Details:

Journal Title:
Ecological Modelling
Personal Author:
Whitehouse, George A. ; Aydin, Kerim Y.
Whitehouse, George A. ; Aydin, Kerim Y. Less -
NOAA Program & Office:
NMFS (National Marine Fisheries Service) ; AFSC (Alaska Fisheries Science Center) ; CICOES (Cooperative Institute for Climate, Ocean and Ecosystem Studies)
NMFS (National Marine Fisheries Service) ; AFSC (Alaska Fisheries Science Center) ; CICOES (Cooperative Institute for Climate, Ocean and Ecosystem Studies) Less -
Description:
Ecosystem modelling is a useful tool for exploring the potential outcomes of policy options and conducting experiments that would otherwise be impractical in the real world. However, ecosystem models have been limited in their ability to engage in the management of living marine resources due in part to high levels of uncertainty in model parameters and model outputs. Additionally, for multispecies or food web models, there is uncertainty about the predator-prey functional response, which can have implications for population dynamics. In this study, we evaluate the sensitivity of large marine food webs in Alaska to parameter uncertainty, including parameters that govern the predator-prey functional response. We use Rpath, an R implementation of the food web modeling program Ecopath with Ecosim (EwE), to conduct a series of mortality-based perturbations to examine the sensitivity and recovery time of higher trophic level groups in the eastern Chukchi Sea, eastern Bering Sea, and Gulf of Alaska. We use a Monte Carlo approach to generate thousands of plausible ecosystems by drawing parameter sets from the range of uncertainty around the base model parameters. We subjected the ecosystem ensembles to a series of mortality-based perturbations to identify which functional groups the higher trophic level groups are most sensitive to when their mortality was increased, whether the food webs returned to their unperturbed configurations following a perturbation, and how long it took to return to that state. In all three ecosystems, we found that the number of disrupted ensemble food webs was positively related to the biomass and the number of trophic links of the perturbed functional group, and negatively related to trophic level. The eastern Chukchi Sea was most sensitive to perturbations to benthic invertebrate groups, the eastern Bering Sea was most sensitive to shrimp and walleye pollock, and the Gulf of Alaska was most sensitive to shrimps, pelagic forage fish, and zooplankton. Recovery time to perturbations were generally less than 5 years in all three ecosystems. The recovery times when fish groups were perturbed were generally longer than when benthic invertebrates were perturbed, and recovery times were shortest when it was pelagic invertebrates. The single model ensemble approach produced simulation results that described a range of possible outcomes to the prescribed perturbations and provided a sense for how robust the results are to parameter uncertainty.
Keywords:
[+]
Bering Sea Chukchi Sea Ecosim Food Web Gulf Of Alaska Rpath
Source:
Ecological Modelling, 429
DOI:
https://doi.org/10.1016/j.ecolmodel.2020.109074
Document Type:
Journal Article
Place as Subject:
Alaska, Gulf of (Alaska) ; Bering Sea
Alaska, Gulf of (Alaska) ; Bering Sea Less -
Rights Information:
CC BY
Compliance:
Submitted
Main Document Checksum:
[+]
urn:sha256:27ee23943640425d3ada9bd4da26ee25064653e20fe75aafc8dd903a771392bd
Download URL:
https://repository.library.noaa.gov/view/noaa/30747/noaa_30747_DS1.pdf
File Type:

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