Premium
Vertical Migration and Mortality of Marine Benthos in Dredged Material: A Synthesis
Author(s) -
Maurer Don,
Keck Richard T.,
Tinsman Jeffrey C.,
Leathem Wayne A.,
Wethe Christian,
Lord Charles,
Church Thomas M.
Publication year - 1986
Publication title -
internationale revue der gesamten hydrobiologie und hydrographie
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.524
H-Index - 52
eISSN - 1522-2632
pISSN - 0020-9309
DOI - 10.1002/iroh.19860710106
Subject(s) - mercenaria , benthic zone , benthos , sediment , invertebrate , silt , polychaete , ecology , estuary , biology , environmental chemistry , oceanography , geology , chemistry , paleontology
This account describes the comparative response of four species of benthic invertebrates to burial in terms of vertical migration and mortality, and provides a synthesis of studies and recommendations upon which to assess future impacts. The species featured were the bivalve Mercenaries mercenaria , the amphipod crustacean Parahaustorius longimerus , and the polychaetes Scoloplos fragilis and Nereis succinea . There was evidence of synergistic effects on burrowing activity and mortality with changes in time of burial, sediment depth, sediment type and temperature. In sediment with silt‐clay, N. succinea was the most resistant species followed by M. mercenaria, S. fragilis and P. longimerus . In sediment without silt‐clay the order of percent mortality was reversed. Studies of surface water chemistry and sediment geochemistry showed that dissolved oxygen decreased significantly and ammonia and sulfide increased significantly between the surface and below 2.0 cm within a 15‐day period. Based on these results and physiological tolerances from the literature it was concluded that M. mercenaria and N. succinea would be relatively resistant to chemical effects of spoil disposal, whereas S. fragilis and P. longimerus would be less resistant to such effects. Vertical migration of benthic invertebrates through dredge disposal can be a viable mechanism of recolonization under certain conditions. Some effects of burial of benthos can be predicted based on morphology, behavior and physiology. These biological features were discussed with examples dealing with molluscs, crustaceans, and polychaetes. Finally, recommendations were made concerning the type of studies to provide additional data to aid management agencies in decision making about future dredging and disposal practices.