Special Topics

Special Topics

Global Warming and Ocean Acidification

The Atmosphere

• Layer of gases surrounding the planet

• Troposphere– Nitrogen – Oxygen– Carbon dioxide– Methane

Global Warming andOcean Acidification

The Greenhouse Effect

The Greenhouse Effect

Human activity releases greenhouse gases:• Burning of fossil fuels (oil and coal) – releases ¾ of the CO2

• Deforestation• Puts CO2 into the atmosphere by burning• Less CO2 is absorbed by trees

• Methane is released by• Burning fossil fuels• Digestive system of cattle and sheep• Rice paddies

The scale of slash and burn agriculture in Western Brazil is almost incomprehensible. During the dry season the forest is put to the torch to make way for unsustainable farming and cattle raising.

Madagascar

Consequences of Global Warming• Rising sea levels as ice caps of Greenland and

Antarctica melt• Changes in precipitation patterns• Changes in habitat– The Arctic and Antarctic are warming 2-3X the

global rate• Loss of ice results in further warming– Bright white ice reflects solar energy back to space– Dark open water absorbs heat

Global Warming Animation

Global Warming and Polar Bears

6CO2 + 6H2O + E C6H12O6 + 6O2

C6H12O6 + 6O2 6CO2 + 6H2O + ATP

Increased CO2 in the ocean results in acidification of theOcean.

Ocean acidification: NRDC

CO2 highly soluble in seawater. The oceans hold morethan 50X more CO2 than the atmosphere.

Baleen WhalesCrabeater SealsLeopard SealsAdelie PenguinsChinstrap PenguinsGentoo Penguins

Light E Food E

The SunPhytoplankton

Krill – Euphausia superba

Photosynthesis

The top predators of the AntarcticPeninsula are seabirds and seals.

The Crabeater Seal is a Krill Specialist

Crabeater seals are krill specialists.Their entire “terrestrial” existence isspent on ice floes, not land.

The distribution of Chinstrap Penguinsis intermediate between the GentooPenguin in the north and the AdeliePenguin in the south.

NorthGentoos

Chinstraps

Adelies

South

Adelie Penguins

Adelie penguins breed on shores aroundthe Antarctic continent, South Shetland,South Orkney, and South Sandwich Islands.At sea they are usually found near the edgeof the shelf-ice to the northern extent ofthe pack-ice. They are a krill dependant species.

On the western sideof the AntarcticPeninsula the ACCupwells and floodsonto the continentalshelf. This bringsnutrients to the coastalwaters leading toblooms of diatomsthat krill feel on.

Upwelling

Some of the larval stages of krill feed on algae that grow on the lower surface of sea ice. One of the factors that determines the annual abundance of krill is the extent of sea ice in winter. Along the northern half of theAntarctic Peninsula there has been an 80% decline inkrill abundance in the past 30 years attributed to aloss of sea ice.