Mary Ann Daher

Biomass of the micronekton in Gulf Stream ring 82-B and environs: changes with time

Micronekton biomass was sampled in warm-core Gulf Stream ring 82-B (at ages 2, 4 and 6 months), the Slope Water, the Gulf Stream and the Sargasso Sea during three multi-ship cruises. There was no significant diel difference in the 0–1000 m integrated biomass for fishes or invertebrate micronekton in 24 paired day-night tows, and no evidence for diel vertical migration across the 1000 m level. Biomass showed a consistent upward shift at night; although it varied with hydrographic regime and sampling date, median biomass depth shift for invertebrates averaged 184 and 137 m for fishes. For total micronekton, median biomass depth ranged from 550 to 750 m by day and 300 to 600 m by night. Fish biomass was always centered deeper than 250 m, while the center of invertebrate biomass rose above that level in only one of 12 night tows. In April, ring-core biomass for fishes and invertebrates (2.2 and 11.9 cc m−2, respectively) was significantly lower than that for the high velocity region (3.6 and 19.8 cc m−2) or that for the Slope Water (4.7 and 20.8 cc m−2). By June, ring-core standing stocks had doubled while that for the high velocity region had been reduced to half of the April levels. No significant changes in Slope Water biomass occurred over the April–August period. Fluctuations in ring-core micronekton biomass were probably due to both in situ processes and advective exchange. On the average, invertebrate biomass was about 4 times that of fish biomass. Total micronekton was 20–30% of the macrozooplankton biomass in April and June, and 7–16% in August. Vertically, the invertebrate fraction overlapped the macrozooplankton more than did the fish fraction. Greater overlap of micronekton and macrozooplankton occurred at night.

Vertical distribution and species composition of midwater fishes in warm-core Gulf Stream meander/ring 82-H

Abstract The integrated abundance and vertical distribution of midwater fishes in the upper 1000 m of warm-core Gulf Stream ring 82-H show that the fauna of the ring was very similar to that of the northern Sargasso Sea. The data, indicate that warm-core rings have a large impact on the fauna of the Slope Water even though only a small fraction of the volume of rings is mixed into the Slope Water and the fishes (mostly non-migratory) are located in the “unreactive” parts of the ring.

SOUND database of marine animal vocalizations : structure and operations

Funding was provided by the Office of Naval Research through the Ocean Acoustics Program (code 11250A) under Contract No. N00014-88-K-0273 and No. N00014-91-J-1445 with supplemental support by ORINCON/DARPA and NRL (code 211).

Software tools for acoustic database management

Funding was provided by the Office of Naval Research through the Ocean Acoustics Program (code 11250) Contract N00014-88-K-0273 and Grant N00014-J-1445 with supplemental support from NOARL (code 211).

UNDERWATER SOUND RECORDING OF ANIMALS

ABSTRACT Underwater sound recording of animals uses specialized techniques to obtain faithful copies of sounds produced by animals during their normal activities underwater. Techniques have to be unobtrusive as well as nondisturbing to avoid changing the animal behaviors. The first scientific recording of underwater sounds from a marine mammal at sea was by William E. Schevill and Barbara Lawrence in 1948. Although the equipment has changed considerably since then, the techniques, approaches to animals and environmental impediments have remained essentially the same. However, the frequency and dynamic ranges of underwater sounds can easily exceed terrestrial sounds, so the selection of suitable equipment is critical. The elements of a useful system for bioacoustic recording of marine animals include the hydrophone, impedance transformer/preamplifier, cable, signal amplifier, recorder and sound monitor. The important criteria for each of these is discussed, along with directional listening systems, and the...

Marine Animal SOUND Database

Abstract : The Marine Animal SOUND Database system encompasses (1) descriptive text databases cataloging the WHOI collection of underwater sound recordings from marine animals, (2) sets of files of digital sound sequences, (3) text databases organizing the digital sound sequences, and (4) software sound files. The text databases index and sort the information on the sounds. The digital sound files are accessed directly from the text record, analyzed on screen, listened to, and compared or exported as desired. These databases provide comprehensive means for quantitative analyses and statistical comparisons of marine animal vocalizations. The objective has been to develop basic tools for the study of maine animal sounds. The text database for cataloging the collection of recordings provides convenient sorting and selection of sounds of interest. Then, as specific sequences are digitized from these recordings, they become part of a second database system that manages these sound data. Once a digital sound is part of the database, several tools are available for interactive spectrogram display, sound playback, statistical feature extraction, and export to other application programs.

Midwater fish data report for warm-core Gulf Stream rings cruises 1981-1982

Funding was provided by the National Scten.ce Foundation under Grant Numbers OCE 80-17270 and OCE 86-20402.

Numbers of calling whales in the North Pacific

Funding was provided by CNO N45 Environmental Program and US Army Corps of Engineers (DCA87-00-H-0026) with funding from the Department of Defense Legacy Resource Management Program.

Distinctions in sound patterns of calls by killer whales (Orcinus Orca) from analysis of computer sound features

Abstract : Calls of killer whales, Orcinus Orca, were analyzed using computed sound features to classify sound patterns and identify call similarities. Calls were classified and separated according to the pod/family group within clans identified previously by John Ford (U. BC) in the Vancouver whale populations. Acoustic characteristics of the same call type from different individuals were extremely similar, so that discriminating these different sounds was the goal. The WHOl AcouStat program and associated database systems were used to define numerical statistics for each call, and then, these were compared to sort and classify the sounds.

Documentation for the CETACEA database of marine mammal literature references

Abstract : This documentation for the CETACEA database of marine mammal literature references updates and expands the original work by Watkins, Bird, Moore, and Tyack 1988 (Reference Database Marine Mammal Literature, Technical Report (WHOI-88-2). The CETACEA database is a comprehensive index of literature references used to file, store, search, retrieve, and format the data on marine animals. Organization of the references is complementary to features developed by William E. Schevill for his library of older cetacean literature, having direct association of species with over 300 indexed subjects, and with observation dates, locations, etc. This documentation describes the operation of the database (3600 records), including indexing, sorting, and retrieval information developed through continued use of these systems. SPECIES and SUBJECT HEADING lists with their codes have been updated. Other databases have also developed around these indexing and sorting strategies to complement the CETACEA database, including databases of animal sounds for both the recording data and the acoustic spectral information stored in libraries of digital sound cuts.