution of each taxon, along with a sketch of 

 the shell, is presented in a series of charts, whereas depth 

 distribution and occurrence and sedimentological rela- 

 tionships are in tabular form. Also included are: 1) author and 

 date of generic descriptions from Neaves' "Nomenclator 

 Zoologicus"; 2) the vernacular name of species when avail- 

 able; and 3) a reference to specific descriptions, the originals 

 of which were examined and cited in the References section. 



The bivalve taxa are discussed in systematic order in the 

 body of the report (see Contents): however, for reference 

 facility figures are arranged alphabetically by genus on the 

 last pages, and are cross referenced by figure number within 

 each taxonomic section. 



MATERIALS AND METHODS 



The Specimen Reference Collection contains over 108.000 

 specimens of bivalve mollusks, 81% of which were alive when 

 captured. The taxonomic groups of bivalves represented in- 

 clude: 5 subclasses, 8 orders, 46 families, 99 genera, and 164 

 species. The specimens are contained in 10.465 lots obtained 

 from 2,767 sampling sites located along the shore, in estuaries 

 and embayments, and on the continental shelf and slope of the 

 eastern coast of the United States between Canada and south- 

 ern Florida (Fig. 1). 



Twenty-one years are represented in these data from the 

 Specimen Reference Collection; included are samples from 

 collections made in 1903, 1904, 1950, 1953 through 1968, 1970, 

 and 1971. Samples obtained from 1972 to the present are not 

 included in this report. 



