CROSS: FIN EROSION AMONG FISHES 



of these collections (F = 17.84, P < 0.0001) 

 (Table 6). 

 The total number of Dover sole collected in a 



Table 3. — Results of Newman-Keuls multi- 

 ple range test for equality of regression coeffi- 

 cients (6) for the incidence of fin erosion 

 among calico rockfish. s = station; un- 

 derscored stations are not significantly dif- 

 ferent. 



b: 



s: 



0.678 

 T4-61 m 



0410 

 T5-61 m 



0.125 



T1-61 m 



0010 

 TO-61 m 



10-min trawl declined significantly at three of the 

 eight stations (Table 5). ANCOVA detected a sig- 

 nificant difference among the regression coeffi- 

 cients of these collections (F = 3.43, 

 0.001 < P < 0.003) (Table 6). 



Size-Frequency Distributions 



The size distributions of Dover sole with and 

 without fin erosion were examined (Fig. 3). Most 

 Dover sole recruit to the study area when they are 

 40-50 mm BSL (broad standard length). Fin ero- 



TABLE 4. — Linear regressions of A) the proportion (p) of rex sole, Glyp- 

 tocephalus zachirus, in one 10-min trawl with fin erosion (transformed to arcsin 

 \ p) and B) the total number of rex sole caught in one 10-min trawl 

 [transformed to logio (J: -i- D] against time (numbered in consecutive months 

 from 1971 through 1982). See Table 2 for explanation of column headers. 



Station 



Y =a +bX 



LI 



L2 



A) TO- 137 m 

 T1-137 m y = 10.217 - 0.085X 

 T4-137 m y = 18.259 - 0.151X 

 T5-137 m y = 10.733 - 0.087X 



B) TO-137 m y = 1.828 - 0.0038X 

 T1-137m y = 1.326 - 0.0012X 

 T4-137 m y = 0.976 + 0.0023X 

 T5-137 m y = 1.182 - 0.0013X 



[only 7 of 1,520 fish (0.5%) had fin erosion] 



Table 5. — Linear regressions of A) the proportion (p) the Dover sole, Micros- 

 tomas pacificus, in one 10-min trawl with fin erosion (transformed to arcsin \ p) 

 and B) the total number of Dover sole caught in one 10-min trawl [transformed 

 to logio (x -I- 1)] against time (numbered in consecutive months from 1971 

 through 1982). See Table 2 for explanation of column headers. 



Table 6. — Results of Newman-Keuls multiple range test for equality of regression 

 coefficients (6) for A) the proportion of Dover sole. Microstomas pacificus, with fin 

 erosion and B) the total catch of Dover sole, s = station; underscored stations are not 

 significantly different. 



199 



