the average weight of Connecticut River fish was 

 considerably less (Table 1). The difference in average 

 weight between sea lampreys in the two populations 

 is not due to the difference in location of upstream 

 sampling sites, but possibly to differences in 

 energetic requirements, food supplies, or some 

 aspect of the environment during the oceanic 

 parasitic phase. A difference in weight between 

 populations has previously been found in landlocked 

 sea lampreys in the Great Lakes (Smith 1971). 



Acknowledgments 



This project was supported by Federal Aid Pro- 

 ject AFS-4-R-21 and D-J Project 5-29328 to the 

 Massachusetts Division of Fisheries and Wildlife and 

 the Massachusetts Cooperative Fishery Research 

 Unit. We thank P. Eschmeyer for a valuable review 

 of the manuscript. 



Literature Cited 



Applegate, V. C. 



1950. Natural history of the sea lamprey, Petromyzon 

 marinus, in Michigan. U.S. Fish Wildl. Serv., Spec. Sci. 

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 Beamish, F. W. H. 



1980. Biology of the North American anadromous sea lam- 

 prey, Petromyzon marinus. Can. J. Fish. Aquat. Sci. 37: 

 1924-1943. 

 Beamish, F. W. H., and I. C. Potter. 



1975. The biology of the anadromous sea lamprey (Petro- 

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 57-72. 

 Beamish, F. W. H., I. C. Potter, and E. Thomas. 



1979. Proximate composition of the adult anadromous sea 

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 BlGELOW, H. B., AND W. C. SCHROEDER. 



1953. Fishes of the Gulf of Maine. U.S. Fish Wildl. Serv., 

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Davis, R. M. 



1967. Parasitism by newly-transformed anadromous sea lam- 

 preys on landlocked salmon and other fishes in a coastal 

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 Hardisty, M. W. 



1954. Sex ratio in spawning populations of Lampetra 

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Moffitt, C. M., B. Kynard, and S. G. Rideout. 



1982. Fish passage facilities and anadromous fish restoration 



in the Connecticut River basin. Fisheries (Bethesda) 7(6): 



2-11. 

 Potter, I. C, F. W. H. Beamish, and B. G. H. Johnson. 



1974. Sex ratios and lengths of adult sea lampreys (Petro- 

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Ricker, W. E. 



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Smith, B. R. 



1971. Sea lampreys in the Great Lakes of North America. 



In M. W. Hardisty and I. C. Potter (editors), The biology of 

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Kathleen Stier 

 Boyd Kynard 



Massachusetts Cooperative Fishery Research Unit 

 204 Holdworth Hall 

 University of Massachusetts 

 Amherst, MA 01003 



AN IMPROVED 

 OTTER SURFACE SAMPLER 



Field trials using a neuston sampler described by 

 Sameoto and Jaroszynski (1969) revealed serious 

 sampling problems associated with coastal waters 

 of British Columbia. Due to extensive freshwater 

 runoff in the vicinity of large rivers, sampling con- 

 ditions including choppy surface waters of lowered 

 salinity and vertically depressed distributions of 

 near-surface larval and juvenile fishes. Under such 

 conditions, the S-J sampler behaved erratically, 

 throwing considerable spray, and, when adjusted to 

 increase depth of tow, the body and control surfaces 

 deformed at speeds in excess of 5 knots. The modifi- 

 cations described here reflect our objectives of im- 

 proving performance, increasing durability, and 

 ease of handling, without increasing costs other than 

 those incurred by adding a flowmeter to provide 

 quantitative catches. The complete unit is depicted 

 in Figure 1. 



Detailed Description 



Sampler Box 



Constructed of 1/8" marine aluminum, this alu- 

 minum is folded into a body with one welded seam 

 (Fig. 2). The leading edges are reinforced with 1/4" 

 aluminum for attaching the bridles and depressor. 

 The square mouth opening was sized to accomo- 

 date 0.25 m 2 bongo nets having a circumference 

 of 185 cm. Body dimensions are 46 x 46 x 60 

 cm. 



480 



FISHERY BULLETIN: VOL. 84, NO. 2, 1986. 



