TRANSDUCERS, CABLES AND KELP: ACOUSTIC MAPPING OF SHALLOW WATER ROCKFISH HABITAT IN CALIFORNIA KELP FORESTS

Abstract

Recent interest in the quantification of critical fisheries habitats has lead to an increase in the application of acoustic remote sensing techniques for this purpose. The transducers for acoustic instrumentation (such as side scan sonar, single and multibeam bathymetry), however, must generally be deployed and towed via a cable or arm which is subject to entanglement from floating material. This constraint poses special problems for mapping the sea floor within kelp forests; habitats which are being increasingly targeted by the rockfish fishery and therefore of special concern to resource managers. Here we present our solution to the problem of transducer/kelp entanglement which enabled us to map the shallow water rockfish habitat within the Big Creek Marine Reserve along the California Big Sur coast.