Aquatic Sciences Meeting, Albuquerque 2001

CS05 Benthos: Ecology and Ecotoxicology

Date: Friday, February 16, 2001, Time: 10:15:00 AM

Location: Cimarron

Laetz, C, A, State University of New York Stony Brook, Stony Brook, USA, cathy.laetz@msrc.sunysb.edu

Cerrato, R, M, State University of New York Stony Brook, Stony Brook, USA, Robert.Cerrato@sunysb.edu

RECONSTRUCTING THE GROWTH OF HARD CLAMS, MERCENARIA MERCENARIA, UNDER BROWN TIDE CONDITIONS USING SHELL MICROGROWTH ANALYSIS

Hard clams are a large economic resource in Great South Bay, New York, but their numbers have been declining in recent years. One suspected cause of the declining populations are brown tides, monospecific phytoplankton blooms of Aureococcus anophagefferens that cause bivalve filtering activities to cease under high bloom densities. Marked clams were planted in Great South Bay in July 2000, sampled monthly, and their shells were thin-sectioned for microgrowth analysis using a light microscope. Patterns of growth bands and growth breaks were compared to archived shells from previous years, including years prior to the first documented brown tides. Analysis indicated that growth breaks occurred more frequently in clams exposed to brown tides of long duration and high density, making the clams appear older than they actually were at the time of harvest. This suggests that the conditions of the growing environment are essential for accurate aging of clams, and has implications in population studies and management decisions.

This Session Listing

Aquatic Sciences Meeting, Albuquerque 2001

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