Wednesday 7 May 2014 at 3:00pm
Title: “Integrated Study of the Maryland Coastal Bays Ecosystem Processes and Dynamics: Influence of Environmental Factors on Zooplankton and Benthic Macroinvertebrate Abundance and Distribution”
Speaker: Paulinus Chigbu, Ph.D.
Professor, UMES
Director, LMRCSC & CREST Programs
Abstract:
Little is known about the factors influencing benthic macroinvertebrate and mesozooplankton densities in the Maryland Coastal Bays (MCBs). In 2010, a study of the MCBs was initiated using various types of sampling gear to assess patterns in the dynamics of the biota in relation to climatic factors and water quality conditions. Benthic macroinvertebrates were dominated by amphipods (75%), decapods (13%) and mysids (5%). Newport Bay, with degraded water quality, had one of the lowest densities and diversities of the macrobenthic fauna, whereas the less degraded Sinepuxent Bay had the highest diversity. Mysid density, dominated by Neomysis americana, was relatively high in winter/early spring and low in summer, perhaps due to fish predation. Densities of amphipods and mysids were higher in the northern than southern bays, and were positively associated with macroalgae density. Mesozooplankton densities varied temporarily, with the lowest densities in spring/early summer and highest from late summer to winter. This seasonal pattern may be due to the absence of spring phytoplankton bloom, coupled with predation by the ctenophore (Mnemiopsis sp.) in the system. Sinepuxent Bay had the highest densities of crab zoea, especially during the summer. Cladocerans were represented by two species – Pleopis polyphemoides and Evadne nordmanni. Their densities were relatively high in Sinepuxent and northern Bays, and were negatively correlated with temperature, especially in June and July. Sand shrimp (Crangon septemspinosa) was relatively high in abundance in spring, but scarce in summer. Their relative abundance was highest in Sinepuxent and Isle of Wight Bays at sites closest to the Ocean City inlet, especially in May and June prior to their disappearance from the system. There were significant negative relationships between CPUE of sand shrimp at the sites and mean temperature suggesting that the shrimp seek waters with lower temperatures.
Host: J. Sook Chung, Ph.D.