| MMS ENVIRONMENTAL STUDIES PROGRAM: ONGOING STUDIES | ||||||
| MMS OCS Region: | Pacific | |||||
| Title: | Site Fidelity of Characteristic Fish Species at Offshore Petroleum Platforms in the Santa Barbara Channel | |||||
| Actual Costs: | $200,000.00 | Period of Performance: | FY2004-2006 | |||
| Conducting Organization: | California State University-Long Beach (Contact: Christopher Lowe) | |||||
| MMS Contact: | Dr. Ann.S.Bull | |||||
| Description: | ||||||
| Background | ||||||
| A major question in the platform reefing debate deals with the issue of whether platforms are important to rebuilding local fish stocks whose populations have been seriously depleted. A new study funded by MMS POCSR to be entitled “Ecological Performance of OCS Platforms as Fish Habitat off California” will begin sometime in FY 2003 and should help to answer the questions spawning populations and habitat. However, it remains unclear how long fishes are resident around a platform. Do the large numbers of fishes, particularly such species as the overfished bocaccio and cowcod, remain around the platforms for extended periods? In a pilot study conducted in association with Dr. Chris Lowe at California State University at Long Beach, a few individuals of a surrogate rockfish species were successfully captured and acoustically tagged at a platform and their residence was determined for a short time period. Site fidelity and diel movement patterns were assessed using acoustic monitoring techniques. This monitoring technology allows for continuous monitoring of up to 250 uniquely coded acoustic transmitters on as many fish. Transmitter battery life of 2-4 years is expected and the V16 tags have a minimum estimated range of 700m. Data retrieved from the monitors would determine residence time and site fidelity over time. Knowledge of the residence time of these species would allow a more accurate determination of whether platforms form optimal habitat for depleted species and if they are indeed acting as long-term population reserves. | ||||||
| Objectives | ||||||
| As in the pilot study, rockfish will be captured, tagged and monitored using acoustic tags and monitoring equipment to determine their residence time and site fidelity. (1) Capture and implant acoustic transmitters in a sufficient number of rockfish surrogate species at two platforms in the Santa Barbara Channel. (2) Strategically place four acoustic monitors whose detection areas overlap around the platforms. (3) Retrieve, download, and service acoustic monitors on a quarterly basis. (4) Determine the residence time, site fidelity, and movement patters of the implanted fish. | ||||||
| Methods | ||||||
| Using greenspotted rockfish as a surrogate for bocaccio, and greenblotched rockfish as a surrogate for cowcod, at least 40 fish will be captured and tagged at two platforms in the Santa Barbara Channel. Rockfishes will be surgically fitted with coded acoustic transmitters using methods specifically developed for deepwater rockfish. Fish will be caught at two platforms (likely Gail and Grace) using hook and line and brought up to a depth of 20 m to reduce damage due to pressure changes and thermal shock. A team of divers will acquire angled fish from the line and take them to an underwater surgery station attached to the supporting structures of the rig. The fish will be anesthetized using MS222 (200mg/l) delivered via a squirt bottle directly into the mouth and fish will be secured to V-board for surgical implantation of acoustic tags. Once fish are fully anesthetized and secured, the swim bladder will be deflated using a small hypodermic needle if necessary. Divers will make a small incision (~2cm) along the ventral side between the anus and pelvic fins, parallel to the body midline, and through the peritoneal lining. An acoustic transmitter will be gently inserted into the peritoneal cavity. Transmitters will be coated with a mixture of beeswax and paraffin to reduce the immune rejection of the transmitter. The wound will be coated with a triple antibiotic ointment to reduce risk of infection and encourage healing. Several interrupted sutures will be used to close the wound. Prior to release, fish will be measured and tagged with an external marker for easy visual identification by divers, sub, or by fishers. Four acoustic monitors whose detection areas overlap will either be attached to the outside of the platforms or placed in a secure location adjacent to the platforms. The monitors will be retrieved, downloaded, and serviced on a quarterly basis. The residence time, site-fidelity, and movement patters for each transmitting fish will be mapped over time in relation to the platforms and any nearby reef sites. | ||||||
| Importance to MMS | ||||||
| MMS studies indicate that platforms do create habitat for several species of rockfish. The Department of Commerce in January 2000 declared the West Coast rockfish fishery a disaster with extremely small populations remaining. The Pacific Fishery Management Council began to severely restrict fishing for these species in 2002. Also in 2002, bocaccio, a rockfish species know to inhabit POCSR platforms in large numbers was a candidate for listing as threatened under the Endangered Species Act. The fate of spent offshore oil platforms in California recently has been a subject of considerable debate, much of which is focused on the potential importance of the platforms as artificial reef systems. Knowledge of the potential importance of platforms to the survival of depleted rockfish stocks is essential for fully evaluating the various options proposed for decommissioning California’s offshore oil platforms. | ||||||
| Current Status: | ||||||
| This study is in its final phase. Statistical analyses are complete and the draft Technical Summary and Final Reports will be received by MMS for review in February 2007. | ||||||
| Final Report Due: | 2/5/2007 | |||||
| Publications: | ||||||
| Affiliated WWW Sites: | http://www.csulb.edu/web/labs/sharklab/research/drlowe/rockfish.shtml | |||||
| Revised date: | November 30, 2006 | |||||
| ESPIS |
ESPIS - All completed
ESP Studies: |
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