Table 4.— Population estimates for juvenile English sole in the open coast survey area 

 by date (month/year) and by stratum (1-4). The 95% confidence interval for total popula- 

 tion is obtained by adding or substracting the value in parentheses. 



Date 



Depth 

 (m) 



Density 

 (no./ha) 



Population 

 (millions) 



Depth Density 

 Date (m) (no./ha) 



Population 

 (millions) 



5/83 



7/83 



8/83 



9/83 



5-15 

 15-40 

 40-75 

 Total 



5-15 

 15-40 

 40-75 

 Total 



5-15 

 15-40 

 40-75 



Total 



5-15 

 15-40 

 40-75 



Total 



6 



100 



11 



2 



20 



8 



54 

 35 

 12 



12 



32 



3 



0.115 

 4.881 

 0.887 



5.883 (4.666) 



0.044 

 0.983 

 0.680 

 1.707 (1.840) 



1.028 

 1.709 

 0.991 

 3.728 (2.390) 



0.230 

 1.547 

 0.269 



2.045 (0.902) 



4/84 



5/84 



6/84 



8/84 



9/84 



be of shorter duration, though again, the survey 

 lacked sampling effort from October through March. 

 Recently transformed juveniles were captured only 

 during May in 1983 and were found from April to 

 September in 1984. Peak abundance was observed 

 in May as in the estuary. 



Populations of 0-age fish were determined using 

 estimates of total juvenile population (Tables 3, 4) 

 and size-frequency data (Table 5). These estimates 

 show that English sole had higher recruitment to 

 the estuary than to the open coast for early spring 

 of both years. The estuarine population of young- 

 of-the-year exceeded that of the open coast by over 

 four times (6.4 vs. 1.5 million) in May 1983. The dif- 

 ference was less pronounced in May 1984, but the 

 estuarine population was again higher (22.8 vs. 19.0 

 million). Later in summer in both years, the estu- 

 arine population of 0-age fish declined to a greater 

 extent than that along the open coast, but some of 

 the relative change is likely due to emigration from 

 the estuary. 



Densities were plotted by 5 mm length interval 

 for the estuarine and open coast study areas for May 

 each year, a period of high settlement (Fig. 3). Den- 

 sities of juveniles <25 mm were more than 10 times 

 greater in the estuary, indicating disporportionately 

 higher direct settlement and/or higher mortality of 

 newly settled juveniles in the open coast area. When 



Table 5.— Length ranges (mm TL) of 0-age English sole deter- 

 mined from visual inspection of length-frequency distributions by 

 study area and by date (month/year). Modal and mean lengths, and 

 the proportion of total population comprised by the 0-age group 

 are also indicated. 



828 



