Infaunal Invertebrates and Contaminants in Saint John Harbour, New Brunswick, Canada

Drs. Heather Hunt (University of New Brunswick) and Karen Kidd (McMaster University) have been leading a long-term project sampling infaunal invertebrates, sediment contaminants, and sediment characteristics at subtidal sites in Saint John Harbour, NB, Canada. This multi-year project is establishing baseline data that can be used to assess cumulative environmental effects in Saint John Harbour.

Samples were collected yearly from 2011-2013 and from 2017-2021 in Fall (October or November) at 6 reference sites (3 in the inner harbour and 3 in the outer harbour) as well as at 15 potentially impacted sites (not all potentially impacted sites were sampled in all years). Samples were collected using a 0.1 m2 Smith McIntyre grab sampler. Infaunal invertebrates were counted from a portion of the grab with a surface area of 321 cm2 and identified to species level. Concentrations of contaminants (metals and other elements; polycyclic aromatic hydrocarbons until 2018, and polychlorinated biphenyls in 2011) were measured in surface sediment (upper 5 cm). Percent organic content (loss on ignition (LOI) at 550 and 950°C), total organic carbon (calculated from LOI), percent moisture, and % composition by grain size Wentworth size classes of the sediment were determined. See Van Geest et al. (2015) and Guerin et al. (2023) for detailed field and laboratory methods.

Fisheries and Oceans Canada and the Port of Saint John provided funding to collect this data. This project is part of the Coastal Environmental Baseline Program Initiative under the Oceans Protection Plan of Fisheries and Oceans Canada.

REFERENCE:

• Guerin, A. J., Kidd, K. A., Maltais, M.-J., Mercer, A., & Hunt, H. L. (2024). Spatial patterns of sediment contamination and their influence on benthic infaunal communities in a highly tidal and industrial estuary in Atlantic Canada. Marine Pollution Bulletin, 198, 115872.

• Guerin, A. J., K. A. Kidd, M.-J. Maltais, A. Mercer, and H. L. Hunt. 2023. Temporal and spatial trends in benthic infauna and potential drivers, in a highly tidal estuary in Atlantic Canada. Estuaries and Coasts. https://doi.org/10.1007/s12237-023-01222-w.

• Van Geest, J. L., K. A. Kidd, H. L. Hunt, M.-J. Abgrall, M.-J. Maltais, and A. Mercer. 2015. Development of baseline data for long-term monitoring of sediment conditions at reference sites in Saint John Harbour, New Brunswick: benthic infaunal invertebrates and sediment contaminants 2011-2013. Canadian Manuscript Report of Fisheries and Aquatic Sciences 3076: 97.

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