In British Columbia, we rely on salmon that migrate thousands of kilometers through our waterways to shape our landscapes and provide nourishment to our ecosystems as well as to ourselves. With more than 9,000 salmon populations in British Columbia, salmon play an integral role in maintaining the health of the province [1]. For example, salmon carry important nutrients from the ocean back to their home rivers and streams to nourish healthy terrestrial and freshwater ecosystems [2–4]. Salmon are also an important food source for many animals, including bears, orcas and birds [5,6]. Additionally, salmon are a cherished food for many people, especially those belonging to the First Nations of B.C. who have relied on this resource since time immemorial [7]. For many B.C. First Nations, salmon have largely shaped their cultural identities and ways of life [8]. Unfortunately, the future of these iconic fish is in jeopardy and they require our protection—now more than ever—to ensure that future generations can continue to enjoy this invaluable resource. Salmon-Safe BC recognizes the importance of salmon and is working to address the growing threats these fish face from development.
Impacts of Development
Salmon experience many threats during their complex life cycles, as they migrate from streams and rivers out to the ocean and back. The threats salmon face during their freshwater journeys include community and agricultural development, which can affect salmon in several different ways. The first way is through changes to salmon habitat that can take many forms including building culverts or dams, paving over streams, or removing nearby vegetation that might prevent erosion [9]. Another way development can affect salmon is by altering the flow of water in rivers and streams, which is important for salmon survival and migration [10,11]. For example, removing water from streams to irrigate crops can reduce the amount of water available to salmon and aquatic organisms. As another example, constructing impervious surfaces, like roads, parking lots, and buildings, near rivers and streams can prevent water from naturally seeping into the ground and can cause flooding [9,12]. Another impact of development is increasing water temperatures, which can be caused by removing vegetation that normally provides shade or by altering water flows [13,14]. Lastly, development can lead directly to water pollution as chemical fertilizers, pesticides, metals, and sediment are emptied into nearby bodies of water [9,15,16]. These changes in water quality are harmful to salmon and to entire freshwater ecosystems.
Salmon-Safe Standards
While past community and agricultural developments have been detrimental to salmon and to our ecosystems, growing scientific research provides accessible solutions to help prevent and mitigate some of the most damaging impacts. Salmon-Safe BC is an eco-certification program that encourages developers, landowners and agricultural producers in British Columbia to adopt practices that help them protect salmon and natural ecosystems. These standards are based on the latest scientific research and take a holistic approach to land and water management by focusing on salmon as the link between ecosystems and as indicators of overall ecosystem health. Even if salmon are not present on a development site, Salmon-Safe standards still apply because doing the right thing for salmon means doing the right thing for our natural ecosystems. Since the population of British Columbia is expected to grow by 25% in the next 20 years [17], it is critical that we take action by adopting Salmon-Safe standards as soon as possible to ensure a healthy future for salmon, natural ecosystems, and for ourselves.
Healthy Salmon and Ecosystems
Salmon-Safe standards encourage developers, landowners and agricultural producers to utilize nature-based solutions to mitigate development impacts on salmon. One common land and water management issue in developed areas, especially large cities, is caused by stormwater runoff from impervious surfaces, which can cause the deposition of contaminants into streams and rivers where salmon live. Salmon-Safe standards call for the reduction of impervious surfaces in urban areas and an increase in green stormwater infrastructure, such as green roofs and rain gardens, to help filter out pollutants from stormwater and reduce flooding [18–20]. In nearby Washington state, stormwater runoff from urban areas wass causing the death of salmon [21,22]. However, when the stormwater was filtered through a column filled with a meter of gravel, sand, compost, and bark in an experimental setting, the salmon in the filtered water survived as well as they did in clean water [23]. In agricultural settings, Salmon-Safe standards also emphasize the importance of protecting or planting vegetation, specifically along stream banks, to prevent water pollution, which could come from the application of agrichemicals such as pesticides. These streamside buffers also help to stop erosion, an issue that can cause many problems for salmon by reducing oxygen to salmon eggs, creating poor visibility which leads to difficulty feeding, and by altering the structure of streams which can cause changes to habitat and water flow [24,25]. Salmon-Safe encourages these simple, nature-based solutions that can make a big difference for salmon as British Columbia continues to grow.
Salmon-Safe standards are not only good for salmon, but they are also beneficial for British Columbia’s diverse ecosystems. Research shows that green stormwater infrastructure can help maintain healthy freshwater communities that may suffer from pollutants in stormwater runoff [23]. Healthy salmon populations also support healthy freshwater and nearby terrestrial ecosystems because when salmon die they release an abundance of nutrients into the environment. Researchers found that trees and shrubs near salmon-bearing streams derived around 20% of the nitrogen found in their leaves from salmon [2]. One study even found that salmon can provide nutrients that support cultivated crops [26]. Other research has shown that the number of aquatic insects increases with increasing salmon density in streams, which is beneficial to salmon populations and the biodiversity of British Columbia’s ecosystems [4]. Salmon-Safe practices also include encouraging developers to conserve or restore local vegetation, which creates habitats for local and diverse wildlife, such as honeybees, birds, and rabbits, that may live in or migrate through developed areas. Therefore, Salmon-Safe practices are not just beneficial to salmon, but they are beneficial to all kinds of wildlife across the province.
Healthy Communities and People
Salmon-Safe BC standards are designed to promote healthy communities and people in addition to healthy salmon and ecosystems. Some of the Salmon-Safe standards include planting vegetation or leaving it undisturbed, which can help improve both air and water quality [19,27,28]. Vegetation helps by intercepting pollution that is in the air or water by physically trapping and sometimes absorbing pollutants through their roots or leaves. Salmon-Safe practices, such as green roofs, can also help to mitigate the urban heat island effect [29,30]. The urban heat island effect takes place when areas with high densities of development and activity have higher temperatures than surrounding areas. This is related to a concentration of energy-intensive activities and also the materials used to construct these areas, which trap heat. Furthermore, increasing green landscapes—especially in highly developed areas—can improve the mental health and increase the physical activity of people living in these spaces [31–33]. Lastly, Salmon-Safe standards include limiting the application of chemicals, like pesticides, which have been found to have harmful impacts on human health in some cases [34–37]. Whether salmon are directly present or not, adopting Salmon-Safe standards can be beneficial to the health of communities and people across British Columbia.
A Salmon-Safe Future
Building a Salmon-Safe future means reimagining the design of urban, suburban, and rural areas so that salmon, natural ecosystems, and the people of British Columbia can thrive. A great example of this can be found in Vancouver’s Still Creek, which runs through the city and is surrounded by intensive development on all sides. In 2002, the city started to rehabilitate this creek to bring back salmon that had not been seen there for many years. This process included enhancing streamside vegetation, removing some nearby parking lots, and adding more public greenspaces, walkways and bike paths for people to enjoy [38]. In 2012, the residents of Vancouver were thrilled to see salmon return to this stream for the first time in 80 years. This is just one story of how we can change the outcome for salmon, for ecosystems, and for ourselves through Salmon-Safe practices. This starts not only with developers, landowners, and agricultural producers, but also with consumers. Our everyday choices and actions can encourage businesses and local governments to enact safe and environmentally friendly practices that promote healthy salmon, healthy ecosystems, and healthy people.
References
1. Slaney TL, Hyatt KD, Northcote TG, Fielden RJ. Status of anadromous salmon and trout in British Columbia and Yukon. Fisheries. 1996;21: 20–35. doi:10.1577/1548-8446(1996)021<0020:soasat>2.0.co;2
2. Helfield JM, Naiman RJ. Effects of salmon-derived nitrogen on riparian forest growth and implications for stream productivity. Ecology. 2001;82: 2403–2409. doi:10.1890/0012-9658(2001)082[2403:EOSDNO]2.0.CO;2
3. Hocking MD, Reynolds JD. Impacts of salmon on riparian plant diversity. Science. 2011;331: 1609–1612. doi:10.1126/science.1201079
4. Verspoor JJ, Braun DC, Stubbs MM, Reynolds JD. Persistent ecological effects of a salmon-derived nutrient pulse on stream invertebrate communities. Ecosphere. 2011;2: 18. doi:10.1890/ES10-00011.1
5. Ford MJ, Hempelmann J, Hanson MB, Ayres KL, Baird RW, Emmons CK, et al. Estimation of a killer whale (Orcinus orca) population’s diet using sequencing analysis of DNA from feces. PLoS ONE. 2016;11: e0144956. doi:10.1371/journal.pone.0144956
6. Schindler DE, Scheuerell MD, Moore JW, Gende SM, Francis TB, Palen WJ. Pacific salmon and the ecology of coastal ecosystems. Frontiers in Ecology and the Environment. 2003;1: 31–37. doi:10.2307/3867962
7. Fisheries and Oceans Canada. Wild Salmon Policy 2018-2022 Implementation Plan. 2018. Available: https://waves-vagues.dfo-mpo.gc.ca/Library/40728109.pdf
8. Kooy R. Food. In: Canadian Geographic: Indigenous Peoples Atlas of Canada. [cited 2 Jul 2020]. Available: https://indigenouspeoplesatlasofcanada.ca/article/food/
9. Paul MJ, Meyer JL. Streams in the urban landscape. Annual Review of Ecological Systematics. 2001;32: 333–365. doi:10.1007/978-0-387-73412-5_12
10. Sykes GE, Johnson CJ, Shrimpton JM. Temperature and flow effects on migration timing of Chinook salmon smolts. Transactions of the American Fisheries Society. 2009;138: 1252–1265. doi:10.1577/t08-180.1
11. Petrosky CE, Schaller HA. Influence of river conditions during seaward migration and ocean conditions on survival rates of Snake River Chinook salmon and steelhead. Ecology of Freshwater Fish. 2010;19: 520–536. doi:10.1111/j.1600-0633.2010.00425.x
12. Wissmar RC, Timm RK, Logsdon MG. Effects of changing forest and impervious land covers on discharge characteristics of watersheds. Environmental Management. 2004;34: 91–98. doi:10.1007/s00267-004-0224-5
13. Booth DB, Kraseski KA, Rhett Jackson C. Local-scale and watershed-scale determinants of summertime urban stream temperatures. Hydrological Processes. 2014;28: 2427–2438. doi:10.1002/hyp.9810
14. LeBlanc RT, Brown RD, FitzGibbon JE. Modeling the effects of land use change on the water temperature in unregulated urban streams. Journal of Environmental Management. 1997;49: 445–469. doi:10.1006/jema.1996.0106
15. King KA, Grue CE, Grassley JM, Fisk RJ. Pesticides in urban streams and early life stages of Pacific coho salmon. Environmental Toxicology and Chemistry. 2013;32: 920–931. doi:10.1002/etc.2117
16. Food and Agriculture Organization of the United Nations. More People, More Food, Worse Water?: A Global Review of Water Pollution from Agriculture. Rome; 2018. Available: http://www.fao.org/3/ca0146en/CA0146EN.pdf
17. Ip F, Lavoie S. PEOPLE 2019: BC Sub-Provincial Population Projections. Government of British Columbia; 2019. Available: https://www2.gov.bc.ca/assets/gov/data/statistics/people-population-community/population/people_2019_population_projections-highlights.pdf
18. Hatt BE, Fletcher TD, Deletic A. Hydrologic and pollutant removal performance of stormwater biofiltration systems at the field scale. Journal of Hydrology. 2009;365: 310–321. doi:10.1016/j.jhydrol.2008.12.001
19. Barrett M, Lantin A, Austrheim-Smith S. Storm water pollutant removal in roadside vegetated buffer strips. Transportation Research Record: Journal of the Transportation Research Board. Washington D. C.; 2004. doi:10.3141/1890-16
20. Lee JY, Moon HJ, Kim TI, Kim HW, Han MY. Quantitative analysis on the urban flood mitigation effect by the extensive green roof system. Environmental Pollution. 2013;181: 257–261. doi:10.1016/j.envpol.2013.06.039
21. Feist BE, Buhle ER, Baldwin DH, Spromberg JA, Damm SE, Davis JW, et al. Roads to ruin: Conservation threats to a sentinel species across an urban gradient. Ecological Applications. 2018;27: 2382–2396. doi:10.1002/eap.1615
22. Scholz NL, Myers MS, McCarthy SG, Labenia JS, McIntyre JK, Ylitalo GM, et al. Recurrent die-offs of adult coho salmon returning to spawn in Puget Sound lowland urban streams. PLoS ONE. 2011;6: e28013. doi:10.1371/journal.pone.0028013
23. McIntyre JK, Davis JW, Hinman C, Macneale KH, Anulacion BF, Scholz NL, et al. Soil bioretention protects juvenile salmon and their prey from the toxic impacts of urban stormwater runoff. Chemosphere. 2015;132: 213–219. doi:10.1016/j.chemosphere.2014.12.052
24. Bjornn TC, Reiser DW. Habitat requirements of salmonids in streams. American Fisheries Society, Special Publication. 1991;19: 83–138.
25. Nelson EJ, Booth DB. Sediment sources in an urbanizing, mixed land-use watershed. Journal of Hydrology. 2002;264: 51–68. doi:10.1016/S0022-1694(02)00059-8
26. Macneale KH, Kiffney PM, Scholz NL. Pesticides, aquatic food webs, and the conservation of Pacific salmon. Frontiers in Ecology and the Environment. 2010;8: 475–482. doi:10.1890/090142
27. Carpenter KD, Kuivila KM, Hladik ML, Haluska T, Cole MB. Storm-event-transport of urban-use pesticides to streams likely impairs invertebrate assemblages. Environmental Monitoring and Assessment. 2016;188: 345. doi:10.1007/s10661-016-5215-5
28. Merz JE, Moyle PB. Salmon, wildlife, and wine: Marine-derived nutrients in human-dominated ecosystems of central California. Ecological Applications. 2006;16: 999–1009. doi:10.1890/1051-0761(2006)016[0999:SWAWMN]2.0.CO;2
29. Nowak DJ, Hirabayashi S, Bodine A, Greenfield E. Tree and forest effects on air quality and human health in the United States. Environmental Pollution. 2014;193: 119–129. doi:10.1016/j.envpol.2014.05.028
30. Davis AP, Shokouhian M, Sharma H, Minami C, Winogradoff D. Water quality improvement through bioretention: Lead, copper, and zinc removal. Water Environment Research. 2003;75: 73–82. doi:10.2175/106143005X94376
31. Susca T, Gaffin SR, Dell’Osso GR. Positive effects of vegetation: Urban heat island and green roofs. Environmental Pollution. 2011;159: 2119–2126. doi:10.1016/j.envpol.2011.03.007
32. Lehmann S. Low carbon districts: Mitigating the urban heat island with green roof infrastructure. City, Culture and Society. 2014;5: 1–8. doi:10.1016/j.ccs.2014.02.002
33. Beil K, Hanes D. The influence of urban natural and built environments on physiological and psychological measures of stress—A pilot study. International Journal of Environmental Research and Public Health. 2013;10: 1250–1267. doi:10.3390/ijerph10041250
34. Hartig T, Mitchell R, de Vries S, Frumkin H. Nature and health. Annual Review of Public Health. 2014;35: 207–228. doi:10.1146/annurev-publhealth-032013-182443
35. Song C, Ikei H, Park BJ, Lee J, Kagawa T, Miyazaki Y. Psychological benefits of walking through forest areas. International Journal of Environmental Research and Public Health. 2018;15: 2804. doi:10.3390/ijerph15122804
36. Alavanja MCR, Hoppin JA, Kamel F. Health effects of chronic pesticide exposure: Cancer and neurotoxicity. Annual Review of Public Health. 2004;25: 155–197. doi:10.1146/annurev.publhealth.25.101802.123020
37. Bassil KL, Vakil C, Sanborn M, Cole DC, Kaur JS, Kerr KJ. Cancer health effects of pesticides: Systematic review. Canadian Family Physician. 2007;53: 1704–1711.
38. Sanborn M, Kerr KJ, Sanin LH, Cole DC, Bassil KL, Vakil C. Non-cancer health effects of pesticides: Systematic review and implications for family doctors. Canadian Family Physician. 2007;53: 1712–1720.
39. Weisenburger DD. Human health effects of agrichemical use. Human Pathology. 1993;24: 571–576. doi:10.1016/0046-8177(93)90234-8
40. City of Vancouver. Still Creek rehabilitation and enhancement study. 2002. Available: https://vancouver.ca/files/cov/still-creek-rehabilitation-enhancement-study.pdf
Mendeley
1. Slaney TL, Hyatt KD, Northcote TG, Fielden RJ. Status of anadromous salmon and trout in British Columbia and Yukon. Fisheries. 1996;21: 20–35. doi:10.1577/1548-8446(1996)021<0020:soasat>2.0.co;2
2. Helfield JM, Naiman RJ. Effects of salmon-derived nitrogen on riparian forest growth and implications for stream productivity. Ecology. 2001;82: 2403–2409. doi:10.1890/0012-9658(2001)082[2403:EOSDNO]2.0.CO;2
3. Hocking MD, Reynolds JD. Impacts of salmon on riparian plant diversity. Science. 2011;331: 1609–1612. doi:10.1126/science.1201079
4. Verspoor JJ, Braun DC, Stubbs MM, Reynolds JD. Persistent ecological effects of a salmon-derived nutrient pulse on stream invertebrate communities. Ecosphere. 2011;2: 18. doi:10.1890/ES10-00011.1
5. Ford MJ, Hempelmann J, Hanson MB, Ayres KL, Baird RW, Emmons CK, et al. Estimation of a killer whale (Orcinus orca) population’s diet using sequencing analysis of DNA from feces. PLoS ONE. 2016;11: e0144956. doi:10.1371/journal.pone.0144956
6. Schindler DE, Scheuerell MD, Moore JW, Gende SM, Francis TB, Palen WJ. Pacific salmon and the ecology of coastal ecosystems. Frontiers in Ecology and the Environment. 2003;1: 31–37. doi:10.2307/3867962
7. Fisheries and Oceans Canada. Wild salmon policy 2018-2022 implementation plan. 2018. Available: https://waves-vagues.dfo-mpo.gc.ca/Library/40728109.pdf
8. Kooy R. Food. In: Canadian Geographic: Indigenous Peoples Atlas of Canada [Internet]. [cited 2 Jul 2020]. Available: https://indigenouspeoplesatlasofcanada.ca/article/food/
9. Paul MJ, Meyer JL. Streams in the urban landscape. Annual Review of Ecological Systematics. 2001;32: 333–365. doi:10.1007/978-0-387-73412-5_12
10. Sykes GE, Johnson CJ, Shrimpton JM. Temperature and flow effects on migration timing of Chinook salmon smolts. Transactions of the American Fisheries Society. 2009;138: 1252–1265. doi:10.1577/t08-180.1
11. Petrosky CE, Schaller HA. Influence of river conditions during seaward migration and ocean conditions on survival rates of Snake River Chinook salmon and steelhead. Ecology of Freshwater Fish. 2010;19: 520–536. doi:10.1111/j.1600-0633.2010.00425.x
12. Wissmar RC, Timm RK, Logsdon MG. Effects of changing forest and impervious land covers on discharge characteristics of watersheds. Environmental Management. 2004;34: 91–98. doi:10.1007/s00267-004-0224-5
13. Booth DB, Kraseski KA, Rhett Jackson C. Local-scale and watershed-scale determinants of summertime urban stream temperatures. Hydrological Processes. 2014;28: 2427–2438. doi:10.1002/hyp.9810
14. LeBlanc RT, Brown RD, FitzGibbon JE. Modeling the effects of land use change on the water temperature in unregulated urban streams. Journal of Environmental Management. 1997;49: 445–469. doi:10.1006/jema.1996.0106
15. King KA, Grue CE, Grassley JM, Fisk RJ. Pesticides in urban streams and early life stages of Pacific coho salmon. Environmental Toxicology and Chemistry. 2013;32: 920–931. doi:10.1002/etc.2117
16. Food and Agriculture Organization of the United Nations. More people, more food, worse water?: A global review of water pollution from agriculture. Rome; 2018. Available: http://www.fao.org/3/ca0146en/CA0146EN.pdf
17. Ip F, Lavoie S. PEOPLE 2019: BC Sub-Provincial Population Projections. 2019. Available: https://www2.gov.bc.ca/assets/gov/data/statistics/people-population-community/population/people_2019_population_projections-highlights.pdf
18. Hatt BE, Fletcher TD, Deletic A. Hydrologic and pollutant removal performance of stormwater biofiltration systems at the field scale. Journal of Hydrology. 2009;365: 310–321. doi:10.1016/j.jhydrol.2008.12.001
19. Barrett M, Lantin A, Austrheim-Smith S. Storm water pollutant removal in roadside vegetated buffer strips. Transportation Research Record: Journal of the Transportation Research Board. Washington D. C.; 2004. doi:10.3141/1890-16
20. Lee JY, Moon HJ, Kim TI, Kim HW, Han MY. Quantitative analysis on the urban flood mitigation effect by the extensive green roof system. Environmental Pollution. 2013;181: 257–261. doi:10.1016/j.envpol.2013.06.039
21. Feist BE, Buhle ER, Baldwin DH, Spromberg JA, Damm SE, Davis JW, et al. Roads to ruin: Conservation threats to a sentinel species across an urban gradient. Ecological Applications. 2018;27: 2382–2396. doi:10.1002/eap.1615
22. Scholz NL, Myers MS, McCarthy SG, Labenia JS, McIntyre JK, Ylitalo GM, et al. Recurrent die-offs of adult coho salmon returning to spawn in Puget Sound lowland urban streams. PLoS ONE. 2011;6: e28013. doi:10.1371/journal.pone.0028013
23. McIntyre JK, Davis JW, Hinman C, Macneale KH, Anulacion BF, Scholz NL, et al. Soil bioretention protects juvenile salmon and their prey from the toxic impacts of urban stormwater runoff. Chemosphere. 2015;132: 213–219. doi:10.1016/j.chemosphere.2014.12.052
24. Bjornn TC, Reiser DW. Habitat requirements of salmonids in streams. American Fisheries Society, Special Publication. 1991;19: 83–138.
25. Nelson EJ, Booth DB. Sediment sources in an urbanizing, mixed land-use watershed. Journal of Hydrology. 2002;264: 51–68. doi:10.1016/S0022-1694(02)00059-8
26. Merz JE, Moyle PB. Salmon, wildlife, and wine: Marine-derived nutrients in human-dominated ecosystems of central California. Ecological Applications. 2006;16: 999–1009. doi:10.1890/1051-0761(2006)016[0999:SWAWMN]2.0.CO;2
27. Nowak DJ, Hirabayashi S, Bodine A, Greenfield E. Tree and forest effects on air quality and human health in the United States. Environmental Pollution. 2014;193: 119–129. doi:10.1016/j.envpol.2014.05.028
28. Davis AP, Shokouhian M, Sharma H, Minami C, Winogradoff D. Water quality improvement through bioretention: Lead, copper, and zinc removal. Water Environment Research. 2003;75: 73–82. doi:10.2175/106143005X94376
29. Susca T, Gaffin SR, Dell’Osso GR. Positive effects of vegetation: Urban heat island and green roofs. Environmental Pollution. 2011;159: 2119–2126. doi:10.1016/j.envpol.2011.03.007
30. Lehmann S. Low carbon districts: Mitigating the urban heat island with green roof infrastructure. City, Culture and Society. 2014;5: 1–8. doi:10.1016/j.ccs.2014.02.002
31. Beil K, Hanes D. The influence of urban natural and built environments on physiological and psychological measures of stress—A pilot study. International Journal of Environmental Research and Public Health. 2013;10: 1250–1267. doi:10.3390/ijerph10041250
32. Hartig T, Mitchell R, de Vries S, Frumkin H. Nature and health. Annual Review of Public Health. 2014;35: 207–228. doi:10.1146/annurev-publhealth-032013-182443
33. Song C, Ikei H, Park BJ, Lee J, Kagawa T, Miyazaki Y. Psychological benefits of walking through forest areas. International Journal of Environmental Research and Public Health. 2018;15: 2804. doi:10.3390/ijerph15122804
34. Alavanja MCR, Hoppin JA, Kamel F. Health effects of chronic pesticide exposure: Cancer and neurotoxicity. Annual Review of Public Health. 2004;25: 155–197. doi:10.1146/annurev.publhealth.25.101802.123020
35. Bassil KL, Vakil C, Sanborn M, Cole DC, Kaur JS, Kerr KJ. Cancer health effects of pesticides: Systematic review. Canadian Family Physician. 2007;53: 1704–1711.
36. Sanborn M, Kerr KJ, Sanin LH, Cole DC, Bassil KL, Vakil C. Non-cancer health effects of pesticides: Systematic review and implications for family doctors. Canadian Family Physician. 2007;53: 1712–1720.
37. Weisenburger DD. Human health effects of agrichemical use. Human Pathology. 1993;24: 571–576. doi:10.1016/0046-8177(93)90234-8
38. City of Vancouver. Still Creek rehabilitation and enhancement study. 2002. Available: https://vancouver.ca/files/cov/still-creek-rehabilitation-enhancement-study.pdf