Nekton References and Targets: Assessing the Abundance and Density of Fish and Invertebrates Associated with Louisiana’s Marsh Habitat Active
The National Oceanic and Atmospheric Administration (NOAA) is leading a Monitoring and Adaptive Management (MAM) activity with USGS collaborators to establish reference ranges and restoration targets, assess data gaps for focal nekton species and/or guilds associated with Louisiana’s estuarine and coastal habitats, implement the fixed-area sampling strategy to quantify fishes and invertebrates, and analyze collected data.
Note: NOAA is leading this effort with USGS personnel as collaborators.
The Science Issue and Relevance: This Monitoring and Adaptive Management (MAM) activity is a targeted data collection and analysis effort to establish reference ranges and restoration targets, and assess data gaps for focal nekton species and/or guilds associated with Louisiana’s estuarine and coastal habitats. Nekton reference ranges and restoration targets are needed as a basis for evaluating progress and success of Louisiana Trustee Implementation Group (LA TIG) restoration activities which are intended to provide habitat for injured nekton. Reference ranges would identify the typical ranges in variation for marsh associated nekton communities and be reflective of a relevant ‘baseline’ immediately prior to the onset of the majority of Natural Resource Damage Assessment (NRDA) restoration activities, including existing salinity regimes. However, these reference conditions (Jakobsson et al. 2020) would also require characterization of natural spatiotemporal variability at intra- and interannual, and perhaps longer, time scales. Reference ranges will serve as a point of comparison for nekton community conditions observed at restoration sites, where monitoring data are often collected over a much shorter time period. Restoration targets will be developed by studying change in previously restored marsh habitats, and using said data to inform the creation of temporally variable restoration targets. Both reference ranges and restoration targets would be used to assess the effect of localized marsh creations on nekton, such as changes in species’ abundance and/or community composition, at locations adjacent to ongoing and future marsh creation activities.
Methodology for Addressing the Issue: This effort encompasses three primary tasks. Task 1 will review and synthesize existing datasets (e.g., U.S. Army Corps of Engineers – Fire Island Inlet to Montauk Point [FIMP] project data and other published/unpublished data, nearby Coastwide Reference Monitoring System [CRMS] sites for habitat characteristics, USGS landscape configuration metrics) and identify previously constructed marsh restoration projects (e.g., Coastal Wetlands Planning, Protection and Restoration Act [CWPPRA]) for development of nekton abundance reference ranges and restoration targets; such as abundances, biomass, size distribution, community composition, and diversity (e.g., richness, Shannon diversity), as well as identify data gaps and/or limitations.
Task 2 will implement the fixed-area sampling strategy developed during Task 1 to quantify fishes and (non-sessile) invertebrate (e.g., shrimps/crabs) communities on a per-unit area basis, and with respect to marsh sub-habitats by directly targeting the marsh platform itself and waters immediately adjacent to it.
Task 3, with which USGS investigators are primarily involved, will analyze the newly collected fixed-area nekton data collected under Task 2. These analyses would complement those conducted under Task 1 and, where possible, incorporate those habitat characteristics (e.g., CRMS hydrologic metrics, landscape metrics) and marsh creation design/construction aspects as identified during Task 1 that correlate with or drive nekton communities during the development of nekton density and community composition reference ranges and restoration targets.
Future Steps: Lessons learned as well as identification of data gaps and/or limitations resulting from these analyses will be important for implementation of future fixed area monitoring.
The National Oceanic and Atmospheric Administration (NOAA) is leading a Monitoring and Adaptive Management (MAM) activity with USGS collaborators to establish reference ranges and restoration targets, assess data gaps for focal nekton species and/or guilds associated with Louisiana’s estuarine and coastal habitats, implement the fixed-area sampling strategy to quantify fishes and invertebrates, and analyze collected data.
Note: NOAA is leading this effort with USGS personnel as collaborators.
The Science Issue and Relevance: This Monitoring and Adaptive Management (MAM) activity is a targeted data collection and analysis effort to establish reference ranges and restoration targets, and assess data gaps for focal nekton species and/or guilds associated with Louisiana’s estuarine and coastal habitats. Nekton reference ranges and restoration targets are needed as a basis for evaluating progress and success of Louisiana Trustee Implementation Group (LA TIG) restoration activities which are intended to provide habitat for injured nekton. Reference ranges would identify the typical ranges in variation for marsh associated nekton communities and be reflective of a relevant ‘baseline’ immediately prior to the onset of the majority of Natural Resource Damage Assessment (NRDA) restoration activities, including existing salinity regimes. However, these reference conditions (Jakobsson et al. 2020) would also require characterization of natural spatiotemporal variability at intra- and interannual, and perhaps longer, time scales. Reference ranges will serve as a point of comparison for nekton community conditions observed at restoration sites, where monitoring data are often collected over a much shorter time period. Restoration targets will be developed by studying change in previously restored marsh habitats, and using said data to inform the creation of temporally variable restoration targets. Both reference ranges and restoration targets would be used to assess the effect of localized marsh creations on nekton, such as changes in species’ abundance and/or community composition, at locations adjacent to ongoing and future marsh creation activities.
Methodology for Addressing the Issue: This effort encompasses three primary tasks. Task 1 will review and synthesize existing datasets (e.g., U.S. Army Corps of Engineers – Fire Island Inlet to Montauk Point [FIMP] project data and other published/unpublished data, nearby Coastwide Reference Monitoring System [CRMS] sites for habitat characteristics, USGS landscape configuration metrics) and identify previously constructed marsh restoration projects (e.g., Coastal Wetlands Planning, Protection and Restoration Act [CWPPRA]) for development of nekton abundance reference ranges and restoration targets; such as abundances, biomass, size distribution, community composition, and diversity (e.g., richness, Shannon diversity), as well as identify data gaps and/or limitations.
Task 2 will implement the fixed-area sampling strategy developed during Task 1 to quantify fishes and (non-sessile) invertebrate (e.g., shrimps/crabs) communities on a per-unit area basis, and with respect to marsh sub-habitats by directly targeting the marsh platform itself and waters immediately adjacent to it.
Task 3, with which USGS investigators are primarily involved, will analyze the newly collected fixed-area nekton data collected under Task 2. These analyses would complement those conducted under Task 1 and, where possible, incorporate those habitat characteristics (e.g., CRMS hydrologic metrics, landscape metrics) and marsh creation design/construction aspects as identified during Task 1 that correlate with or drive nekton communities during the development of nekton density and community composition reference ranges and restoration targets.
Future Steps: Lessons learned as well as identification of data gaps and/or limitations resulting from these analyses will be important for implementation of future fixed area monitoring.