eCite Digital Repository

MSC Low Trophic Level Project: Ecosystem impacts of fishing low trophic level groups Northern Humboldt Current case study

Citation

Marzloff, MP and Tam, J, MSC Low Trophic Level Project: Ecosystem impacts of fishing low trophic level groups Northern Humboldt Current case study, Marine Stewardship Council Science Series, Marine Stewardship Council Science Series, London, United Kingdom, 1 (2013) [Magazine Article]


Preview
PDF
Pending copyright assessment - Request a copy
3Mb
  

Abstract

Using two validated marine ecosystem models (Ecosim and the spatially-explicit individual-based model Osmose) applied to the highly productive Humboldt upwelling ecosystem, we simulate the ecological effects of fishing low trophic level groups (e.g. anchovy) on the Peruvian coastal ecosystem. Specifically, we ran some depletion experiments on anchovy, mesopelagic fish, macrozooplankton, sardine and jack mackerel. Because of different key assumptions behind the two frameworks (e.g. predetermined diet in Ecosim as opposed to size-based opportunistic predation in Osmose), the magnitude of responses to the depletion experiments is generally larger in Ecosim than in Osmose, where ecosystem structure and functioning is more plastic and resilient. However, across both models and out of currently fished species, the depletion of anchovy has the highest ecosystem impacts: while it benefits other low trophic level groups (e.g. mesopelagic fish and sardine) through reduced competition on plankton resources, it is likely to affect higher trophic levels (including jumbo squid, seabirds and sea mammals) negatively as strongly suggested by simulations with Ecosim. The depletions of the currently unfished low trophic level groups, such as mesopelagic fishes and macrozooplankton, are predicted to quite dramatically impact other model groups.

Item Details

Item Type:Magazine Article
Keywords:ecosystem modelling, effects of fishing low trophic level species, North Humboldt coastal ecosystem, Peruvian anchovy 'anchoveta', OSMOSE ecosystem model, Ecosim With Ecopath mode
Research Division:Environmental Sciences
Research Group:Ecological Applications
Research Field:Ecosystem Function
Objective Division:Environment
Objective Group:Ecosystem Assessment and Management
Objective Field:Ecosystem Assessment and Management of Marine Environments
Author:Marzloff, MP (Dr Martin Marzloff)
ID Code:103362
Year Published:2013
Deposited By:IMAS Research and Education Centre
Deposited On:2015-10-07
Last Modified:2015-10-07
Downloads:0

Repository Staff Only: item control page