Gender-Mediated Habitat Associations of Kelp Greenling (Hexagrammos Decagrammus) Along the Central Coast of California
Marine fish assemblages are broadly associated with physical habitat attributes such as water temperature and depth. At smaller spatial scales fishes are known to associate with specific substrate types such as rocky reef or unconsolidated sediments. Understanding these fine-scale habitat associations for economically and ecologically important species allows for more refined resource management and spatial planning efforts against a framework of increasing use of the marine environment. This study quantified the distribution and habitat associations of kelp greenling (Hexagrammos decagrammus) at four locations across north-central California, ranging from Point Arena to Pillar Point. Data on the distribution of kelp greenling were extracted from continuous video and still photographic imagery collected by a remotely operated vehicle between 2010 and 2011 as part of the baseline characterization of the newly implemented network of California marine protected areas (MPAs). Results indicate kelp greenling associate with low-relief, continuous rock substrates at each of the four sites. Distribution of fish within sites varied significantly based on gender, with females occurring more frequently in sand habitat than males, particularly in areas immediately adjacent to hard substrate. The geo-referenced kelp greenling observations were coupled with bathymetry-derived environmental parameters using generalized linear models to predict areas of fish occurrence beyond the sampled areas. These results advance our understanding of how kelp greenling utilize the habitats in which they occur, while the resulting predictive maps provide information on their distribution at spatial scales appropriate for MPA management and marine spatial planning.