shallow Laminaria zone, a deeper Agarum zone and a diverse 

 assemblage of two or three functional groups in the deepest zone. 

 Other studies on subtidal zonation have correlated differences in 

 pigment composition ("chromatic adaptation") with depth such that 

 from shallow to deep water: brown, green and red algae (Larkum et 

 al., 1967; Dring, 1981; Littler et al . , 1986) are said to dominate 

 respectively. Interestingly at Ammen Rock Pinnacle, there is no 

 green zone, the brown zone is compressed and the red zone exists 

 over the entire vertical range of algae. Although our site may be 

 too deep for a green zone, the zonation pattern appears to 

 correspond more closely to morphological types than to 

 pigmentation . 



The repeating pattern of zonation at a functional group level 

 begs the question: are these morphologies adaptive, and if they 

 are what is it about them that allow certain forms to consistently 

 dominate particular depth zones? Littler et al., (1986) have, in 

 part, provided an answer, by showing that encrusting tropical deep 

 water algae are photosynthetically two to three orders of 

 magnitude more efficient than algae exposed to near surface light 

 environments. This paper provides a first step in documenting the 

 patterns in distribution and abundance for a temperate/boreal 

 community - the processes controlling those patterns will require 

 further study. 



ACKNOWLEDGEMENTS 



We appreciate considerable help in the field from Jon Witman, 

 Ken Sebens, Jim Sears and Ivar Babb. Jim Sears and Bob Wilce 

 assisted in taxonomic identifications and critically read an early 

 draft of the manuscript. We thank Susan Forward Stilwell for 

 assistance with searching literature, F.P. Ojeda and Wes Wright 

 for assistance with graphics and Jean Ketch for typing the ms. 

 Ship and submersible facilities were provided by NOAA's National 

 Undersea Research Program through the University of Connecticut, 

 Avery Point. Equipment, supplies and travel costs were provided 

 by The University of Maine Sea Grant Program (Grant # NA-80AA- 

 D00034 to RLV), Maine Agricultural Experiment Station, the Center 

 for Marine Studies and from The National Science Foundation 

 (Grants # OCE 8315136 and OCE 8600262 to RSS). This is 

 contribution number 17 of the Maine Benthic Oceanography Group, 

 number 1 of Submersible Investigations of the Gulf of Maine. 



LITERATURE CITED 



Adey, W.H. 1973. Temperature control of reproduction and 



productivity in a subarctic coralline alga. Phycologia 

 12:111-118. 



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