89 research outputs found

    Proceedings of the US and Canada Scallop Science Summit: St. Andrews, New Brunswick, May 6–8, 2014

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    A council of stakeholders ranging from fishermen, to scientists, and fisheries managers from both Canada and the United States convened on May 6, 7, and 8, 2014 in St. Andrews, New Brunswick to review and discuss the most recent scientific information relevant to the sea scallop fisheries and aquaculture efforts in the US and Canada. The US and Canada Scallop Summit aimed to strengthen and broaden the knowledge base in the scallop fisheries, with a focus on the nearshore fisheries in the Gulf of Maine and Bay of Fundy, as well as aquaculture efforts, and develop research priorities that aim to assist in the goal of profitable, sustainable fisheries that support coastal communities. More specifically, the overarching goals of this meeting were: i) to review and discuss the most recent scientific information relevant to the sea scallop fisheries and aquaculture efforts in the US and Canada among stakeholders – scientists, harvesters, and managers, ii) to bring together relevant groups – including scientists, harvesters, and managers, to increase coordination and collaboration on future scientific research opportunities, and iii) to provide an inclusive and participative forum to engage industry in scientific discussions and knowledge sharing. The summit involved 41 participants (mainly from Atlantic Canada and New England) and 14 presentations over four theme sessions. These proceedings provide an overall summary of the meeting presentations, questions, and discussion sessions

    Feeding behavior of the ctenophore Thalassocalyce inconstans : revision of anatomy of the order Thalassocalycida

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    © 2009 The Authors. This article is distributed under the terms of the Creative Commons Attribution Noncommercial License. The definitive version was published in Marine Biology 156 (2009): 1049-1056, doi:10.1007/s00227-009-1149-6.Behavioral observations using a remotely operated vehicle (ROV) in the Gulf of California in March, 2003, provided insights into the vertical distribution, feeding and anatomy of the rare and delicate ctenophore Thalassocalyce inconstans. Additional archived ROV video records from the Monterey Bay Aquarium Research Institute of 288 sightings of T. inconstans and 2,437 individual observations of euphausiids in the Gulf of California and Monterey Canyon between 1989 and 2005 were examined to determine ctenophore and euphausiid prey depth distributions with respect to temperature and dissolved oxygen concentration [dO]. In the Gulf of California most ctenophores (96.9%) were above 350 m, the top of the oxygen minimum layer. In Monterey Canyon the ctenophores were more widely distributed throughout the water column, including the hypoxic zone, to depths as great as 3,500 m. Computer-aided behavioral analysis of two video records of the capture of euphausiids by T. inconstans showed that the ctenophore contracted its bell almost instantly (0.5 s), transforming its flattened, hemispherical resting shape into a closed bi-lobed globe in which seawater and prey were engulfed. Euphausiids entrapped within the globe displayed a previously undescribed escape response for krill (‘probing behavior’), in which they hovered and gently probed the inner surfaces of the globe with antennae without stimulating further contraction by the ctenophore. Such rapid bell contraction could be effected only by a peripheral sphincter muscle even though the presence of circumferential ring musculature was unknown for the Phylum Ctenophora. Thereafter, several live T. inconstans were collected by hand off Barbados and microscopic observations confirmed that assumption.Supported by the David and Lucile Packard Foundation and NOAA Grant #NA06OAR4600091

    Vertical distribution of fish larvae in the Canaries-African coastal transition zone, in summer

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    13 pages, 6 figures, 2 tables.-- Printed version published Jul 2006.This study reports the vertical distribution of fish larvae during the 1999 summer upwelling season in the Canaries-African Coastal Transition Zone (the Canaries-ACTZ). The transition between the African coastal upwelling and the typical subtropical offshore conditions is a region of intense mesoscale activity that supports a larval fish population dominated by African neritic species. During the study, the thermal stratification extended almost to the surface everywhere, and the surface mixed layer was typically shallow or non-existent. Upwelling occurred on the African shelf in a limited coastal sub-area of our sampling. The vertical distributions of the entire larval fish population, as well as of individual species, were independent of the seasonal thermocline. Fish larvae and mesozooplankton were concentrated at intermediate depths regardless of the thermocline position, probably because of its weak signature and spatial and temporal variability. Day/night vertical distributions suggest that some species did not perform diel vertical migration (DVM), whereas others showed either type I DVM or type II DVM. The opposing DVM patterns of different species compensate for each other resulting in no net DVM for the larval fish population as a whole.Fieldwork was carried out as part of the CANIGO project, funded by the EU, and of the "Pelagic (EU-CICYT 1FD97-1084)" project from the Spanish Ministry of Education and the European Union

    Meso- and macrozooplankton communities in the Weddell Sea, Antarctica

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    The present paper describes composition and abundance of meso- and macrozooplankton in the epipelagic zone of the Weddell Sea and gives a systematic review of encountered species regarding results of earlier expeditions. Material was sampled from 6 February to 10 March 1983 from RV Polarstern with a RMT 1+8 m (320 and 4500 μm mesh size). In agreement with topography and water mass distribution three distinct communities were defined, clearly separated by cluster analysis: The Southern Shelf Community has lowest abundances (approx. 9000 ind./1000 m3). Euphausia crystallorophias and Metridia gerlachei are predominating. Compared with the low overall abundance the number of regularly occurring species is high (55) due to many neritic forms. Herbivores and omnivores are dominating (58% and 35%). The North-eastern Shelf Community has highest abundances (about 31 000 ind./1000 m3). It is predominated by copepodites I–III of Calanus propinquus and Calanoides acutus (61%). The faunal composition is characterized by both oceanic and neritic species (64). Fine-filter feeders are prevailing (65%). The Oceanic Community has a mean abundance of approximately 23 000 ind./1000 m3, consisting of 61 species. Dominances are not as pronounced as in the shelf communities. Apart from abundant species like Calanus propinquus, Calanoides acutus, Metridia gerlachei, Oithona spp. and Oncaea spp. many typical inhabitants of the Eastwind Drift are encountered. All feeding types have about the same importance in the Oceanic Community
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