Now showing items 1-12 of 12

  • Analysis of energy flow in US GLOBEC ecosystems using end-to-end models 

    Ruzicka, James J.; Steele, John H.; Gaichas, Sarah K.; Ballerini, Tosca; Gifford, Dian J.; Brodeur, Richard D.; Hofmann, Eileen E. (The Oceanography Society, 2013-12)
    End-to-end models were constructed to examine and compare the trophic structure and energy flow in coastal shelf ecosystems of four US Global Ocean Ecosystem Dynamics (GLOBEC) study regions: the Northern California Current, ...
  • Are there eco-metrics for fisheries? 

    Steele, John H. (2005-11-03)
    Ecosystem based management of marine resources is a worthy ideal. At present, however, the science is unable to measure and relate the fundamental concepts of diversity, productivity and resilience required for management ...
  • Balancing end-to-end budgets of the Georges Bank ecosystem 

    Steele, John H.; Collie, Jeremy S.; Bisagni, James J.; Gifford, Dian J.; Fogarty, Michael J.; Link, Jason S.; Sullivan, B. K.; Sieracki, Michael E.; Beet, Andrew R.; Mountain, David G.; Durbin, Edward G.; Palka, D.; Stockhausen, W. T. (2007-05-09)
    Oceanographic regimes on the continental shelf display a great range in the time scales of physical exchange, biochemical processes and trophic transfers. The close surface-to-seabed physical coupling at intermediate scales ...
  • Comparing species and ecosystem-based estimates of fisheries yields 

    Steele, John H.; Gifford, Dian J.; Collie, Jeremy S. (2011-06)
    Three methods are described to estimate potential yields of commercial fish species: (i) single-species calculation of maximum sustainable yields, and two ecosystem-based methods derived from published results for (ii) ...
  • Constructing end-to-end models using ECOPATH data 

    Steele, John H.; Ruzicka, James J. (2011-03)
    The wide availability of ECOPATH data sets provides a valuable resource for the comparative analysis of marine ecosystems. We show how to derive a bottom-up transform from the top-down ECOPATH; couple this to a simple NPZD ...
  • Construction kits or virtual worlds; management applications of E2E models 

    Steele, John H.; Aydin, Kerim; Gifford, Dian J.; Hofmann, Eileen E. (2011-10)
    We review briefly the diversity of modeling activity that comes under the rubric of end-to-end (E2E) models, but the focus of this paper – of joint concern to researchers and to managers - is on applications to management ...
  • Dividing up the pie : whales, fish, and humans as competitors 

    Ruzicka, James J.; Steele, John H.; Ballerini, Tosca; Gaichas, Sarah K.; Ainley, David G. (2013-04-29)
    Similarly structured food web models of four coastal ecosystems (Northern California Current, Central Gulf of Alaska, Georges Bank, southwestern Antarctic Peninsula) were used to investigate competition among whales, ...
  • End-to-end foodweb control of fish production on Georges Bank 

    Collie, Jeremy S.; Gifford, Dian J.; Steele, John H. (2009-05-06)
    The ecosystem approach to management requires the productivity of individual fish stocks to be considered in the context of the entire ecosystem. In this paper, we derive an annual end-to-end budget for the Georges Bank ...
  • Productivity and linkages of the food web of the southern region of the western Antarctic Peninsula continental shelf 

    Ballerini, Tosca; Hofmann, Eileen E.; Ainley, David G.; Daly, Kendra L.; Marrari, Marina; Ribic, Christine A.; Smith, Walker O.; Steele, John H. (2013-11-23)
    The productivity and linkages in the food web of the southern region of the west Antarctic Peninsula continental shelf were investigated using a multi-trophic level mass balance model. Data collected during the Southern ...
  • Reconciling end-to-end and population concepts for marine ecosystems 

    Steele, John H.; Gifford, Dian J. (2010-05-06)
    The inherent complexities in the structure and dynamics of marine food webs have led to two major simplifying concepts, a species-centric approach focused on physical processes driving the population dynamics of single ...
  • Understanding patterns and processes in models of trophic cascades 

    Heath, Michael R.; Speirs, Douglas C.; Steele, John H. (John Wiley & Sons, 2013-12-16)
    Climate fluctuations and human exploitation are causing global changes in nutrient enrichment of terrestrial and aquatic ecosystems and declining abundances of apex predators. The resulting trophic cascades have had profound ...
  • Why compare marine ecosystems? 

    Murawski, Steven A.; Steele, John H.; Taylor, Phillip; Fogarty, Michael J.; Sissenwine, Michael P.; Ford, Michael; Suchman, Cynthia (Oxford University Press, 2009-08-30)
    Effective marine ecosystem-based management (EBM) requires understanding the key processes and relationships controlling the aspects of biodiversity, productivity, and resilience to perturbations. Unfortunately, the scales, ...