Restored freshwater flow and estuarine benthic communities in the northern Gulf of Mexico: research trends and future needs

Abstract

Restoring river connectivity to rebuild and sustain land is a promising restoration strategy in coastal areas experiencing rapid land loss, such as the Mississippi river delta. Results of these large-scale hydrologic changes are preliminary, and there exists limited empirical evidence regarding how benthic communities will respond, specifically in Barataria Bay and Breton Sound in southeast Louisiana. In this review, the body of existing research in this geographic region pertaining to the drivers of benthic community response that are related to restored freshwater flow and sediment deposition is examined. Overall trends include (1) potential displacement of some species down-estuary due to reduced salinities; (2) temporary lower diversity in areas closest to the inflow; (3) increased benthic production along the marsh edge, and in tidal bayous, as a result of nutrient loading; (4) more habitat coverage in the form of submerged aquatic vegetation; and (5) reduced predation pressure from large and/or salinity-restricted predators. These trends highlight opportunities for future research that should be conducted before large-scale hydrologic changes take place.

Patterns and consequences of life history diversity in salinity exposure of an estuarine dependent fish

“…In contrast, Red Drum spent time in both oligohaline and meso-polyhaline salinities, and life history diversity in oligohaline exposure was only present in juvenile fish. This continuous use of estuarine nursery habitats provides resiliency to the inevitable future fluctuations of estuarine salinity (Scavia et al 2002;Gillanders et al 2011;Tupitza and Glaspie 2020). Facultative occupancy of oligohaline salinities is likely present in other estuarine dependent fishes and should be investigated further, elucidating resiliency in other economically valuable species.…”