EXECUTIVE SUMMARY 



The Saco Bay Disposal Site (SBDS) was approved for one- 

 time use by two projects at the nearby Biddeford Pool. From 9 

 January to 11 May 1989, approximately 34,800 cubic meters of 

 dredged sediment were disposed at the site. The objectives of this 

 monitoring cruise at SBDS were to measure the areal extent of 

 dredged material and to assess the status of benthic recolonization 

 on and adjacent to the disposal site. 



The acoustic survey did not show a distinct mound at the buoy 

 position, although several small topographic features (less than 1 

 m high) were noted in the vicinity. Due to the lack of a pre- 

 disposal baseline survey and the lateral distribution of dredged 

 material, bathymetry proved inadeguate for detecting the areal 

 extent of most dredged sediment at SBDS. REMOTS® sampling found 

 dredged material at most stations in the central and southwestern 

 portions of the survey grid. However, the full extent of dredged 

 sediments was not measured at SBDS, extending beyond the southern 

 and western stations of the survey grid. Calculations of dredged 

 sediment volume based on REMOTS® photographs indicated that at 

 least 38% of the reported scow deposition at SBDS was encompassed 

 by the REMOTS® survey. The actual amount was probably much larger, 

 because almost all REMOTS® photographs at stations with dredged 

 material present showed deposited sediment egual to or greater than 

 the penetration depth of the camera. Although the entire extent of 

 dredged material at SBDS was not measured, it is likely that most 

 sediment is confined to a relatively small region extending south 

 and west of the disposal site center. 



Benthic recolonization at SBDS was largely as expected, 

 with the exception that Stage II taxa were not observed on the 

 disposal site stations. The presence of Stage I on III taxa at 

 many stations on dredged material indicated that indigenous inf auna 

 were recolonizing the affected area. Given more time for the 

 further establishment of Stage III taxa, it is expected that the 

 infaunal community will return to an assemblage similar to the 

 reference areas. 



