Christmas Tree Black Corals Surveyed Near Channel Islands, Southern California

The SWFSC Fisheries Ecology Division’s Habitat Ecology Team completed a successful October 2010 research cruise onboard the F/V Velero IV.

Underwater surveys of thousands of deepsea corals, sponges, and associated fishes were conducted on rocky banks at depths of 110-475 meters off southern California using non-extractive transect methodologies and direct observations from Nuytco Research’s Dual DeepWorker manned submersible. About 17 hours of annotated high-definition video was collected along navigated track lines. Data also were collected on environmental conditions, including depth, temperature, salinity, dissolved O2, and substratum type to help understand habitat factors that influence deepsea coral settlement and distribution.

Specific research objectives were to quantify habitat-specific abundance and size composition of the black Christmas tree coral, evaluate changes in the coral communities eight years after initial baseline surveys, and determine fish associations with black corals to help us understand the role of corals as essential fish habitat. A few corals and sponges were collected in order to confirm taxonomic identifications and for genetic and reproductive analyses.

This was a cooperative project among investigators from SWFSC and University of California Santa Barbara, with additional funds from NOAA’s Deepsea Coral Program. All objectives were met and data analyses are underway.

Read more about the Habitat Ecology Team’s coral research: Deep sea coral communities and fisheries habitats off California

(October 15, 2010)