Monitoring

Exploring the Mysteries of Wild Salmon at Sea

Since the 1990s, there have been sharp declines in catches of wild Pacific salmon, which are important to the economy of British Columbia and the Yukon. Since this species spends most of its life deep in the ocean, far from shore, any management or conservation discussions or measures need to consider the impact of the ocean on salmon. However, what juvenile salmon do, where they go, and what happens to them after they leave their home stream or river and return to the sea is not fully known or understood.

To unravel some of these mysteries, the High Seas Salmon Program at the Pacific Biological Station is exploring how varying ocean conditions affect salmon migration and their chances for growth and survival at sea. The program team, under the leadership of Dr. Marc Trudel, spends up to 11 weeks at sea each year collecting samples of salmon, associated fish communities, water and plankton. Since 1998, the team has carried out juvenile salmon surveys from the west coast of Vancouver to southeast Alaska to determine ocean migration speeds and routes along the continental shelf. They are also exploring regional stock compositions and growth rates, the effects of ocean conditions and climate change on the salmon, and the overall capacity of the Pacific Ocean to support salmon stocks under changing climates. One unexpected finding is that even small changes in prey quality appear to have a large effect on the growth of juvenile Coho Salmon.

The team is also developing new salmon forecasting models based on the oceanic conditions they have monitored over the past 12 years. In 2009–2010, testing of these models determined that they perform better than the methods currently used by the Department to assess stocks of Coho Salmon off the west coast of Vancouver Island. As a result, it is expected that the new models will be incorporated into the annual assessment of those salmon stocks in the near future.

Factors Affecting Sea Level in Coastal British Columbia

Long-term water level observations from around the world confirm that mean sea level — the level of the sea with waves and other motions averaged out — has been increasing by about 30 centimetres per century. Most scientists now accept that this rise is the direct result of global climate change that is driven, in large part, by greenhouse gas emissions related to human activities.

Along the coast of British Columbia, areas that are particularly vulnerable to the rising seas include the Fraser River Delta region and the east coast of Graham Island in Haida Gwaii (Queen Charlotte Islands). Although there are large uncertainties in projected sea level rise relative to the position of the land, scientists are confident in the general trends.

It is important that coastal communities and governments at all levels be aware of these projected changes and potential impacts when planning coastal infrastructure and land use. To this end, Fisheries and Oceans Canada research scientist Dr. Richard Thomson of the Institute of Ocean Sciences in Sidney, British Columbia, led a study on projected sea level change in the province. Among the study’s findings:

• Based on present rates of sea level rise and a projected 30 cm rise in mean eustatic sea level (global scale changes in mean sea level due to changes in the volume of water in the ocean) during the 21^st century, Vancouver, Victoria and Prince Rupert are predicted to undergo a mean relative sea level rise of 20 to 30 cm by 2100, while a rise of 50 cm is predicted for the Fraser River Delta region. These estimates are up to 70 cm higher when one includes the possibility that rapid ice sheet melting will cause a 100 cm increase in global mean sea levels by 2100.
• Superimposed on the climate-related trend are annual cycles of 30 to 50 cm due to seasonal fluctuations in regional atmospheric pressure, ocean temperature, and alongshore winds and currents.
• Major El Niño events in the North Pacific add another 30 to 40 cm to coastal sea level, while intense storm surges in low-lying regions such as the Fraser River Delta can add another 100 cm. If the frequency and magnitude of these events increase with climate change, the impacts of storm surges will become increasingly more severe, with the potential for greater land erosion and flooding during periods of high tide.
• There is a 5 to 10 percent probability of a magnitude 9.0 earthquake occurring off the West Coast of North America in the next 50 years. Such an event would cause a sudden land subsidence (rapid sea level rise) of 30 to 200 cm on the west coast of Vancouver Island.

Oceanographic Monitoring Supports Salmon Aquaculture on the South Coast of the Island of Newfoundland

Significant investment in salmon aquaculture in Newfoundland and Labrador has increased activity in the province’s aquaculture sector. As a result, the increasing biomass and number of companies operating, the diversity of production strategies, and the increasing concentration of farm sites challenges biosecurity and the sustainability of this growth.

In 2008 it was recognized that there was a lack of data and understanding about the oceanography of the outer Bay d’Espoir and Fortune Bay areas, which precludes establishment of scientifically validated production and management areas to guide site licensing, production planning and sustainable management of the industry. To address this knowledge gap, a team of Fisheries and Oceans Canada scientists initiated an aquaculture oceanography project under the Program for Aquaculture Regulatory Research. This study is setting the foundation for Newfoundland and Labrador to understand the environmental effects and map potential zones of influence, which will ultimately be used to establish production management areas.

During the 2009 and 2010 field seasons, a significant amount of oceanographic data was collected off the south coast, including data on currents in the Bay D’Espoir-Hermitage Bay and Fortune Bay regions. Salinity, temperature, depth and other parameters were collected throughout the area. Multiple CTD (conductivity, temperature, depth) surveys were carried out over the two years to learn more about seasonal variations in the water column. A program using satellite-tracked surface drifting buoys was also launched to monitor the surface currents between various areas off the south coast. Data analysis is ongoing and work is under way to model currents in the region.

Monitoring Ocean Colour from Space for Ecosystem-Based Fisheries Management

Since healthy fish populations depend on healthy ecosystems, having an efficient and economical way to monitor the state of marine environments is essential. Ocean colour radiometry — remote sensing of the Earth’s oceans by optical (light-sensing) satellite instruments — provides a continuous stream of information on the state of marine ecosystems in near-real time on a global scale.

At the Bedford Institute of Oceanography in Halifax, Nova Scotia, federal researchers are analyzing ocean colour imagery for a wide variety of information (e.g. chlorophyll concentration, bloom timing, presence of diatoms and sediment concentration ) with a view to developing remote sensing approaches, methods, applications and products for improving ecosystem-based fisheries management.

The surface layers of the ocean vary in colour over time and space depending on a variety of conditions. For example, more greenish water generally indicates a higher production of phytoplankton, which forms the foundation of the oceanic food web. Differences in ocean colour, digitally recorded by remote sensing instruments, can be converted into estimates of phytoplankton biomass, productivity and functional types, which play different biogeochemical roles in the ocean. A time series of images reveal variations in biomass from season to season and year to year.

Much work remains to be done in order to fully utilize ocean colour data for improving ecosystem-based fisheries management. Ongoing ocean colour radiometry research will:

• measure variations in phytoplankton biomass and other ecosystem variables that may affect the recruitment and growth of various commercial fish stocks. This application has already been demonstrated in Atlantic Canada for Haddock and Northern Shrimp;
• develop methods to improve the analysis of phytoplankton functional-type dominance in marine ecosystems;
• detect and monitor harmful algal blooms. Work continues on the development of a warning indicator for the presence of harmful algal blooms in the Bay of Fundy; and
• study interannual variations in marine production at large scales, thereby contributing to discussions on the role of marine biota in the global carbon cycle and climate change.

Integrated Coastal Zone Management — Bridging the Land-Water Divide

Under the Health of the Oceans Initiative (2007–2012), the Centre of Expertise on Coastal Management was established within the Department’s Oceans and Science sector to increase the understanding of international tools and practices to support national integrated coastal zone management initiatives.

There are many definitions of the coastal zone including “the area where the ocean meets the land, which constitutes 10 percent of the ocean’s area but contains 90 percent of all marine species.” However it is defined, one thing is certain; the coastal zone is very challenging to manage for many reasons:

• it is very ecologically complex;
• it is a zone of change and where three different ecosystems (land, fresh water and marine waters) meet in a very dynamic setting; and
• it is a zone of connectivity and transition between habitats and processes.

These interactions make coastal zones among the most productive on Earth. However, these ecosystems are also are under stress around the world due to population growth, pollution, habitat degradation, multiple resource use conflicts, over-exploitation of resources and other human activities.

Given this setting, it is particularly important that integrated coastal zone management be carried out strategically and efficiently with the best available information and tools. One of the objectives of the centre is to apply risk analysis principles to the development of ecosystem-based management approaches in order to avoid cumulative environmental effects. This can help decision-makers to deploy resources strategically to optimize management of human activities and ensure the conservation and protection of aquatic ecosystems. At its core, risk analysis assists decision-making. It provides a systematic way of gathering, evaluating, recording and disseminating information leading to recommendations for the consideration of management. These approaches can result in more effective and sustainable coastal zone management practices along Canada’s 244,000 kilometres of coastline.

Mission to Map Arctic Seabed Succeeds in Proving New AUV Technology

Surveying the Arctic seabed is a challenging task due to the remoteness of the region and unpredictable weather and ice conditions. The successful use of an autonomous underwater vehicle (AUV) in the collection of bathymetric data in the North is preparing this new technology to play other roles in long-range, unescorted missions in harsh environments. Testing and using the new AUV technology to map the seabed involved a team composed of the Canadian Hydrographic Service of Fisheries and Oceans Canada, Defence Research and Development Canada and the Geological Survey of Canada, part of Natural Resources Canada. Their mission is to determine how far Canada’s continental shelf extends under the sea. The collected data will become an integral part of Canada’s submission to the Commission on the Limits of the Continental Shelf. Pursuant to article 76 of the United Nations Convention on the Law of the Sea, coastal countries with a continental shelf extending beyond 200 nautical miles must make a submission regarding the proposed outer limits to the Commission within 10 years of ratification (in Canada’s case, by December 2013).

In a typical mission, the battery-operated AUV is launched from an ice camp in the Northwest Territories near Borden Island and follows a pre-programmed mission plan.

After diving to a predetermined operating altitude above the seabed, the AUV switches on its bathymetric sensors and moves from one way point to the next. At the end of the mission segment, it turns off the sensors and homes in on a beacon deployed through an ice hole at the camp. Back at home base, researchers download the bathymetric data from the AUV, then recharge and redeploy it to collect more data.

The surveys will augment spot soundings, and seismic, gravity and magnetic data collected to date. All of this data will be analyzed and then submitted, demonstrating that the areas and ridges surveyed meet the requirements of article 76 of the United Nations Convention on the Law of the Sea and are part of Canada’s extended continental shelf. Since the surveys began, the underwater vehicles have covered approximately 1,000 kilometres. Another mission is planned for 2011 to gather the remaining Arctic Ocean data required for Canada’s submission. This time the vehicles will be deployed from Canada’s largest icebreaker, the CCGS Louis S. St-Laurent.

Probing Ocean and Ice Fluxes Passing Through Barrow Strait

Since 1998, researchers at the Bedford Institute of Oceanography have been exploring the flow of ocean water and sea ice (transports) passing through Barrow Strait, one of the three main pathways through the Canadian Arctic Archipelago. The aim of the research, which is part of the Arctic/Sub-Arctic Ocean Fluxes and the International Polar Year programs, is to measure and model the variations in ocean water and sea ice transports passing between the Arctic Ocean and sub-Arctic seas, including the North Atlantic. The Arctic Ocean Fluxes component of this project concentrates on the direct effect of these transports on North Atlantic (Labrador Sea) circulation.

Increased knowledge of the processes that control these transports, and their relationship to the ocean and ice conditions of the Arctic Ocean and circulation and vertical ventilation of the Labrador Sea, will aid in the development of global climate models to predict the impacts of climate change on pack ice and marine ecosystems in the Arctic and Sub-Arctic regions.

• validating international climate models to enhance the accuracy of global warming projections of the Arctic and Sub-Arctic pack ice and marine ecosystem;
• managing marine transportation, offshore operation regulation codes, and search and rescue in the Northwest Passage as the open water season increases;
• regulating industrial developments in the Canadian Arctic and monitoring the oceanographic and pack ice conditions of the proposed National Marine Conservation Area in Lancaster Sound;
• assist in developing biological and food web models of marine ecosystems to predict climate change impacts; and
• managing national security and sovereignty issues in the Canadian Arctic.

Record-Breaking Temperatures in the Gulf of St. Lawrence

An annual helicopter-based survey of the physical oceanographic conditions in the Gulf of St. Lawrence, led by Peter Galbraith of the Maurice Lamontagne Institute in Mont-Joli, Quebec, reported record-high winter temperatures in March 2010. This anomaly is linked to air temperatures, measured at nine stations in the Gulf, which were 5.1°C above normal — the warmest on record since at least 1945.

Sea ice was all but absent in the Gulf during the unusually mild winter of 2010, the least amount of ice coverage registered by the Canadian Ice Service since it began gathering data in 1969.

The survey, conducted by lowering a probe from a hovering helicopter into the water to measure temperature and salinity at more than 85 locations in the Gulf, revealed that the winter season surface mixed layer of water was exceptionally warm in March. About 75-metres thick, this layer usually nears the freezing point — around -1.7°C — in the Gulf; in 2010, it was on average 1°C warmer than normal. Temperatures were even higher in some areas, exceeding 0°C northeast of the Cabot Strait and in the St. Lawrence Estuary. This is the warmest winter season surface mixed layer ever recorded over the 15-year history of the survey.

Analysis of the winter season surface mixed layer makes it possible to forecast summer oceanographic conditions, which is useful for biologists assessing fish, crab and shrimp stocks. While the surface waters warm in springtime, a subsurface cold layer remains partially insulated until the following winter, sometimes maintaining temperatures below 0°C at the height of summer. The record warm water temperatures in March led to above-normal core cold layer water temperatures in the summer of 2010. Ice-free winter conditions in the Gulf of St. Lawrence — likely to occur more regularly with climate change — may introduce a new dynamic in the formation of these layers.

New Identification Guide to Marine Fishes of the Gulf of St. Lawrence

Every year, Fisheries and Oceans Canada conducts a major biological survey aboard the trawler CCGS Teleost, a key source of information on the status of marine resources harvested in the estuary and northern Gulf of St. Lawrence. The main objective of the survey is to estimate the abundance and biomass of commercially important species, including Atlantic Cod, Greenland Halibut, Acadian and Deepwater Redfish and Northern Shrimp.

In recent years, biologists have sought to more fully integrate information on the status of these stocks and the ecosystems in which they live; to do so, they need to quickly and properly identify the dozens of other fish and invertebrate species caught during surveys. To facilitate this task, in 2010 Fisheries and Oceans Canada published the Identification guide for marine fishes of the estuary and northern Gulf of St. Lawrence and sampling protocols used during trawl surveys between 2004 and 2008. It describes the size and depth distribution of fish species encountered during surveys and provides colour plates and identification sheets for 115 marine fish species that occur in the region.

An essential volume for biologists and technicians, the guide is also a valuable tool for people who make their living from the sea or are simply interested in the diversity of marine organisms. It is available in PDF format or in hard copy with an accompanying CD at the Maurice Lamontagne Institute library at biblioIML@dfo-mpo.gc.ca or 418-775-0500.