Drifter studies in warm core rings

The results of multiple deployments of surface drifters in warm core rings of the Gulf Stream are presented. Four satellite drifters (tracked by the Argos system) were deployed on nine separate occasions and two LORAN-C drifters (operated by the University of Miami) were deployed three times. Drifter studies were conducted during four cruises aboard the R/V Endeavor in 1982 in conjunction with the Warm Core Rings Experiment and one cruise of the USNS Bartlett in January 1983 which was sponsored by the Office of Naval Research. Translational velocities and periods of rotation are provided for two rings: 82B and 82H.National Science Foundation under grant OCE80-1698

Observations and Predictions of Arctic Climatic Change: Potential Effects on Marine Mammals

Recent analyses have revealed trends over the past 20-30 years of decreasing sea ice extent in the Arctic Ocean coincident with warming trends. Such trends may be indicative of the polar amplifications of warming predicted for the next several decades in response to increasing atmospheric CO2. We have summarized these predictions and nonuniform patterns of arctic climate change in order to address their potential effects on marine mammals. Since recent trends in sea ice extent are nonuniform, the direct and indirect effects on marine mammals are expected to vary geographically. Changes in the extent and concentration of sea ice may alter the seasonal distributions, geographic ranges, patterns of migration, nutritional status, reproductive success, and ultimately the abundance and stock structure of some species. Ice-associated seals, which rely on suitable ice substrate for resting, pupping, and molting, may be especially vulnerable to such changes. As recent decreases in ice coverage have been more extensive in the Siberian Arctic (60 E-180 E) than in the Beaufort Sea and western sectors, we speculate that marine mammal populations in the Siberian Arctic may be among the first to experience climate-induced geographic shifts or altered reproductive capacity due to persistent changes in ice extent. Alteration in the extent and productivity of ice-edge systems may affect the density and distribution of important ice-associated prey of marine mammals, such as arctic cod, Boreogadus saida, and sympagic ("with ice") amphipods. Present climate models, however, are insufficient to predict regional ice dynamics, winds, mesoscale features, and mechanisms of nutrient resupply, which must be known to predict productivity and trophic response. Therefore, it is critical that mesoscale process-oriented studies identify the biophysical coupling required to maintain suitable prey availability and ice-associated habitat for marine mammals on regional arctic scales. Only an integrated ecosystems approach can address the complexity of factors determining reproductivity and cascading trophic dynamics in a warmer Arctic. This approach, integrated with monitoring of key indicator species (e.g., bowhead whale, ringed seal, and beluga), should be a high priority.Des analyses récentes ont fait apparaître des tendances, au cours des 20 à 30 dernières années, à la diminution de l'étendue des glaces de mer dans l'océan Arctique qui coïncident avec des tendances au réchauffement. Ces tendances pourraient être symptomatiques de l'amplification polaire du réchauffement prédit pour les prochaines décennies suite à la hausse de CO2 dans l'atmosphère. Cet article offre un résumé de ces prédictions et des schémas non uniformes de changement climatique dans l'Arctique, en vue d'examiner leurs retombées potentielles sur les mammifères marins. Vu que les tendances récentes de l'étendue des glaces de mer ne sont pas uniformes, les retombées directes et indirectes sur les mammifères marins devraient varier sur le plan géographique. Des changements dans l'étendue et la concentration de la glace de mer peuvent modifier les distributions saisonnières, les aires géographiques, les schémas de migration, l'état nutritionnel, le succès de la reproduction, et, en fin de compte, l'abondance et la structure de la population de certaines espèces. Les phoques associés à la glace, qui dépendent d'un support glaciel pour le repos, la mise bas et la mue, seraient particulièrement affectés par de tels changements. Vu que les diminutions récentes de couverture de glace ont été plus importantes dans l'Arctique sibérien (de 60° E. à 180° E.) que dans la mer de Beaufort et les secteurs occidentaux, on pense que les populations de mammifères marins dans l'Arctique sibérien pourraient être les premières à faire l'expérience de variations géographiques dues au climat ou d'une modification de leur capacité de reproduction causée par des changements chroniques dans l'étendue de glace. Une modification de l'étendue et de la productivité des systèmes de la marge glaciaire pourrait affecter la densité et la distribution de proies associées à la glace importantes pour les mammifères marins, comme la morue arctique Boreogadus saida et les amphipodes vivant en contact avec la glace. Les modèles climatologiques actuels ne sont toutefois pas en mesure de prédire les dynamiques régionales de la glace, les vents, les caractéristiques à mésoéchelle ainsi que les mécanismes de réapprovisionnement en éléments nutritifs, tous éléments que l'on doit connaître pour pouvoir prédire la productivité et la réponse trophique. Il est par conséquent critique que des études à mésoéchelle axées sur les processus identifient les interactions du milieu naturel nécessaires pour maintenir, à des échelles arctiques régionales, une disponibilité de proies et un habitat associé à la glace appropriés aux mammifères marins. Seule une approche intégrée des écosystèmes peut envisager la complexité des facteurs déterminant la productivité et les dynamiques trophiques qui en résultent dans un Arctique plus tempéré. Cette approche, intégrée avec la surveillance d'espèces indicateurs clés (p. ex., la baleine boréale, le phoque annelé et le bélouga), devrait constituer une haute priorité

Physical and biological variables affecting seabird distributions during the upwelling season of the northern California Current

Author Posting. © The Authors, 2004. This is the author's version of the work. It is posted here by permission of Elsevier B. V. for personal use, not for redistribution. The definitive version was published in Deep Sea Research Part II: Topical Studies in Oceanography 52 (2005): 123-143, doi:10.1016/j.dsr2.2004.08.016.As a part of the GLOBEC-Northeast Pacific project, we investigated variation in the abundance of marine birds in the context of biological and physical habitat conditions in the northern portion of the California Current System (CCS) during cruises during the upwelling season 2000. Continuous surveys of seabirds were conducted simultaneously in June (onset of upwelling) and August (mature phase of upwelling) with ocean properties quantified using a towed, undulating vehicle and a multi-frequency bioacoustic instrument (38-420 kHz). Twelve species of seabirds contributed 99% of the total community density and biomass. Species composition and densities were similar to those recorded elsewhere in the CCS during earlier studies of the upwelling season. At a scale of 2-4 km, physical and biological oceanographic variables explained an average of 25% of the variation in the distributions and abundance of the 12 species. The most important explanatory variables (among 14 initially included in each multiple regression model) were distance to upwelling-derived frontal features (center and edge of coastal jet, and an abrupt, inshore temperature gradient), sea-surface salinity, acoustic backscatter representing various sizes of prey (smaller seabird species were associated with smaller prey and the reverse for larger seabird species), and chlorophyll concentration. We discuss the importance of these variables in the context of what factors may be that seabirds use to find food. The high seabird density in the Heceta Bank and Cape Blanco areas indicate them to be refuges contrasting the low seabird densities currently found in most other parts of the CCS, following decline during the recent warm regime of the Pacific Decadal Oscillation.Support from National Science Foundation Grant OCE-0001035, National Oceanic and Atmospheric Administration (NOAA)/Woods Hole Oceanographic Institution-CICOR Grant NA17RJ1223 is gratefully acknowledged

Finishing the euchromatic sequence of the human genome

The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead

Modeling the relationship of Antarctic minke whales to major ocean boundaries

The population size of Antarctic minke whales Balaenoptera bonaerensis has been changing simultaneously with profound changes in the physics, i. e., mesopredator habitat features, of the Southern Ocean. Although the two trends may not be related, distinguishing among the factors responsible requires a better understanding of minke whale habitat preferences. For the first time at a large geographic scale, i. e., between 140° E and 35° W, we use data not constrained by vessels needing to avoid sea ice to model the habitat affinities of this pagophilic mesopredator. Using Maxent, we modeled minke whale proximity to the Antarctic Shelf Break Front (ASBF) and the southern boundary of Antarctic Circumpolar Current (sbACC), as well as association with sea ice, given that global climate change is altering the positions or intensity of these features. We also included water depth and chlorophyll (proxy for productivity) as variables. Minke whale presence data were gathered using strip and line census on 55 cruises on board icebreakers during late spring and summer, 1976-2005. The most important variable was distance to ASBF, followed by water depth and sea-ice concentration. That is, found principally in waters south of the sbACC during summer, minke whales were most abundant near the outer edge of the continental shelf (shallow depth), including areas heavily covered by sea ice. We propose that as the sbACC moves south and sea ice disappears, as projected by global climate models, minke whale habitat will shrink, and likely intra- and inter-specific competition will increase

Cruise Event Logs from 15 vessels for 116 U.S. GLOBEC cruises from 1997-2004 in the Northeast Pacific and Gulf of Alaska areas (NEP program)

Dataset: eventlogsCruise Event Logs from 15 vessels for 116 U.S. GLOBEC cruises from 1997-2004 in the Northeast Pacific and Gulf of Alaska areas For a complete list of measurements, refer to the full dataset description in the supplemental file 'Dataset_description.pdf'. The most current version of this dataset is available at: https://www.bco-dmo.org/dataset/2341NSF Division of Ocean Sciences (NSF OCE) OCE-0000733, NSF Division of Ocean Sciences (NSF OCE) OCE-9732386, National Oceanic and Atmospheric Administration (NOAA) NA67RJ0151 (NEP), National Oceanic and Atmospheric Administration (NOAA) NA86OP0589 (NEP

Cruise Event Logs from 15 vessels for 116 U.S. GLOBEC cruises from 1997-2004 in the Northeast Pacific and Gulf of Alaska areas (NEP program)

Dataset: eventlogsCruise Event Logs from 15 vessels for 116 U.S. GLOBEC cruises from 1997-2004 in the Northeast Pacific and Gulf of Alaska areas For a complete list of measurements, refer to the full dataset description in the supplemental file 'Dataset_description.pdf'. The most current version of this dataset is available at: https://www.bco-dmo.org/dataset/2341NSF Division of Ocean Sciences (NSF OCE) OCE-0000733, NSF Division of Ocean Sciences (NSF OCE) OCE-9732386, National Oceanic and Atmospheric Administration (NOAA) NA67RJ0151 (NEP), National Oceanic and Atmospheric Administration (NOAA) NA86OP0589 (NEP