Download MidTerm Review Oct2014 OCN331 - School of Ocean and Earth

OCN331
Our Objective:
Insights for Your Lifetime
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
Variability
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
Dry climate and high pressure in the
vicinity of 30o latitude
Wet climate and low pressure in the
vicinity of the equator and 60o
latitude
Bermuda: 32.3 N
Honolulu: 21.3 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.
Things to Remember
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 and
currents can lead to conditions (EL NIÑO)
that disrupt upwelling
Hugo Grotius
Mare Liberum
1609
•
•
•
•
•
Whales
Norwegian herring
Japanese sardine
Peruvian anchovy
Can. N. Atlantic cod
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•
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•
•
Technology
Capital Investment
Fisheries Information
Politics
Social Issues
Tragedy of commons
Population
Total Global Fisheries Harvest ~160Mt
•
•
•
•
•
•
Year
2002
2003
2004
2005
2006
CAP
94.5
91.8
96
95.5
93.1
AQ
52
55.2
60
63.3
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
– Lobsters,crabs
• Gill Nets
~6%
– Squid,salmon,billfish
~8%
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
• By 1970, the largest fishery in the world
• Susceptible to disruptions by ENSOs
•
Lessons may have been learned
Alaskan Pollock
• Not heavily fished until the 1960s
• Improvements in processing ability
were important
• Overfishing a real concern
• Monitoring and managing techniques
may be improving
Skipjack Tuna
• Another recently developed fishery
• Catches are trending upwards
• This resource may be underutilized
• 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
25.6%
Pacific
62.6%
Indian
10%
Other
1.7
Percentages of global marine capture fishery production accounted by regions of the ocean
Fishing area
Atlantic
% global capture production
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
Indian
18.4
10.0
East
5.5
West
4.5
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
Age
Spawn Date
Hatch Date
Metamorphosis
Growth History
Beverton-Holt Model:
Application to a Resource-Limited Population
Mortality declines with
fishing because:
1. Caught fish don’t die
a natural death;
F
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 Before
Establishment of a Moratorium: No Recovery
of the Stock, No Recovery of the Fishery
Social
Concerns
Information
Quality
Natural
Variability
Characteristics of r-selected and K-selected populations
parameter
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
springspawning
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
Habitat
Recruitm’t Closure of
Capitlizat’n destruction overfishing fishery
Japanese
Pilchards
Norwegian
springspawning
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
200
200
8-12
40
Southern
bluefin
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 – 1972
NMFS 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 plan
1. Main markets didn’t want to buy dead dolphin
2. 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
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 productivity
by 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 Resources
and 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 Resources
and 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 of
taking yet more fish from a
stressed population?
Benefit: I get all the biomass generated by
those 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 resources
to 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 aligned
more with tourism than with commercial
fishing
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 vessel
Entangle the propellor
Result in a navigational hazard
Result in a safety risk for those
onboard
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
Gambierdiscus  Macroalgae  Herbivorous Fish  Carnivorous Fish  Fishing Pressure
Fish  Humans
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
40
= selenium
35
= mercury
µM
.
30
25
20
15
10
5
0
YF MM SJ SF WH AL BE MC SM BM OP ES TS SW MS PW
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
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).