Project Title: Characterizing the habitat of deep-sea coral and sponges assemblages and associated demersal fishes in the Southern California Bight
Goal or Purpose

To develop habitat-based models to predict the distribution and abundance of deep-sea corals and sponges associated with groundfishes in the Southern California Bight

Anticipated Management Application(s)

This project will assist the Pacific Council, NMFS, and the Channel Islands National Marine Sanctuary in predicting the locations that have the greatest potential to contain deep-sea coral assemblages that may provide essential fish habitat. Outputs from our models will identify regions with deep-sea coral habitat that remain unprotected from fishing and other anthropogenic impacts. Specifically, we will identify areas that contain deep-sea coral assemblages that have the potential to provide essential fish habitat for important groundfish species. These model outputs (including distribution maps) will be provided to the coordinators of the national Deep Sea Coral Research and Technology Program for use in communicating with management partners (sanctuaries, fishery management councils, etc.). The novel approach used in this study could be used to inform the development of similar analytical tools in other regions, both nationally and internationally.

Fiscal Funding:
  • FY 2015 @ $55,000

 
Region(s):
  • Pacific Council
Location(s):
  •  None Defined.
Project Type:
  • Habitat Suitability Modeling
Point of Contact: Office of the Point of Contact:
  • NMFS SWFSC
Team Members:
  •  None Defined.
Project Title: Characterizing the habitat of deep-sea coral and sponges assemblages and associated demersal fishes in the Southern California Bight
Methods/Approach

We propose to develop habitat-based models to predict the distribution and abundance of deep-sea corals and sponges (DSC) associated with rockfishes and other groundfishes in the Southern California Bight (SCB). We will analyze SCB demersal community data from underwater video transect surveys conducted between 1999 and 2010 (Yoklavich and O’Connell 2008). Our first step will be to group DSC assemblages associated with various habitats using a cluster analysis. We will calculate Bray–Curtis dissimilarities between all pairs of transects based on abundances of all invertebrate taxa found at more than one of these transects. The transects will then be clustered using the flexible-β algorithm (Legendre and Legendre 1998, McCune et al. 2002) and we will prune the dendrogram based on optimizing the number and size of the cluster groups to the most informative level (Dufrene and Legendre 1997). Based on these assemblage groupings, we will use the indicator species method of Dufrene and Legendre (1997) to identify fishes that are indicative of particular DSC assemblages. The statistical significance of the indicator value for each fish species will be assessed with a randomization procedure. Our analysis will focus on the DSC assemblages that exhibit significant relationships with fishes. If there are no significant relationships between DSC assemblages and fishes, we will continue the analysis with the most widespread DSC assemblages and summarize fish species data for those that co-occur with them. We will construct generalized additive models (Hastie and Tibshirani 1990) with DSC abundance as the response and various associated habitat variables (e.g., depth, substratum type, temperature) as the predictors. Habitat variables will be based on in situ observations, high-resolution (3 km) regional oceanographic model output (Shchepetkin and McWilliams 2005), and satellite-derived surface productivity data (Suryan et al. 2012). Selected models will be fit to a random subset of the data and model predictions will be validated using the remainder of the dataset (Huff et al. 2013). Model results will identify and characterize important environmental relationships that impact DSC size, distribution, and abundance. We will use these results to develop maps of essential fish habitat for those species associated with DSC assemblages. We will then identify regions with DSC habitat that remain unprotected from fishing and other anthropogenic impacts. This novel approach may be used to inform the development of similar analytical tools in other regions, both nationally and internationally.

Project Results and Management Outcomes  None Defined
Project Title: Characterizing the habitat of deep-sea coral and sponges assemblages and associated demersal fishes in the Southern California Bight
Internal References:
  •  None Defined
 
Backlinks:
  •  None Defined

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