1. Fishing Methods
Compare and Contrast

2. Gillnetting

3. Gillnetting

4. 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.

5. 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.

6. 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.

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

8. Longlining

9. 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.

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

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

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

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

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

15. 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.

16. Trawling

17. 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.

18. Trawling

19. 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.

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

21. 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.

22. 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.

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

24. 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.

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

26. “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.

27. 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.

28. 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.

29. Suspended Shellfish

30. 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.

31. 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..

32. 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

33. Fish Ponds
Ecuador

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

35. 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

36. 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.

37. Recirculating Systems

38. 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.

39. 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.

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

41. 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

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