sections from mature sandbar sharks collected 

 by the fishery operator^ from various sets in 

 winter and spring 1978; he stated the animals 

 were alive when retrieved from the lines. The 

 samples consisted of: sample 1 — ventricle com- 

 plete with atrium, conus arteriosus, and short 

 ventral aorta section; sample 2 — ventricle as 

 above and an epidermal section from the same 

 animal; sample 3 — ventricle as above within 

 the pericardial chamber, intact with coracoid bar 

 and transverse septum; sample 4 — two branchial 

 arches. Sample 5 was an entire male sandbar 

 shark, 153 cm total length (TL), collected in July 

 1978; it was retrieved dead from the line. 



Sample 1 was subsequently examined histo- 

 pathologically; the entire specimen was serially 

 sectioned and all sections studied microscopically. 

 The material was paraffin embedded, cut to 6-7 

 /u,m thickness, and stained with hematoxylin 

 and eosin. 



Locations of isopods within the samples, sites of 

 attachment, evidence of feeding, and morphologi- 

 cal distinctions were noted on initial examination. 

 Isopods removed during subsequent dissection 

 were measured to the nearest 0.1 mm TL; length 

 data were classed (2 mm classes) for frequency 

 distributions. Species identification, sex, and 

 stage of development were determined. Isopods 

 were transferred into 70% isopropyl alcohol after 

 detachment. 



Results 



Sampling 



All teleost samples were negative for C. borealis. 

 Those obtained during the pilot project in October 

 1978 were possibly within the chronological period 

 of isopod occurrence in nearshore waters. Occur- 

 rences of other parasites and pathologies noted 

 in the fishes (ectoparasitic crustaceans, ces- 

 todes, monogenetic and digenetic trematodes, 

 nematodes, infections, etc.) were within normal 

 levels. Reports from finfish processors and historic 

 faunal records from the area are consistent with 

 the finding that C. borealis are not a problem for 

 teleostean fishes. Elasmobranchs collected in 1979 

 and 1980 were also negative for the isopods. No 

 C. borealis were produced by the field trials. 



Bottom samples were also negative. Historic 

 faunal surveys revealed only one recent record 



of C. borealis (provisionally identified), taken 

 in the South Atlantic Outer Continental Shelf 

 Benchmark Study^ that sampled continental shelf 

 waters from Daytona Beach, Fla., through Geor- 

 gia during 1977. The season and location in which 

 the species was collected are unknown because 

 Benchmark faunal lists are not yet keyed for 

 retrieval of these data. The report would place 

 C. borealis in Atlantic Shelf waters within 

 the chronological period of shark infestation by 

 the isopod. 



Water Parameters 



The currents and eddies off the Florida Atlantic 

 coast are particularly dynamic. Recent data show 

 that deep, cold, nutrient-rich Gulf Stream waters 

 advect onto the continental shelf many times 

 during the year (Atkinson et al. 1978). Spin-off 

 eddies become larger north of Jupiter, and an 

 established, persistent upwelling feature occurs to 

 the north of Cape Canaveral. Lee et al. (in press) 

 noted that eddy events appear in surface waters 

 as warm, southward-oriented extrusions of the 

 Gulf Stream, coupled to cold, upwelled cores. 

 They documented an unusually strong eddy in 

 April 1977; the eddy apparently coincided with 

 the vertical stratification of the water, which 

 strengthened the extrusion and brought it closer 

 to shore. Water near the bottom (63 m depth) at 

 the shelf break from St. Augustine south had the 

 characteristics of water from depths of from 200 to 

 300 m. Its Gulf Stream origin was indicated by low 

 temperature, salinity, oxygen content, and high 

 nutrient concentration. The eddy, which was fol- 

 lowed by a second strong eddy event, was 225 km 

 long (parallel to the shelf) and approximately 35 

 km wide; upwelling of the cold core extended into 

 the euphotic zone (45 m depth). Lee^ stated that 

 the coastal area from St. Augustine to Cape 

 Canaveral in which C. borealis was found in 

 sharks in 1977 and 1978 coincided with the area 

 influenced by the especially strong eddies in 

 spring of 1977. 



"Joe D. Walker, PO. Box 356, Cape Canaveral, FL 32920. 

 378 



^South Atlantic OCS Benchmark Program, 1977 Report. 

 1979. Texas Instrument Contract AA550-CT7-2, Bureau of 

 Land Management, Vol. 1-6. Bureau of Land Management, 

 Department of the Interior, Federal Building, New Orleans, 

 LA 70113. 



""Thomas N. Lee, University of Miami, Department of Energy, 

 Rosenstiel School of Marine and Atmospheric Science, 4600 

 Rickenbacker Causeway, Miami, FL 33149, pers. commun. 

 March 1980. 



