they immigrate through tidal passes during night and day is useful in develop- 

 ing accurate and efficient sampling techniques for measuring relative abundance. 

 This study determined the vertical distribution of immigrating postlarval brown 

 and white shrimp through Bolivar Roads Tidal Pass, the major entrance to 

 Galveston Bay, Texas. The average catch of both brown and white postlarval shrimp 

 was highest in the upper 2 meters of the water column at night and at middepths 

 during the day. These depths would probably yield the most accurate abundance 

 estimates of the postlarval populations. 



43. EBERT, T.A., "An Experimental Analysis of Sea Urchin Dynamics and Community 

 Interactions on a Rock Jetty," Journal of Experimental Marine Biology and 

 Ecology, Vol. 27, No. 1, Apr. 1977, pp. 1-22. 



During 1972-73 in Mission Bay, San Diego, California, the biomasses of 

 Strongyloaentrotus purpuratus (Stimpson) and S. franeisaanus (A. Ag.) were 

 manipulated in 21 experimental cells constructed on the rocks of the entrance 

 channel breakwater. Cells were set up with 5. purpuratus only, with S. franeis- 

 aanus only, and with half of the biomass of each species. The rate of change of 

 biomass was positively correlated with original density. Because barriers 

 were not totally effective in restricting movement, the correlation is possibly 

 best interpreted as one of diffusion rather than density-dependent mortality. 

 The difference in the rate of loss between cells with single urchin species 

 and with mixed species may indicate that intraspecif ic is more intense than 

 interspecific competition. 



Individual growth rates were determined and step-wise multiple regression 

 analysis was used to examine the relationships between growth increment and 

 initial size, total biomass, interaction of biomass and initial size, and posi- 

 tion along the jetty. Only the original size and the total urchin biomass were 

 significant . 



The density of certain marine invertebrates was found to be correlated 

 with urchin biomass. The hard-shelled sessile mollusks Hinnites multirugosus 

 (Gage) and Serpulorbis squamigerus (Carpenter) were positively correlated, 

 whereas the soft-bodied tunicates Ciona intestinalis (L) and Styela spp. were 

 negatively correlated. 



44. ELSER, A. A., "Fish Populations of a Trout Stream in Relation to Major 

 Habitat Zones and Channel Alterations," Transactions of the Meriean 

 Fishery Society, Vol. 97, No. 4, Oct. 1968, pp. 389-397. 



The relationship of fish populations to major habitat zones and channel 

 alterations was studied in Little Prickly Pear Creek, Montana, during the 

 summers of 1965 and 1966. Fish populations were estimated, using a simple 

 mark-and-recapture census. Nontrout species were absent from the altered 

 stream sections, but made up 30 and 58 percent of the total number and weight, 

 respectively, in the unaltered stream sections. Trout were 78 percent more 

 abundant in the unaltered sections than in the altered. A statistical test 

 indicated a significant difference between the two trout populations. 



45. FAZIO, F.R., "The Effects of Dredging on the Nutrient Cycles of Goose 

 Creek, New Xon'^," American Voctoval Dissertations, Fordham University, 

 1968-69, and University Microfilms International, Ann Arbor, Mich. 1977. 

 A study was conducted for 1 year to determine the effects of dredging 



on the cycle of nutrients in Goose Creek, New York. Parameters measured were 

 phosphorus, nitrogen, silicate, and chlorophyll. Other variables monitored 

 were temperature, salinity, oxygen, pH, and light. Dredging had no apparent 



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