30 Habitat Vulnerability
Description: A summary of habitat vulnerability and the importance of such habitats to managed species.
Indicator category: Extensive analysis, not yet published
Found in: State of the Ecosystem - New England (2021), State of the Ecosystem - Mid-Atlantic (2021)
Contributor(s): Mark Nelson, Mike Johnson, Emily Farr, Grace Roskar
Data steward: Grace Roskar grace.roskar@noaa.gov
Point of contact: Mark Nelson, Mike Johnson, Emily Farr
Public availability statement: Data from the Northeast Fish Climate Vulnerability Assessment and ACFHP’s species-habitat matrix are publicly available. However, the data from the Northeast Habitat Climate Vulnerability Assessment are not yet published. Please email emily.farr@noaa.gov or mike.r.johnson@noaa.gov for further information and queries.
30.1 Methods
30.1.1 Data sources
Data came from the Northeast Habitat Climate Vulnerability Assessment (HCVA; not yet published), the Northeast Fish and Shellfish Climate Vulnerability Assessment (FCVA) and the Atlantic Coastal Fish Habitat Partnership’s (ACFHP) Species-Habitat Matrix.
30.1.2 Data analysis
We assessed the vulnerability of 52 marine, estuarine, and riverine habitats in the Northeast U.S. to climate change. The northern and southern boundaries of the study area are the U.S./Canadian border and Cape Hatteras, NC, respectively, and the study includes habitats out to the U.S. EEZ and up-river to capture the full range of diadromous species.
This habitat climate vulnerability assessment (HCVA) builds on the Northeast Fish and Shellfish Climate Vulnerability Assessment (FCVA) completed in 2016 (W. E. A. N. Hare Jonathan A. AND Morrison (2016)), and uses a similar framework. While the species assessment primarily examined climate vulnerability based on life history, the HCVA assesses the vulnerability of the habitats themselves to climate change, and complements the species assessment by improving our understanding of how vulnerable habitats will impact fish and invertebrate populations.
To better understand which species depend on vulnerable habitats, the Atlantic Coastal Fish Habitat Partnership (ACFHP) habitat-species matrix (Kritzer2016) was used in conjunction with the results of the HCVA and the FCVA. The ACFHP matrix identified the importance of nearshore benthic habitats to each life stage of select fish species, which helps elucidate species that may be highly dependent on highly vulnerable habitats that were identified in the HCVA.
30.1.2.1 HCVA Methods:
The Northeast HCVA is a trait-based vulnerability assessment which was adapted from the framework developed for NOAA’s Fish Stock Climate Vulnerability Assessment (Morrison et al. (2015)). The HCVA considers the overall vulnerability of habitat to climate change to be a function of two main components: exposure and sensitivity. The exposure component considers the magnitude and overlap of projected changes in climate with the distribution of each habitat. Climate exposure is assessed using end-of-century climate projections based on the Intergovernmental Panel on Climate Change RCP 8.5 emissions scenario. The sensitivity component includes nine habitat attributes, or traits, that are believed to be indicative of the response of a habitat to potential changes in climate. The assessment methodology relies on an expert opinion-based approach to determine the sensitivity of each habitat to potential climate change related impacts. The sensitivity is combined with the climate exposure information to determine the overall vulnerability rank.
30.1.2.2 Methods for linking habitat vulnerability results with species:
The Atlantic Coastal Fish Habitat Partnership (ACFHP) habitat-species matrix (Kritzer et al. (2016)) was consulted and linked with the results of the HCVA and the FCVA in order to understand which federally managed species that are highly dependent on highly vulnerable habitats.
The ACFHP habitat-species matrix evaluated the importance of 26 benthic habitat types to select fish and invertebrate species. Each habitat type was assigned a rank of “very high,” “high,” “moderate,” or “low,” reflecting a species’ use of the habitat at a specific life stage. Detailed descriptions of the rationale behind the rankings can be found in Kritzer et al. (2016).
Using habitat descriptions from Kritzer et al. (2016), the 26 habitats analyzed by ACFHP were matched with HCVA habitats that best fit under the same description. Several habitat types that were included in the HCVA but not assessed by ACFHP were omitted from this analysis (e.g., manmade hard bottom habitats, aquaculture, invasive salt marsh and wetlands, water column habitats). A species-habitat matrix was then created using the species that were assessed in both the FCVA and by ACFHP, and the habitat importance ranking (very high, high, moderate, low) from the ACFHP matrix for each habitat type. Because the ACFHP habitat types were broader, several HCVA habitats often fit under a single ACFHP habitat; therefore, to determine which HCVA habitat a species/life stage actually uses under the broader ACFHP habitat, species profiles from the Northeast Regional Habitat Assessment (NRHA) and EFH Source Documents were consulted.
Species highlighted here are those that are highly dependent on highly vulnerable habitats. A ranking matrix was created using the habitat vulnerability rankings compared to the habitat importance rankings to determine the criteria, and for the purposes of this submission, “high dependence on a highly vulnerable habitat” encompasses moderate use of very highly vulnerable habitats, high use of highly or very highly vulnerable habitats, or very high use of moderately, highly, or very highly vulnerable habitats.
30.1.3 Data Processing
The Habitat Vulnerability information table was formatted for inclusion in the ecodata R package with the code found here.