What Kind of 

 Research Was 

 Done? 



The researchers at the Woods Hole 

 Oceanographic Institution were 

 presented with the problem of develop- 

 ing an experimental design that would 

 best document the effects of the West 

 Falmouth spill on benthic (bottom- 

 dwelling) communities of marine 

 animals, whether the effects were 

 gross, subtle or non-existent. This 

 involved deciding where, when and 

 how bottom samples would be taken, 

 processed and analyzed. The major 

 factors considered in making these 

 decisions were the distribution of the 

 oil, the expected rates of change in the 

 benthic communities, and the state- 

 of-the-art of benthic sampling and 

 sample processing. 



Sampling Methods 



Where — Chemical analysis of bottom samples 

 was used to determine where biological samples 

 would be taken. The aim was to sample heavily 

 oiled, moderately oiled and lightly oiled or con- 

 trol stations. This allowed comparison of com- 

 munity response to different levels of pollution. 

 Two types of communities were sampled, the in- 

 tertidal marsh and the subtidal offshore. Sedi- 

 ment types found at sampling stations were 

 compared to ensure that subtidal stations 

 represented the same basic bottom community 

 type. 



When — Deciding when and how frequently to 

 sample is difficult. Seasonal and spatial dif- 

 ferences in normal benthic communities are con- 

 siderable, and communities under stress may 

 vary even more dramatically. On the other hand, 

 to acquire and process benthic samples is time 



consuming and costly. Sampling was initiated 

 immediately after the spill, and it was decided to 

 sample frequently, every month when possible. 

 As time passed the frequency of sampling 

 decreased somewhat. 



How — Bottom samples were collected with a 

 hand-held coring device at the intertidal marsh 

 stations, and with a remote operated grab at the 

 subtidal stations. A small portion of each sample 

 was frozen and stored for chemical analysis. The 

 biological samples were washed using a fine 

 sieve, and the material retained on the sieve, in- 

 cluding the animals, was placed in a preservative 

 solution. In the laboratory, the animals were 

 sorted from the debris using a microscope; iden- 

 tified and counted. The data analysis ranged 

 from simple tallies of species and individuals to 

 various statistical characterizations of the 

 benthic communities. 



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