NOAA Technical Report NMFS 140 



Specimens of each taxon were bottled separately in 

 70% ethanol and labeled. Subsequently, specimens were 

 assembled bv taxonomic groups and sent to cooperat- 

 ing systematists for species determinations. There were 

 more than 40 specialists from the United States and from 

 other countries cooperating in this part of the study. 



Data Treatment 



Information pertaining to the location, collecting meth- 

 ods, physical and chemical characteristics of the envi- 



ronment, and the number and weight of the biological 

 components of each sample was recorded on preprinted 

 data forms. The coded information and quantitative 

 data from the records were entered on automatic data- 

 processing cards. Data were summarized by computer 

 in a form similar to that presented in the tables appear- 

 ing in the body of this report. 



The principal units used for expressing the quantity 

 of benthic in\ertebrates (quantity per unit area) are: 1) 

 density — number of individual specimens per square 

 meter of bottom area, and 2) biomass — wet weight, in 

 grams, per square meter of bottom. 



Fattnal density values used in constructing quantitative 

 geographic distribution charts for the various taxonomic 

 groups (Figs. 12, 27, 33, 39, 45, etc.) are mean values for 

 all samples within each unit area as shown in Figure 2. 



Qualitative and quantitative differences between sea- 

 sons and between years were sufficiently small to permit 

 the consolidation of all samples for purposes of this 

 report. Some seasonal and yearly differences in taxo- 

 nomic composition and quantity of animals were de- 

 tected within specific geographic localities that were 

 repeatedly sampled. With few exceptions, however, the 

 dissimilarities were relatively minor in comparison to 

 the differences from one geographic locality to an- 

 other. One of the chief reasons for the temporal stabil- 

 ity was the presence of many animals having a long 

 (one year to a century or more) life span. The common 

 occurrence of sessile forms and nonmigratory motile 

 forms also contributed to the observed constancy in 

 biomass. Similar conditions were reported by Zatsepin 

 (1968, in Steele, 1973) in reference to macrobenthos 

 samples taken in the Barents Sea and Norwegian Sea 

 over a 30-year period. He found that a comparison of 

 samples taken in the same regions in different years 

 ". . . showed no substantial changes in the quantitative 

 distribution of the bottom fauna." Several recent re- 

 ports also allude to the temporal persistence of certain 

 dominant components of the macrobenthos of the re- 

 gion (Steimle, 1990a, 1990b; Maurer 8 ; Michael etal. 9 ). 



Geographic Areas 



For purposes of detecting and reporting regional dif- 

 ferences in fauna! composition the region has been 



s Maurer. D. 1983. Review of benthic invertebrates of Georges 

 Bank in relation to gas and oil exploration with emphasis on 

 management implications. Natl. Mar. Fish, Sen.. Northeast Fisher- 

 ies Center, Woods Hole. Massachusetts. Woods Hole Lab. Ret. 

 Doc. 83-16, 329 p. (mimeo). L'npubl. manuscript. 



" Michael, A. D.. C. D. Long. IX Maurer. and R. A. McGrath. 1983. 

 ( ieorges Bank benthic infauna historical study. Final report to U.S. 

 Dep. Interior, Minerals Management Service, Washington, DC, 

 Rep. 83-1 bv Taxon Inc. Salem. MA 01970. 171 p. 



