Lecture 25: Anthropogenic Changes: Oceans pick up HW 7, 10 older HW - - PDF document

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Lecture 25: Anthropogenic Changes: Oceans pick up HW 7, 10 older HW - - PDF document

Oct 06, 2023 316 likes •466 views

Lecture 25: Anthropogenic Changes: Oceans pick up HW 7, 10 older HW outside *** check your grades online! *** HW9/aqu trip 1 will be destroyed today 2 office hours: tomorrow, next MONDAY 2 discussion sessions this week (none next week)

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Lecture 25-2018: Anthropogenic Changes: Water and Oceans

Lecture 25: Anthropogenic Changes: Oceans

Humpback Whale

2 office hours: tomorrow, next MONDAY 2 discussion sessions this week (none next week) early final exam (tue or wed; noon) email glaske@ucsd.edu for details pick up HW 7, 10

  • lder HW outside

*** check your grades online! *** HW9/aqu trip 1 will be destroyed today

Lecture 25-2018: Anthropogenic Changes: Water and Oceans

Friday 12/1/18 M=7.0 Alaska earthquake

M=7.0 Anchorage normal EQ mechanism AK has largest EQs in U.S., and plenty this was NOT the big one! Not even close! Not even for this year! (Mw=7.9 Jan 2018)

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Lecture 25-2018: Anthropogenic Changes: Water and Oceans

Alaska oil pipeline

above-ground/on stilts sliders to accommodate EQ motion survived 2002 M=7.9 Denali EQ

Lecture 25-2018: Anthropogenic Changes: Water and Oceans

we allow 10.5 PQ credits

PQ13: for a total credit of 0.6 pts (0.15 pts attendance credit) Use our form only! in class < 25 min – no PQ! we check ID!

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Lecture 25-2018: Anthropogenic Changes: Water and Oceans

The Earth’s Oceans

  • 70.8% of Earth’s surface
  • hold 95% of Earth’s water
  • oil fields/resources
  • take up heat
  • take up CO2
  • food source

(200 Mio people depend on fishing)

  • 60% of population live along coasts

sea level rise!

Lecture 25-2018: Anthropogenic Changes: Water and Oceans

The Warming Oceans

sea level rise (1 m by 2100) -> costal erosion; loss of habitable space warm freshwater on top -> stable layering -> no upwelling -> no food (e.g. Peru during El Nino as example of things to come) weakening of cold currents -> no upwelling -> hurricanes advance (i.e. landfall of hurricanes in San Diego possible) coral bleaching if T rises 1-2ºC corals face multiple threats -> 2003: 25% gone compared to 1980s

coral reefs: “the rain forest of the ocean” (high biodiversity!)

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Lecture 25-2018: Anthropogenic Changes: Water and Oceans

California’s Kelp Forest

  • important habitat
  • resource (iodine, alkali)
  • used for things from soap to glass
  • alginate thickens ice cream, jelly,

toothpaste

giant brown algae (kingdom protista)

  • grows up to 30cm/day to 60m
  • needs water < 20ºC (68ºF)

Garibaldi Cali state fish Lecture 25-2018: Anthropogenic Changes: Water and Oceans

Ocean Acidification

  • ocean chemistry changes 100 times faster

than in last 650,000 yrs

  • acidity increased by 30% in 150 years

(pH from 8.16 to 8.05)

  • projected decrease to pH 7.85 by 2100

(150%)

  • cannot produce protecting

carbonate shell -> dies ?? interruption of base of food chain

  • > mass extinction??

0.138”=3.5 mm

check grade for HW7 2a)

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Lecture 25-2018: Anthropogenic Changes: Water and Oceans

‘Hawaiian’ Humpback whales – 12/2/18

  • cause for decline: too early to tell
  • lack of food in Arctic?
  • annoyed by humans -> relocated?
  • baleen whale
  • food: krill, small fish
  • Arctic in summer (to feed)
  • Hawaii during winter (to fast, calve)

Lecture 25-2018: Anthropogenic Changes: Water and Oceans

sewage waste disposal unregulated disposal from cruise ships World: 200 large cruise ships Amount of waste of each/day:

95,000 l raw sewage from toilets 540,000 l sewage from sinks, galleys and showers 6 tons of garbage and solid waste

56 l of toxic chemicals 26,500 l oily waste water

dredging draining development

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Lecture 25-2018: Anthropogenic Changes: Water and Oceans

Plastic, the Wonder Resource … or is it?

  • made from petroleum
  • plastic not bio-degradable
  • plastic difficult to recycle
  • only small fraction is recycled (3.5%)
  • it takes sunlight a long time to break down plastic
  • plastic now finds its way to remotes oceans
  • ocean fish and birds mistake plastic for food

a plastic bottle takes 450 years to degrade

Lecture 25-2018: Anthropogenic Changes: Water and Oceans

  • discovered in 1997 by Cpt. Charles Moore (Algalita)
  • North Pacific Ocean Gyre
  • at least 2x Texas
  • “so bad it may be is economical to remove”
  • plastic bottles take 450 years to disintegrate

The Great Pacific Garbage Patch – Pacific Vortex

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Lecture 25-2018: Anthropogenic Changes: Water and Oceans

SD Tribune 11/29/08: “…98% of Albatross chicks have plastic in their stomach…”

Over 200,000 Laysan Albatross Chicks/year Die Loaded w/ plastic

Lecture 25-2018: Anthropogenic Changes: Water and Oceans

1972: The Club of Rome: The “Limits of Growth”

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Lecture 25-2018: Anthropogenic Changes: Water and Oceans

The Consequences:

  • 11 of 15 of most important fishing areas fully or overexploited
  • 70% of major fish species affected
  • landings of cod, tuna, haddock dropped by 95% since 1970
  • many > 90% exploited: tuna, cod, marlin, swordfish, halibut
  • aquaculture masks effects of overfishing

Source: FAO/Wikipedia

1950: 20 Mio tons worldwide 1997: 122 Mio tons

The “Healthy” Ocean:

Lecture 25-2018: Anthropogenic Changes: Water and Oceans

The Oceans as a Food Source

aquaculture (farming in the water)

2005: accounts for about 30% of fish catch, and growing 2016: up to 44% and growing, stress on wild populations

  • good example: catfish (majority in U.S.)
  • bad example: salmon (feeds on small wild fish)/spread of pests/diseases
  • color-coded fish cards help consumers decide; UPDATED EVERY YEAR!!
  • industry DELIBERATELY mislabeling fish for larger profits

Source: Science News 9/17/16

MSC founded 1997 in London

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Lecture 25-2018: Anthropogenic Changes: Water and Oceans

1498 Cabot: “codfish ran so thick they were easily caught by dangling a wicker basket over the side of the vessel” 6-7ft long; 200 pounds

Source: Wikipedia; Hans-Petter Fjeld

Cod thrives in 0-10ºC

  • > sensitive to global warming

who is next? Pacific Salmon???

Lecture 25-2018: Anthropogenic Changes: Water and Oceans

Fish cards -Salmons: farmed- red /wild - green

Earthwatch Nov 06, 2017 Earthwatch Nov 06, 2017

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Lecture 25-2018: Anthropogenic Changes: Water and Oceans

  • poisoning with sodium cyanide (S.E. Asia)
  • dynamite (Mediterranean; abandoned?)
  • gillnets/drift nets

(trap/drown large mammals)

  • trawling (all shelves at least once in 2 years)

150 x area of clearcutting global forest

from: http://www.wikipedia.org

Trawling Source: World Watch Institute

from: “Essential of Oceanography” by Trujillo

purse seine nets Lecture 25-2018: Anthropogenic Changes: Water and Oceans

* 20 Mio tons (~20%) thrown away as by-catch

  • fish too small
  • not marketable
  • lack of permit
  • this number does not include

killed mammals and birds

  • use fine nets
  • 5 kg unwanted species

for every 1 kg shrimp

Source: World Watch Institute

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Lecture 25-2018: Anthropogenic Changes: Water and Oceans

  • Loggerhead Turtle
  • up to 450 kg
  • lifespan up to 67 years
  • maturity: 17-33 years
  • Loggerhead and Leatherback

migrate across oceans (need international protection!)

Lecture 25-2018: Anthropogenic Changes: Water and Oceans

Vaquita

By-Catch

  • world’s smallest dolphin
  • Gulf of California
  • less than 30 left
  • CRITICALLY ENDANGERED
  • catch-to-protect FAILED!

Illegally fished

  • for Chinese meds
  • Gulf of California
  • Mexico banned harvest in 1975
  • CRITICALLY ENDANGERED

Totoaba

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Lecture 25-2018: Anthropogenic Changes: Water and Oceans

Sharks

Whale Shark Georgia Aquarium (Zac Wolf, wikipedia) Thresher Shark (Paul Ester, wikipedia) Whitetip Shark (OldakQuill, wikipedia)

true fish whale shark largest fish has lived on Earth for 450 Mio yrs

Lifespan Greenland shark: > 400 years

Lecture 25-2018: Anthropogenic Changes: Water and Oceans

sharks fined, then thrown out to die 1 bowl of soup cost $200 -> booming industry 100 Mio sharks caught each year -> 8000 tons of fins now banned in Atlantic and Mediterranean

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Lecture 25-2018: Anthropogenic Changes: Water and Oceans

Declining Shark Population in NW Atlantic

come in all sizes (few inches to 15m) some species declined by 80% and more in just 15 years!

89% 65% 80%

Lecture 25-2018: Anthropogenic Changes: Water and Oceans

The Oceans as a Food Source

The Consequences of Declining Supply:

  • out-of-work fishermen (Canada, Europe)
  • tension over fisheries worldwide (Canada-Spain, 1995)
  • piracy (South China Sea) SOMALIA!!!!!!
  • food ?????

Source: World Watch Institute Somali Pirates Source: wikipedia/U.S. Navy