A standard, universally useful classification scheme for deepwater habitats needs to be established so that descriptions of these habitats can be accurately and efficiently applied among scientific disciplines. In recent years many marine benthic habitats in deep water have been described using geophysical and biological data. These descriptions can vary from one investigator to another, which makes it difficult to compare habitats and associated biological assemblages among geographic regions. Using geophysical data collected with a variety of remote sensor systems and in situ biological and geologic observations, we have constructed a classification scheme that can be used in describing marine benthic habitats in deep water. 0 1999 Ifremer / CNRS / IRD / Editions scientifiques et medicales Elsevier SAS habitat / universal classification / benthic I fisheries management Resume .-Une classification des habitats benthiques profonds. Un systeme de classification des habitats benthiques profonds, pour avoir valeur de reference g&r&ale, doit pouvoir etre mis en pratique avec precision et efficacite dans les disciplines scientifiques. Ces dernieres an&es, les habitats marins benthiques profonds ont tte decrits a partir de dontrees geophysiques et biologiques ; les descriptions varient d'un chercheur a l'autre, rendant la comparaison difficile entre les habitats et les populations de differentes regions geographiques. Des donnees geophysiques obtenues par plusieurs systemes de detection a distance, et des observations biologiques et geologiques in situ, ont permis d'etablir une classification qui est proposee pour decrire les habitats marins benthiques en eau profonde. 0 1999 Ifremer / CNRS / IRD / Editions scientifiques et medicales Elsevier SAS habitat I classification universelle I benthique I gestion des pecheries

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A three-dimensional localization method for tracking sperm whales with as few as one sensor is demonstrated. Based on ray-trace acoustic propagation modeling, the technique exploits multipath arrival information from recorded sperm whale clicks and can account for waveguide propagation physics like interaction with range-dependent bathymetry and ray refraction. It also does not require ray identification (i.e., direct, surface reflected) while utilizing individual ray arrival information, simplifying automation efforts. The algorithm compares the arrival pattern from a sperm whale click to range-, depth-, and azimuth-dependent modeled arrival patterns in order to estimate whale location. With sufficient knowledge of azimuthally dependent bathymetry, a three-dimensional track of whale motion can be obtained using data from a single hydrophone. Tracking is demonstrated using data from acoustic recorders attached to fishing anchor lines off southeast Alaska as part of efforts to study sperm whale depredation of fishing operations. Several tracks of whale activity using real data from one or two hydrophones have been created, and three are provided to demonstrate the method, including one simultaneous visual and acoustic localization of a sperm whale actively clicking while surfaced. The tracks also suggest that whales' foraging is shallower in the presence of a longline haul than without.

Residence time and movement rates of lingcod (Ophiodon elongatus) were recorded in an area closed to fishing in southeast Alaska to evaluate the potential effects of reserves on mortality, egg production, and fishery yield. In 1999, 43 lingcod were tagged with sonic transmitters, and an array of receivers moored in the reserve recorded signals transmitted from tagged fish for 14 months. Most of the tagged fish frequently left the reserve but were only absent for short time periods. Tagged fish showed a high degree of site fidelity. Models generated from the tag data provided a way to predict the effects of marine reserves on yield and eggs per recruit for a cohort of female lingcod. Model results indicated that for lingcod stocks with low abundance, marine reserves could improve egg production while having a small effect on fishery yield. For more abundant stocks, if a portion of the stock is protected in reserves, fishing rates could be increased outside reserves without reducing egg production relative to egg production levels in the absence of reserves.

Sperm whales (Physeter macrocephalus) have learned to remove fish from demersal longline gear deployments off the eastern Gulf of Alaska, and are often observed to arrive at a site after a haul begins, suggesting a response to potential acoustic cues like fishing-gear strum, hydraulic winch tones, and propeller cavitation. Passive acoustic recorders attached to anchorlines have permitted continuous monitoring of the ambient noise environment before and during fishing hauls. Timing and tracking analyses of sperm whale acoustic activity during three encounters indicate that cavitation arising from changes in ship propeller speeds is associated with interruptions in nearby sperm whale dive cycles and changes in acoustically derived positions. This conclusion has been tested by cycling a vessel engine and noting the arrival of whales by the vessel, even when the vessel is not next to fishing gear. No evidence of response from activation of ship hydraulics or fishing gear strum has been found to date.