Science Advisory Report 2012/046
State of the Pacific Ocean 2011
- This report summarises the thirteenth annual workshop on the state of physical, biological, and selected fishery resources of Canadian Pacific marine ecosystems.
- The average global temperature in 2011 was warmer than average almost everywhere, but not in the eastern Pacific Ocean, where cool waters have been present in almost every year since 2008, part of a Pacific-wide weather pattern associated with La Niña conditions of these years.
- Sea surface measurements from shore stations along the coast of British Columbia, and in the Strait of Georgia, confirm that ocean conditions were cooler in 2011 than in 2010.
- The spring bloom of phytoplankton in the Strait of Georgia in 2011 was later than normal, due to stronger winds of March and early April, but once it began the growth was unusually strong. Observations of this bloom by satellite and by ship-based surveys reveal that it peaked in June and extended into July, and had unusually high biomass of the harmful algae Heterosigma akashiwo.
- The copepod community of zooplankton on the Oregon continental shelf was dominated by lipid-rich “northern” copepods in 2011, suggesting strong survivals for coho and Chinook salmon returning to the Columbia River in 2012 and 2013. When combined with other factors, the general assessment is for average returns of these salmon stocks.
- Off the west coast of Vancouver Island, the zooplankton community, as well as other oceanic indicators, was more or less average, implying average marine survivals for salmon that went to sea in 2011.
- Within the Strait of Georgia, conditions in 2011 were generally favourable for juvenile sockeye salmon, whereas poor returns are projected for coho salmon returning in 2012, Chinook salmon returning in 2013 and 2014, and chum salmon returning in 2013.
- An estimated 5 million Fraser River sockeye returned to British Columbia coastal waters in 2011, well within the range of predictions provided the previous year. This number contrasts with the record high of about 30 million in 2010 and record low of 1 million in 2009. The 10% and 90% range of predictions for returns in 2012 are 0.7 and 7 million sockeye.
- A detailed examination of smolt survivals of Chilko Lake sockeye salmon revealed a sharp pattern break in 1990, when the trend in marine survival changed from increasing prior to 1990 to decreasing after 1990. In contrast, marine survivals for Fraser pink salmon were without trend, and recent increases in pink salmon returns were attributed to be primarily the result of reduced fishing.
- A separate research effort, using ecosystem models that include most marine species and climate variability in the Strait of Georgia, identified a shift to lower growth rate of phytoplankton beginning in 1990 and continuing to present, which is attributed to stronger wind speeds in spring and summer since 1990. This lower primary production is manifested in the model as declines, after 1990, of coho and Chinook salmon, herring, dogfish, and killer whales.
- 2011 saw decreased pink shrimp biomass west of Vancouver Island from higher values in 2009 and 2010, likely as a result of warmer waters in spring two years previously when the shrimp were young.
- Biomass indices for most groundfish species in Hecate Strait and Queen Charlotte Sound are trending upwards after several years of decline.
- Eulachon populations coast-wide remain at low levels, while Pacific sardine biomass off the west coast of Vancouver Island increased in 2011 compared to 2010.
- Herring biomass forecasts for Haida Gwaii and Central Coast stocks are below fishery thresholds, while for Strait of Georgia and Prince Rupert stocks, forecasts are above thresholds. Declines in lengths and weights-at-age of post-recruit BC herring since the 1970s continue, and is not believed to be due to fishing.
- Breeding success of Triangle Island Cassin’s Auklets in 2011 was better than the long-term average and well above that of 2010.
- In Pacific Rim National Park Reserve, 2011 seabird abundance remained high and similar to 2010. Intertidal bivalves in the Barkley Sound part of this reserve were about average, while manila clams continue to decline. SARA-listed Olympia oyster has increased, but remains less common than in the late 1990s.
- Polychlorinated biphenyls (PCBs) declined significantly in Salish Sea harbour seals between 1984 and 2009, based on observations at a repeat-sampling station in the southern part of this sea. Polybrominated diphenyl ethers (PBDEs) continued to increase until mid-2000s, followed by a decline.
- Lowest oxygen concentrations have been recorded off southwest Vancouver Island since 2002, but mortality of bottom life has not been reported.
- Deep water in the North Pacific Ocean is already the most acidic in the global ocean and the British Columbia continental shelf might see negative impacts of this feature sooner than most oceanic waters.
- Scientists hope to collaborate in the next year to produce more quantitative ocean indices to rank the health of the ocean and its marine species, as part of an ongoing ecosystem approach to management (EAM).
This Science Advisory Report is from the February 15-16, 2012 State of the Pacific Ocean: 2012 Workshop. Additional publications from this process will be posted as they become available on the Fisheries and Oceans Canada Science Advisory Schedule.
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