Chapter 12: Food from the Oceans

Major Sources of Ocean Pollution 4 major types 1.Oil 2.Toxic Material 3.Dangerous Debris 4.Withdrawals and Deposits

Major Sources of Ocean Pollution… 1. OIL Disasters make headlines, but hundreds of millions of gallons of oil quietly end up in the seas every year, mostly from non-accidental sources When it comes to mixing oil and water, oceans suffer from far more than an occasional devastating spill.

Major Sources of Ocean Pollution… 2. Toxic Material Industrial, agricultural, household cleaning, gardening, and automotive products regularly end up in water. TBT, or tributyl tin, is added to boat paints to kill or repel barnacles and other nuisance organisms that foul ships' hulls.

Major Sources of Ocean Pollution… 3. Dangerous Debris Our trash kills. When odds and ends of life on land-- particularly plastics--end up in the sea, they pose hazards to marine life.. Animals drown or strangle from getting tangled in discarded or lost fishing gear, or suffer and even die from eating plastics and other garbage

What is the relationship between these pictures?

Major Sources of Ocean Pollution… 4. Withdrawals and Deposits For thousands of years humans have viewed oceans as vast dumps for domestic, municipal, and industrial garbage Enormous deep-sea resources will undoubtedly attract more miners in the future, as easy-to-reach deposits on land are depleted.

Example: Mining sand from the shores of Belize for landfills in Central America

Impact of New Catch Technology on the Environment Factory freezer Trawlers have likely had the most significant and negative impact Highly efficient at catching fish which greatly reduces the population & reproduction. Large diesel engines, echo sounding equipment, onboard freezers, and GPS navigation contribute to their efficiency.

Destruction of the ocean floor by trawls/draggers eliminates good spawning locations for fish. Furthermore it disperses eggs making fertilization more difficult. By catch is often discarded. Some regulations require ships to return with low levels of by catch. Traveling great distances and being able to stay at sea for long periods allows trawlers from all over the world to congregate in good fishing areas. This puts added pressure on the fish stock.

Declining fish resource & the livelihood of fishers. The declining fish resources may have a variety of affects on fishers. Fishers may concentrate more on conservation.

Fishers and the community they live in will have to diversify or die. Develop aqua-culture ex. Bay d’Espoir Golf course construction ex. Frenchman’s cove Sea weed aqua-culture ex. Isle aux Morts Eco-tourism ex. Northern Peninsula Fish underutilized species

Fishing Technology Gear & technology = (figure on page 206 shows all fishing gear very well) Fixed gear such as: gill nets, long lines purse seines Otter trawls Trolling lines

Fishing Gear is divided into 2 types: 1. Pelagic 2. Demersal Pelagic means living in open oceans, fish include capelin, cod and herring Demersal mean to dwell at or near the bottom of a body of water, fish species include flounder, halibut and turbot

Demersal Fishing Gear The funnel shaped net scoops the fish off the bottom. However there is a lot of concern lately over the amount of damage the trawl does as it scraps along the ocean floor 1. Otter Trawl is the most common method used to catch demersal species Otter Trawl at Marine Institute Flume Tank

Otter Trawling

The term ghost nets usually refer to this type of net that has gotten away from its mooring or been lost. It is believed to continue catching fish for years as it drifts though the ocean. 2. Gill Nets Can catch pelagic or demersal species. The thin mesh hangs in the water and fish get caught up as they try to swim through it

This is one of the techniques that has very little environmental opposition. 3. Longline: This is a more efficient way of doing the old fashion baited hook It is commonly used to catch dermersal species but can be used to catch pelagic species The difference is that many hooks are hung off a long main line which floats on top of the water.

LONGLINES

They crawl in and can not crawl out. The lobster and crab pots are good examples. 4. Traps: Traps are specifically designed for certain pelagic species.

Pelagic Fishing Gear Fishing lines are dragged behind the boat which trolls along at slow speed. 1. Trolling: works well for pelagic species like salmon, tuna & bill fish.

The purse string closes the bottom of the net catching the fish inside. 2. Purse Seines: These are particularly good for pelagic species. Two boats are required as one holds one end of the net while the other circles the net around the school of fish.

Sustainability in Fisheries… Sustainability refers to the ability to keep a resource in existence or to maintain a resource for the future. There are several ways to make our fishing resources sustainable for the future. 1. Aquaculture and Fish Hatcheries 2. Habitat Preservation or Restoration 3. Quotas that can support the stocks 4. Using Gear that is less damaging to fish and fish habitat 5. Fishing of alternative and under-utilized species