<?xml version="1.0" encoding="UTF-8"?><xml><records><record><source-app name="Biblio" version="6.x">Drupal-Biblio</source-app><ref-type>6</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Dalsgaard, J.</style></author><author><style face="normal" font="default" size="100%">Jarre-Teichmann, A.</style></author><author><style face="normal" font="default" size="100%">Walters, C.</style></author><author><style face="normal" font="default" size="100%">Pauly, D.</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">An approach to the modelling of persistent pollutants in marine ecosystems</style></title></titles><keywords><keyword><style  face="normal" font="default" size="100%">ANE,</style></keyword><keyword><style  face="normal" font="default" size="100%">Atlantic cod</style></keyword><keyword><style  face="normal" font="default" size="100%">Atlantic herring</style></keyword><keyword><style  face="normal" font="default" size="100%">Baltic Sea</style></keyword><keyword><style  face="normal" font="default" size="100%">biomass</style></keyword><keyword><style  face="normal" font="default" size="100%">Chernobyl accident</style></keyword><keyword><style  face="normal" font="default" size="100%">Clupea harengus</style></keyword><keyword><style  face="normal" font="default" size="100%">coral reefs</style></keyword><keyword><style  face="normal" font="default" size="100%">food consumption</style></keyword><keyword><style  face="normal" font="default" size="100%">food webs</style></keyword><keyword><style  face="normal" font="default" size="100%">Fucus</style></keyword><keyword><style  face="normal" font="default" size="100%">Gadus morhua</style></keyword><keyword><style  face="normal" font="default" size="100%">marine</style></keyword><keyword><style  face="normal" font="default" size="100%">Mytilus edulis</style></keyword><keyword><style  face="normal" font="default" size="100%">Pollution monitoring</style></keyword><keyword><style  face="normal" font="default" size="100%">Q5 01504 Effects on organisms</style></keyword><keyword><style  face="normal" font="default" size="100%">Radioactivity</style></keyword><keyword><style  face="normal" font="default" size="100%">vesiculosus</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">1998</style></year></dates><publisher><style face="normal" font="default" size="100%">ICES</style></publisher><pub-location><style face="normal" font="default" size="100%">Copenhagen (Denmark)</style></pub-location><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">An approach for modelling trophic transfer of persistent pollutants within aquatic food webs is described, using radioactivity as an example. This involves constructing a mass-balance trophic model of the ecosystem in question, applying the Ecopath software, which uses the biomass, production/biomass, and food consumption rates of the various functional groups in the ecosystem as its basic inputs, along with a diet matrix. The Ecopath outputs used in this study are the estimates of biomass flow between functional groups, and the corresponding predation mortality matrix, whose columns represent the intake of, and the rows the losses of biomass from a compartment. A set of first order differential equations, relating the intake and loss of biomass to the amounts of radioactivity in the compartments, are then set up. There is additional accounting for loss of radioactivity due to physical decay of the radioisotopes. The equations are integrated over time and calibrated by minimizing the sum of squared deviations between the observed and predicted levels of radioactivity, thus mapping the transfers of radioactivitiy onto the transfers of biomass. The method is demonstrated through (a) a case study of beta radioactivity in a coral reef ecosystem used as testing ground for nuclear weapons (Enewetak Atoll, Marshall Islands, Micronesia), and (b) preliminary data on '3'Cs in the upper trophic levels of the Central Baltic Sea ecosystem, following the 1986 Chernobyl accident. The results support the applicability of the approach, for which a general solution, involving an `importance-sampling' routine, is proposed.</style></abstract><accession-num><style face="normal" font="default" size="100%">4644100</style></accession-num><notes><style face="normal" font="default" size="100%">International Counc. for the Exploration of the Sea Copenhagen (Denmark) Theme Sess. on Recovery and Protection of Marine Habitats...Conference Counc. Meet. of the Int. Counc. for the Exploration of the Sea, Cascais (Portugal), 16-19 Sep 1998ICES, Copenhagen (Denmark), 1998, 16 ppIces-cm-1998/v:10EnglishBook Monograph; Conference</style></notes><auth-address><style face="normal" font="default" size="100%">University of British Columbia, Fisheries Centre 2204 Main Mall, Vancouver, BC V6T 1Z4 Canada; E-mail: johanne@fisheries.com</style></auth-address></record></records></xml>