Unit 4: Primary Resources Food From the Oceans

Technology and Fishing Activity The commercial fishery in most countries consists of two sectors. Inshore Offshore Both sectors use a wide range technology that allows them exploit the fishery.

Inshore Fishery Inshore Fishery: Boats under 25 m Owner operated Suitable for shallow water within 20 miles of shore No refrigeration on board Small Crews Return to port everyday Cannot operate in poor weather

Offshore Fishery Offshore Fishery: Capital intensive: Requires large investments of capital resources (boats, gear, crew) Less labour intensive Large trawlers 35-45m Boats owned by large companies Large range, can fish anywhere They have refrigeration on board so they can stay at sea for long periods

Categories of Fish Caught There are three main categories of fish that are caught in the commercial fishery Demersal: fish that live near the ocean floor; also known as groundfish. Ex: Cod, halibut, and shellfish. Pelagic: Fish that live in schools near the ocean surface. Ex: Mackerel, Herring and Salmon. Shellfish: Aquatic animals that have a shell. Ex: Lobster, crab, mussels.

Fishing Gear There are four types of gear that we will be discussing: 1. Otter trawl 2. Gill net 3. Purse seine net 4. Trolling

1. Otter Trawl Otter Trawl: A funnel shaped net attached to the stern (back) of a trawler by towing cables. Used for demersal species (cod) The net is towed along the sea floor Two boards hold the mouth open Fish are scooped up Only suitable in water no less than 200m deep.

2. Gill Nets Gill Net: A nearly invisible mesh net Held up by floats Dragged down by weights Hangs like a wall in the ocean Mesh is large enough to allow fish to swim into the net but not through it In trying to get out the fish get tangled

3. Purse Seine Net Purse Seine Nets: best looked at as a procedure. Used for pelagic fish. 1. Fish are spotted 2. Net is put out 3. High powered small boat takes the end of the net and circles around the fish, trapping them in. 4. A cable that runs along the bottom of the net is drawn in causing the net to come to the surface. 5. As the net surfaces it is taken into the boat full of fish... Hopefully.

4. Trolling Trolling: Fishing poles with many hooks are extended over each side of the vessel The lines have numerous lures on each line The fish take the lures and are caught. Pelagic fishing.

Trends in global fish catches The location of major fishing grounds: 1. About 80% of fish harvested come from oceans Why is this obvious? Most of the world’s water is ocean therefore it would be expected that fresh water would only contain a small portion of the world’s fish. 2. There are 4 major fishing regions North east Atlantic (England/Norway) North west Pacific (Japan) West central pacific (China/Indonesia) South east pacific. (Western South America)

These images are found in your textbook on pages 199 and 202.

Trends continued The continental shelf Most fishing grounds are found on continental shelves for 2 reasons: 1. The shallow waters of the shelf make harvesting more cost effective. 2. The shallow waters of the shelf promote plankton production which serve as the base of the marine food web including fish Shallow water ensures: enough light for phytoplankton. Effective circulation of nutrients

Trends in NL fish catches… Diagrams & on pages 212 and 213 are graphs that show the long term trends in fish catches in Newfoundland. Figure shows the steady decline in the fishery from 1962 to In the late 1970s-early 1980s there was a small rise in fish stocks which gave scientists hope for the cod stocks. Unfortunately, by the early 1990s it was clear that if drastic measures were not taken the fishery might never come back. This lead to the complete shutdown of the commercial cod fishery in NL, known as a moratorium, in 1992.

Trends… As the ground fish stocks were proving unreliable fishermen began to explore other types of fish through the 1980s. A growing trend in shellfish has come on stream and pelagic fish such as mackerel and capelin have become popular as well. Aquaculture is also fast become a vital part of the Newfoundland fishing economy.

Why? Why did the cod stocks collapse? There were several things that lead to the ultimate collapse of one of the world’s most lucrative groundfish fisheries. Technology – the introduction of factory freezer trawlers, otter trawls, and radar and sonar all allowed fishermen to catch more fish in one voyage than ever before. Ecology – Large by-catches of non-commercial species such as capelin disrupted the food chain, rising ocean temperatures due to climate change affected the survival of the species and inadequate data regarding the ocean ecosystem lead to mismanagement.

Impacts on Marine Ecosystems Types of gear: Some types of fishing gear such as otter trawls greatly disturb the ocean floor and destroy spawning grounds. Air pollution: Damage to the ozone layer has been linked to a decrease in plant production. Phytoplankton is a major food source for fish and it needs sunlight to grow; just like plants on land. Water pollution: Chemicals and waste products that are dumped in oceans affect the entire marine food chain. Plankton, fish, sea birds and sea mammals are all impacted through poisoning, sickness loss of habitat or loss of a food source.

Impacts continued… Over fishing: Severe over fishing of a particular species has led to the collapse of fish stocks and the disruption of the food chain in some areas. Climate change: Climate change has lead to a global change in ocean temperature. While it’s only a few degrees, that is enough to kill off entire species which are accustomed to a particular temperature. Lack of pack ice leads to a decrease in the number of seals as they have no where to give birth.

Major Sources of Ocean Pollution Ships at sea dumping bilge and waste materials such as plastics and other garbage. Runoff from industrial facilities on land. Oil spills from tanker ships transporting oil, or leaks from offshore oil rigs. Air pollution – not only does damage to the ozone layer affect marine life but physical particles of pollution in the air settle on the ocean and hurt marine life. “Down the Drain” mentality – the dumping of oil and chemicals from household use. Used oil from vehicles, chemical cleaners, paint, and road runoff are a huge contributor to ocean pollution. Natural disasters and storms often end up spreading large amounts of debris and pollution into the ocean.

The value of aquaculture Aquaculture is the cultivation of aquatic animals and plants, especially fish, shellfish, and seaweed, in natural or controlled marine or freshwater environments. Economic effects? Provides jobs: fisherpeople, plant workers, truck drivers Helps other industries: nets, ropes, shipbuilding, fibreglass workers, creates work in these areas Facilitates partnerships world wide: governments trade fish quotas with other countries in return for other goods, services, tax breaks, etc. Can create problems when the economy is based too much on one thing. In NL, when the fish stocks collapsed, the economy collapsed too.

Environmental effects? Ocean ecosystems are disturbed by some types of gear If too much of one species is taken the food chain could be disrupted Sometimes some food chains are kept in balance when species are hunted. Ex: Seal hunt kept the seal population in check. Seals are over abundant now and put a lot of stress on cod stocks. Ships that do not follow proper procedures at times dump oil and chemicals in the ocean rather than face the expense of proper disposal. Large by-catches of some species can create problems in the ecosystem. Ex: Dolphins are often caught in Tuna nets. Turtles are often caught on trolling lines.

Issues in a sustainable fishery To maintain a sustainable fishery means learning how to control how much of the resource we use and how to keep the quality of the resource at a high level. It is equally important that once these methods have been discovered, we must practice them. The world’s average consumption of fish is only about 16%. However, in regions with large populations (such as Africa and Asia) fish is much more heavily relied upon as a source of protein. Researchers estimate that as the world’s population rises there will be a greater and greater demand for fish. The current pressure on fish stocks have already cause some to collapse.

Issues continued… Some nations maintain huge fleets of factory-freezer trawlers, factory ships and smaller trawlers and support vessels. These large fleets put enormous pressure on fish stocks and tend to put the small boat fisherman out of work. This causes them to leave their homes and entire communities have disappeared as a result. Many countries with coastline (maritime countries) have extended their legal jurisdiction to 320km offshore to help combat these trends. However, governments often sell licenses to foreign countries to fish within these limits. As well, many foreign countries still send factory-freezer trawlers and fish without permission in (or just outside of) these zones. Some countries have vast maritime regions and do not have the resources to police their 320km limit zones.

These trends have angered inshore fishermen who try to fish in more traditional ways. The foreign fleets put a lot of stress on the offshore stocks, and eventually the inshore stocks. Pages in the text outline some examples of “fish wars” in India and Canada where fish stocks and migrating patterns have caused problems with the neighbours. In 1995 the Canadian government, lead by Newfoundland politicians took on the government of Spain in what became the “turbot war”. The government of NL accused the Spanish government of illegally overfishing within the Canadian zone and also using nets that were too small. There were a lot of disputes with actions almost escalating to violence. In the end there were new treaties and groups put in place to manage such international disputes.