WHALES, WHALING, AND OCEAN ECOSYSTEMS ppt

[...]... at South Georgia and Signy Island, South Orkney Islands 224 17.7 Temporal trends in population size and size of krill in the diet of krill predators at Bird Island, South Georgia 225 17.8 Temporal trends in population size and proportion of krill in the diet for two krill predators at Bird Island, South Georgia 226 18.1 Sequential declines of pinnipeds and sea otters in Aleutians and Pribilof regions... 26.1 Predator-prey and potential competitive relationships between whales, groundfish, forage fish, benthic, and pelagic invertebrates 336 26.2 Strongly inverse abundance trends of predator and prey populations in the North Atlantic (Newfoundland Shelf) and North Pacific (Gulf of Alaska) 337 26.3 Trajectories of reconstructed fin and minke whale abundance, and catches, groundfish abundance, and forage fish abundance,... whales and whaling on ocean ecosystems in rigorous and compelling ways, and the challenges of this task are substantial For one, the events of interest are behind us We have relatively little information on ocean ecosystems from earlier periods when whales were abundant This difficulty is compounded by the facts that estimates of abundance for many of the whale populations are poorly known and that the ocean. .. during, and after the whaling era (Pauly et al 1998, 2002) The largely unknown food web effects of these fisheries, while potentially of great importance, confound our efforts to understand the effects of whales and whaling on ocean ecosystems The news is not all bad There are reasons to hope that significant progress will be made in understanding the ecological consequences of whales and whaling Ocean ecosystems. .. biomass and community structure in the monsoonal Arabian Sea Limnology and Oceanography 47: 1307–1323 Hairston, N G., F E Smith, and L B Slobedkin 1960 Community structure, population control, and competition American Naturalist 94: 421–425 Hall, J D., W E Cooper, and E E Werner 1970 An experimental approach to the production dynamics and structure of freshwater animal communities Limnology and Oceanography... on the flux of carbon and other nutrients via scavengers and other detritivores These food web pathways provide a roadmap for where and how to look for the influences of whales and whaling on ocean ecosystems The big question, of course, is whether or not any or all of these imagined pathways are important At one extreme, the great whales may be little more than passengers in ocean ecosystems largely under... pathways drive the structure and function of ocean ecosystems in significant ways Given the enormous number of whales that inhabited the world’s oceans before the whalers took them, the diversity of habitats they occupied and prey they consumed, and their large body sizes and high metabolic rates, it is easy to imagine that their losses were important ecologically Imagining and knowing, however, are very... most issues of substance, and feelings ran strong in a number of cases The most contentious issues were also the simplest and most fundamental things one would like to know about the great whales: How many existed before commercial whaling, and how many live in the oceans today? These numbers are essential for any theoretical evaluation of how whales and whaling influenced ocean ecosystems Another issue... effects on production, temperature, and the distribution and abundance of species (Mantua and Hare 2002; Chavez et al 2003) El Niño–Southern Oscillation (ENSO) events, which have been widely recognized and carefully studied only during the past several decades, exert strong influences on ocean ecosystems over even shorter time periods (Diaz and Pulwarty 1994) Furthermore, open ocean ecology seems to have focused... wolves in North America (McLaren and Peterson 1994; Ripple and Larsen 2000; Berger et al 2001); coyotes in southern California (Crooks and Soulé 1999); fishes in North American lakes (Carpenter and Kitchell 1993) and rivers (Power 1985); large carnivores in Venezuela (Terborgh et al 2001); and what Janzen and Martin (1982) termed “neotropical anachronisms”—dysfunctional ecosystems resulting from early . Brenda Konar 24 Whales, Whaling, and Ecosys- tems in the North Atlantic Ocean 314 Phillip J. Clapham and Jason S. Link 25 Sperm Whales in Ocean Ecosystems. Mills Endowment to the Center for Ocean Health, University of California, Santa Cruz. WHALES, WHALING, AND OCEAN ECOSYSTEMS Edited by JAMES A. ESTES DOUGLAS