Seabirds an indicator of marine ecosystem status for Coastal British Columbia

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Environment Canada's Canadian Wildlife Service
  Seabird Monitoring Areas of Coastal BC

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Seabird winter population in the Georgia Basin of British Columbia

Table 1. The seabird wintering data is from the National Audubon Society Christmas Bird Count (CBC) historical results for Pigeon Guillemot, Marbled Murrelet and Common Murre seabird species and are from 13 circle counts within the Georgia Basin (Pender Island, Sooke, Sunshine Coast, Squamish, Nanaimo, Victoria, Comox, Duncan, Vancouver, Ladner, White Rock,  Deep Bay and Campbell River). The data is collected 1 day a year on or near Christmas Day by varying numbers of volunteers. As the coverage and the level of effort varies from year to year for each circle count or geographical area, the counts per species is expressed as the number of birds reported per party hour. This is calculated by dividing the number of birds for each species by the number of party hours for each count reporting that species. These values for each circle count are then averaged to generate the values reported in the following table for each species. The date (year) relates to the wintering period spanning the end of  year 1 and beginning of year 2 (i.e. 1998 refers to 1998-99 winter). 

Note: although the CBC is the best available multi-species, broad-scale survey on winter distribution, the effort is not consistent and coverage is not even. Some caution in interpreting counts should be exercised since some changes in distribution can be mistaken for changes in population abundance.

Common Murre (Uria aalge)

Marbled Murrelet (Brachyramphus marmoratus)

Pigeon Guillemot (Cepphus columba)

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Ancient Murrelet

Deep within the moss-carpeted Sitka Spruce and western Hemlock forests of the Haida Gwaii islands, this small seabird constructs burrows under fallen logs, tree roots and stumps. At the end of the tunnel, in a shallow nest cup loosely lined with leaves and twigs, it hatches 2 eggs. The chicks, once hatched, leave the burrow at two days of age and make their way over downed trees and cliffs to the rocky shores where they swim out to be reunited with their parents on the ocean.

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Table 2. Numbers of Ancient Murrelet chicks trapped at standard catching sites on Reef and East Limestone islands. Breeding data are from A.J. Gaston, CWS, Ottawa, Ont. and Laskeek Bay Conservation Society.

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Table 3. The timing of breeding for seabirds on Triangle Island, British Columbia with values expressed as mean Julian calendar hatch dates (with 95% confidence intervals). The values for Common Murre are dates when nestlings were first observed. Data are from D. Bertram, CWS, Delta, BC, 2002.

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Table 4. Growth rate for chicks of each seabird species on Triangle Island, British Columbia expressed as anomalies from average growth rate for the period 1976 to 2001. Data are from D. Bertram, CWS, Delta, BC, 2002.

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References used in the  indicator:

• BC Ministry of Water, Land and Air Protection. 2002. Indicators of Climate Change for British Columbia 2002. March 2002, Victoria, British Columbia.
• Bertram, D.F. 1995. The roles of introduced rats and commercial fishing in the decline of Ancient Murrelets on Langara Island, BC. Conservation Biology 9: 865-872.
• Bertram, D.F. 1999. Report from Triangle Island seabird research and monitoring station: Changes in the 1990s. Env. Can., Can. Wildl. Serv., Bird Trends No. 7: 26.
• Bertram, D.F. 2001. Seabirds reflect changes in ocean climate. In Alexander, V., A.S. Bychkov, P. Livingston, and S. M. McKinnell (Editors). Proceedings of the PICES/CoML/IPRC Workshop on "Impact of climate variability on observation and Prediction of ecosystem and biodiversity changes in the North Pacific" PICES Scientific Report No. 18.
• Bertram, D.F., I.J. Jones, E. Cooch, H. Knechtel and F. Cooke. 2000. Survival rates of Cassin's and Rhinoceros Auklest at Triangle Island, British Columbia. Condor 102: 155-162.
• Bertram, D.F., D.L. Mackas and S.M. McKinnell. 2001. The seasonal cycle revisisted: interannual variation and ecosystem consequences. Prog. Oceanogr. 49: 283-307.
• Burger, A.E. 1993. Effects of the 'Nestucca' oil spill on seabirds along the coast of Vancouver Island in 1989. Can. Wildl. Serv. Tech. Rep. Ser. No. 179. Pacific and Yukon Region, British Columbia.
• Cam, E., L. Lougheed, R. Bradley and F. Cooke. 2002. Demographic assessment of a Marbled Murrelet population from capture-recapture data. Conservation Biology. In Press.
• DFO, 2001. 2000 Pacific Region State of the Ocean. DFO Science Ocean Status Report 2001-01 (2001).
• DFO, 2002. 2001 Pacific Region State of the Ocean. DFO Science Ocean Status Report 2002-01 (2002).
• Ford, R.G., J.L. Casey, C.H. Hewitt, D.B. Lewis, D.H. Varoujean, D.R. Warrick and W.A. Williams. 1991. Seabird mortality resulting from the Nestucca oil spill incident, winter 1988-89. Report for Washington Dept. Wildlife. Ecological Consulting Inc., Portland, Oregon.
• Furness, R.W. and J.J.D. Greenwood. 1993. Birds as monitors of environmental change. Chapman and Hall. London, U.K. 
• Gjerdrum, C., A.M.J. Vallée, C.C. St. Clair, D.F. Bertram, J.L. Ryder and G.S. Blackburn. 2003. Tufted puffin reproduction reveals ocean climate variability. Proc. Nat. Ac. Sci. 100: 9377-9382.
• Mackas, D., R. Goldblatt and A.G. Lewis. 1998. Interdecadal variation in developmental timing of Neocalanus plumchrus populations at Ocean Station P in the subarctic North Pacific. Canadian Journal of Fisheries and Aquatic Sciences 55: 1878-1893.
• Lemon, J.F. and A.J. Gaston. 1999. Trends in Ancient Murrelet populations since 1980. Env. Can., Can. Wildl. Serv., Bird Trends No. 7: 22-25.
• Lougheed, L.W., C. Lougheed, B.A. Vandekist, S. Webster, R. Bradley, M. Drever, I.A. Manley, W.S. Boyd, G.W. Kaiser, and F. Cooke. 1998. Demography and Ecology of Marbled Murrelets in Desolation Sound, British Columbia (1997). CWS/NSERC Wildlife Ecology Chair Technical Report No. 003. CWS/NSERC Wildlife Ecology Chair, Simon Fraser University, Burnaby, British Columbia.
• Rodway, M.S. 1991. Status and conservation of breeding seabirds in British Columbia. In "Seabird status and conservation: a supplement" (J.P. Croxall, ed.). ICBP Technical Publication No. 11.

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