An ecosystem modelling approach to deriving viable harvest strategies for multispecies management of the Northern Gulf of California

2009 ◽  
Vol 19 (4) ◽  
pp. 384-397 ◽  
Author(s):  
Diego Lercari ◽  
Francisco Arreguín-Sánchez
2007 ◽  
Vol 56 (6) ◽  
pp. 19-27 ◽  
Author(s):  
F. De Laender ◽  
K.A.C. De Schamphelaere ◽  
C.R. Janssen ◽  
P.A. Vanrolleghem

Ecological effects of chemicals on ecosystems are the result of direct effects of the chemical, determined in single-species toxicity testing, and indirect effects due to ecological interactions between species. Current experimental methods to account for such interactions are expensive. Hence, mathematical models of ecosystems have been proposed as an alternative. The use of these models often requires extensive calibration, which hampers their use as a general tool in ecological effect assessments. Here we present a novel ecosystem modelling approach which assesses effects of chemicals on ecosystems by integrating single-species toxicity test results and ecological interactions, without the need for calibration on case-specific data. The methodology is validated by comparing predicted ecological effects of copper in a freshwater planktonic ecosystem with an experimental ecosystem data set. Two main effects reflected by this data set (a decrease of cladocerans and an increase of small phytoplankton) which were unpredictable from single-species toxicity test results alone, were predicted accurately by the developed model. Effects on populations which don't interact directly with other populations, were predicted equally well by single-species toxicity test results as by the ecosystem model. The small amount of required data and the high predictive capacity can make this ecosystem modelling approach an efficient tool in water quality criteria derivation for chemicals.


2011 ◽  
Vol 68 (7) ◽  
pp. 1403-1416 ◽  
Author(s):  
Didier Gascuel ◽  
Sylvie Guénette ◽  
Daniel Pauly

Abstract Gascuel, D., Guénette, S., and Pauly, D. 2011. The trophic-level-based ecosystem modelling approach: theoretical overview and practical uses. – ICES Journal of Marine Science, 68: 1403–1416. A trophic-level (TL)-based ecosystem modelling approach is presented, where ecosystem functioning is modelled as a flow of biomass up the foodweb through predation and ontogenetic processes. The approach, based on simple equations derived from fluid dynamics, provides insights into ecosystem functioning and the impact of fishing. A virtual ecosystem is simulated and the model shown to be capable of mimicking the effects of various exploitation patterns on ecosystem biomass expected from the theory. It provides the theoretical basis to explain complex patterns, such as cascading effects, maximum sustainable ecosystem yield, and fishing down the foodweb. The utility of the TL-based approach as a practical tool for determining fishing impacts in specific ecosystems is illustrated using the Guinean ecosystem as a case study, showing how current fishing effort levels led to full exploitation of higher TLs, confirming and generalizing previous single-species assessment results. Finally, catch trophic spectrum analysis is presented to show that it provides reliable biomass estimates when catches per TL and primary production are known.


Chemosphere ◽  
2008 ◽  
Vol 71 (3) ◽  
pp. 529-545 ◽  
Author(s):  
Frederik De Laender ◽  
Karel A.C. De Schamphelaere ◽  
Peter A. Vanrolleghem ◽  
Colin R. Janssen

2012 ◽  
Vol 166-167 ◽  
pp. 188-200 ◽  
Author(s):  
Anna Maria Jönsson ◽  
Leif Martin Schroeder ◽  
Fredrik Lagergren ◽  
Olle Anderbrant ◽  
Benjamin Smith

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