MATERIALS AND METHODS 



Adult abundance studies 



Abundance estimation of the Niantic River population of adult winter flounder has been based on 

 mark and recapture methodologies and details concerning annual surveys from 1973 through 1986 are 

 summarized on Table 1. Fish tagging began in 1973 and 1974, but Niantic River spawners were not 

 specifically targeted; the numbers marked were inadequate for abundance estimation (see NUSCo 1975 for 

 additional details). The 1975 survey design was based on the requirements of the deterministic triple-catch 

 model (Ricker 1958). Fish captured by trawl in various portions of the river were marked by fm clips 

 over a 7-wk period beginning on March 31; recaptures were not remarked (NUSCo 1976). From 1976 

 through 1981, surveys commenced in early to mid-March and ended during early to mid- May, after all 

 spawning was completed (NUSCo 1977, 1978a, 1979, 1980, 1981a, 1982). Since 1982, each survey started 

 after ice-out in the river from mid to late February and ended in early April, when the proportion of 

 reproductively active females decreased to less than 10% of all females examined for two consecutive weeks 

 (NUSCo 1983a, 1984, 1985, 1986a). In all years since 1975, sampling took place on 2 to 3 d of each week. 



In 1976, the Niantic River was subdivided into a number of areas (stations) for each survey (Fig. 1). 

 Stations 1, 2, and 4 were in the navigational chatmel of the lower to mid-river and 3, 6, 7, and 8 were in 

 the adjacent shallows. After 1979, no tows were made outside of the navigational channel in the lower 

 portion of the river due to an agreement with the East Lyme-Waterford Shellfish Commission to protect 

 bay scallop (Argopeclin irradiam) habitat. In 1983, station 5 in the upper river was subdivided into 

 stations 51-53; station 54 in the upper arm was not established until 1986 (Fig. 2). Some tows in station 

 51 during 1984-86 along the eastern shore of the upper river extended into the deeper northern portion of 

 former station 6. Tows each week were usually allocated to stations according to station area and the 

 expected abundance of winter flounder; more tows were made where fish were most numerous. In most 

 years, heavy accumulations of macroalgae and detritus that occurred in the deeper portion of station 51 

 hindered sampling there. 



