Atlantic Estuarine Fish Habitat

This indicator measures the condition of estuarine fish habitat along the Atlantic coast using metrics of water quality, marsh edges, seagrass and oyster reefs, fragmentation, human development, and more. Areas of excellent fish habitat are already in good condition and face few threats; restoration opportunity areas are doing well in some respects, but restoration projects could significantly improve them; degraded areas of opportunity face many challenges, and restoration projects are unlikely to increase available fish habitat unless particularly large in scope and scale. This indicator originates from the Atlantic Coast Fish Habitat Partnership’s fish habitat conservation area mapping and prioritization project.

Reason for Selection

This indicator captures many factors influencing Atlantic estuarine fish habitat quality and promotes consistency with the priorities of the Atlantic Coast Fish Habitat Partnership. Estuarine habitat provides critical food resources and serves as a refuge from predators for many recreational and commercial fish, crabs and small animals (Naturally Resilient Communities 2017). Submerged aquatic vegetation in coastal and estuarine ecosystems is a food source for waterfowl and, along with marsh edges and sea grass, serves as important nursery habitat for many species (Dennison et al. 1993). Oyster reefs and beds also help to improve surrounding water quality, buffer coasts from waves, and reduce erosion (Naturally Resilient Communities 2017).

Input Data

• Atlantic Coast Fish Habitat Partnership (ACFHP) Fish Habitat Conservation Area Mapping and Prioritization Project – South Atlantic and Mid Atlantic Estuarine Analysis
• Base Blueprint 2022 subregions
• Base Blueprint 2022 extent

Mapping Steps

• Convert the South Atlantic Estuarine Analysis from vector to a 30 m raster using the FINALSCORE field.
• Convert the Mid-Atlantic Estuarine Analysis from vector to a 30 m raster using the TotalPoints field.
• Combine the above rasters using the ArcPy Spatial Analyst Cell Statistics-Maximum function.
• Reclassify the above raster into 9 classes, seen in the final indicator values below.
• Clip to the Atlantic Coastal Plain subregion, where this indicator was used in Zonation. The source data also covers the Piedmont and Florida Peninsular subregions, but those areas were not used in the Blueprint priorities for those subregions. We didn’t use the source data that extended into parts of Florida Peninsula because the lack of data coverage for the full subregion caused problems in the Blueprint priorities. We didn’t include the Piedmont data due to an oversight in which indicators were included for that subregion.
• As a final step, clip to the spatial extent of Base Blueprint 2022.

Note: For more details on the mapping steps, code used to create this layer is available in the Southeast Blueprint 2022 Data Download under BlueprintInputs > BaseBlueprint2022 > 6_Code.

Final Indicator Values

Indicator values are assigned as follows:

• 8 = Final score of 80 (areas of excellent fish habitat)
• 7 = Final score of 70 (areas of excellent fish habitat)
• 6 = Final score of 60 (restoration opportunity areas)
• 5 = Final score of 50 (restoration opportunity areas)
• 4 = Final score of 40 (restoration opportunity areas)
• 3 = Final score of 30 (restoration opportunity areas)
• 2 = Final score of 20 (restoration opportunity areas)
• 1 = Final score of 10 (degraded areas of opportunity)
• 0 = Final score of 0 (degraded areas of opportunity)

Known Issues

• This indicator underestimates scores in parts of Georgia and North Florida that weren’t well-surveyed for oyster reefs at the time of the ACFHP assessment.
• While the indicator source data extends into parts of the Piedmont and Florida Peninsula subregions, those areas are not included in the indicator because they were not used in the Blueprint priorities for those subregions. We didn’t use the source data that extended into parts of Florida Peninsula because the lack of data coverage for the full subregion caused problems in the Blueprint priorities. We didn’t include the Piedmont data due to an oversight in which indicators were included for that subregion.

Disclaimer: Comparing with Older Indicator Versions

There are numerous problems with using Southeast Blueprint indicators for change analysis. Please consult Blueprint staff if you would like to do this (email hilary_morris@fws.gov).

Literature Cited

Dennison, William C., Robert J. Orth, Kenneth A. Moore, J. Court Stevenson, Virginia Carter, Stan Kollar, Peter W. Bergstrom, Richard A. Batiuk, Assessing Water Quality with Submersed Aquatic Vegetation: Habitat requirements as barometers of Chesapeake Bay health, BioScience, Volume 43, Issue 2, February 1993, Pages 86–94, [https://doi.org/10.2307/1311969].

Martin, Erik, Kat Hoenke, and Lisa Havel. Atlantic Coast Fish Habitat Partnership. Fish Habitat Conservation Area Mapping and Prioritization Project: A Prioritization of Atlantic Coastal, Estuarine, and Diadromous Fish Habitats for Conservation. August 2020. [https://www.atlanticfishhabitat.org/wp-content/uploads/2020/08/ACFHP-Mapping-and-Prioritization-Final-Report.pdf].

Naturally Resilient Communities. 2017. Solution: Oyster Reefs. [https://nrcsolutions.org/wp-content/uploads/2017/03/NRC_Solutions_Oyster_Reefs.pdf].