Fishing Methods Compare and Contrast

Gillnetting

Gillnetting

Gillnetting Description: • Curtain of netting hangs in water and traps fish by their gills. • Open water on surface or below. • Shallow inlets across entire vertical water.

Gillnetting Problems? • Bycatch marine mammals, turtles, smaller (nonedible fish) – smaller fish removed from food chain. • Seafloor habitat damaged as dragged a little on bottom with tides and currents. • Across migration inlets – will take EVERYTHING. • Abandoned.

Gillnetting Solutions? • Nets can be left for shorter periods of time. • In estuaries and bays, nets NOT across entire area (allows some to pass by). • Bycatch released (difficult because usually kills them). • Laws passed and enacted to prohibit nearshore gillnetting – increased Redfish Populations.

Longlining Description: •Long lines (up to 50 miles long) with more than 40,000 hooks are laid on ocean floor and then reeled in.

Longlining

Longlining Problems? •Turtles & sharks often caught. • Birds get caught in the hooks because when first put out bait and hook float on surface for a while. Tempting to birds. • Abandoned – problem ocean liners.

Longlining Solutions? •Weight on hooks – sink faster. • Loud cannons or streamers help keep birds away. • Circle hooks can be used to void hooking turtles.

Purse Seining Description: • Net is cast out using a smaller boat, then the net is closed like a “drawstring” bag.

Purse Seining Description: • Net is cast out using a smaller boat, then the net is closed like a “drawstring” bag.

Purse Seining Problems: • Dolphins, sharks, turtles, and immature fish are often caught. • Dolphins feeding on fish.

Purse Seining Solutions? • Nets can be loosened at top to let out dolphins. • Called “backing down” – reverse boat. Does same thing.

Trawling Description: • Boats drag a net that scrapes along bottom of ocean. • Net is “weighted” with wooden “doors.” • Used for many things but common for shrimping.

Trawling

Trawling Problems? • Destroys entirely habitat on ocean floor. • Bycatch. In case of shrimping in nearshore waters – for every 1 lb. of shrimp caught – 10 lbs. bycatch. • Much bycatch is juvenile fishing in estuaries. • Drowns turtles. • Drowns dolphins.

Trawling

Trawling Solutions? •TED’s – Turle Exclusion Devices added to allow turtles to escape. • Turles can be resuscitated. • Laws passed to limit nearshore trawling for shrimp & other species.

Traps/Pots Description: •Baited traps trap lobster and many different crab species.

Traps/Pots Problems? •Females with eggs & Immature animals caught. • Traps are lost and become trash & “ghost” traps that entangle boats. • Traps drag on bottom & destroy habitat. • Marine mammals get tangled in lines.

Traps/Pots Solutions? •Make holes large enough for younger animals to escape. • Educate people on what “gravid” females look like. • Enact laws for “size limits.” • Enact laws for number of traps allowed.

Hand Line Description: • Small boat with hand lines that contain 20-30 hooks each. • Locally target red snapper & grouper. • Sometimes referred to as “bandit” fishing.

Hand Line Problems: • Undesirable species & immature caught. • If caught from deep water, pressure differences cause air bladder to blow up when bring to surface. • Can’t return to bottom fast enough without being eaten by predators even if released.

Hand Line Solutions: • Throw back immature, young or undesired bycatch. • For deep species, slit air bladder before throwing back. Educate people to this.

“General” Solutions for MOST fishing methods. • Enact QUOTA laws. Resistance? “You are taking away our jobs and our livelihood.” • Enact laws related to “time of year” can fish (pertains to commercial AND recreational) – allows gravid females and juveniles to be left alone. Allows species to recover.

Aquaculture and Mericulture Aquaculture – any man raised species. Mericulture – any “marine” man raised species. May be fish or shellfish (clams, oyster, shrimp) Note: Over 50% of all marine fish and shellfish come from mericulture facilities – NOT caught in wild.

Suspended Shellfish Description: • Shellfish (different species of clams/oysters etc.) raised on lines or in mesh bags suspended vertically in a NATURAL aquatic ecosystem. • Like any other “commercial” operation – can be VERY large scale.

Suspended Shellfish

Suspended Shellfish Problems: • Lead to concentration of waste. Increased nitrates and phosphates – harmful algal blooms. • Non-native species can be introduced to natural environments. May outcompete native species.

Suspended Shellfish Solutions? • Laws related to population densities enacted. Reduce waste accumulation. • Laws related to NO non-native species. • Laws enacted to create these “farms” well offshore to prevent waste accumulation due to mixing of water..

Fish Ponds Description: • Fish and shrimp are raised in “enclosed” inland ponds. Often near coast for “water” source. • In U.S., common way to raise shrimp in South Texas. Ponds are near power plants and they use heated “effluent” water to raise shrimp in winter. • Also used heavily in Caribbean areas including Islands to raise shrimp. Belize

Fish Ponds Ecuador

Fish Ponds Problems: • Habitat Destruction. In Caribbean destruction of important Mangrove Forests. • Concentrated Waste. Phosphate, Nitrate  eutrophication of associated waters. Belize

Fish Ponds Solutions: • Wastes can be collected, contained, and treated much as they do with feedlot waste and human waste. • Laws enacted on where and how “dense” to build to protect habitats. Belize

Recirculating Systems Description: • Fish are raised in enclosed tanks where water is treated and recirculated in system. • Here is U.S., freshwater Tilapia (aquaculture – not mericulture) is a common species. Can be raised in barns by farmers, but also big business. Tilapia can also be raised in OUTDOOR fish ponds.

Recirculating Systems

Recirculating Systems Problems? • Uses LOTS of electricity – heating water, pumps, etc. • Feed has been shown to contain pollutants – increases concentration in fish. For example – farm raised salmon – increased concentration of mercury.

Recirculating Systems Solutions? •Educate people to limit the amount they eat per month. • Use nutrients from plants in a combined “aquaculture/hydroponics” system to reduce amount of harmful food to fish.

Fish Cages Description: • Fish are raised in enclosed cages in a NATURAL aquatic ecosystem. • Hundreds of cages.

Fish Cages Problems? •Fish escape? – non-native species introduced • Can also occur because eggs/sperm released into water (just like shellfish) • Concentration of waste ->eutrophication • Spread of disease (any time organisms are concentrated) • Interbreeding takes place

Fish Cages Solutions? •Native species only. • Limited populations to reduce waste and spread of disease. • Laws related to this.