Biological Oceanography

Biologists have named about 1.8 million species.

Estimates of total species range from 10 million to over 200 million.

MICROBESThey make up 98% of the biomass of the world’s oceans.Supply more than half the world’s oxygen.Major processors of the world's greenhouse gases.About 1.5 million species have been named.Tens of millions of more species may exist.We know more about distant stars and planets than we do about the microbes living in our oceans.

The Multicellular KingdomsFungi Bodies usually made of filaments.

Absorb digested food from environment.e.g.

We won’t be talking about fungi much.

Yeah… only one percent of fungi are marine.

The Multicellular KingdomsPlantsMulticellular.

Photosynthetic.

The Multicellular KingdomsAnimals Multicellular.

Ingest food.

Life Zones of the

Oceans

Intertidal ZonesBetween high

and low tide levels.Alternates: wet/dry.

Many organisms attach to rocks or burrow.

Strandline – line of seaweed and debris deposited on the beach by each high tide.

Below low tide line.Coastal life zone that remains underwater.

Heavy wave impact and underwater turbulence.

Subtidal Zone

Pelagic Zone -The entire ocean of water above the sea bottom.

The blue stuff you’re looking at is the pelagic zone!

Pelagic Zone =The neritic and oceanic zones.

Neritic Zone – Over the continental shelf.Between low tide levels and the continental slope. ~ 200 meters at its deepest. Richest in life forms. Area of most commercial fishing.

Some areas have dense forests of seaweed.

Oceanic Zone – Beyond the continental shelf.

Photic Zone - the depth of the water with sufficient sunlight for photosynthesis to occur.

Aphotic Zone – Not enough light for photosynthesis.The majority

of “plant” life is planktonic.

Benthic Zone – The bottom.

Benthic Zone – The bottom.

Benthic organisms of the deep depend on detritus from above.

Detritus – Organic material “raining down” from above.

EstuariesWhere freshwater and saltwater meet.

Mixture of salt and fresh water.

Brackish -

An estuary is a semi-enclosed body of water connected to the sea.

Estuaries are regions of transition and sharp gradients.

Estuaries support fauna recruited mostly from the sea.

• Estuaries are nutrient rich – important breeding grounds.

• Calm water - protected by Barrier Beaches.

Estuaries –• Have more food for organisms.• But the organisms usually have to deal with large temperature and salinity changes, high silt content and pollution.

Why is high silt a problem for marine organisms?

Hint: How does this guy get food?

Many marine organisms are filter feeders so silt can be a major problem.

The number of species in an estuary is greatly reduced, but the number of individuals is large.

What the heck does that mean?

It means that if you can survive here you will find a lot of food.

But there is low biodiversity.

The Salt Marsh

• Controlled by tides•Marsh grasses

• The“nurseries” of the estuary.

Mud Flats• No grasses. Little or no aeration in the sand.• Caused by decomposing bacteria turning the

wastes in the sand into a dark mud. • Considered the “graveyards” of the estuary.

CHESAPEAKE BAY

Anyone know the largest estuary in the U.S.?

Can you name the 6 states that make up the watershed of the Chesapeake Bay?

A watershed is the drainage area for a bay.

VirginiaMarylandWest VirginiaDelawareNew YorkPennsylvania

Estuary TypesThe Chesapeake Bay is a

drowned river valley. This is the most common type of

estuary. It was formed after the last ice age some 12,000

– 18,000 years ago.

Bar-Built EstuariesThese are found where sand bars and barrier

islands form.The shallow water

behind these barrier islands forms low salinity estuaries.

Tectonic EstuariesThese

estuaries form where land sank or

subsided.e.g. San Francisco Bay.

Anyone know the last type of estuary?e

Hint: Think viking.

Fjords! Created when

retreating glaciers cut deep into the earth.

End point marine bio quiz 1.