This indicator measures the condition of migratory fish habitat along the Atlantic coast within each catchment, using metrics of water quality, aquatic connectivity, habitat fragmentation, flow alteration, 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 represents aquatic connectivity between fresh and salt water in Atlantic drainages. It incorporates both physical barriers to connectivity and indirect barriers related to habitat quality. It also promotes consistency with the priorities of the Atlantic Coast Fish Habitat Partnership.
Input Data
Mapping Steps
- Convert the South Atlantic Diadromous Analysis from vector to 30 m raster using the FINALSCORE field.
- Convert the Mid-Atlantic Diadromous Analysis from vector to 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 8 classes, seen in the final indicator values below.
- Clip to the Atlantic Coastal Plain and Piedmont subregions, where this indicator was used in Zonation. The source data also covers the Appalachian 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 Appalachian 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 under and overrepresents migratory fish habitat in some areas. The South Atlantic and Mid-Atlantic Diadromous Analysis did not include fish presence and fishing data because of inconsistent sampling methods across the study area and because this data was unavailable in many shallow water habitats.
- While the indicator source data extends into parts of the North and South Appalachians 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 North and South Appalachians data due to an oversight in which indicators were included for those subregions.
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
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].