HARVESTED SPECIES

Recently, the California Department of Fish and Game (CDFG) created teams to deal with specific fishery issues. The Nearshore Fish Team has met several times to discuss how to evaluate and regulate, if necessary, the live fish fishery. In its spring 1999 meeting, the team noted many gaps in knowledge on this fishery and its target species, including accurate estimates of the abundance (from both fishery-dependent and -independent catch and effort data sources), species composition, natural history, bycatches, effect of changing ocean conditions, socio-economic factors, and the ecosystem role of species subject to fisheries. The team estimated that the costs of doing the necessary research to fill these gaps would be approximately $10 M just for the first year!

Some scientists think the live fish fishery will fail because it targets mainly small, immature individuals of shallow, nearshore fishes. Certainly, fisheries for juvenile fishes, especially if they target all areas where these juveniles live, cannot last long. Of special concern is the fact that many of these fishes are being harvested before they get a chance to reproduce for the first time. Since rockfish are typically long-lived, often take many years to mature, and are known to have highly-variable, successful recruitment, harvesting them before they mature and reproduce can be disastrous for their populations.

In addition, the live fish fishery targets sizes and species of fishes not taken by many fishermen prior to now. Many of these nearshore fishes are very site-intensive. Thus, any heavy fishing on their populations—most of which have established home sites and will not move much after settling, except to forage and perhaps reproduce—could be very deleterious to the local population densities.

In June 1999 the U.C. Sea Grant Marine Advisory Program and CDFG sponsored a Workshop on Assessing and Managing Nearshore Fisheries. Recommendations from fishery biologists who attended include the need to obtain the best possible data on catch, effort, species and size composition, reproduction, maturity, location, site specificity, larval dispersal and recruitment, and socio-economic variables to enable CDFG to evaluate the trends in this increasing fishery and manage it appropriately.

Two pieces of California legislation, enacted in 1998, require Fishery Management Plans (FMPs), shift the nearshore fishery regulatory authority from the California Legislature to the Fish and Game Commission, and establish size limits for selected species. Size limits between 10-12" were established for six species of rockfish, including the black and yellow, gopher, kelp, China, grass, and brown rockfishes, and limits of 10" for scorpionfish, 12" for sheephead, and 14" for cabezon. Other species taken in this fishery include greenlings, surfperches, deep-water thornyhead fishes, and crustaceans such as the spot prawn. However, for most of these species, there have not been validated age determination or estimates of age/size at maturity studies. Also, size limits may not be very effective because many of the undersized fishes with swim bladders will suffer barotrauma (disorientation and possible death caused by pressure change) and not survive well when returned to the sea.

--Gregor M. Cailliet
Moss Landing Marine Laboratories

In August 1997, however, an unusual seabird stranding event was detected by the Monterey Bay National Marine Sanctuary's Beach COMBERS program (see Bird Section for program details). Several hundred dead Common Murres were found on a 14-km section of beach in southern Monterey Bay. Because of the localized nature of the strandings, and because Common Murres had a history of significant mortality in gillnets, fishery entanglement was considered a possible cause of death for these birds.

Halibut set gillnet fishery records revealed that effort had increased substantially between 1994 and 1998 and had also shifted to the southern areas of Monterey Bay (Figure 1). Increasing effort was taking place just offshore of the beaches exhibiting high seabird deposition rates. This area historically had high bycatch rates of harbor porpoise, southern sea otter, and Common Murres. There was, therefore, concern over potential increased fishery mortality for all three species, particularly given an increase in harbor porpoise stranding rates and an apparent decline in the sea otter population after 1995 (see article in Endangered Species section). Without observer data for 1995-98, however, it was not possible to estimate accurately the level of mortality during those years.

Figure 1: Halibut set gillnet fishery effort for Monterey Bay in the 1990s.

Multi-agency efforts are presently underway to evaluate and address this mortality. The central California harbor porpoise population is estimated to be about 5,700 animals, and under the Marine Mammal Protection Act, the maximum allowable incidental mortality of this species is forty-two animals per year. NMFS is therefore currently working with fishermen to implement voluntary measures to reduce the mortality of harbor porpoise, including the use of acoustical devices ('pingers'), which have been extremely effective at reducing marine mammal entanglements in other gillnet fisheries. Studies are also underway to identify the potential impacts of the present gillnet mortality on southern sea otters and Common Murres.

--Karin A. Forney
Southwest Fisheries Science Center

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