About CATC

The Project

We are working directly with the recreational fishing community, the California Department of Fish and Game, and the San Diego Oceans Foundation to implement an assessment of Paralabrax populations, vital rates, and movement patterns. A broad and intensive tagging project focusing on the stock evaluation of these important fisheries species will help clarify their status and trends for the purpose of identifying appropriate population monitoring metrics for adaptive management. Importantly, such a study can be directly compared with historical (1960s and 1990s) tag-recapture studies of kelp bass, barred sand bass, and spotted sand bass that were conducted by the California Department of Fish and Game. This will allow an assessment of long-term trends and stock status in the context of historical fisheries information.

Where

All tagging trips are being conducted at six sites: Dana Point/San Onofre, La Jolla, Point Loma, Imperial Beach, Mission Bay, and San Diego Bay. Fishing effort is being separated into two types: ¾-day sportfishing vessel charters, and private boat trips that are run by local boat owners who are willing to use their own boats to help with the tagging as research volunteers. The charter tagging trips focus on tagging at the four coastal sites only, and the private boat owner volunteers help with tagging at all six sites. Approximately 40 charters are being run during the next two years, and any interested anglers are invited to volunteer with the tagging. This allows the core sampling design using charters to be supplemented by additional tagging efforts. Fishing efforts are being conducted with hook and line, and all angler information, fishing methods, gear types, and fish measurements are recorded for each fish.

Tagging Methods

Two tagging methods are being employed: mark-recapture and acoustic telemetry. Mark-recapture consists of small external tags that are inserted into the dorsal musculature of each fish. Each tag has an individual fish ID number and a contact phone number. Recreational anglers who catch a tagged fish can report it any of three different ways: they can call the phone number on the tag, they can upload the recapture information on the project website, or they can use our brand new Catch ReporterTM cell phone application. Any angler who reports a tagged kelp (calico) bass, barred sand bass, or spotted sand (bay) bass with a digital photograph of the tagged fish will be entered into a monthly raffle organized by the San Diego Oceans Foundation, with prizes worth approximately $200. The second type of tagging approach, acoustic telemetry, involves the use of acoustic transmitters that are surgically implanted into a subset of the fish for measurements of behavior and mortality. These fish will be detected by an array of underwater acoustic receivers that are currently deployed in the La Jolla area.

Analysis

Data analysis will be accomplished using a Bayesian mark-recapture model that will incorporate mortality (natural, harvest, and catch-and-release) for each species at each site. Population abundance, catch-per-unit-effort, size structure, and movement patterns will also be quantified and analyzed at each site for each species. Movements will be analyzed using spatial statistics in a Geographic Information System (GIS).