DISTRIBUTION, ABUNDANCE AND BEHAVIOR OF SEA PENS, 

 PENNATULA SP. IN THE GULF OF MAINE. 



Richard W. Langton 



Maine Department of Marine Resources 



West Boothbay Harbor, Maine 04575 



Elizabeth W. Langton 



Resource Enterprises 



Edgecomb, Maine 04556 



Roger B. Theroux and Joseph R. Uzmann 



Northeast Fisheries Center 



Woods Hole, MA 02543 



ABSTRACT 



Sea pens, of the genus Pennatula , are major components of 

 the macrobenthic fauna in the Gulf of Maine. In the 1960s the 

 Gulf of Maine was studied as part of a quantitative and 

 qualitative survey of the macrobenthic invertebrate fauna of the 

 east coast of the U.S.A. These data were gathered using 

 traditional benthic sampling gear such as the Smith Mclntyre 

 grab, Campbell grab and 0.2 m Van Veen grab. Benthic samples at 

 62 stations in the Gulf contained sea pens. In the 1980s a 

 macrobenthic study was initiated using a four man submersible 

 system, the Johnson Sea Link , to conduct quantitative 

 photographic surveys with 35 mm still cameras and a video camera 

 and recording system. In 1983-84 these efforts were concentrated 

 in the eastern part of the Gulf including Jordan Basin, Truxton 

 Swell and Georges Basin. In this region pennatulids were 

 ubiquitous but highly variable in density with values ranging 

 from to as high as 8.0/m per still photograph. The greatest 

 numbers occurred in the basins on soft mud bottoms although 

 pennatulids were observed in gravelly substrates on the Swell. 

 In 1985 a dive was made in the western Gulf, in Wilkinson Basin, 

 to complete the distributional survey. In this basin no sea pens 

 were observed over the course of a two and one half hour dive. 

 This suggests that there are fundamental differences in the 

 macrobenthos between the eastern and western Gulf of Maine. 



In 1986, the submersible Delta was used to conduct a sea pen 

 behavior experiment on Jeffreys Bank. At the experimental site, 

 four, one-meter square quadrats were deployed and in situ 

 monitoring of sea pen behavior was initiated. Sea pens are 

 capable of retracting into the sediment and the objective of the 

 experiment was to document this behavior for identifiable 

 individuals. The quadrat was visited five times over the next 24 

 hours. Relatively little change in sea pen behavior was noted. 

 Two sea pens out of seventeen retracted completely. 



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