Oceans Canada

Oceanography in Atlantic Canada

Aquaculture, or the “farming” of aquatic organisms, has been around for thousands of years. It is only in the last thirty or so years, however, that it has become so important. This importance has been driven by the increase in the world’s population, dietary shifts and a decrease in the numbers of many traditional fish species. Currently, one-quarter of the fish consumed in the world is produced by aquaculture methods!

This industry has a long history in Canada. There is anecdotal evidence that our native peoples practiced basic aquaculture. Written records of fish egg incubation, hatching, and release in the mid-1800s have been found. Prince Edward Island is reported to have had oyster cultivation in the late 1800s.

Despite this seemingly long history, aquaculture on a commercial scale in Canada has only been around for about thirty years. In Atlantic Canada, salmon, trout, oysters, mussels, scallops, and seaweeds are all grown, mainly for the food industry. These organisms may be confined to artificial ponds, pools or tanks or barricades may be erected along the coasts. These enclosures keep the crop protected from many predators and concentrated in one place for easy operation and harvesting.

Before aquaculture sites are created there is research to be done. Oceanographers and biologists determine the best site to place the farms. Water currents, temperature, oxygen content, and water depth are measured in an effort to estimate the carrying capacity of the area and the impact aquaculture would have on the natural area. Studies are also conducted to determine what impact escaped aquaculture organisms would have, and to determine the potential spread of disease between the wild and the farmed organisms.

After aquaculture sites have been created, there is still research to be done. Oceanographers determine the long-term impact of aquaculture on the natural environment. The uneaten food and solid wastes can cause an increase in the sediments on the sea floor; as the amount and type of sediment change, so to do the type and number of wild organisms. Government scientists monitor the activity taking place in an area to determine the amount and type of sediment change. Excessive changes are monitored so that the aquaculturist can adjust the practice to minimize damages. As most farms strive to find a balance with the environment, this is not a common occurence.

Oceanographers may also work with aquaculturists to find ways to increase the yield of fish and seaweed. They may also work together to investigate diseases in aquaculture organisms.

There are as many different types of careers in oceanography as there are different types of fish in the sea. Okay, that may be a slight exaggeration, but there is no one definition that fully describes all of the career opportunities available in this industry.

The first career that most people immediately identify when they think of oceanography is that of a scientist. Biologists, chemists, physicists, and geologists are all employed in this field. On any given day, these professionals may be conducting field research on-board a ship, conducting experiments in a lab, interpreting data they have gathered, writing scientific papers, making recommendations to government and industry, working with engineers and tradespeople to develop new machinery, or any of a number of other tasks. While the specific aim of each discipline’s research may be different, all attempt to understand the physical and chemical properties of ocean water, as well as the life within it, the sea-floor and the ocean’s connection to the rest of the planet.

If you are interested in computers, oceanography may also be the field for you. Computer technicians and scientists are needed to design and use computer programs that control many instruments used in research. They are also needed to process the vast amounts of data that are collected by these instruments and that are collected by the numerous instruments used in this field. This data can then be used to create pictures and mathematical models to represent the processes the scientists are attempting to explain and understand.

Many other professionals are needed to support oceanographic research. Machinists and electricians build the varied instruments required. Photographers document the research. Cartographers create maps of the ocean floor using the data gathered. Still other men and women are required to operate the boats and helicopters that take scientists out to conduct research.

In addition, there are many careers working in government to help create policy, develop educational campaigns regarding the oceans industry, guard our coastlines, and many other areas. Check out the Canadian Department of Fisheries and Oceans website as well as the Nova Scotia Department of Agriculture and Fisheries and other government fisheries departments in your area for other career options in this industry.

Whatever your interests, consider a career in oceanography or the oceans sector!

When John Cabot first sailed to Atlantic Canada’s coastline over 500 years ago, he saw waters teeming with life. He is credited with proclaiming that there were so many fish that they could “not only be taken with the net but in baskets let down with a stone, so that it sinks in the water!” Over the next few hundred years, fishermen from Britain, France, Ireland, Portugal, Spain and other nations sailed to our waters to catch fish. Thus began our commercial fishing industry.

In those early years, fish were being caught in a sustainable manner. This means that enough fish were left in the sea to reproduce to replace those that were taken; the size of the population remains stable. This changed during the 1900’s when many species of fish were caught more quickly than the population could restore itself. Technological advances, like sonar, allowed fishing boats to locate and catch large schools of fish more quickly and more easily than ever before. New, more efficient harvesting methods, like modern trawling nets, were used to catch more fish than previously. For many species, especially groundfish, this proved to be unsustainable. For example, it is estimated for the first 300 years of commercial fishing activity off what is now Atlantic Canada, less than 200,000 tonnes of cod were harvested each year. In 1968, almost 1,500,000 tonnes were caught! By the early 1990s the commercial cod fisheries off Atlantic Canada’s coast were closed, as the number of fish had plummeted. Other species, however, especially lobster, shrimp and crab have shown tremendous resource strength in recent years. These shellfish species are supporting fisheries that have reached record levels.

Overfishing is not the only reason why the numbers of some species of fish are declining. Changes in water temperature and currents, as well as global warming and pollutants are also being blamed for the decrease in fish stocks. Also, natural variations in population size may play a role in the low numbers of some species.

Governments around the world have recognized the need to create a sustainable fishery for some time. The Canadian government acknowledges that the fisheries resource must be carefully managed to:

1. Ensure commercial and recreational fishing is sustainable in the long-term;
2. Maximize our economic gain; and
3. Provide access to the resource for all Canadians.

To create a sustainable fishery, policies must be enacted that balance the long-term economic interests of players in the industry with the conservation efforts needed to protect the population. Oceanographers conduct various studies to create models and recommendations to policy makers. As there are many variables to consider when predicting how the size of a population will change over time, many different studies are performed.

Variations in temperature and ocean currents can affect both the survival and the location of the early stages of an organism’s life cycle. It can also change the numbers of predators and prey for this species. Oceanographers, in trying to understand the effects these variations have on the size of a population, strive to understand many different organism life cycles, its interactions in the food web (especially in regards to its predators and prey), and the impact of a changing ocean habitat.

Using the data gathered, models are created to predict the effect of different conditions on the population. Policy makers can then use these models to make informed decisions for managing the fisheries. Quotas more in line with sustainable harvesting can be set based on the research, as will the types and amount of fishing gear can be used to catch various fish species.

In order to be effective, fisheries management activities must be backed by sound research and good management decisions, and involve the co-operation of the fishing industry. While this is not an easy task, it is definitely necessary to minimize the ecological damage caused by the industry and maximize the economic benefit.

Play the Fish Habitat Activity. (requires Macromedia Shockwave)

Hundreds of years ago, explorers charted the ocean depths by dropping lead lines from their boats to the ocean floor. While this may have been sufficient then, increasing sea-lane traffic has fueled the need for more accurate information on the depth of the water and the contour of the ocean floor. Offshore drilling activities, fishing boats, recreational crafts, cargo ships, all require the safe navigation of Canada’s waterways. With sophisticated sounding equipment, modern day hydrographers chart these physical features, faster and more accurately than ever before.

Making Charts:

When making nautical charts, great care must be taken to have accurate representations of the coastline. Researchers take detailed measurements from the shore and the water to gather data to reproduce the coastline on charts.

Typically, two main types of sensing systems are used to determine the water depth and the contours of the ocean floor. A sidescan sonar sends out acoustic pulses sideways and downward as the research vessel tows it. Different materials on the sea-floor will reflect the pulses at different speeds and different levels. The towed “fish”, as it is called, records all of this data, which can then be used to display a profile of the sea floor, and indicate its composition. The second system that is often used is the multi-beam sonar, which is usually attached directly to the research ship, instead of being towed like the sidescan sonar. This system also sends out acoustic pulses, and then measures and records the time it takes for the pulses to return. The depth of the water and the bottom’s profile can then be determined.

Bottom Composition:

The composition of the ocean floor in a given area has an impact on anchoring vessels, cable and pipeline placement, biological communities and the types of fishing methods that can be used in that area. Researchers also study the ocean floor to determine the probability of fossil fuel deposits in that area, and to determine the impact of exploring for and development of these deposits on the environment.

In Atlantic Canada, many different types of equipment are used to obtain bottom samples. With some devices, the sample is obtained blindly, meaning the researchers hoist a collector over the side of the vessel without seeing exactly where it lands. This is the case with this sediment sampler. Heavy devices are driven into the ocean bottom by its weight and gravity, to obtain a core sample of the bottom. (see pictures)

Unfortunately researchers have no way of sampling very precise areas with these two pieces of equipment. The Benthic Video-Grab was designed to overcome this obstacle. It has two video cameras, a black and white one that is used to guide the device to a spot on the ocean floor, and a high resolution colour camera that is mounted above the sampling bucket. The Benthic Video-Grab can be triggered to take a sample from the ship when the researchers are satisfied with its placement. A hydraulic ram creates a force up to 1 tonne to slowly force the sampling bucket into the sea floor. The lid then closes and the device is hoisted to the surface where the sediments can be analyzed.

Seawater is made up of approximately 96.5% water, 3.5% sea salts, some dissolved organic matter, other sediments, dissolved gases, and trace metals. Any changes to the amount of these substances, even just a minute amount, can have great consequences for marine organisms. For instance, dissolved salts affect osmotic pressure. The greater the amount of salt, the greater the amount of energy marine organisms need to use to stop water from flowing out of their bodies. Another example is related to the amount of dissolved carbon dioxide in the water. This dissolved gas causes seawater to be slightly alkaline, at a pH of 8.1. Organisms are adapted to this pH, and even slight changes can affect them.

Changes in the amounts of natural substances and the addition synthetic chemicals are altering the chemistry of seawater. Chemical oceanographers study the sources, the movement and the fate of natural and artificial chemicals in the ocean, as well as the general chemical composition of seawater. This data can then be used to determine the impact of these substances on marine life and the environment.

In the series of photographs below, researchers are conducting experiments to determine how deeply the oil descends through the sand on a beach. This will help them determine the impact of a spill on the organisms that live in the sand.

The Batfish is a case designed at the Bedford Institute of Oceanography to hold a variety of sampling equipment. Marine chemists first equipped this case with sensors to measure the salinity, temperature and depth as it is towed through the water. Currently it can be used to measure the amount of light, dissolved oxygen, suspended particles and chlorophyll.

Another area of exciting oceanographic research that occurs in Atlantic Canada is in the area of global climate change. Researchers here are actively participating in The Joint Global Ocean Flux Study (JGOFS), which examines changes in the amount of carbon dioxide in the ocean. Since the ocean contains about fifty times as much of this gas as the air does, any small changes in the ocean’s carbon cycle can have profound effects on the atmosphere’s carbon cycle. These effects may be important when considering a worldwide strategy for dealing with the Greenhouse Effect.

Small plants and animals that can not move independent of ocean currents are called plankton. The plants, called phytoplankton, capture the sun’s rays and fix this energy into biomass. The small animals, called zooplankton, range from microscopic, single-celled organisms, to fish larvae, and all the way up to larger jellyfish. They may feed on phytoplankton, dead organic materials, other animals, or a combination of the three. Both phytoplankton and zooplankton form the basis of any marine food chains and food webs.

Researchers have known for a long time, that the health of plankton communities is often an indicator of the overall health of the marine ecosystem. Oceanographers study the quantity, type and movement of the various species of plankton in the water column, using many pieces of equipment. One piece of equipment, the Batfish, can be used to estimate the quantity of phytoplankton (using the fluorometer, marked F) and zooplankton (using the optical zooplankton counter, marked OPC). Plankton nets, can vary in both overall size and mesh size, depending on what type of plankton is being sampled. It is towed by the research vessel, and the plankton is collected in the bottle at the end of the net. Oceanographers can then determine the quantity, type and vertical distribution of the organisms collected. An interesting component of sampling with these nets is that the types of zooplankton collected depends on the time of day and the depth at which the sample was taken. Most of these small animal species migrate up and down the water column depending on the time of day.

Oceanographers in Atlantic Canada are also participating in several international studies, one of which is the Global Ecosystems Dynamic Program. The Program examines how changes in the environment affect the productivity, quantity and distribution of populations of marine organisms. The research conducted by oceanographers in Atlantic Canada helps to create a clearer picture of the population dynamics of cod, haddock and two zooplankton species on the Georges Bank. Scientists can then create models to help predict the changes in location and numbers of these species as environmental conditions change.

Off the coast of Atlantic Canada lie vast deposits of oil and gas, the most valuable resources that can be taken from the ocean. Oil and gas are the remains of ancient plants and animals buried in sediment layers and then altered by heat. Five kilometres down beneath the ocean floor, 100 to 150 degree Celsius heat can transform deposits of organic matter into oil. If the heating continued for an extended period of time, or if the temperature increased, natural gas or substances we can not use as fuel, may have been made.

About 70% of the undiscovered reservoirs of oil and natural gas are expected to be found beneath continental shelves and shallow marginal ocean basins. As these areas are rich in marine life, the environmental risks and impacts of searching for these fossil fuels and then developing the deposits must be considered. A balance must be struck between the needs of the rapidly developing industry, the economic needs of people who depend on the deposit, and the environmental needs of the natural surroundings.

Researchers in Atlantic Canada gather information on water depth, currents, water temperature, sediments, turbulence, particulate matter, and the biological inhabitants of the drill site, just to give a few examples. All of these factors, in combination, affect the level of impact of any accidental leakage and drilling particulate matter has on the environment. Relevant recommendations on how to minimize or prevent both short- and long-term impacts can then be made.

Oceanographers have many tools at their disposal to collect data. Let’s look at two in particular: a) the BOSS; and b) the Campod.

The BOSS

Current government regulations and guidelines allow the unlimited release of some types of drill mud into the ocean. What happens to these particles as they are released from the drill site? The BOSS was developed to sample the particulate matter in the water at various depths. The spring-loaded syringes are triggered to take a sample and then close at a certain depth. Researchers can then examine the samples to determine which are naturally occurring and which are from the drill site.

The Campod

Some drill wastes aggregate into clumps in seawater. These clumps are so fragile, that sampling with the BOSS can break them apart, making them impossible to study. The Campod has a high-resolution video camera, a camera with flashes and a special sampler called the Slurper. The clumps can then be collected and analyzed to determine what impact the drilling had on their formation, and their impact on the environment.

Using the insight provided by this research, oceanographers interact with policy makers and the oil industry to minimize the impact that oil and gas exploration has on the ocean. In this way we can maximize the economic benefit these opportunities bring, while minimizing the ecological damage.