Habitat Associations

 

Rhina inornataThe PSRC has been working in closely with the Monterey Bay Aquarium Research Institute (MBARI) and has been using archived video footage of elasmobranchs taken from remotely-operated vehicles and manned submarine dives in Monterey Bay to review and relate to existing habitat maps of the region to estimate distribution, abundance, species composition, habitat associations, and potential nursery grounds for deep-water sharks. Images captured from a remotely-operated submersible recently helped the PSRC name and describe a new species of chimaera, Hydrolagus melanophasma, from the North East Pacific Ocean. The footage of this new species can be found here.

Three elasmobranch species, the filetail catshark (Parmaturus xaniurus), California skate (Raja inornata), and longnose skate (R. rhina) are commonly observed during manned submersible dives and their habitat associations are currently under investigation. Similar studies are being initiated using data obtained from fishery-independent trawl and longline surveys conducted by the NMFS Santa Cruz Lab.

The PSRC has initiated several projects intended to determine which marine and estuarine habitats might serve as Essential Fish Habitat for several species of central California elasmobranchs. This research will include an evaluation of the bays, estuaries, and deep-water habitats along the Pacific coast to examine their role as nursery grounds. We are currently examining the spatial and temporal patterns in habitat utilization and movements of leopard sharks inside Elkhorn Slough, CA using acoustic telemetry techniques. A mixture of both active and passive tracking techniques will allow us to collect data on short- and long-term movements and habitat use by transient and resident sharks. With increased knowledge of spatial utilization, proper steps can be taken to protect critical areas of the slough that will lead to more effective management of the species.