Presentation on theme: ".t.y.p.e.s..o.f..f.i.s.h.i.n.g. [ netting ] ( drift netting & gill netting ) [ seining ] ( purse seine and beach seine) [common in BC] ( trawling and."— Presentation transcript:
.t.y.p.e.s..o.f..f.i.s.h.i.n.g. [ netting ] ( drift netting & gill netting ) [ seining ] ( purse seine and beach seine) [common in BC] ( trawling and trolling )
.n.e.t.t.i.n.g. DRIFT Is one of the most destructive methods of fishing; known as the 'wall of death' Strong plastic webbing up to 15 m in height & up to 64 km long Forms a wall beneath the water & catches anything!
.n.e.t.t.i.n.g. GILL NET Is a wall of netting set in a straight line Fish swim through the virtually invisible netting, & are entangled when their gills are caught in the webbing Most commonly used on the Fraser River
.s.e.i.n.i.n.g. PURSE A long and deep net with small webbing Uses a net which can be "pursed up" around a school of fish Used to catch surface dwelling species such as tuna, & mackerels
.s.e.i.n.i.n.g. BEACH SEINE Surrounding of a school of fish using a single boat Sardine, mackerel, Spanish mackerel, hard tail, sea bream and flat fish, may be caught by this method
TRAWLING Funnel shaped net attached to a ship by long ropes Can harvest bottom- dwelling fish when dragged along the ocean floor Leaves ‘trawl marks’ on the oceans floor and damages coral reefs.c.o.m.m.o.n..i.n. b.c.
.c.o.m.m.o.n..i.n. b.c. TROLLING Dragging a flashing lure or a herring bait behind a boat Trolling is simply towing single fishing lines behind a moving boat
.f.i.s.h.i.n.g. WHAT PROBLEMS are caused by these FISHING TECHNIQUES? Kills other marine mammal (entangle other marine life) since the nets are not picky Destroys the wild habitats when they drag on the ocean floor Rob the ocean’s biodiversity
.b.i.o.s.p.h.e.r.e. Loss of biodiversity could threaten the food supply of other species (Alteration of the food chain) Add stress to marine organism & may lead to species extinction Entangled marine animals and birds causes unnecessary deaths Dredging and trawling: Destruction of habitats adds stress to other species Overpopulation of one species, under population of another (due to over-fishing)
Nets destroy coral reefs results in greater waves more wave erosion on land.l.i.t.h.o.s.p.h.e.r.e. B e f o r e A f t e r
.a.t.m.o.s.p.h.e.r.e. Less fish more plankton More O2 in water
.h.y.d.r.o.s.p.h.e.r.e. Pollution From ships and equipment
.p.o.s.s.i.b.l.e..s.o.l.u.t.i.o.n.s. Practice selective fishing Install devices to allow unwanted animals to escape - Reserve and protect certain areas for fish harvesting Instead of fishing, turn to aquaculture Limit fishing (Fishing seasons) More strict penalties on fishing violations Lower the amount of fish that companies can catch Stop commercial fishing for several years
.p.o.o.r.l.y..m.a.n.a.g.e.d. The commercial catch in California has raised from around 2.1 billion pounds (1990) to 430 million in (1998) Every year about 70 marine mammals die in drift nets in the waters off the California coast. About 35 species dies in the hands of the “wall of death.” Why did this happen? Population is high & demands for great quantity of fish Overfishing To make money and raise up the economy
E n v i r o n me n t a l l y The Packard Foundation Conservation Program seeks to ensure a healthy future for all life by conserving critical natural systems, addressing key threats to these systems, and providing the scientific information and training that will enhance their conservation. Progress has been made at regional fishery management councils to reduce fishing for depleted species, reduce bycatch, and improve provisions for habitat protection. WHY? To protect the oceans and its living organisms
A big thank you to these websites: Fishing: tm TypesOfFishing.htm
.a.q.u.a.c.u.l.t.u.r.e. What is aquaculture? Aquaculture or fish farming, is the farming of fish, shellfish and aquatic plants in fresh or salt water. Why do we farm fish? To bridge the gap between the wild catch and the demand for fish.
What kinds of species are farmed? Salmon Farming: Salmon, trout & char Mollusk farming: Oysters, mussels, scallops & clams Tilapia and carp farming Crustaceans farming: shrimp, prawns & crabs.a.q.u.a.c.u.l.t.u.r.e.
Some of the most common methods of aquaculture are: Pond Culture Raceway Culture Cage Culture Tank Culture.a.q.u.a.c.u.l.t.u.r.e.
.p.o.n.d..c.u.l.t.u.r.e. Pond culture is … The most widely practiced form of aquaculture Natural ponds mimic nature have a natural supply of food healthier fish production
.r.a.c.e.w.a.y. Raceway Culture is… Flow through or open systems Enclosures where the water moves through at a rapid rate, carry wasters out at the lower end Production is intensive (why? Due to a steady flow of water) Trout are most commonly produced in raceways
.c.a.g.e..c.u.l.t.u.r.e. Cage Culture is….. Involves placing a mesh or wire cage in a flowing, open water system, such as a lake, stream, reservoir or ocean Constant H 2 0 flow is critical as it renews the O 2 supply & removes waste products Salmon & barramundi are often grown in cages
.c.a.g.e..c.u.l.t.u.r.e. Very large cages are constructed w/nylon or plastic netting are often called net pens Generally constructed in open H 2 O Disadvantages: Fish escapment & rapid spread of diseases
.t.a.n.k..c.u.l.t.u.r.e. Tank Culture is……. Often are a closed system Water is recirculated through filters & pumped back in the tank Expensive to operate Used as a commercial holding facilities for the live export of crayfish
.a.q.u.a.c.u.l.t.u.r.e. WHAT PROBLEMS DOES AQUACULTURE CAUSE? Pollution to the environment (organic & chemical pollutants) Brings diseases to wild mammals Adds stress to the wild mammals living in that ecosystem
.b.i.o.s.p.h.e.r.e. Increase food population Medical & educational purposes Organic pollutants (uneaten fish food and waste) Adds stress on the marine organisms Increase in bacteria, viruses and other pathogen Exposes farmed and wild fish to the ill effects Chemical pollutants (antibiotics, pesticides) Toxic effects on marine habitat species extinction Alteration of the food cycle
Dropping of nets and other equipment smothers organisms and physically alter the habitat Escaped farm-raised fish Drive some species to extinction due to competition for food and shelter Disruption of ecological process Threat to biodiversity Salmon and shrimp farming negative ecological impact.b.i.o.s.p.h.e.r.e.
.a.t.m.o.s.p.h.e.r.e. Increase in waste material less O 2 increase in CO 2
.h.y.d.r.o.s.p.h.e.r.e. Salmon and Shrimp Farming: Intensive aquaculture overcrowding poor water quality Mollusk farming: Clams & oysters filters the water Cleaner water
.p.o.s.s.i.b.l.e..s.o.l.u.t.i.o.n.s. THE BEST SOLUTION: Replace net cages with closed-loop containment systems -Complete separation of wild & farm environments - No pollution in the local environment - Zero escapes - More efficient use of food
.p.o.s.s.i.b.l.e..s.o.l.u.t.i.o.n.s. OTHER SOLUTIONS: Use native salmon only (prohibit the use of exotic species) Educate aquaculture companies and to raise awareness Hype up the mollusk farming (safer) Escape prevention programs
In August 2000, more than 32,000 Atlantic salmon escaped from net pens in Johnstone Strait off northeastern Vancouver Island. Why did it happen? Net pens are cheaper to operate Provides needed year-round employment in coastal areas hard hit by a downturn in logging A money maker (Economy goes up) There is no escape prevention (Government standards to not protect the ocean and marine life).p.o.o.r.l.y..m.a.n.a.g.e.d.
.e.n.v.i.r.o.n.m.e.n.t.a.l.l.y..m.a.n.a.g.e.d. In Flour Bluff, Texas, there are 6 mariculture ponds which are homes to crustaceans. That includes everything from indoor tanks to greenhouse-enclosed "raceways" & open-air ponds where large numbers of juvenile shrimp are placed for their final growth. Why did it happen? To protect the environment and living organisms To achieve sustainability
Aquaculture: aculture/ farm31m.html A big thank you to these websites:
Hey, YOU wake up!! :)
.s.h.e.l.l.f.i.s.h..h.a.r.v.e.s.t.i.n.g. What are shellfish? An aquatic animal, such as a mollusk or crustacean, that has a shell or shell-like exoskeleton Shellfish include clams, oysters, and mussels. The term shellfish does not include crabs, lobsters/shrimp Filter-feeding animals (get food & O 2 by pumping large quantities of H 2 O across their gills)
.s.h.e.l.l.f.i.s.h..h.a.r.v.e.s.t.i.n.g. What is shellfish harvesting? Farmers’ takes a shellfish from their own habitat Bringing them to a new area Making them reproduce faster
.s.h.e.l.l.f.i.s.h..h.a.r.v.e.s.t.i.n.g. The methods of shellfish harvesting are: [ dredging ] [ raking ] [ trapping ]
.s.h.e.l.l.f.i.s.h..h.a.r.v.e.s.t.i.n.g. Dredging is … Used for the commercial harvesting of scallops, clams, oysters & mussels Consists of a metal rectangular frame to which a bag-shaped net of metal rings is attached Raking bar, and is often equipped with metal teeth used to dig up the bottom
.s.h.e.l.l.f.i.s.h..h.a.r.v.e.s.t.i.n.g. Raking is … Used to harvest clams and seaweed Scratch rakes or clam rakes are like heavy garden rakes with longer, sharper teeth that are often curved upward toward the inside of the rake
Potting/Trapping is … Often designed specifically for one type of fish or shellfish Generally baited and equipped with one or more funnel openings, they are weighted to rest on the bottom.s.h.e.l.l.f.i.s.h..h.a.r.v.e.s.t.i.n.g.
.b.i.o.s.p.h.e.r.e Due to human activities or natural biotoxins Shellfish contamination pose a threat to human health and a threat to the other living organisms Alteration in the food cycle Loss of biodiversity Loss of environmental indicator Increase food production
.h.y.d.r.o.s.p.h.e.r.e Less shellfish Contaminated water Since only the shellfish classed as bivalve mollusks feed by filtering the water that washes over the shellfish bed, when there is a decrease of mollusks due to commercial fishing, there is an increase of pollutants in the ocean.
.a.t.m.o.s.p.h.e.r.e Less shellfish in the ocean to filtrate the water Water becomes contaminated Temperature rises, evaporation takes place Evaporates the contaminated and polluted water We breathe in the polluted air
.l.i.t.h.o.s.p.h.e.r.e Dredging destroys coral reefs results in greater waves more wave erosion on land
.p.o.s.s.i.b.l.e..s.o.l.u.t.i.o.n.s. Closed seasons (the period during which removal of a resource is not allowed) Size and bag limits Direct discharges of raw sewage from moored or anchored boats and from shore-side residences
.p.o.o.r.l.y..m.a.n.a.g.e.d. In Florida, over-harvesting shellfish for the seafood industry alters the complex food web of the coral reef community. The destructive method of dredging for shellfish has destroyed the ‘once beautiful and colourful coral reef community.’ Why is this happening? Population is high & demands for great quantity of fish Overfishing To make money Carelessness, insensitivity & ignorance
Shellfish Harvesting: mpo.gc.ca/ops/fm/shellfish/Biotoxins/biotoxins.htm TON_SHIPPING_DIBDENBAY0.html agency.gov.uk/yourenv/eff/water/213925/shellfish/?version=1&lang= _e A big thank you to these websites:
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