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Levin Lab Benthic Studies. (1) Assess benthic faunal colonization on banks (2) Assess trophic status of restored salt marshes. Goal: Develop metrics for healthy salt marsh and subtidal habitat. Bank Macrofauna. What are macrofauna? small worms, clams, crustaceans and other invertebrates
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Levin Lab Benthic Studies (1) Assess benthic faunal colonization on banks (2) Assess trophic status of restored salt marshes Goal: Develop metrics for healthy salt marsh and subtidal habitat
Bank Macrofauna • What are macrofauna? • small worms, clams, crustaceans and other invertebrates • Significance of macrofauna: • major agents of sediment stability/instability • primary food items for bottom feeding fish, shrimp • Strategy: • sample macrofauna at time intervals following bank placement • Sampling and analysis methods • field - sediment coring, vertical sectioning, preservation • laboratory - sieving, sorting under dissecting microscope, • counting, species identification (~ 1 da/sample) • statistical measures of diversity and community structure • What we learn: • proxy for ecosystem successional state and health
Salt Marsh Trophic Function What is Trophic Function? A key ecosystem property, Food web and energy transfer Goal:Develop a method for assessing recovery of trophic function in restored Venice Lagoon salt marshes Rationale: Most measures of recovery examine structural properties rather than function Approach: Use stable isotopic analyses to examine food web organization (isotopic signatures differ for different plants/algae and are passed from food to consumer) Compare food webs in natural and restored salt marshes of different ages Methods: Sample primary producers and consumers, dry and powder Analyze isotopic signatures (d13C, d15N) on a mass spectrometer. Use mixing models to establish trophic structure
What we learn What forms the base of the food chain in undisturbed marshes? How many trophic levels are present in a healthy marsh? Are these similar in restored marshes? After how many years? Can we develop a functional measure of marsh recovery? Salicornia? Spartina? Limonium? Phytoplankton? Cyanobacteria?