CAPTURE FISHERIES | MARINE INVASIONS | MARINE POLLUTION

CAPTURE FISHERIES

I. Strategies to combat overfishing of target species

A) Spatial management

1. Establish rotating or permanent no-take zones
2. Designate no-human-entry zones
3. Designate temporal closures (e.g., during spawning aggregations)
4. Prohibit gear types in certain areas
5. Plan for uses that discourage fishing practices (e.g., wind farms)

B) Nationalization or privatization of resources

1. Expand exclusive economic zones (EEZs) more than 200 meters offshore
2. License individual fishers and boats
3. Privatize fishing rights
4. Establish fisheries management organizations for high seas management

C) Effort and capacity reduction

1. Establish quotas for fisheries catches
2. Eliminate fisheries subsidies that encourage overfishing (e.g., fuel subsidies)
3. Restrict number of fishing days
4. Enforce gear and vessel restrictions (e.g., ban gear types, set caps on engine power)
5. Encourage gear innovation to improve selectivity (e.g., www.smartgear.org)
6. Promote gear exchange programs
7. Finance low-interest loans to convert gear to more sustainable types
8. Restrict vessel numbers
9. Organize boat buyback schemes
10. Ban nonselective fishing practices
11. Ban high-grading (in which only the most profitable individuals or species are landed)

D) Alternatives that augment demand for certain species

1. Enhance fisheries with hatcheries
2. Enhance supply using aquaculture

E) Reduction or encouragement of demand for certain species

1. Use boycotts
2. Promote certification (e.g., ecolabels)
3. Distribute seafood guides (i.e., on what to eat, where to eat)
4. Substitute products (e.g., Omega-3-rich oilseeds, cloned Omega-3-rich pigs)
5. Improve conversion ratios of fishmeal to farmed fish
6. Subsidize and incentivize herbivore cultivation
7. Encourage fishmeal alternatives (e.g., vegetable, soy, or insect meals)

II. Strategies to reduce ghost fishing by lost or discarded fishing gear

A) Reduction of snagging and gear loss

1. Create zones for active and passive fishing
2. Modify gear

B) Reduction of ghost gear efficiency

1. Encourage use of biodegradable panels in traps

C) Improved accountability for owners of gear

1. Attach transponders to gear
2. Use satellite detection of gears and traps
3. Establish means of reporting lost gear
4. Issue fines for late return (i.e., after close of season) of gear leased from government
5. Register gear

D) Gear recovery programs

1. Take advantage of opportunistic gear recovery during fishing surveys
2. Make use of scuba diver recovery
3. Offer rewards for finding and returning lost gear

III. Strategies to ameliorate indirect impacts of fishing on habitat and sessile organisms

A) Coral reef restoration

1. Build rock piles, reef balls to rehabilitate coral reef
2. Use steel cages fed with electric current to rebuild coral reefs
3. Farm juvenile corals and/or coral fragments

B) Gear modification

1. Outfit trawls with raised footrope so bottom habitat is avoided

C) Installation of physical barriers to prevent certain fishing gears (e.g., trawls)

1. Install artificial reefs or other barriers that deter trawling

IV. Strategies to lessen bycatch of fish and discards

A) Reduction of effort

1. Set bycatch quotas
2. Establish time-area restrictions
3. Implement ‘move-along’ rules, which require boats to avoid areas where bycatch could be high

B) Improved survival of bycatch

1. Release live bycatch first before handling target species

C) Gear modification to improve selectivity

1. Include escape gaps in fish traps
2. Use bycatch reduction devices in trawls that allow the escape of finfish via an opening or group of openings in a trawl (e.g., Nordmore rigid grids, square mesh codends rather than diamond mesh, benthos release panels in trawls)

V. Strategies to reduce bycatch of marine megafauna (i.e., mammals, turtles, elasmobranchs)

A) Reduction of dolphins caught in purse seines

1. Employ back-down maneuver for purse seines
2. Use acoustic deterrents
3. Create and enforce regulations

B) Reduction of marine mammal mortality in gill nets

1. Deploy net at different levels in the water column
2. Deploy rescue groups to release tangled individuals
3. Use acoustic deterrents

C) Reduction of marine mammals caught in trawls

1. Use acoustic deterrents
2. Use bycatch reduction devices in trawls that allow the escape of mammals via an opening or group of openings in a trawl (e.g., excluder panels, escape hatches, large mesh in leaders)

D) Reduction of turtles caught in trawls

1. Use bycatch reduction devices (e.g., turtle excluder devices (TEDs))

E) Reduction of turtles caught in longlines

1. Use blue-dyed bait
2. Use circle hooks in place of Japan hooks and J hooks
3. Change fish for bait (e.g., using mackerel instead of squid)
4. Shorten daytime gear soak times
5. Deepen daytime gear soak times
6. Use treated bait (e.g., with quinine, hydrochloride, habanero chili extract, urea, squid ink, cilantro, sea hare ink)
7. Use countershaded floats (blue on bottom, orange on top)
8. Use dark gray lines
9. Paint hardware to remove metallic shine
10. Use downwelling narrow-frequency yellow electronic diode light sticks
11. Attach lead weights to gear
12. Attach 1–2 midwater floats to main line

F) Reduction of elasmobranch catches in longlines

1. Ban wire leaders in pelagic longlining
2. Use magnetic gear components

VI. Strategies to avoid bycatch of seabirds

A) Reduction of bird bycatch in longlines

1. Use streamer lines to scare birds
2. Deploy sets underwater
3. Weight the lines
4. Use shark liver oil (to deter seabirds from diving for bait)
5. Use blue-dyed bait
6. Use a bait-casing machine
7. Be strategic when discharging offal
8. Use a water cannon
9. Use acoustic deterrents
10. Deploy sets at night
11. Enforce seasonal and area closures
12. Externally weight and/or integrate the weights of the lines
13. Set lines at the side rather than the stern because birds avoid foraging closer to boats
14. Use an underwater setting funnel (deploys the longline 1-2 m below the surface)
15. Thaw the bait
16. Tow buoys

B) Reduction of bird bycatch in gill nets

1. Add a string of lightly visible netting to the upper part of the net
2. Use acoustic deterrents
3. Reduce deployment time (eliminating down sets)
4. Modify drift gill nets to reduce bycatch of auks

C) Reduction of bird bycatch in trawls

1. Use orange plastic cones to reduce seabird collisions with trawler warp cables
2. Use streamer lines
3. Use anticollision devices (e.g., Brickle curtain)

VII. Strategies to encourage compliance

A) Surveillance

1. Deploy patrol boats
2. Organize vessel monitoring systems
3. Make use of citizen surveillance
4. Use onboard human observers
5. Enforce port controls
6. Monitor with onboard closed-circuit television
7. Identify nationality of ship with flags

B) High fines and penalties
C) Licensing

1. License boats
2. License buyers

D) Eliminate flags of convenience
E) Monitor the seafood and wildlife trade

MARINE INVASIONS

I. Invasion vector: ballast water

A) Reduction or elimination of living organisms in ballast water and sediments

1. Avoid ballasting in departure port when harmful species are known to be present
2. Avoid ballasting at night to reduce intake of vertical migrators
3. Avoid ballasting if propeller wash, dredging, or other disturbances have suspended benthic species
4. Exchange coastal ballast water with high-seas water in the midocean¹
5. Chemically treat water on intake, during transport, or upon discharge (e.g., nitrogen supersaturation, sodium chlorine)²
6. Physically treat water on intake, during transport, or upon discharge (e.g., heating, filtration, ultraviolet, centrifugation)²

II. Invasion vector: vessel fouling

A) Reduction or elimination of living organisms on hulls, anchors, sea chests, and other fouled surfaces

1. Increase frequency of vessel hull, sea chest, and seawater piping system cleaning
2. Wash anchor chain and anchor upon seabed retrieval with high-power hose systems
3. Increase maintenance frequency of nontoxic antifouling coatings on vessel surfaces
4. Use alternative hull-treatment antifouling strategies (electrical, ultrasound) to prevent settlement and transport of species
5. In dry dock, require that all biological materials removed from vessel be disposed of on land
6. When vessels are dry-docked, change vessel support blocks at each docking, and thus reduce the amount of space not regularly resurfaced with antifoulants
7. Reduce port residency time, with concomitant economic benefits

III. Invasion vector: mariculture or aquaculture

A) Reduction or elimination of organisms associated with importation of nonnative species

1. Physically remove epibiota or endobiota
2. Chemically remove epibiota or endobiota

B) Reduction of species escape from open sea cages, seaside ponds, or other vulnerable enclosures

1. Increase security of pens, cages, and ponds

C) Reduction of escape of fouled gear from aquaculture facilities

1. Increase security of gear, with concomitant economic incentives to reduce the need to replace lost gear

IV. Invasion vector: sea level or lock canals

A) Creation of barriers

1. Install electrical barriers to reduce or eliminate movement of nektonic species
2. Create chemical barriers to reduce or eliminate movement of nektonic species, using nontoxic repellent chemicals, such as heterotelergones, that keep species from moving into new regions

V. Invasion vector: public release of aquarium animals and plants

A) Regulatory ban

1. Increase enforcement and fines
2. Prohibit sale of species likely to successfully invade the region where they are sold

VI. Invasion vector: live seafood industry

A) Reduction or elimination of organisms associated with transfer of live seafood

1. Physically remove epibiota or endobiota
2. Chemically remove epibiota or endobiota

B) Inspection of products for associated species

1. Intercept shipments for quarantine, treatment, or destruction as necessary

VII. Invasion vector: live bait (marine worm) industry

A) Elimination of transfer of nontarget species

1. Inspect bait shops and bait buckets in field³
2. Require on-land disposal of live bait
3. Restrict sale/transportation of nonnative bait
4. Replace seaweed dunnage with abiotic packing material

VIII. Invasion vector: footwear of fishermen, birders, students, researchers, etc.

A) Reduced transport of species on boots and other footwear

1. Use footwear that reduces entrainment and attachment of living organisms
2. Wash footwear with water or chemical baths
3. Physically inspect footwear and remove entrained organisms

IX. Invasive invertebrates, fish, or plants (general)

A) Chemical treatment

1. Use microencapsulated salts and amines (“biobullets”) that treat bivalves, sea squirts, sponges, bryozoans, and other species⁴
2. Generally apply biocides (pest or nonpest specific) to treat target species (and often nontarget sacrificial species as well)

B) Physical treatment

1. Hand-harvest using volunteer or paid personnel, or mechanically harvest using specialized or nonspecialized equipment, or employ nonspecialized, broadcast destructive treatment⁵
2. Offer a public bounty (per specimen retrieved) on target species; nontarget species are often misidentified as target species and taken in large numbers by public
3. Use large-scale trapping efforts for mobile animals
4. Use baited or pitfall traps
5. Use sex pheromones for targeting and trapping

C) Biocontrol

1. Introduce prey- or host-specific nonnative predators or parasites (including castrators) to control invasive species;⁶ the exotic biocontrol agent must have been exhaustively documented as solely host-specific with no chance of jumping to nontarget species
2. Augment native predators, parasites, or other biological agents^6,7

D) Genetic engineering (in all cases accompanied by a management plan that prevents backflow or transport of genetically modified species into their native regions, if native species are being used)

1. Decrease pest viability by genetically modifying individuals of invasive species to reduce environmental tolerance, fitness, or reproductive capacity (e.g., ploidy manipulation, release of sterile males, immunocontraception); or introduce an inducible fatality gene and then flood environment or target populations with these farm-raised populations^3,7
2. Genetically modify native species to use them as vectors for physiological inhibitors⁶
3. Genetically modify prey- or host-specific nonnative predators or parasites

E) Physiological control/modification

1. Use chemical inhibitors or disruptors, including those that interfere with feeding, locomotion, or reproduction

F) Environmental remediation

1. If invasive species are thriving in degraded areas, restore the habitat, abate pollution, restores fisheries (and native predators and general ecosystem functioning), etc.^6,7,8

G) Exploitation

1. Encourage commercial utilization (though use of a species for commercial purposes may encourage spreading it to new regions to establish new exploitable—harvestable—populations; in addition, harvest for sport or commercial fisheries must demonstrate that the product is not a health hazard)

H) Early detection/rapid response (EDRR)

1. Establish monitoring and surveillance programs to detect arrival of new invasives, followed by a preestablished isolation and eradication program⁷

X. Invasive ctenophore

A) Biocontrol

1. Use a prey-specific nonnative predator, such as the comb jelly (Beroe ovata), to prey on invasive comb jellies (Mnemiopsis leidyi); Beroe has invaded the Black Sea and Mnemiopsis has declined, but Mnemiopsis remains predator-free in the Caspian Sea

XI. Invasive algal blooms

A) Chemical treatment

1. Use biocides to treat the green alga Caulerpa taxifolia (e.g., chlorine, copper sulfate)

B) Physical treatment

1. Use a “super sucker,” a barge-mounted underwater vacuum cleaner, to eradicate nonnative algae
2. Use opaque tarps to cover and kill the plants

XII. Spread of parasites from mariculture

A) Eliminating sea lice

1. Locate mariculture sites at a distance from potential sources of infection⁹
2. Separate smolts by year-class and do not introduce to a site with older fish⁹
3. Fallow mariculture sites two to six weeks to break the life cycle of the louse⁹
4. Try a therapeutant option (e.g., organophosphorous pesticides or emamectin benzoate (SLICE))⁹
5. Limit density of fish in mariculture sites and try spacing pens more widely

MARINE POLLUTION

I. Organic, inorganic, and toxic pollution from human waste and terrestrial industrial activity

A) Bans/regulations

1. Prevent use of certain chemicals
2. Maintain, enhance, or protect natural biological filters (wetlands, mangroves, reedbeds)

B) Treatment

1. Use secondary and tertiary treatment of human, terrestrial agricultural, and industrial waste
2. Subsidize treatment plants in developing countries to protect sensitive coastal habitats
3. Employ dispersants for oil

C) Gear innovation

1. Encourage use of double hulls to prevent oil spills
2. Encourage use of biodegradable packing bands

D) Clean up

1. Physically remove the pollution (e.g., for oil, use booms and skimmers)
2. Biologically remove (e.g., bioremediation)
3. Chemically remove

II. Organic and chemical pollution from carnivorous mariculture

A) Bans/regulations on type of aquaculture or type of antibiotics used
B) Integrated multitrophic aquaculture systems

1. Grow mussels and kelp alongside salmon
2. Farm fish and shrimp along with seaweed and filtering bivalves
3. Culture carps of different trophic levels

C) Reducing waste from fish meal

1. Improve pellet integrity
2. Use technology to monitor and reduce amount of uneaten pellets

III. Noise pollution

A) Bans/regulations

1. Make use of spatial planning (e.g., disallow shipping lanes in critical habitats)
2. Establish maximum noise ratings

B) Reduction of noise pollution from shipping/boats

1. Change ship design
2. Reduce speed
3. Establish noise ratings

C) Reduction of demand for shipping

1. Produce and use locally, reduce need for shipping, and use land-based transport where possible

D) Reduction of seismic noise pollution

1. Improve design of air guns to achieve more directionality
2. Encourage soft starts

E) Reduction of civilian sonar use

1. Avoid sensitive regions in the sound spectrum
2. Switch off sonars when not in use

IV. Nuclear pollution

A) Implement a regulatory ban on marine burial of nuclear waste
B) Locate use, processing, and storage in close proximity

References

1. Carlton, JT, Reid, DM & van Leeuwen, H. Shipping Study: The Role of Shipping in the Introduction of Non-indigenous Aquatic Organisms to the Coastal Waters of the United States (other Than the Great Lakes) and an Analysis of Control Options. National Sea Grant College Program/Connecticut Sea Grant Project R/ES-6. Report no. CG-D-11-95. Government Accession Number AD-A294809 (Department of Transportation, US Coast Guard, Washington, DC, and Groton, CT, 1995).
2. Dobroski, N, Scianni, C, Gehringer, D &Falkner, M. Assessment of the Efficacy, Availability, and Environmental Impacts of Ballast Water Treatment Systems for Use in California Waters (California State Lands Commission, Marine Facilities Division, Sacramento, 2009).
3. Grosholz, E & Ruiz, G, eds. Management Plan for the European Green Crab (Green Crab Control Committee, Aquatic Nuisance Species Task Force, Washington, DC, 2002) [online]. www.anstaskforce.gov/Species%20plans/GreenCrabManagementPlan.pdf.
4. Aldridge, DC, Elliott, P & Moggridge, GD. Microencapsulated BioBullets for the control of biofouling zebra mussels. Environmental Science and Technology 40, 975–979 (2006).
5. Fisk, DA, Vail, L & Hoggett, AK in The Great Barrier Reef: Science, Use and Management, a National Conference; Proceedings Vol. 2 (Campbell, J & and Dalliston, C, comps), Cost-effective small-scale crown-of-thorns starfish eradication procedures using acid injections (Great Barrier Reef Marine Park Authority, Townsville, Australia, 1997).
6. Thresher, RE & Kuris, AM. Options for managing invasive species. Biological Invasions 6, 295–300 (2004).
7. GESAMP. Opportunistic Settlers and the Problem of the Ctenophore Mnemiopsis leidyi Invasion in the Black Sea. GESAMP Reports and Studies no. 58 (IMO, London; UNEP, Geneva, 1997).
8. Bax, N et al. The control of biological invasions in the world’s oceans. Conservation Biology 15, 1234–1246 (2001).
9. Roth, M, Richards, RM & Sommerville, C. Current practices in the chemotherapeutic control of sea lice infestations in aquaculture: A review. Journal of Fish Disease 16, 1–26 (1993).