Analyses/Maps

Fish

HSI Integration - Rockfish

About these maps:
The maps displayed here provide one approach to assess habitat suitability based on HSI results for multiple species. HSI model results were averaged to assess the potential distribution of suitable habitats for 8 species of adult rockfish (left) and 3 species of subadult rockfish (right). Predicted HSI values range in scale from 10 (highest) to 0 (unsuitable). HSI results were grouped into five classes: highest suitability (10-8), moderate (7-5), low (4-2), lowest (1), and unsuitable (0).

Data sources:
Adult rockfish - bocaccio, blue rockfish, canary rockfish, chilipepper rockfish, darkblotched rockfish, yelloweye rockfish, yellowtail rockfish, and widow rockfish (CD-Rom). Subadult rockfish - bocaccio, chilipepper rockfish, and darkblotched rockfish (CD-Rom).

Methods:
See HSI Methods for HSI map development. Maps of mean HSI were developed by overlaying each individual HSI map and calculating the arithmetic mean across grid cells.

Results and Discussion:
Eight species HSI maps for adult rockfish and three maps of subadults were combined to view the distribution of potential areas of suitability based on these assemblages. Highly suitable areas for adults were located in waters containing rocky substrate, which comprised less than 1% of the available habitat within the study area. These habitats were all located within sanctuary boundaries. Highly suitable habitat for subadults was more diverse, yet also comprised a small percentage of the available habitat (6%) within the study area.

For the most part, these species share similar preferences for substrate types; however, depth preferences vary from species to species. Careful consideration should be taken when examining HSI maps as assemblages and to ensure that groups contain species with similar affinities for the environmental variables, or are based on a more robust statistical analysis.