SCHERBA and GALLUCCI: SYSTEMATIC SAMPLING OF INFAUNA 



silty area. Further studies are being conducted to 

 develop hypotheses for Garrison Bay. 



Newell's (1965) hypothesis does not appear to 

 explain the abundance and apparent sediment 

 preferences of T. tantilla. Maurer (1969) found T. 

 tantilla to be ubiquitous in a bay with a sediment 

 gradient similar to that of Garrison Bay, while 

 attaining its greatest numbers in a region com- 

 posed principally of finer sediment particle sizes. 

 Excluding subarea 3A, similar results follow for T. 

 tantilla in Garrison Bay. The increased abundance 

 of this bivalve in the summer on both strata of 

 subarea 3A indicates that the principal response of 

 T. tantilla may be to something other than just 

 sediment composition. The extensive covering of 

 subarea 3A by a dense algal mat of Enteromorpha 

 sp. is probably involved in the population explo- 

 sion. Transennella tantilla would gain protection 

 from some physiological stresses such as elevated 

 temperatures and increased water evaporation by 

 the sun and wind. Similar dense mats of Enter- 

 omorpha sp. were not found in the other three 

 areas at the sampling times. 



The polychaete assemblage in Garrison Bay is 

 described by a distribution which is apparently 

 sediment and season dependent. The limited data 

 on the distribution of bivalves does not have the 

 same patterns. Preliminary analyses from an 

 investigation (Gallucci)^ involving the collection of 

 large numbers of bivalves in Garrison Bay sub- 

 stantiates the lack of a simple gradient relation- 

 ship for bivalves. Life in a calcium carbonate shell 

 seems to allow for greater independence from 

 environmental fluctuations than life near the 

 sediment surface without such a shell. 



Although the effects of seasonal and sediment 

 type variations are often evident, causal links 

 must be established by the examination of specific 

 factors, e.g., competition, predation, food 

 availability and selection, salinity, and tempera- 

 ture. Toward this end, Hylleberg and Gallucci 

 (1975) and Gallucci and Hylleberg (1976) have 

 examined the role of food availability and 

 sediment composition upon the growth of the 

 deposit feeder Macoma nasuta in Garrison Bay. 

 Garrison Bay daylight summer surface water 

 temperatures are about 1°C higher in the closed 

 end than in the open end (Gallucci, unpubl. data), 

 and short stretches of intertidal areas sustain a 



^Gallucci, V. F. 1976. Bivalve community relationships as 

 determined from age composition and growth rates. Unpubl. 

 manuscr., 30 p. 



subsurface freshwater runoff. 



In this paper we have developed an appropriate 

 sampling method for marine studies and the 

 statistical machinery for testing certain relevant 

 hypotheses. We have applied these methods in an 

 intertidal study. The biological results pertain to 

 sediment and animal gradients under seasonal 

 change. Conclusions are based upon statistical 

 comparisons in which the null hypothesis was 

 rejected, tempered by extensive biological studies. 



The data and results of the Garrison Bay study 

 have obvious significance for shellfish culture. 

 Factors such as the selection of sediment type in 

 which to establish seed beds, interspecies associa- 

 tions, the season in which to make population 

 assessments, and the sampling techniques should 

 all be considered if sound management decisions 

 are to be made. 



ACKNOWLEDGMENTS 



We are grateful to A. 0. D. Willows, director of 

 the Friday Harbor Marine Laboratories, for 

 providing excellent research facilities. The coop- 

 eration of C. E. Lindsay, Washington Department 

 of Fisheries, and S. J. Zachwieja, National Park 

 Service, in establishing the research areas is 

 gratefully acknowledged. The research was sup- 

 ported by the National Institutes of Health 

 Biometry Training Grant (#67-0488) and by 

 WashingtonSeaGrantFunds(SG61-8227),fromthe 

 National Oceanographic and Atmospheric Ad- 

 ministration. This paper is based upon portions of 

 a thesis by S. Scherba, Jr. accepted by the 

 Biomathematics faculty, University of Washing- 

 ton, in partial fulfillment of the requirements for 

 the Master of Science degree. The untiring field 

 and typing assistance of Elaine Scherba is grate- 

 fully acknowledged. 



LITERATURE CITED 



BiRNBAUM, Z. W., AND R. A. HaLL. 



1960. Small sample distributions for multi-sample statistics 

 of the Smirnov type. Ann. Math. Stat. 31:710-720. 

 Bloom, S. A., J. L. Simon, and V. D. Hunter. 



1972. Animal-sediment relations and community analysis of 

 a Florida estuary. Mar. Biol. 13:43-56. 

 Cochran, W. G. 



1963. Sampling techniques. 2d ed. John Wiley & Sons, Inc., 



N.Y., 413 p. 

 Conover, W. J. 



1971. Practical nonparametric statistics. John Wiley & 

 Sons,N.Y.,462p. 



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