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Objectives
 

1)   To determine diel movement patterns, home ranges, and habitat preferences of adult ocean whitefish within the Catalina Marine Science Center Marine Life Refuge (CMLR) over short time scales (< 1 month) using acoustic telemetry tracking.

2)     To determine the degree of site fidelity of adult ocean whitefish in CMLR over a 1-year period using passive acoustic monitoring.

3)     To integrate fish movement data with high resolution habitat maps of CMLR and adjacent areas using a GIS (Geographic Information System) for analysis of habitat preference and fine-scale movement patterns.

4)     To use the information gained to educate the public about the value of ecological monitoring and fisheries research.

Methods
There are two methods being employed, active tracking and passive monitoring, to quantify movement patterns of ocean whitefish at multiple spatial and temporal scales.  Each method requires different types of acoustic telemetry equipment, and when used together can effectively provide a clear picture of how individuals behave over time.  In the case of active tracking, fish locations are recorded every five minutes from a skiff using a GPS, acoustic receiver, and hydrophone over multiple twenty-four hour periods during the two-month transmitter battery life. Passive monitoring simply requires the monthly recovery, download, and replacement (over a 1-year time period) of multiple underwater automated acoustic receivers fixed on subsurface moorings throughout the study site.

All ocean whitefish are caught within the CMLR using both baited traps and hook and line. The fish are then anesthetized with clove oil, and small acoustic transmitters are surgically implanted through an incision in the peritoneal cavity (these surgical protocols have been approved by the CSULB Animal Welfare Board). Each individual is also fitted with color-coded external tags inserted through the dorsal musculature and pterygiophores to allow easy identification. Following the tagging, the fish are placed in fresh seawater to allow a brief recovery period. The fish are then released at which time measuring movement begins via active tracking or passive monitoring. To control for stress associated with capture and surgical implantation procedures, SCUBA divers feed transmitters hidden in squid to ocean whitefish that are then actively tracked until the transmitter is passed.

The representation and analysis of movement data in this study is accomplished using a GIS with the Arcview Animal Movements Analyst Extension software program. This calculates and analyzes individual home ranges, which are incorporated with a high resolution habitat map of the CMLR and adjacent areas. Home ranges are calculated using the kernel utilization distribution as well as minimum convex polygon methods. A linearity ratio is used to measure relative site fidelity, and a chi-square goodness of fit is used to measure habitat preference.

Importance
Conclusions from this study will provide fisheries managers with essential information about ocean whitefish movement patterns, which is important in order to provide effective management to sustain this growing fishery. This information will also be useful in design of future marine reserves if they are to effectively conserve local populations. Additionally, this project will serve as a model for future research focusing on quantifying reserve effectiveness for other fish species. Both sport and commercial fishermen will benefit from knowledge gained about the survivorship and movement patterns of ocean whitefish, and the effectiveness of marine reserves. Thus, understanding ocean whitefish populations carries both scientific benefits, through increased understanding of movement and habitat preference, and social benefits, through conservation of the species, allowing fishing to continue at sustainable levels.