passage of Hurricane Gloria. Apparently, seasonal hypoxic effects 

 in 1987 and the first half of 1988 (up until the July 1988 survey) 

 were not as severe as they were in the past, and the benthic 

 communities in and around the disposal site were not showing as much 

 evidence of stress as they had in previous years. 



5 . CONCLUSIONS 



Both the precision bathymetric and REMOTS® surveys at WLIS 

 indicated an accumulation of recently-deposited dredged material at 

 the "B" mound. The deposited material occurred around the buoy in 

 a broad, circular mound up to 2.0 m thick having a radius of about 

 100 m. The minimum depths of the "C" and "A" disposal mounds 

 remained unchanged since the previous bathymetric survey in November 

 1987. Relict dredged material was visible in the REMOTS® photos 

 from stations at and in the vicinity of these two mounds, consistent 

 with the results of the November 1987 REMOTS® survey. 



The lack of significant differences between reference and 

 on-site stations in such REMOTS® parameters as RPD depths, 

 percentage of Stage III organisms, and OSI values suggested that 

 any seafloor disturbance related to dredged material disposal at 

 the site was minimal. This disturbance primarily was physical in 

 nature and limited to the immediate vicinity of the active "B" 

 disposal mound. The July 1988 results further suggested a 

 continuation of the trend of improving benthic habitat conditions 

 at the site since it was severely stressed by the passage of 

 Hurricane Gloria in September 1985 and by region-wide near-bottom 

 hypoxia in August 1986. This trend was marked by continued 

 colonization of the site by Stage III taxa. 



The generally healthy benthic conditions observed in the 

 REMOTS® photos suggested an absence of stress related to near-bottom 

 hypoxia in the weeks and months preceding the survey. At the time 

 of sampling, dissolved oxygen levels in near-bottom waters were near 

 the hypoxic range at both disposal and reference stations. This 

 might have signaled the beginning of seasonal near-bottom hypoxia 

 in this region of the Sound, as it developed in response to thermal 

 stratification of the water column. No evidence of extreme adverse 

 effects of the low dissolved oxygen levels were apparent in the 

 sediments. The low DO levels measured near the bottom at both the 

 disposal site and reference stations support earlier studies which 

 showed this was a region-wide phenomenon unrelated to disposal. 



Overall, the results of the July 1988 survey indicate a 

 continuation of the trend of improved benthic conditions noted at 

 WLIS after the November 1987 REMOTS® survey (SAIC, 1990) . Similar 

 to conclusions reached from the November 1987 survey, it appears 

 that this trend represents a return to relatively "normal" 

 conditions at the site. Such conditions were noted after the August 

 1985 REMOTS® survey, prior to both Hurricane Gloria in September 



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