Being Productive in the Arctic Ocean

Where is the Arctic Ocean?

The Artic Ocean is also knowns as the ____________ _____________?North Pole

Some facts• Smallest of the worlds

oceans (14 million km2)• Widest continental shelf

(750 miles)• Covered almost entirely

with ice for 8 months a year not easily explored

• 3 distinct biological communities– Sea Ice Realm– Pelagic Realm– Benthic Realm

Sea Ice Realm• Includes plants/animals

that live on and just under the ice

• Only 50% melts in summer

• Sea ice is not solid—has network of tunnels (brine channels)

• Inhabited by: diatoms, algae, bacteria, viruses, and fungi

Pelagic Realm• Organisms that live

between the ocean surface and the bottom

• Algae grow rapidly here during summer (sun shines 24 hrs a day)

• Lots of zooplankton (floating animals)– crustaceans and jellyfish

• Fishes, squids, seals, whales

Benthic Realm

• The ocean bottom• Dead organisms settle

here as detritus • Energy source for:

– Sponges, bivalves (oysters), crustaceans (lobsters, barnacles), polychaete worms, sea anemones, bryozoans, tunicates and ascidians (sea squirts)

bryozoan

Sea squirt

Research• Very little research has been done on the sea ice,

pelagic, and benthic realms in the deepest parts of the Arctic.

Primary Productivity• What is it?• The transfer of chemical

or solar energy to biomass

• What’s this process called?

• Photosynthesis!

Algae bloom. June, 2006, Ireland

Photosynthesis and Limiting Factors

• How does it work? • Water + carbon dioxide + light = sugar + oxygen• What’s the formula? Can you write it out?• 6H2O + 6CO2 + light energy = C6H12O6 + 6O2

• What else is required?• Photosynthetic plants (chlorophyll)

– In the Arctic Ocean, most photosynthesis takes place in phytoplankton (microscopic floating algae)

• Plant material, light, and nutrients can limit the amount of photosynthesis

• We don’t know which of them limit PP in the Arctic…

Algae are the base• All three realms ( sea ice,

pelagic, benthic) are coupled.

• Algae are the base of the food chain for this entire environment

• Photosynthesis can be limited. What are those limiting factors?– Plant material, light, and

nutrients

Arctic ice algae

You will be examining 10 different data sets taken at 10 different times in the year.

The meaning of each set of cards• Ice Cover: describes the percent of sea surface that is covered with ice

• PAR: amount of photosynthesis active radiation (sunlight that is usable for photosynthesis) available as a percentage of the maximum radiation that occurs during the year.

• Chlorophyll a: amount of chlorophyll a (which is a measure of the amount of photosynthetically-capable plant material present) in the surface of the seawater.

• Nitrate: the amount of nitrogen-containing nutrients present

• Primary Productivity: the amount of organic matter that has been produced through photosynthesis at the sea surface.

The Data and Your Interpretation1. Each group will read aloud to the class their data for

Day 1. Everyone else needs to to record this data.2. Within your group, discuss the results3. As a class, we will discuss results4. Repeat steps 1-3 for the next 4 days5. For days 6-10, after collecting data from the class,

you will write down your OWN interpretation of the data WITHOUT sharing

6. Discuss ALL the results as a class7. Each student write down individual summaries of

factors that limit primary productivity in the Arctic Ocean.