Whitlatch, R. B. University of Connecticut, whitlatc@uconnvm.uconn.edu
Osman, R. W. Academy of Natural Sciences, osman@acnatsci.org

 
FIELD MEASUREMENTS OF INITIAL BENTHIC INVERTEBRATE LARVAL SETTLEMENT: PHYSICAL CONTROLS AND GEOCHEMICAL IMPLICATIONS
 
A newly developed instrument has been designed to examine the effects of environmental conditions on the initial settlement patterns of marine benthic invertebrates. The device exposes sediments at four discrete levels of naturally varying environmental conditions and repeatedly exposes the sediments over 1-3 wk periods in order to obtain sufficient numbers of recruits. Field experiments with the device examined how the settlement patterns of several species of infaunal invertebrates varied with tidal state, current velocity and photoperiod. Results indicate that initial settlement patterns of most species were generally not affected by photoperiod but were influenced by tidal state and current velocity. Most recruitment occurred during periods of slack water, particularly at low tide. These recruitment patterns are apparently independent of sediment type (sands vs muds) and are consistent with other studies which have documented the release of algal spores, invertebrate larvae, or gametes during clam water or low tide periods in order to enhance fertilization or settlement success. These findings point to the need for conducting geochemical studies during specific periods of intitial invertebrate settlement in order to more fully partition the relative role of physical and geochemical cues in affecting the recruitment dynamics in soft-sediment habitats.
 
Day: Thursday, Feb. 4
Time: 11:00 - 11:15am
Location: Hilton of Santa Fe
 
Code: SS30FR1100S