Early reproductive success of the hard clam (Mercenaria mercenaria) from Five Sites in Long Island Sound
- National Oceanic and Atmospheric Administration, Milford, CT (United States)
Early reproductive success of hard clams (Mercenaria mercenaria) in Long Island Sound was measured to determine whether pollution may have adverse effects on fragile recruitment to fisheries. Clams were collected at five sites in 1987 when ready to spawn naturally, along with water from within 39 cm of the bottom. Levels of polychlorinated biphenyls (PCBs), copper, and cadmium were measured in the mature gonad and were found to be generally low. Clams were spawned and the gametes were collected and cultured both in their respective site waters and in reference laboratory seawater. In both site and reference seawater, embryos of clams from the most highly industrialized area (Bridgeport) with higher contaminant levels exhibited more irregularity in chromosome numbers and greater larval abnormality, possible indicators of long-term sublethal effects. Fertilization and early meiotic success at 1 to 1 1/2 h were significantly lower for clams from Norwalk than for those from Greenwich. At 48 h, mortality was lowest for Greenwich larvae and highest for Norwalk larvae in their respective site waters, but the mortality for these two sites was significantly lower than for other sites in reference water. This suggests sporadically poor environmental quality. Milford larvae also had significant mortality. Population-level significance of pollution effects on clam reproduction will depend on how contaminated the environment is over the entire reproductive season of the clams in Long Island Sound, and over how large a portion of the spawning grounds.
- OSTI ID:
- 5810158
- Journal Information:
- Estuaries; (United States), Vol. 14:3; ISSN 0160-8347
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
CLAMS
REPRODUCTION
LONG ISLAND SOUND
ENVIRONMENTAL QUALITY
CADMIUM
CHLORINATED AROMATIC HYDROCARBONS
CHROMOSOMAL ABERRATIONS
CONNECTICUT
COPPER
EMBRYOS
FERTILIZATION
GAMETES
LARVAE
MEIOSIS
MORTALITY
SEAWATER
WATER QUALITY
ANIMALS
AQUATIC ORGANISMS
AROMATICS
ATLANTIC OCEAN
CELL DIVISION
DEVELOPED COUNTRIES
ELEMENTS
ESTUARIES
GERM CELLS
HALOGENATED AROMATIC HYDROCARBONS
HYDROGEN COMPOUNDS
INVERTEBRATES
METALS
MOLLUSCS
MUTATIONS
NORTH AMERICA
ORGANIC CHLORINE COMPOUNDS
ORGANIC COMPOUNDS
ORGANIC HALOGEN COMPOUNDS
OXYGEN COMPOUNDS
SEAS
SURFACE WATERS
TRANSITION ELEMENTS
USA
WATER
540320* - Environment
Aquatic- Chemicals Monitoring & Transport- (1990-)