OCN331

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OCN331

• How do the oceans make fish?

• How do we extract fish from the oceans?

• What other living resources do the world’s oceans hold?

• Why do we care?

Social Concerns

Information Quality

Natural Var iability

Some Wind and Current Fundamentals

I. Effect of Differential Heating on Atmospheric Circulation

II. The Coriolis Effect

III. Trade Winds and Westerlies

IV. Air-Sea Interactions

V. El Niño

Some effects of atmospheric circulation cells

Wet climate and low pressure in the vicinity of the equator and 60o latitude

Dry climate and high pressure in the vicinity of 30o latitude

Honolulu: 21.3 N

Bermuda: 32.3 N

There are five major coastal upwelling regions in the world, along the coasts of California, Namibia, Mauritania, and Somalia.

Effects of Walker Cell circulation

Wet climate and low pressure at the western margin of the ocean basin near the equator

Dry climate and high pressure at the eastern margin of the ocean basin near the equator.

I. High atmospheric pressure at 30° N and 30° S latitude governs major wind patterns

II. The Coriolis Effect deflects winds and currents to the RIGHT in the Northern Hemisphere

and to the LEFT in the Southern Hemisphere

III. These wind and current phenomena generate coastal UPWELLING of deep ocean water

IV. Variations in the strength of these winds andcurrents can lead to conditions (EL NIÑO)that disrupt upwelling

Things to Remember

Hugo GrotiusMare Liberum

1609• Whales• Norwegian herring• Japanese sardine• Peruvian anchovy• Can. N. Atlantic cod

• Technology• Capital Investment• Fisheries Information• Politics• Social Issues• Tragedy of commons• Population

Total Global Fisheries Harvest ~160Mt

• Year CAP AQ• 2002 94.5 52• 2003 91.8 55.2• 2004 96 60• 2005 95.5 63.3• 2006 93.1 66.7

• Capture Fisheries are constant at ~90-95Mt

• Aquaculture is steadily increasing

Disposition of the total aquatic catch for 2002

Use % of total (by weight)

Human consumption 75.8

Fresh 39.7

Frozen 20.0

Cured 7.3

Canned 8.7

Reduction 19.0

miscellaneous 5.3

Why Do We Care?

• Calories

• High Quality Protein• Essential Amino Acids

• Essential Fatty Acids (PUFA’s)

EPA & DHA Content of Fish

• Cod• Flounder• Mackerel• Pollock• Salmon, farmed• Shrimp• Trout• Tuna, bluefin• Tuna, canned

• 0.13• 0.43• 1.57• 0.46• 1.83• 0.27• 0.80• 1.28• 0.73

ω3 Fatty Acids & Fetus Health

• “Fish is Brainfood”• EPA & DHA (from week 20)• Important for Infants’

– Nerve, Visual, Immune system development– DHA Supplements Breast Milk & Formulas

Important for Infants’ Intellect -IQ-fish consumption correlation

How the Oceans Make Fish

• Primary Production Commercial Fish

• 3 Types of Ocean Areas– Open Ocean– Coastal Areas– Upwelling Areas

Open Ocean Area

• Deep• Low inputs• Mostly Regen. Nutrs.• Stable Temporally• Nutrient Limited

• Small Phytoplankton

• Long Food Chains

• Low Comm.Fish Yield

Coastal Areas

• Shallow• Seasonal Inputs• Seasonal Variability• ~50% New Nutrients

• Larger Phytoplankton

• Shorter Food Chains

• Benthic Food Chains• Gadoid fishes

• High Comm. Fish Yield

Upwelling Areas

• Shallow• Seasonal Inputs• Seasonally Steady• Mostly New Nutrients

• Larger Phytoplankton

• Short Food Chains

• Clupeid fish

• High Comm. Fish Yield

Harvesting

• How it’s done

• What’s caught

• Changes over time

Old & New Methods

• Spear• Hook-n-line

• Traps

• Exploding harpoon• Trolling• Trolling-n-chumming• Demersal Trawl line• Pelagic Trawl line• 2000 hooks; 3-4%• Traps• FADs

Nets

• Gill Nets• Floats & weights• Drift nets

– Efficiency– Fiber advances– Bycatch– 33000km—80%– Banned in 1992

• Trawl Nets• demersal & pelagic• Power needed• Beam• beam Otter• 10-100m opening• Echo-sounder• sonar

Table 2.2 Major species of fish caught with otter trawls

Species Major fishing countries Areas fished

Alaska pollock Russia, Japan, South Korea Northwestern Pacific

USA Northeastern Pacific

Atlantic cod Iceland, Norway, Russia Northeastern Atlantic

Blue whiting Norway, Iceland, Russia, Faeroe Islands

Northeastern Atlantic

Largehead hairtail China, South Korea Northwestern Pacific

Purse Seines

• Globally, most fish catch…by far

• Catch fish schooling near surface

• 100km x 100m

• Fish must aggregate in large schools

• Powerful means to deploy & retrieve

• Dories (50’s) to power block

Catch Amount by type

• Purse Seine ~50%– Herring,sardine,anchovies,tuna,mackerel

• Otter Trawl ~17%– Pollock, cod,whiting

• Lines ~ 9%– Tunas,swordfish,cod,halibut,haddock,etc

• Pound/trap nets ~8%– Lobsters,crabs

• Gill Nets ~6%– Squid,salmon,billfish

OVERVIEW OF WORLD FISHERIES

I. Reporting and Measurement Issues

II. Major Fisheries - By Fish

III.Major Fisheries - By Nation

IV.Major Fisheries - By Ocean

V. Economic Values

II. Major Fisheries - by Fish

THE FIRST TIER

• Peruvian Anchovy

• Alaskan Pollock

• Skipjack Tuna

• Capelin

Peruvian Anchovy

• Not heavily fished until the 1950s

• Susceptible to disruptions by ENSOs

• By 1970, the largest fishery in the world

• Lessons may have been learned

Alaskan Pollock

• Not heavily fished until the 1960s

• Overfishing a real concern

• Improvements in processing ability were important

• Monitoring and managing techniques may be improving

Skipjack Tuna

• Another recently developed fishery

• This resource may be underutilized

• Catches are trending upwards

• Monitoring and managing techniques are a challenge

III. Major Fisheries - by Nation

THE FIRST TIER

• China

• Peru

• United States

• Indonesia

III. Major Fisheries - by Nation

THE SECOND TIER

• Japan

• Chile

• India

• Russia

IV. Major Fisheries - by Ocean

Atlantic

Pacific

Indian

Other

25.6%

62.6%

10%

1.7

Percentages of global marine capture fishery production accounted by regions of the ocean

Fishing area % global capture production

Atlantic 25.6 Northwest 2.4

West central 2.1

Southwest 2.7

Northeast 12.7

East central 4.1

Southeast 1.6

Pacific 62.6 Northwest 26.9

West central 11.5

Southwest 0.9

Northeast 2.9

East central 2.0

Southeast 18.4

Indian 10.0 East 5.5

West 4.5

Mediterranean and Black Seas 1.7

V. Economic Values

Fish eaten by humans have high market value

Fish used for reduction have low market value

Reasons to Fish Below the MSY

I. Inaccurate Information

A. I Fish Therefore I Lie (Schaefer Model)

B. Not Enough Biological Data (Beverton-Holt Model)

II. Variable Recruitment

III. Resource Mismatch

IV. Presence of Competitors

V. Stock Stability

VI. Economics (Law of Diminishing Returns)I. T

Schaeffer Model

Requirements:

Measurement of Fish Caught

Measurement of Fishing Effort

Beaverton-Holt Model

Requirements:

Measurement of Fish Caught

Knowledge of Fish Biology

Population Size (Tagging)

Age (Otoliths)

Reproductive Biology

OTOLITHS: Information that can be obtained from the

analysis of otolith biomineralization patterns

Spawn Date

Hatch Date

Metamorphosis

Growth History

Age

Beverton-Holt Model: Application to a Resource-Limited Population

F

Mortality declines with fishing because:

1. Caught fish don’t die a natural death;

2. A fished population is a younger population, with a lower death rate;

3. Individuals in a fished population have access to more resources, so they are healthier and have a lower death rate.

The Canadian Cod Example:

Fished to Commercial Extinction BeforeEstablishment of a Moratorium: No Recoveryof the Stock, No Recovery of the Fishery

Social Concerns

Information Quality

Natural Var iability

Characteristics of r-selected and K-selected populationsparameter r-selected K-selected

Environment variable and/or unpredictable

constant and/or predictable

Lifespan short long

Growth rate fast slow

Fecundity high low

Natural mortality high low

Population dynamics unstable stable

HOW MANY FISH SHOULD WE CATCH?

SUBSTANTIALLY LESS THAN THE

MAXIMUM SUSTAINABLE YIELD

THAT IS CALCULATED

Clupeid & Gadoid Fisheries

r – Selected Species

~1/3 Global Fisheries

Instability Management Challenges

Commercial catch of Japanese pilchards

Migration routes of the Norwegian spring-spawning herring during the period 1963-1966.

The location of the nine major populations of

British Columbia herring.

Commercial catches of cod in the North Sea

(A) Catch of North Sea Herring and (B) spawning stock biomass of the autumn spawning herring. The dashed line in panel B is the target spawning stock of 1.3 Mt recommended by the ICES.

Harvest of sexually immature fish

Over Capitlizat’n

Habitat destruction

Recruitm’t overfishing

Closure of fishery

Japanese Pilchards

Norwegian spring-spawning Herring

Canadian Pacific Herring

Canadian Atlantic Cod

N. Sea Cod

N. Sea Herring

TUNA TALES

TUNA I

The World’s Tuna Fisheries

TUNA II

A Fishery Management Case Study:Yellowfin Tuna and Dolphins in the Eastern Tropical Pacific

TUNA III

The Mighty Bluefin

Pertinent information on commercially important tuna species

Species Length(cm)

Weight(kg)

Age of sexual maturity(years)

Lifespan(years)

Albacore 60-90 10-20 5 10

Bigeye 80-180 15-20 4 10

Skipjack 30-80 8-10 2 12

Yellowfin 40-180 5-20 3 10

Atlantic bluefin

45-450 135-680 4-8 15-30

Pacific bluefin

150-300 300-555 6 30

Southern bluefin

200 200 8-12 40

Skipjack information

Most catch occurs in the Pacific (70%) and Indian (24%) oceans.

Smallest of the commercially important tunas

Tendency to school

Most skipjack are caught with purse seines.

Diet includes clupeids, crustaceans, and mollusks

Major market for skipjack tuna is canned tuna

Yellowfin information

Geographical distribution and spawning behavior similar to skipjack.

Tend to associate with dolphins more than any other species.

Pacific (67%) and Indian Ocean (22%) account for most of the catch.

Much of the fishing is done with purse seines.

Canned tuna (light tuna) is again the primary market.

Albacore information

Temperate water fish, and stocks in the N and S hemisphere are disjoint.

The principal fishing areas are the western and central Pacific

Caught with pole-and-line, surface trolling, or long lines, no purse seine

The principal market for albacore is canned tuna… “white tuna”.

Japan and Taiwan dominate the catch.

Atlantic Bluefin information

Atlantic Bluefin found only in the N. Atlantic, Mediterranean, Black Sea. Bluefin in the South Atlantic are S. Bluefin.

Atlantic bluefin are the largest of the tunas

Two spawning areas: Gulf of Mexico and Mediterranean Sea

Controversy over whether the stocks should be considered separately these tuna definitely make trans-Atlantic migrations.

<1970 ~$0.10/kg….Now$20-70/kg Increasing demand to supply the Japanese sushi and sashimi markets development of air freight in the early 1970s

Management: International Commission for the Conservation of Atlantic Tunas (ICCAT) formed in 1969.

Pacific Bluefin information

The only unregulated Bluefin fishery in the world.

Japan accounts ~64% of catch, most from NW Pacific.

Unlike the Atlantic Bluefin…only one stock of Pacific Bluefin tuna.

Caught on a variety of gear…bycatch….often juveniles

Almost all taken in the eastern Pacific are sexually immature

Southern Bluefin information

Overexploited.

Only one known breeding ground (Indian Ocean) The fishery is dominated by Japan and Australia.

As with other Bluefins, surface gear takes sexually immature fish.

Since1980… victim of recruitment overfishing

Commission for the Conservation of Southern Bluefin Tuna (CCSBT) set catch quotas...no evidence that the spawning stock is recovering …further reductions in the catch quotas will be needed to give the stock a chance to recover.

The long time to reach sexual maturity makes this species particularly vulnerable to overfishing.

Marine Mammal Protection Act – 1972NMFS Implementation of MMPA with respect to dolphin stocks

Early 1980s – U.S. wants to put observers on all tuna boats. Observers on fewer than 50% of U.S. boats and only a handful of foreign boat-trips.

Early 1980s – U.S. wants to ban sundown sets

Tuna boats start to drop out of U.S. fleet

Late 1980s – dolphin kills start to increase

Lessons Learned?

Pluses

Consumers, via their government, pushed effectively for the implementation of management

Benefits to the fishery from accepting the management plan1. Main markets didn’t want to buy dead dolphin2. Spared dolphins live to help find tuna again

Minuses

Expenses to the industry have forced much of the fishing fleet to jurisdictions where the management plan can

be evaded

Peruvian Anchoveta Fishery

I. The Physical Setting

II. The Upwelling Ecosystem

III. Anchoveta Ecology

IV.History of the Anchoveta Fishery

V. Managing the Anchoveta Fishery

The Upwelling Ecosystem

I. Nutrient-rich waters from beneath the nutricline fertilize the euphotic zone with nitrate and phosphate

II. High nitrate and phosphate enables high primary productivityby phytoplankton

II. Anchoveta graze this nutritional resource

III. Anchoveta are then eaten by mackerel (from below) and guano birds (from above)

Anchoveta Ecology

I. Population is confined to the Peru Coastal Current system

II. Feed low on the food chain

III. 4-year lifespan

IV. Spawning year-round, with peaks in Sept-Oct and Feb-Mar

V. Recruited to the fishery at 5 months of age

Anchoveta Ecology

V. Recruited to the fishery at 5 months of age

VI. Sexual maturity at 12 months of age

VII. Very high fecundity: 15,000 eggs/spawn, 24 spawns/year

VIII. Very high mortality prior to recruitment: > 99%

IX. After recruitment, mortality is ~ 16%

X. A modest drop in population size enhances recruitment

Effects of El Niño on Anchoveta Catch

Impact of El Niño on Peruvian anchovies

Possible impacts:

anchovies starve

poor recruitment

changes in predation

Response of anchovies

concentrate in cold water nearer the coastline

move into deeper water and disperse

Ecological Summary

Advantages:

• An Extraordinary Combination of Nutritional Resourcesand an r-Selected Fish

• Short Food Chain

• “Simple” Sources of Mortality

Problems:

• Complex Biological-Meteorological Interactions

• Variable Recruitment

Management Summary

Advantages:

• An Extraordinary Combination of Nutritional Resourcesand an r-Selected Fish

• Fishery within the Peruvian EEZ

• National and International Fisheries Scientists Involved

Problems:

• Complex Biological-Meteorological Interactions

• Harvesting Prior to Sexual Maturity

• Overcapitalization and Socio-Political Pressures

• MSY as a target

Tragedy of Freedom in a Commons

Pasture Example (the village green)

Grazing Example (the wide open west)

“Inexhaustible” Resources of the Ocean

National Parks

Tragedy of Freedom in a Commons

Oceans Example (fisheries)

What are the benefits and costs to me oftaking yet more fish from a stressed population?

Benefit: I get all the biomass generated bythose fish.

Costs: The fish population is further degraded, but that degradation is shared by all my competitors.

Recognition of Necessity

The Commons is justifiable only under conditions of low population density

Injustice is preferably to total ruin

Freedom is the recognition of necessity

The Ingredients for Avoiding a Tragedy of the Commons:

Elinor Ostrom

1. The nature of the resource

2. Recognition of resource depletion

3. Nature of the community:

“Small and stable populations with a thick social network and social norms promoting conservation do better”

The Bermuda Fisheries: A Tragedy of the Commons Averted?

Background:

1. A Problem Perceived

2.A Study Undertaken

3. A Policy Changed

Prior to 1970:

Resource was in excess of the demand.

A “Commons” use of the resource seemed OK.

Policy was to increase fisheries activity.

In 1975:

Policy was to “exploit the harvestable resourcesto their maximum sustainable levels

1980 and 1984 attempts to regulate the use of fish pots, but problems remained:

Pots were too indiscriminately efficient

Pot fishery was too difficult to police

Fishermen used more pots than they were allotted - and tagged their illegal pots with other fisher’s names!

Fishermen took other fisher’s pots

1980s: A growth in the use of the resource by other economic interests.

Tourism: Scuba, Snorkel, Glass-Bottom Boat

Charter fishermen found their interests alignedmore with tourism than with commercialfishing

The Bermuda Example of Averting a “Tragedy of the Commons”

Made possible by a fortuitous set of circumstances:

A. Affluence

B. Isolation

C. Changing Economic Interests

D. An Advantageous Political Environment

Important events in the history of Hawaiian commercial fisheries

1976 – Congress passes the Fisheries Management and Conservation Act

1984 – closure of Hawaiian Tuna Packers cannery

1987 – beginning of buildup of longline fleet

1990 – amendments to FMCA recognize need for management of highly migratory species

2000 – recognition that swordfish longline fishery is taking turtles

2000 – President Clinton creates northwestern Hawaiian Islands coral reef ecosystem reserve

2006 – President Bush makes NWHI a marine national monument; closes bottomfishing

Hawaiian commercial pelagic fish catch by weight (A) and value (B)

Commercial landings of skipjack tuna

What are precious corals?

Colonial coelenterates living below the euphotic zone.

Valuable as a source of raw material for jewelry.

Main production centers at the present time are Taiwan and Japan.

Value of 1980 fishery is about $50 million [~50X stony coral imports]

Most precious corals live at depths of hundreds of meters, making harvest by other than remote methods impractical.

Precious corals are very much K-selected.

Skeletons are made of calcium carbonate, protein, or a mixture of the two. Color due to organic matter in skeleton.

Management of Precious Corals

• Susceptible to Over-exploitation

• Historical Attempts– Total Ban – Reserves– Limited Entry– Benign Neglect– Size & Weight Quotas

Problems with Marine Debris

Wildlife Entanglement

Entanglement/Injury

Ingestion/Starvation

Both can lead to death

Navigational Hazards that may cause Vessel Damage

Large accumulations of derelict fishing gear can:

Damage a vesselEntangle the propellor

Result in a safety risk for those onboard

Result in a navigational hazard

The Sea & Human Evolution

• Context• Dr. Michael Crawford

– Director, Institute for Brain Chemistry and Nutrition, London Metropolitan Museum

– Author, “The Driving Force: Food, Evolution and the Future”

– Seafood & Human Health 2005– Honoring the Omega-3 Pioneers– The Role of Seafood in Human Evolution

The Sea & Human Evolution

• Savannah scenario: big brain via fierce competition with big carnivores (Lamarcian)

• Fish: LIPIDS >> Se,Fe,Cu,Zn,I >> Protein

• Brain size: (1y) ≈ (mother) = PRIORITY!

• Brain Size: 2% sm animals, %↓ and size↑– Except humans

• Humans: good sources of preformed DHA

The Sea & Human Evolution

• Humans exploiting coastal foods: 150,000y• Savannah hypothesis: male-centric

– females make the next generation

• Life centers: Euphrates, Ganges, Nile, Tiber• DHA conveys advantage to coastal dwellers

over inland meat-eaters • 70% energy to fetus brain development

Health

• Rimm et al. (Harvard School of Public Health)• J. American Medical Association• “The health benefits of eating fish greatly

outweigh the possible risks”– Heart health –Omega 3 fatty acids– Fish >= Twice/week

Ciguatera Fish Poisoning

• Occurs in tropical and subtropical regions

• Vector is exclusively reef fish

• Affects hundreds of thousands of people annually

• Underreported; misdiagnosed

Ciguatera Sequence

Environmental conditions Gambierdiscus

Fish Humans

Gambierdiscus Macroalgae Herbivorous Fish Carnivorous Fish Fishing Pressure

Mercury in Fish: hazard or hype?

John Kaneko MS, DVM

PacMar Inc. and

Hawaii Seafood Project NOAA

Take Home Message• There are no confirmed cases of mercury poisoning from

eating tuna or open ocean fish.

• “Dose makes the poison”, mercury may be toxic at high levels, but not at low levels.

• Yellowfin tuna protects against mercury poisoning because it contains more selenium than mercury.

• Pilot whales are mammals, not fish!

Advisory is NOT for the General Consumer

• There are no advisories for the general consumer

• Vast majority of consumers can benefit by eating more fish

• Caution: avoiding fish may increase risk of heart disease

Babies need fish oils

The benefits of healthy fish oils for brain development are known and widely-accepted.

The potential harmful effects of low levels of mercury from open ocean fish are uncertain, undocumented and hypothetical.

Pregnant women should eat fish!• October 5, 2007 Announcement from

National Healthy Mothers Healthy Babies Coalition (w/150 member organizations)

• Recommends women eat at least 2 meals of fish (12 oz) per week.

• To get enough omega-3 fatty acids for their baby’s brain development.

• Recognized that selenium appears to protect against toxic effects of mercury.

http://www.sciencedaily.com/releases/2007/10/071004133313.htm

Has mercury poisoning ever happened from eating Open

Ocean Fish?

• NO

• There has never been a case of mercury poisoning from eating pelagic fish, including tuna, swordfish and others.

Selenium Health Benefits

• Essential antioxidant effects (ex. glutathione peroxidase)

• Anti-cancer effects (ex. prostate, breast)

• Promote immune system function

• Metal detoxification (ex. mercury)

Results: Hg & Se µmole/kg

0

5

10

15

20

25

30

35

40

YF MM SJ SF WH AL BE MC SM BM OP ES TS SW MS PW

µM

.

YF=Yellowfin; MM=Mahimahi; SJ=Skipjack; SF=Spearfish; WH=Wahoo; AL=Albacore; BE=Bigeye; MC=Monchong; SM=Striped Marlin; BM=Blue Marlin; OP=Opah; ES=Escolar; TS=Thresher shark; SW=Swordfish; MS=Mako Shark; PW=Pilot whale

= selenium

= mercury

Kaneko, JJ and NVC Ralston 2007. Selenium and Mercury in Pelagic Fish in the Central North Pacific Ocean near Hawaii. Biological Trace Element Research 119 (3): 242-254. (NOAA Award No. NA05NMF4521112)

Conclusion

• Pelagic fish are generally rich in selenium, therefore, they are far more likely to prevent mercury toxicity than to contribute to causing it.

• Pilot whale meat is high in mercury, but not in selenium and may contribute to mercury toxicity.

John Kaneko and Nick Ralston, PacMar Inc., Hawaii Seafood Project (NOAA Award No. NA05NMF4521112).