BC Conservation Data Centre: Conservation Status Report
Phocoena phocoena
Harbour Porpoise
| Scientific Name: | Phocoena phocoena |
|---|---|
| English Name: | Harbour Porpoise |
| Provincial Status Summary | |
| Status: | S3S4 |
| Date Status Assigned: | January 08, 2022 |
| Date Last Reviewed: | January 08, 2022 |
| Reasons: | Harbour Porpoises occur in the inshore coastal waters of British Columbian year-round. Threats include entanglement in fishing gear, competition with human fisheries for prey, including Pacific Herring, and sensitivity to noise from marine vessel traffic. There is too little data to determine trends for this species. |
| Range | |
| Range Extent: | G = 200,000-2,500,000 square km |
| Range Extent Estimate (km2): | 257,499 |
| Range Extent Comments: | Harbour Porpoises are found primarily in shallow, inshore coastal waters of BC year-round, mostly in areas < 150 m deep but occasionally in much deeper waters (Ford 2014). Harbour Porpoises occur in a variety of inshore marine habitats in BC, including confined bays, inlets, channels and passes, as well as in shallow portions of more open waters, such as Hecate Strait and Dixon Entrance, and on banks off the west coast of Vancouver Island (Ford 2014; Wright et al. 2021). The extent of occurrence given in COSEWIC (2016o) is 257,499km2. |
| Area of Occupancy (km2): | GI = 501 to >12,500 |
| Area of Occupancy Comments: | COSEWIC (2016o) gives the index of area of occupancy as >2,000 km2 (>500 2x2 km grid cells). COSEWIC also reports AOO as 107,184km2 (26,796 2x2km grid cells) based on "sightings and the area defined by the writers" and 8,572km (2,143 2x2km grid cells) based on B.C. Cetacean Sightings Network sightings only." |
| Occurrences & Population | |
| Number of Occurrences: | U = Unknown |
| Comments: | Harbour Porpoises are widely scattered in inner coast waters along the entire BC coast and it is not possible to determine the number of occurrences. |
| Number of Occurrences with Good Viability / Ecological Integrity: | U = Unknown |
| Percent Area with Good Viability / Ecological Integrity: | DF = Moderate to excellent (>10%) |
| Comments: | Harbour Porpoises occur in a variety of inshore marine habitats in BC, including confined bays, inlets, channels and passes, as well as in shallow portions of more open waters, including Hecate Strait and Dixon Entrance (Ford 2014; Wright et al. 2021). Many of these areas are remote and would appear to have good ecological integrity. Areas of particularly high densities occur in the Salish Sea, especially in waters to the east of Saanich Peninsula, Boundary Bay, northern and central Georgia Strait, and off Victoria (Wright et al. 2021). These areas have relatively heavy use by recreational and commercial vessel traffic, which is a potential source of disturbance to Harbour Porpoises. However, surveys over the years have shown that Harbour Porpoise densities near Victoria have persisted for the past two decades (Ford 2014; COSEWIC 2016; Wright et al. 2021). |
| Number of Occurrences Appropriately Protected & Managed: | A = None |
| Comments: | No marine areas are protected specifically for Harbour Porpoises in BC. |
| Population Size: | E = 2,500 - 10,000 individuals |
| Comments: | A series of line-transect vessel surveys in inner coast waters of BC during 2004-2008 yielded an average abundance of 8,091 Harbour Porpoises (95% CL 4,885?13,401; Best et al. 2015). These surveys did not include areas off the west coasts of Vancouver Island and Haida Gwaii. A more recent survey off the entire BC coast in 2018, including waters off west Vancouver Island and Haida Gwaii, resulted in an estimate of total abundance of 7,364 individuals (95% CL 3,616?15,000; Doniol-Valcroze et al. in press). Using this latter estimate and assuming 50% of individuals are mature (Taylor et al. 2007), the current population is approximately 3,682 Harbour Porpoises. |
| Threats (to population, occurrences, or area affected) | |
| Degree of Threat: | BC = High - medium |
| Comments: | The presence of Harbour Porpoises in nearshore waters makes them particularly vulnerable to impacts from human activities. The main source of direct anthropogenic mortality to Harbour Porpoises is entanglement in fishing gear, especially commercial salmon gillnets. Estimates ranged up to 100 deaths per year in BC in the early 2000s (Hall et al. 2002; Williams et al. 2008), although that number appears to have declined substantially with the reduction in gillnet fishing activity over much of the coast, particularly in the Salish Sea (Ford 2014; Carretta et al. 2020). Another potential threat to Harbour Porpoises is competition with human fisheries for prey. Pacific Herring constitutes a major part of the diet of Harbour Porpoises (Nichol et al. 2013; Ford 2014), but most herring stocks in BC have declined significantly since the 1980s and 1990s, and show little sign of recovery (DFO 2020). New fishery restrictions for 2022 (Fisheries and Oceans Canada 2021) may improve the availability of herring for Harbour Porpoises. Harbour Porpoises appear to be particularly susceptible to disturbance from noise and disruption caused by marine vessel traffic, which can potentially displace animals from important habitats (Fisheries and Oceans Canada 2009; COSEWIC 2016o). Other threats to Harbour Porpoises, described in detail in COSEWIC (2016o), include: urbanization of coastal areas causing physical exclusion from habitats, toxic spills, vessel strikes, urban waste water and runoff, biological pollutants, runoff from agricultural biocides, ingestion of marine debris including microplastics, airborne pollutants, and various potential effects of climate change. |
| Trend (in population, range, area occupied, and/or condition of occurrences) | |
| Short-Term Trend: | U = Unknown |
| Comments: | Harbour Porpoises are difficult to detect and count at sea so comparisons between surveys using different observers and platforms must be done with caution. Best et al. (2015) estimated a total of 8,091 Harbour Porpoises (95% CI 4,885-13,401) in coastal BC waters from surveys in 2004-2008. Estimated abundance for roughly the same area in 2018 (Doniol-Valcroze et al. in press) were 6,188 (95% CI 2,293?17,683). Given the wide confidence intervals for both surveys, it is not possible to make any conclusions about a potential short-term trend broadly in BC waters. However, there is evidence that the abundance of Harbour Porpoises has increased in the southern Strait of Georgia in recent decades (Ford 2014), and the species is once again common in Puget Sound, WA, after many years of absence (Ford 2014; Jefferson et al. 2016; Carretta et al. 2019). |
| Long-Term Trend: | U = Unknown |
| Comments: | Harbour Porpoises were hunted for subsistence purposes by Indigenous peoples prior to the arrival of Europeans on the BC coast. No information is available, however, on past abundance. |
| Other Factors | |
| Intrinsic Vulnerability: | BC=Moderately vulnerable to not intrinsically vulnerable. |
| Comments: | Harbour Porpoises grow rapidly, mature at a young age (3-4 years), and have a high calving rate (one calf per year) compared to most cetaceans. Thus, they have a substantial reproductive potential. Harbour Porpoises are an important prey of Bigg?s (Transient) Killer Whales, the abundance of which has increased significantly in recent decades, particularly in the Salish Sea (Ford et al. 2007; Ford 2014; Shields et al. 2018). However, the increased occurrence of these predators has not appeared to have affected Harbour Porpoise abundance in this area. |
| Environmental Specificity: | CD = Moderate to broad. |
| Comments: | Harbour Porpoises occupy a diversity of marine habitats in relatively shallow (<150 m) nearshore areas, including bays, inlets, fjords, estuaries, and open straits and sounds. They feed on a wide variety of small fishes and invertebrates (Nichol et al. 2013). |
| Other Rank Considerations: | |
| Information Gaps | |
| Research Needs: | See Management Plan for Pacific Harbour Porpoise (Fisheries and Oceans Canada 2009) |
| Inventory Needs: | See Management Plan for Pacific Harbour Porpoise (Fisheries and Oceans Canada 2009) |
| Stewardship | |
| Protection: | See Management Plan for Pacific Harbour Porpoise (Fisheries and Oceans Canada 2009) |
| Management: | See Management Plan for Pacific Harbour Porpoise (Fisheries and Oceans Canada 2009) |
| Version | |
| Author: | J. Ford (2022), S. Cannings, L. Ramsay and L. Gelling (previous versions) |
| Date: | January 08, 2022 |
| References | |
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Hall, A., G. Ellis, and A.W. Trites. 2002. Harbour porpoise interactions with the 2001 selective salmon fisheries in southern British Columbia and license holder reported small cetacean by-catch. Victoria, BC: Selective Salmon Fisheries Science Program, Fisheries and Oceans Canada. 51 pp |
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Barlow, J., K.A. Forney, P.S. Hill, R.L. Brownell, J.V.Carretta, D.P. DeMaster, F. Julian, M.S. Lowry, T. Ragen, and R.R. Reeves. 1997. U.S. Pacific Marine Mammal Stock Assessments: 1996. NOAA Tech. Memo. NMFS. NOAA-TM-NMFS-SWFSC-248.
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Carretta, J.V., K.A. Forney, E.M. Oleson, et al. 2020. U.S. Pacific Marine Mammal Stock Assessments: 2019 U.S. Department of Commerce, NOAA Technical Memorandum NMFS-SWFSC-629.
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COSEWIC. 2003j. COSEWIC assessment and update status report on the harbour porpoise Phocoena phocoena (Pacific Ocean population) in Canada. Committee on the Status of Endangered Wildlife in Canada. Ottawa. vi + 22 pp.
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COSEWIC. 2016o. COSEWIC assessment and status report on the Harbour Porpoise Phocoena phocoena
vomerina, Pacific Ocean population, in Canada. Committee on the Status of Endangered Wildlife in Canada. Ottawa. xi + 51 pp. |
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DFO (Department of Fisheries and Oceans). 2020. Stock status update with application of management procedures for Pacific Herring (Clupea pallasii) in British Columbia: Status in 2019 and forecast for 2020. DFO Can. Sci. Advis. Sec. Sci. Resp. 2020/004.
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Doniol-Valcroze, T., L. Nichol, B. Wright, et al. In press. Abundance estimates of cetaceans from the 2018 Pacific Region International Survey of Marine Megafauna. DFO Can. Sci. Advis. Sec. Res. Doc.
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Fisher, H.D., and R.J. Harrison. 1970. Reproduction in the common porpoise Phocoena phocoena of the North Atlantic. J. Zool. 161:471-486.
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Ford, J.K.B. 2014. Marine Mammals of British Columbia. Royal BC Museum Handbook, Mammals of BC, volume 6. Royal B.C. Mus., Victoria, BC. 460 pp.
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Gaskin, D. E. 1992. Status of the harbour porpoise, Phocoena phocoena, in Canada. Can. Field-Nat. 106:36-54.
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Gaskin, D.E., P.W. Arnold and B.A. Blair. 1974. Phocoena phocoena. American Society of Mammalogists, Mammalian Species 42:1-8.
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Jefferson, T.A., Smultea, M.A., Courbis, S.S. et al. 2016. Harbor porpoise (Phocoena phocoena) recovery in the inland waters of Washington: estimates of density and abundance from aerial surveys, 2013-2015. Canadian Journal of Zoology 94: 505-515.
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Leatherwood, S., and R. R. Reeves. 1983. The Sierra Club handbook of whales and dolphins. Sierra Club Books, San Francisco. 302 pp.
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Nichol, L.M., A.M. Hall, G.M. Ellis, et al. 2013. Dietary overlap and niche partitioning of sympatric harbour porpoises and Dall?s porpoises in the Salish Sea. Progress in Oceanography, 115, pp.202-210.
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Osborne, R., J. Calambokidis, and E.M. Dorsey. 1988. A guide to marine mammals of Greater Puget Sound. Island Publ., Anacortes, WA. 191pp.
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Osmek, S., J. Calambokidis, J. Laake, P. Gearin, R. DeLong, J. Scordino, S. Jefferies, and R. Brown. 1996. Assessment of the status of harbour porpoise (Phocoena phocoena) in Oregon and Washington waters. NOAA Tech. Memo. NMFS-AFSC-76. 46pp.
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Raum-Suryan, K.L. 1995. Distribution, abundance, habitat use, and respiration patterns of Harbour Porpoise (Phocoena phocoena) off the northen San Juan Islands, Washington, M.Sc. Thesis, San Jose State Univ., San Jose, CA. 79pp.
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Scheffer, V.B., and J.B. Slipp. 1948. The whales and dolphins of Washington state with a key to the cetaceans of the west coast of North America. Am. Midland Nat. 39(2):257-337.
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Taylor, B.L., S.J. Chivers, J. Larese, and W.F. Perrin. 2007. Generation length and percent mature estimates for IUCN assessments of cetaceans. Administrative Report LJ-07-01. National Marine Fisheries Service, Southwest Fisheries Science Center. LaJolla, CA. 24 pp.
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Williams, R. W., A. Hall, and A. Winship. 2008. Potential limits to anthropogenic mortality of small cetaceans in coastal waters of British Columbia. Canadian Journal of Fisheries and Aquatic Science 65:1867-1878.
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Wright, B.M., L.M. Nichol, and T. Doniol-Valcroze. 2021. Spatial density models of cetaceans in the Canadian Pacific estimated from 2018 ship-based surveys. DFO Can. Sci. Advis. Sec. Res. Doc. 2021/049. iii + 46 p.
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Please visit the website Conservation Status Ranks for information on how the CDC determines conservation status ranks. For global conservation status reports and ranks, please visit the NatureServe website http://www.natureserve.org/.
Suggested Citation:
B.C. Conservation Data Centre. 2022. Conservation Status Report: Phocoena phocoena. B.C. Minist. of Environment. Available: https://a100.gov.bc.ca/pub/eswp/ (accessed Oct 4, 2025).