(1) Assess benthic faunal colonization on banks

(2) Assess trophic status of restored salt marshes

Levin Lab Benthic Studies

Goal: Develop metrics for healthy salt marsh and subtidal habitat

Bank Macrofauna

What are macrofauna?• small worms, clams, crustaceans and other invertebratesSignificance of macrofauna:• major agents of sediment stability/instability• primary food items for bottom feeding fish, shrimpStrategy: • sample macrofauna at time intervals following bank placementSampling 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 FunctionWhat is Trophic Function?

A key ecosystem property, Food web and energy transfer

Goal: Develop a method for assessing recovery of trophic functionin 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 powderAnalyze isotopic signatures (13C, 15N) on a mass spectrometer.Use mixing models to establish trophic structure

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What we learn

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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?

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Salicornia? Spartina? Limonium?

Cyanobacteria?Phytoplankton?

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