Long‐term monitoring of bocaccio abundance using passive acoustics.

Abstract

The bocaccio (Sebastes paucispinis) was a part of an important rockfish fishery to California anglers and commercial fishers until they were declared overfished by the Pacific Fisheries Management Council in 1999. Historically, rockfish stocks were estimated using ichthyoplankton sampling and catch per unit effort of the rockfish recreational fishery. More recently, with the closure of the fishery, non‐lethal methods for stock assessment have been in development such as a combination of shipboard multifrequency echosounders and underwater cameras. To augment these methods, passive acoustics have been shown to be a possibility for long‐term monitoring, but a further investigation in its use for rockfish population monitoring is necessary. Sounds produced by bocaccio were recorded off San Clemente Island in the Southern California Bight in the 1960s by Thompson, and again at a near‐by location in 2007. A comparison of these recordings with the contemporary population estimates for bocaccio in the area will shed a light in the feasibility of using passive acoustics for long‐term monitoring of changes in the population abundance of this commercially important species.