FISHERY BULLETIN: VOL. 76. NO. 4 



Figure l. — Site-specific fin erosion concentrated in the midportion of fins in winter flounder (anterior dorsal fin is folded over in this 

 picture). Note melanism in areas of erosion. (Photograph courtesy of J. O'Reilly, Northeast Fisheries Center Sandy Hook Laboratory, 

 NMFS, NOAA, Highlands, N.J.) 



generalized disease signs (one of which is fin ero- 

 sion) may be responsible for the disparate nature 

 of histopathological findings in this report, as 

 compared with those of Murchelano ( 1975). 



Fin rot, with associated mortalities, was re- 

 ported by Couch and Nimmo (1974b) in Atlantic 

 croaker, Micropogon undulatus, and spot, Leio- 

 stomus xanthurus, from Escambia Bay, Fla. The 

 disease syndrome and mortalities were observed 

 for several years during periods of high tempera- 

 ture and low dissolved oxygen. Escambia Bay has 

 been polluted by the PCB (polychlorinated 

 biphenyl), Aroclor^ 1254, for a number of years 

 (Duke et al. 1970). 



Information from southern California (South- 

 ern California Coastal Water Research Project, 

 see footnote 3) also indicates an association of fin 

 rot with degraded habitats; relevant statements 

 are: "The incidence of fin erosion was high in areas 

 with high concentrations of waste water con- 

 stituents in the sediments . . . ." "Although there 

 is a definite association between fin erosion and 

 waste water discharges, the causal factors are un- 

 known." "Nearly half of the 72 species caught off 

 the Palos Verdes Peninsula were affected with 

 this syndrome" (eroded fins). It is interesting that 

 a histopathological study of fin erosion in Dover 

 sole, Microstomus pacificus, from the California 



coast (Mearns and Sherwood 1974; Klontz and 

 Bendele^) produced findings similar to those of 

 Murchelano (1975) — hyperplasia, fibrosis, ab- 

 sence of inflammation, and absence of microbial 

 infection. 



Some species either seem more resistant to fin 

 erosion or are exposed differentially to toxic sub- 

 stances in water or sediments. A recent study by 

 Wellings et al. (1976) in a heavily polluted arm of 

 Puget Sound (the Duwamish River) in which over 

 6,000 fish of 29 species were examined, disclosed 

 fin erosion only in starry flounder, Platichthys stel- 

 latus, and English sole, Parophrys vetulus. Av- 

 erage incidences were 8 and 0.5% respectively. 

 Histopathological findings were similar to those 

 for east coast and California flatfishes — epidermal 

 hyperplasia, fibrosis, resorption of fin rays, aggre- 

 gation of melanophores, mucus cell changes, and 

 absence of bacterial invasion. The authors de- 

 scribed briefly what may be highly relevant obser- 

 vations of liver pathology in starry flounder from 

 the area where fin erosion was common. His- 

 topathology included increased fat deposition in 

 hepatic cells, fibrosis, and vascular distension. 



Recent Japanese publications have mentioned 

 fin erosion in fish from polluted bays. Nakai et al. 



■"Reference to trade names does not imply endorsement by the 

 National Marine Fisheries Service, NOAA. 



^Klontz, G. W..andR. A.Bendele. 1973. Histopathological 

 analysis of fin erosion in southern California marine fishes. 

 Southern Calif Coastal Water Res. Proj., El Segundo, Calif, 

 Rep. TM203, 8 p. 



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