metamorphosing, juvenile, and young adult stages. Settlement panels 

 were valuable biological integrators which provided an easily 

 quantified sample. Since the surface area and time exposed were 

 constant, various parameters, including species diversity, density, 

 and growth, could be determined and compared directly between stations. 



Settlement panels were O.OSm^ squares (about 9 inches x 9 inches) 

 of 1/4 inch untreated plywood. They were attached to PVC racks at 

 Stations 2A, 2B, 3A, 3B, 3C, 5A, 5B, 6A, 6B, 7A, 7B, lOA, and lOB. 

 Each rack held three squares and each month two were collected and 

 two replaced. By rotating one panel, each monthly collection had 

 one panel exposed for thirty days and one exposed for sixty days. 

 Panels were collected in individual labeled polyethylene sacks and 

 analyzed the same day. 



Settlement panels were examined for larger invertebrates and these 

 counted and recorded as to their position on the top or bottom of 

 the panel. A O.OOSm^ plastic grid was then randomly placed on the 

 panel and the smaller organisms counted. During some months, 

 serpulid settlements were so thick that it was not practical to 

 count the whole O.OOSm^. During these periods, five Icm^ sub- 

 samples were marked off and the serpulids counted under a dissecting 

 microscope. 



Diatometers consisted of five glass microscope slides held in a 

 PVC rack at Stations 3A, 3C, 7A, 7B, lOA, and lOB. Benthic diatoms, 

 protozoans, and a variety of invertebrates settled on the slides. 

 Every two weeks the slides were collected and replaced with new ones. 

 The organisms on the exposed slides were counted under a compound 

 microscope using a grid divided into 0.01mm units. Diatom and proto- 

 zoan species and numbers of individual cells were recorded. Other 

 organisms (i.e., barnacles, serpulids, etc.) were noted as present 

 or absent. 



TRANSPLANTS 



To assess the impact of the effluent on individuals of selected 

 species, specimens were transplanted into particular effluent regimes 

 and their survival and growth noted. Sea squirts (Aseidia nigra), 

 sea whips (Pterogorgia anoeps) , turtle grass (Thalassia testudinum) ^ 

 stone crabs (Menippe mercenaria) , and sea urchins (Lytechinus 

 variegatus) were moved from neighboring flats to harbor and control 

 stations. The first two are filter feeding, attached organisms, 

 the last two are motile benthic organisms (L. variegatus is herbivorous 

 and M. mercenaria is carnivorous). 



Previous work (Clarke et al 1970, Chesher, unpublished data) showed 

 stone crabs were relatively resistant to the effluent and sea urchins, 

 sea squirts, and sea whips were highly sensitive to the effluent. 



34 



