LIFE HISTORY STUDIES OF THE SANDWORM, 

 NEREIS VIRENS SARS, IN THE SHEEPSCOT ESTUARY, MAINE 



Edwin P. Creaser and David A. Clifford 1 



ABSTRACT 



Little information is available on the life history of the sandworm, Nereis virens, in Maine despite 

 their commercial importance over more than 40 years. Life history studies were performed in a flat 

 along the Sheepscot River at Wiscasset, Maine, which was closed to commercial digging. Salinity 

 varied between 17 and 29%« at the surface and between 24 and 29%o on the bottom, and temperature 

 varied between -1° and 15°C at the surface and -1° and 14°C on the bottom. The proportions of 

 potential male and female spawners changed with size; for worms <30 cm, the proportions were 

 equal whereas a preponderance of females existed for worms >30 cm. Thirty percent of the largest 

 worms displayed no sign of sexual development. Single eggs of 50 n diameter were first observed in 

 the coelom from October to November. These eggs entered a rapid growth phase between August 

 and December and attained a maximum diameter of from 183 y. (1967) to 194 ^ (1968) at time of 

 spawning during April and May. Maturation could take as long as 18-20 months or as little as 12 

 months. The numbers of eggs laid by sandworms were found to vary between 0.05 (16 cm worm) and 

 1.3 million eggs (54 cm worm). The onset of spawningoccurred when the surface water temperature 

 was between 7.0°C (1968) and 8.1°C (1967) and when the bottom water temperature was between 

 6.7°C (1968) and 7.6°C (1967). During both years, spawning occurred 4 days after full moon during 

 the period of spring tides. Scuba observations revealed that male spawners emerged from the mud 

 about 3 hours after high water. At the peak of spawning, densities of epitokes may reach 1 worm/m 2 . 

 Male spawners are readily consumed by herring gulls, Larus argentatus. 



The sandworm, Nereis virens Sars, commonly 

 occurs on the Atlantic coast from Virginia north- 

 ward to the Arctic region. It is also found in Ice- 

 land. Norway, Ireland, and the North Sea to 

 France (Pettibone 1963). 



Nereis virens is known to inhabit coarse and 

 fine muddy sand, mussel beds, and the roots of 

 decaying marsh and eelgrass (Pettibone 1963). 

 The sandworm population in the Sheepscot River 

 study area at Wiscasset, Maine (lat. 44°N, long. 

 70°40'W), inhabits a gray, silty clay which is mod- 

 erately burrowed and contains shell fragments, 

 mica flakes, and 2% organic carbon (Reynolds et 

 al. 1975 2 ). The mean tidal amplitude in this re- 

 gion is 2.9 m. 



Ecologically, sandworms occupy an important 

 position in the food web of other invertebrates, 

 fish, and shorebirds. They have been harvested 

 commercially for bait along the Maine coast for 

 more than 40 years, with landings of 26.9-38.1 

 million worms/yr and a landed value of $0.5-1.1 



'Maine Department of Marine Resources Research Labora- 

 tory, West Boothbay Harbor, ME 04575. 



2 Reynolds, L., J. Bowman, and E. Kelly. 1975. Unpub- 

 lished summary of sediment size, x-radiography. chemistry, 

 and mass physical properties of six cores and two grabs from 

 Maine. LJ.S. Naval Oceanographic Office, Washington. D.C. 



million reported between 1966 and 1980 (NMFS 

 1966-80). 



Previous research on Maine sandworms in- 

 cluded studies on digging (Ganaros 1951 3 ) and 

 dispersion (Gustafson 1953; Dean 1978). Although 

 intensive harvesting qualifies the sandworm for 

 management considerations, only reports by 

 Glidden (1951) 4 and Dow and Creaser (1970) con- 

 tain life history information pertinent to man- 

 agement of sandworm populations in Maine. The 

 present study was undertaken to provide life his- 

 tory information for a sandworm population in 

 the Sheepscot Estuary at Wiscasset, Maine. It 

 also includes some information on subjects not 

 previously investigated or which differ from 

 findings reported from other geographical loca- 

 tions. 



Other studies on the life history and reproduc- 

 tion of Nereis virens include Brafield and Chap- 

 man (1967) and Bass and Brafield (1972) in the 

 Thames Estuary at Southend, England; Sveshni- 

 kov ( 1955) in Rugozerski Bay near the White Sea, 



Bull. 



3 Ganaros, A. 1951. Commercial worm digging. 

 Dep. Sea Shore Fish., Augusta, Maine, 6 p. 



4 Glidden, P. E. 1951. Three commercially important 

 polychaete marine worms from Maine. Rep. Dep. Sea Shore 

 Fish., Augusta, Maine, 25 p. 



Manuscript accepted April 1982. 



FISHERY BULLETIN: VOL. 80. NO. 4. 1982. 



735 



