Life in the OceanSustainable Fisheries

Lec. 15; March 4th

Blue Ocean FloorJustin Timberlake Thanks to Rachel C.

• Exam 1 Mar. 6 in class.• Review Session tonight,

Mar. 4, 8-10PM, 121 Sparks

Riptide, Vance JoyThanks to Michael F.

Sitting on the dock of the bay, Otis Redding

Mid-Term Exam on Thursday in class

Read Chapters 7, 16 and 12

On-Line Assignment 7 due today, Mar. 4

Mid-term Exam, in class on Thursday (Mar. 6)• Review Session tonight,

Mar. 4, 8-10PM, 121 Sparks

http://news.psu.edu/story/305524/2014/02/25/campus-life/student-group-takes-action-reduce-plastic-bag-use-campus?utm_source=newswire&utm_medium=email&utm_term=306402&utm_content=03-03-2014-16-51&utm_campaign=university%20park%20faculty%20and%20staff%20newswire

The Sea Around Us!

www.teara.govt.nz

http://phys.org/news/2014-03-ninety-five-cent-world-fish-mesopelagic.html

www.teara.govt.nz

www.teara.govt.nz

http://phys.org/news/2014-03-ninety-five-cent-world-fish-mesopelagic.html

• UWA Professor Carlos Duarte led a seven-month circumnavigation of the globe in the Spanish research vessel

• Duarte says mesopelagic fish – fish that live between 100 and 1000m below the surface –constitute 95 per cent of the world's fish biomass.

• This layer must play a more significant role in the functioning of the ocean and affecting the flow of carbon and oxygen in the ocean…

• Most mesopelagic species tend to feed near the surface at night, and move to deeper layers in the daytime to avoid birds.

http://www.economist.com/news/international/21596990-humans-are-damaging-high-seas-now-oceans-are-doing-harm-back-deep-water

• ABOUT 3 billion people live within 100 miles (160km) of the sea…

• The oceans produce $3 trillion of goods and services each year and untold value for the Earth’s ecology.

• Life could not exist without these vast water reserves…

http://www.economist.com/news/international/21596990-humans-are-damaging-high-seas-now-oceans-are-doing-harm-back-deep-water

• it has long been clear that people are damaging the oceans

• Now, the consequences of that damage are starting to be felt onshore.

• More serious is the global mismanagement of fish stocks.

• About 3 billion people get a fifth of their protein from fish, making it a more important protein source than beef.

• A vicious cycle has developed as fish stocks decline and fishermen race to grab what they can of the remainder.

• According to the Food and Agriculture Organisation (FAO), a third of fish stocks in the oceans are over-exploited;

• …big predatory species—such as tuna, swordfish and marlin—may have fallen by as much as 90% since the 1950s.

http://www.economist.com/news/international/21596990-humans-are-damaging-high-seas-now-oceans-are-doing-harm-back-deep-water

http://www.economist.com/news/international/21596990-humans-are-damaging-high-seas-now-oceans-are-doing-harm-back-deep-water

http://www.economist.com/news/international/21596990-humans-are-damaging-high-seas-now-oceans-are-doing-harm-back-deep-water

The problem here is political rather than regulatory: how should mining revenues be distributed? Deep-sea minerals are supposed to be “the common heritage of mankind”. Does that mean everyone is entitled to a part?

Greater than 99% of oceanic fish production occurs in about 10% of ocean area (shelves and upwelling zones).

Why? Because:The production of organic matter (by phytoplankton) is highest per unit area in shelves and upwelling zonesFood chains are shorter (fewer trophic levels), so less overall loss of energy. Efficiency is greater!!

Phytoplankton: Major Groups

Diatoms, Their Shells are made of opal (SiO2),

Coccolithophorids, Their Shells are made of calcite (CaCO3),

Dinoflagellates, Their bodies are organic-walled

http://oceanservice.noaa.gov/facts/redtide.html

Dinoflagellates produce Red Tide (HABS)

www.whoi.edu

There is still some question as to what exactly causes red tide outbreaks. Many factors need to be present in order for these large blooms to occur including nutrients, sunlight, the right water temperature, and cysts. Without sunlight, the phytoplankton would be unable to photosynthesize and unable to multiply in number. Water temperature also plays a role in algae blooms. As ocean water has warmed over the past decade the number of red tides has increased.

www.whoi.edu

Many factors need to be present in order for these large blooms to occur including

• nutrients,

• sunlight,

• the right water temperature,

• cysts.

• Without sunlight, the phytoplankton would be unable to photosynthesize

HARMFUL ALGAL BLOOMSThe most common threat to shellfish-

eating humans is Paralytic Shellfish Poisoning (PSP)

PSP can result from eathing clams, mussels, or other shellfish that have ingested algae laden with a family of poisons called saxitoxins.

Saxitoxins act like corks, blocking the movement of sodium through the nerves and thereby deactivating them. The result is paralysis - only your heart, which runs on a separate system, and your brain remain functional. Eventually you suffocate and die.

There is no known antidote for Paralytic Shellfish Poisoning.

Boston Globe, June 2005

Storm or density-induced mixing

plankton bloom

nutrient-rich deep water

Wind-driven upwelling

wind

nutrient-rich deep water

plankton bloom

River runoff to ocean

riverplankton bloom

photiczone

Nutrient Supply to Photic Zone: How does it work?

nutrient-rich deep water

nutrient-depletedsurface water

Stable stratification inhibits upwelling

Harmful Algal BloomsOne expert points out, there are

many folkloric "rules" among West Coasters about how to detect toxins in shellfish. He cautions against all of them. "Don't believe the common expression that shellfish are safe to eat in months with the letter R in them - blooms can happen any time of the year." In 1999, for example, PSP outbreaks on the West Coast lingered well into October and November. And nibbling on a single clam to see if your lips tingle before chowing down on more - another commonly believed old wives' tale - is not just bad advice; it could spell disaster.

Clicker warm up…..

I know that we have an exam in class on Thursday

a) Trueb) Falsec) Other

Mid-Term Exam on Thursday in class

The Energy cycle of life in the ocean involves plankton, which convert sun light to organic matter. Organic matter is eventually broken down by bacteria and other organisms. This recycles the nutrients for further plankton growth.

a) Trueb) Falsec) Other

The Energy Cycle

Note that photosynthesis (and formation of plant organic matter) requires sunlight and nutrients

Organic matter is consumed by animals and plants (respiration), supporting their growth

Nutrients must be “recycled” (excreted by animals, “regenerated” by bacteria) to be reused by plants

Photosynthesis

Consumers

Consumers

nutrients

Red Tidesa) Typically last from 3 to 4 monthsb) Indicate blooms of potentially toxic dinoflagellatesc) Occur mainly during the summerd) Can be caused by or exacerbated by aquaculturee) All but (a)

Red Tides may be caused by:a) A rapid surge of nutrients into the

photic zoneb) Longer days and more sunlightc) Warm water (which may increase

reproduction rate)d) All of the abovee) None of the above

Which of the following are correct?

A. UWA Professor Carlos Duarte says mesopelagic fish constitute 95 per cent of the world's fish biomass.

B. The mesopelagic layer of the ocean is between 100 m and 1000

C. The mesopelagic layer may play a significant role in the functioning of the ocean, affecting the flow of carbon and oxygen in the ocean…

D. Most mesopelagic species tend to feed near the surface at night, and move to deeper layers in the daytime to avoid birds.

E. All of the above

Harmful Algal Blooms and Aquaculture

Naylor, SCIENCE, 313; 8 SEPTEMBER2006

The burgeoning business of aquaculture, or fish farming, is also a growing source of nutrients for harmful blooms. The fish in enclosed fish farms produce a huge amount of waste, which in turn feeds the blooms.

Recently, an epidemic of toxic blooms spurred Scotland to ban scallop fishing from 8,000 square miles of coastal waters; the blooms were blamed on waste generated by salmon farms. According to the Suzuki Institute, fish farms off the coast of B.C. dump sewage equivalent to that generated by a city of 500,000 people into coastal coves every day.

The US recently introduced legislation to promote offshore aquaculture.

Is There Remediation of HABs?

Perhaps--one strategy is to spray fine clay over surface

The surfaces of the clay (only one type, called montmorillonite, works) attracts algal cells and settles to the bottom thus sweeping out the HAB for awhile

Sustainable Fisheries? Infinite ocean…X

Catch levels off in about 1985 www.fao.org/fishery

Sustainable Fisheries?

FOOD AND AGRICULTURE ORGANIZATION OF THE UNITED NATIONS

Fish production increasing to 172 million tonnes by 2015 (?)

Most of the increase comes from aquaculture

www.fao.org/fishery

www.fao.org/fishery

Where the fish are…

www.fao.org/fishery

And what they are..

http://www.ametsoc.org/atmospolicy/documents/Boris_Worm_MAR19_2007.pdf

Yellowfin Tuna

http://www.ametsoc.org/atmospolicy/documents/Boris_Worm_MAR19_2007.pdf

Swordfish

http://www.ametsoc.org/atmospolicy/documents/Boris_Worm_MAR19_2007.pdf

www.fao.org/fishery

www.fao.org/fishery

Aquaculture: is it sustainable?• Most cultured fish are carnivorous– Wild caught fish needed to feed farmed fish– How many pounds per farmed fish?• Farmed fish are kept at high (unnatural) population densities

(e.g. 25,000 fish per acre enclosure)--prone to injury, parasitism (sea lice) and disease--pollutant concentrations high--drug (e.g. antibiotics) use necessary (contamination of waters)

• Escape of alien speciesGot your interest? Try the link below for a 1-hour radio program (from February, 2006) by Kootenay Radio on Atlantic Salmon farming in the Pacific Ocean. Also, many other links to aquaculture pages there. http://www.cjly.net/deconstructingdinner/020206.htm

The Role of Aquaculture

In 1980, 9% of fish consumed by humans came from aquaculture

Today 43% (45.5 million tonnes, worth $63 billion) of “seafood” eaten results from aquaculture!

“Mariculture:” raised in the ocean

An amazing statistic!

What is the problem?

Overfishing!, made worse by pollution, global warming, habitat destruction…

Tokyo Fish Market, Nov. 2008 This many Tuna EVERY morning

Overfishing!, made worse by pollution, global warming, habitat destruction…

A well known example of overfishing (and success story!)

A well known example of overfishing (and success story!)

Cod: A Rich Atlantic Heritage?

Atlantic Cod Gadus Morhua • The fish that gave Cape Cod

its name is severely overfished.

• Smaller cod marketed as “scrod”

• The collapse of New England groundfish, including cod, has cost $350 million in lost annual income and 14,000 jobs.

• Strict limits imposed on fishing to allow groundfish to recover are beginning to show positive results for some species in some areas.

Check out: http://www.pbs.org/emptyoceans/cod/

The central interior of gyres a) often have lower water levels than surrounding regions b) are called the halocline c) are smaller in the southern hemisphere due to the Coriolis effectd) are where eastern boundary currents are strongeste) none of the above

In the southern hemisphere, water in the central interior of gyres A. is at a lower level than surrounding regions, because the ‘hill’

at the center of gyres in the N. hemisphere is on the outside of gyres in the S. hemisphere

B. is at a higher level than surrounding regions due to Coriolis forcing and Ekman transport

C. is generally greenD. none of the above

The Ekman spiral predicts that net motion of surface waterA. is parallel to the prevailing wind directionB. is 90° to the right of the wind direction in the N.

hemisphereC. is 90° to the left of the wind direction in the entire

PacificD.corkscrews downward to depths of 4000 meters

because of deepwater formation

Which of the following is/are true?A. Ocean deep water

is formed at high latitudes

B. Seawater density involves both temperature and salinity

C. When surface water becomes denser than the underlying water mass, the surface water will sink

D. all of the above

Which of the following is true concerning Earth’s global heat and temperature?

Earth’s global heat and temperature

Outgoing long wavelength radiation

Incoming short wavelength radiation

Which of the following is true concerning Earth’s global heat and temperatureA. Outgoing longwave radiation equals

twice incoming shortwave radiationB. Incoming solar radiation exceeds

outgoing infrared radiationC. Earth radiates heat only during

summerD. Incoming solar radiation at the top of

Earth's atmosphere, minus solar radiation reflected by the atmosphere, is approximately equal to outgoing infrared radiation

E. All of the above