You are here:
Environmental DNA methods to characterize fish communities in Northern Gulf of Mexico estuarine and near‐shore coastal waters
Citation:
Reschke, E. AND L. Harwell. Environmental DNA methods to characterize fish communities in Northern Gulf of Mexico estuarine and near‐shore coastal waters. CERF 2023: 27th Biennial Conference, Portland, OR, November 12 - 16, 2023.
Impact/Purpose:
The eDNA protocols and methodologies presented will ensure the best results with estuarine samples and improve spatial and temporal resolution of fish community data to inform restoration metrics.
Description:
Gulf of Mexico (GOM) estuaries are highly productive systems that are ecologically and economically important. The GOM region provides extensive habitat to high-value fisheries species and valuable ecosystem goods and services such as oil and gas, shipping ports, and tourism. Deepwater Horizon (DWH) spill penalties and settlements provided restoration funds that were aimed at restoring essential spawning, nursery, and feeding habitat for many species in the Gulf of Mexico. Given these investments in restoring GOM habitats and the productivity of the region, it has become increasingly important that resource managers have tools to assess the potential of habitat restoration to meet both ecological and societal goals. Fish community data yield important indicators that help increase our understanding about ecological stressor?response relationships, socio?economic benefits, climate?change impacts, and restoration/conservation effectiveness. Traditional fish sampling methods (e.g., trawls, nets) are costly to implement, time intensive, and often damaging in ecologically sensitive estuarine areas (e.g., seagrasses, bottom substrates). Environmental DNA (eDNA) is a valuable tool that can help mitigate issues with more traditional sampling methods. It can reduce human impact on sensitive areas (restoration, seagrass, etc.) and has the potential to capture information about the presence of valuable, rare, and/or invasive species at a lower effort and cost. Largely, eDNA research efforts have been centered in freshwater environments. In this presentation, we seek to address the following questions: (1) What is the potential feasibility of using eDNA metabarcoding as a tool to characterize fish species assemblages in habitat restoration locations (e.g., seagrasses, oyster reefs, wetland edge, living shoreline) in estuarine systems? and (2) What are the spatial and temporal considerations that must be made to best capture fish community structure in an estuarine environment? This presentation will focus on methodology for our fish eDNA metabarcoding pilot study based in Pensacola and Perdido Bays in the Northern Gulf of Mexico. These bays are the receiving waters of five riverine watersheds and are heavily impacted by urban, agricultural, and recreational land use patterns with rapid suburban and exurban growth. We present our approach to site selection, field sampling methodology, and laboratory practices to ensure the best results with estuarine samples with varied salinities with the goal of improving spatial and temporal resolution of fish community data to inform restoration metrics.
