FIPEX v10.4: An ArcGIS Desktop Add-in for assessing impacts of fish passage barriers and longitudinal connectivity of rivers

Oldford, G., Cote, D., Kehler, D. G., Riefesel, G. R., & Wiersma, Y. F. (2023). FIPEX v10. 4: An ArcGIS Desktop Add-in for assessing impacts of fish passage barriers and longitudinal connectivity of rivers. SoftwareX, 101469.

FIPEX v10.4 is designed to decrease the time required to assess the individual and cumulative effects of river barriers to fish passage and to assess river connectivity from headwaters to outflow (i.e., longitudinal connectivity). FIPEX is developed as an open source VB.NET ‘Add-In’ for ArcGIS Desktop (v10.4+) with an option to run R statistical software scripts to calculate the Dendritic Connectivity Index (DCI).

Published in SoftwareX, 2023

Advances in spatial‐temporal coastal and marine ecosystem modeling using Ecospace (Book Chapter in: Earth Systems and Environmental Sciences)

de Mutsert, K., Coll, M., Steenbeek, J., Ainsworth, C., Buszowski, J., Chagaris, D., Christensen, V., Heymans, S. J. J., Lewis, K. A., Libralato, S., Oldford, G., Piroddi, C., Romagnoni, G., Serpetti, N., Spence, M. A., & Walters, C. (2023). Advances in spatial‐temporal coastal and marine ecosystem modeling using Ecospace. In Reference Module in Earth Systems and Environmental Sciences. Elsevier.

The advancement of ecosystem-based management of aquatic ecosystems should no longer be limited by a lack of tools. However, a lack of comprehensive understanding of the capabilities of existing tools can form a barrier for uptake. With this chapter, we strive to more fully describe one of these tools, the spatial-temporal ecosystem model Ecospace, which is part of the Ecopath with Ecosim (EwE) ecosystem modeling approach and software. Changes and developments in Ecospace have been faster than documented in recent years. Many features of Ecospace, including the most recent that have not been described before, are detailed in this chapter. The applications highlighted showcase the multitude of uses of the spatial application of EwE, which, especially due to expansion of the capabilities to incorporate the effects of environmental change, has facilitated its use outside of fisheries management to protection of biodiversity, ecosystem restoration and environmental impact assessment. New applications of Ecospace can truly contribute to advance modeling of cumulative impacts and management alternatives in marine ecosystems, and can be of interest to inform sectoral and intersectoral policy.

Published in Earth Systems and Environmental Sciences, 2023

Requirements and availability of prey for northeastern pacific southern resident killer whales

Couture, F., Oldford, G., Christensen, V., Barrett-Lennard, L., & Walters, C. (2022). Requirements and availability of prey for northeastern pacific southern resident killer whales. Plos one, 17(6), e0270523.

The salmon-eating Southern Resident killer whale (SRKW) (Orcinus orca) population currently comprises only 73 individuals, and is listed as ‘endangered’ under the Species at Risk Act in Canada. Recent evidence suggests that the growth of this population may be limited by food resources, especially Chinook salmon (Oncorhynchus tshawytscha). We present spatio-temporal bioenergetics model for SRKW in the Salish Sea and the West Coast of Vancouver Island from 1979–2020 with the objective of evaluating how changes in the abundance, age-structure, and length-at-age of Chinook salmon populations has influenced the daily food consumption of the SRKW population. Our model showed that the SRKW population has been in energetic deficit for six of the last 40 years. Our results also suggested that the abundance of age-4 and age-5 Chinook salmon are significant predictors of energy intake for SRKW. We estimated that the annual consumption (April-October) of Chinook salmon by the whales between 1979 and 2020 ranged from 166,000 216,300. Over the past 40 years, the model estimated that the contribution in the predicted SRKW diet of Chinook salmon originating from the Columbia River has increased by about 34%, and decreased by about 15% for Chinook salmon stocks originating from Puget Sound. Overall, our study provides an overview of the requirements and availability of prey for SRKW over the last 40 years, while supporting the hypothesis that SRKW were limited by prey abundance in the study period.

Published in PLOS ONE, 2022

Reconstructing the Pre-European Contact Shoreline of Burrard Inlet (Vancouver, BC, Canada) (2022)

Taft, S., Oldford, G. , M.I., Lilley, P.L., Oetterich, S.B., Morin, J., George, M., George, M., and Christensen, V. . "Reconstructing the Pre-European Contact Shoreline of Burrard Inlet (Vancouver, BC, Canada) using participatory mapping and a two-eyed seeing approach " Institute for Oceans & Fisheries (Fisheries Centre) Research Reports. Vol XX, March 2022

Throughout Canada’s history, colonial settlement and development has greatly altered landscapes and impacted ecosystems through resource extraction, infrastructure development, urbanization, and industrial activity. In many locations, these impacts have occurred and accumulated over decades and centuries, with severe, long-term effects on Indigenous communities, and the ecosystems and physical environments that are intimately tied to traditional cultural practices and lifestyles. Yet despite the significant impacts on Indigenous peoples and ecosystems, there are often limited Western or Euro-Canadian records or documentation focused on these cumulative effects. Together, different types of information from early Euro-Canadian settlers and Indigenous Knowledge can establish a strong understanding of historical environmental conditions, and the pace and magnitude of total regional change since European contact. This method of using both Western and Indigenous ways of knowing is referred to as Two-Eyed Seeing (Bartlett et al. 2012) and has wide applications, including for fisheries management and historical research across Canada (Giles et al. 2016, Mantyka-Pringle et al. 2017, Abu et al. 2019). Importantly, Two-Eyed Seeing can focus on specific places and impacts to more accurately assess long-term change in a region. In this paper, we use this approach to quantify shoreline change within Burrard Inlet, the centre of Tsleil-Waututh Nation’s territory, and the main harbour of metropolitan Vancouver and Canada’s largest port.

Published in UBC Institute for Oceans and Fisheries (Fisheries Centre) Research Reports, 2022

Making spatial-temporal marine ecosystem modelling better

Steenbeek J, Buszowski J, Chagaris D, Christensen V, Coll M, Fulton EA, Katsanevakis S, Lewis KA, Mazaris AD, Macias D, de Mutsert K, Oldford G, Pennino MG, Piroddi C, Romagnoni G, Serpetti N, Shin YJ, Spence MA, Stelzenmuller V. "Making spatial-temporal marine ecosystem modelling better - a perspective " Environmental Modelling and Software. Vol 145, November 2021

Marine Ecosystem Models (MEMs) are rarely systematically validated and calibrated. This can potentially undermine the credibility and uptake of model output in the policy arenas where it is so direly needed. We identify the main technical hurdles that prevent the MEM community from moving forward, and specify a resolving framewo

Published in Environmental Modelling and Software, 2021

End-to-End Spatial Ecosystem Modeling in Support of the Salish Sea Marine Survival Program (dissertation - in prep)

Oldford G, Christensen VC, Buszowski J, Steenbeek J, Hunt B, Pearsall I, Walters CW (in prep). "End-to-End Spatial Ecosystem Modeling in Support of the Salish Sea Marine Survival Program " dissertation. (in prep)

My PhD dissertation involves (1) acquiring and prepping a large amount of ecological and human activities data, (2) co-developing a hydrodynamic-biogeochemical model, (3) development of a spatial-temporal ecosystem model, (4) and application of the model complex to investigate declining trends in marine survival of coho and Chinook salmon in the Salish Sea.

Published in PhD Research, 2021

Depensatory predation may cause catastrophic changes in herring populations (submitted)

Christensen V, Oldford G, Licandeo R, Walters CW (2020). "Depensatory mortality in British Columbia herring populations due to predation by Steller sea lions" PNAS. (submitted)

We showed that including depensatory predation rates caused a fundamental change in the fish population dynamics compared with the traditional approach of ignoring predation scenarios in stock assessments. Increases in pinniped abundance following a history of heavy exploitation make it progressively more difficult to avoid fish stock collapses, and there is evidence of similar impacts for a variety of small pelagic and demersal stocks around the world.

Published in TBD, 2020

Opinion: It’s time to call out denialism.

Oldford, G. (2020). "It’s time to call out denialism — on racism and on climate change." The National Observer. June 4, 2020.

Everyone is entitled to their opinion. But newspapers — especially mass media outlets — should be held accountable when they propagandize dangerous denialism instead of presenting facts

Published in The National Observer, 2020

Technical aspects of Marine Spatial Planning in Burrard Inlet (tech report)

Brownlee G, Lang C, Oldford G, Virgen-Urceley, A (2020). "Technical aspects of Marine Spatial Planning in Burrard Inlet" Tech Report. Tsleil Waututh First Nation

we prepared this report for the TWN by reviewing and synthesizing academic and other available literature from around the world. We focused on three critical aspects of MSP: (1) Data Needs and Management, (2) DSTs and Models, and (3) Outreach and Communication.

Published in TWN, 2020

Dams, culverts, and cumulative effects: quantifying cumulative effects of barriers to longitudinal connectivity on three rivers in Nova Scotia, Canada. (accepted; in revision)

Oldford GL, Duinker P.N., Gunn E.A., Kehler D.G. (TBD). "Dams, Culverts, and Cumulative Effects: Quantifying Cumulative Effects of Barriers to Longitudinal Connectivity on Three Rivers in Nova Scotia, Canada." River Research & Applications. (in revision) TBD

(underway - accepted with minor revisions)
We present a suite of approaches that can be used to quantify and characterize the cumulative effects of different types of riverine barriers. We demonstrate these methods on three river systems in Nova Scotia, Canada, each heavily fragmented by road culverts and dams associated with hydroelectric and other development.

Published in River Research and Applications, 2018

Assessing the contribution of established protected areas towards meeting MPA network objectives in the Northern Shelf Bioregion

Martone R.G., G. Oldford , C. McDougall, J. Cristiani, A. Chow, C. Robb, E. Rubidge, K.S.P. Gale, L. Chaves, E. Damjkar, P. Mahaux, S. Ban. (2018). "Assessing Contribution of Established Protected Areas Towards Meeting MPA Network Objectives in the Northern Shelf Bioregion[in Chandler, P.C., S.A. King, J. Boldt (2018). State of the Physical, Biological and Selected Fishery Resources of Pacific Canadian Marine Ecosystems in 2017. Canadian Technical Report of Fisheries and Aquatic Sciences. No. 3266]" Canadian Technical Report of Fisheries and Aquatic Sciences. 3266

We present an approach for determining how effectively the existing MPAs meet the ecological conservation priority targets in Canada’s Northern Shelf Bioregion, taking potential cumulative impacts from human activities into consideration

Published in Canadian Technical Report of Fisheries and Aquatic Sciences, 2018

Informing Watershed Connectivity Barrier Prioritization Decisions: A Synthesis.

McKay SK, Cooper AR, Diebel MW, Elkins D, Oldford G, Roghair C, Wieferich D. (2016). "Informing Watershed Connectivity Barrier Prioritization Decisions: A Synthesis.." River Research and Applications. 33(6). (

This paper synthesizes 46 watershed-scale barrier planning studies and presents a procedure to guide barrier prioritization associated with connectivity for aquatic organisms.

Published in River Research and Applications, 2016

Spatial Optimisation of River Restoration Planning in Nova Scotia: Masters Thesis.

Oldford G (2013). "Spatial Optimisation of River Restoration Planning in Nova Scotia, Canada [Thesis]" School for Resource & Environmental Studies. (

River restoration is believed to have the greatest chance of success when action is considered in the broader context of the riverscape. However, methods are lacking to fully integrate systemic connectivity into decision-making.

Published in Dalhousie University, Halifax, Nova Scotia, 2013