Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2016 Sep 15;11(9):e0162932.
doi: 10.1371/journal.pone.0162932. eCollection 2016.

Supporting Risk Assessment: Accounting for Indirect Risk to Ecosystem Components

Cathryn Clarke Murray  1   2 , Megan E Mach  1   3 , Rebecca G Martone  3 , Gerald G Singh  1 , Miriam O  4 , Kai M A Chan  1
Affiliations

Supporting Risk Assessment: Accounting for Indirect Risk to Ecosystem Components

Cathryn Clarke Murray et al. PLoS One. .

Abstract

The multi-scalar complexity of social-ecological systems makes it challenging to quantify impacts from human activities on ecosystems, inspiring risk-based approaches to assessments of potential effects of human activities on valued ecosystem components. Risk assessments do not commonly include the risk from indirect effects as mediated via habitat and prey. In this case study from British Columbia, Canada, we illustrate how such "indirect risks" can be incorporated into risk assessments for seventeen ecosystem components. We ask whether (i) the addition of indirect risk changes the at-risk ranking of the seventeen ecosystem components and if (ii) risk scores correlate with trophic prey and habitat linkages in the food web. Even with conservative assumptions about the transfer of impacts or risks from prey species and habitats, the addition of indirect risks in the cumulative risk score changes the ranking of priorities for management. In particular, resident orca, Steller sea lion, and Pacific herring all increase in relative risk, more closely aligning these species with their "at-risk status" designations. Risk assessments are not a replacement for impact assessments, but-by considering the potential for indirect risks as we demonstrate here-they offer a crucial complementary perspective for the management of ecosystems and the organisms within.

PubMed Disclaimer

Conflict of interest statement

The authors have declared that no competing interests exist.

Figures

Fig 1
Fig 1. Risk pathway (food web and biogenic habitat) for all species considered.
Dashed line = Obligate relationship (100% risk transfer).
Fig 2
Fig 2. Direct (dark) and indirect (light) median cumulative risk (10/90th Quantile Error bars) to each of the 17 ecosystem components evaluated.
Fig 3
Fig 3. Comparison of median indirect risk scores with direct risk score of each ecosystem component (left panel), and the number of prey and habitats used for a given ecosystem component’s indirect risk score (right panel).
X and Y-axis error bars represent 10% and 90% quantiles.
See this image and copyright information in PMC

References

    1. Halpern BS, Walbridge S, Selkoe KA, Kappel CV, Micheli F, D'Agrosa C, et al. A global map of human impact on marine ecosystems. Science. 2008. February 15;319(5865):948–52. 10.1126/science.1149345 - DOI - PubMed
    1. Halpern BS, Frazier M, Potapenko J, Casey KS, Koenig K, Longo C, et al. Spatial and temporal changes in cumulative human impacts on the world/'s ocean. Nat Commun. 2015. July 14;6. - PMC - PubMed
    1. Barnthouse LW, Suter GW. User's manual for ecological risk assessment Oak Ridge National Lab, TN (USA); 1986. March 1.
    1. Therriault TW, Herborg LM. A qualitative biological risk assessment for vase tunicate Ciona intestinalis in Canadian waters: using expert knowledge. ICES J Mar Sci 2008. July 1;65(5):781–7.
    1. Hobday AJ, Smith AD, Stobutzki IC, Bulman C, Daley R, Dambacher JM, et al. Ecological risk assessment for the effects of fishing. Fish Res. 2011. March 31;108(2):372–84.

LinkOut - more resources