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Biological Oceanography. Biologists have named about 1.8 million species. Estimates of total species range from 10 million to over 200 million. MICROBES. They make up 98% of the biomass of the world’s oceans. Supply more than half the world’s oxygen.
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Biologists have named about 1.8 million species. Estimates of total species range from 10 million to over 200 million.
MICROBES They 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 Kingdoms Fungi • 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 Kingdoms Plants • Multicellular. • Photosynthetic.
The Multicellular Kingdoms Animals • Multicellular. • Ingest food.
Intertidal Zones • Between 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.
Subtidal Zone • Below low tide line. • Coastal life zone that remains underwater. • Heavy wave impact and underwater turbulence.
Pelagic Zone -The entire ocean of water above the sea bottom.
The neritic zone, also called coastal waters, the coastal ocean or the sublittoral zone,[1] is the part of the ocean extending from the low tide mark to the edge of the continental shelf, with a relatively shallow depth extending to about 200 meters (100 fathoms or 665 feet). The neritic zone has generally well-oxygenated water, low water pressure, and relatively stable temperature and salinity levels. These, combined with presence of light and the resulting photosynthetic life, such as phytoplankton and floating sargassum[2], make the neritic zone the location of the majority of sea life. 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.
Photic Zone - the depth of the water with sufficient sunlight for photosynthesis to occur. The photic zone or euphotic zone (Greek for "well lit”: εὖ “good” + φῶς “light") is the depth of the water in a lake or ocean that is exposed to sufficient sunlight for photosynthesis to occur. The depth of the photic zone can be affected greatly by seasonal turbidity. It extends from the atmosphere-water interface downwards to a depth where light intensity falls to one percent of that at the surface, called the euphotic depth. Accordingly, its thickness varies widely on the extent of light attenuation in the water column. Typical euphotic depths vary from only a few centimetres in highly turbideutrophic lakes, to around 200 metres in the open ocean. Since the photic zone is where almost all of the primary productivity occurs, the depth of the photic zone is generally proportional to the level of primary productivity that occurs in that area of the ocean. About 90% of all marine life lives in the photic zone. A small amount of primary production is generated deep in the abyssal zone around the hydrothermal vents which exist along some mid-oceanic ridges. The zone which extends from the base of the euphotic zone to about 200 metres is sometimes called the disphotic zone.[1] While there is some light, it is insufficient for photosynthesis, or at least insufficient for photosynthesis at a rate greater than respiration. The euphotic zone together with the disphotic zone coincides with the epipelagic zone. The bottommost zone, below the euphotic zone, is called the aphotic zone. Most deep ocean waters belong to this zone. The transparency of the water, which determines the depth of the photic zone, is measured simply with a Secchi disk. It may also be measured with a photometer lowered into the water. Aphotic Zone – Not enough light for photosynthesis. The majority of “plant” life is planktonic.
Benthic Zone – The bottom. Benthic organisms of the deep depend on detritus from above.
Estuaries An estuary is a semi-enclosed body of water connected to the sea. Where freshwater and saltwater meet. Brackish - Mixture of salt and fresh water.
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.
Hint: How does this guy get food? Why is high silt a problem for marine organisms?
Many marine organisms are filter feeders so silt can be a major problem.
What the heck does that mean? The number of species in an estuary is greatly reduced, but the number of individuals is large.
It means that if you can survive here you will find a lot of food. But there is low biodiversity.
The Salt Marsh • Marsh grasses • Controlled by tides • 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.
Virginia Maryland West Virginia Delaware New York Pennsylvania
Estuary Types The 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 Estuaries These are found where sand bars and barrier islands form. The shallow water behind these barrier islands forms low salinity estuaries.
Tectonic Estuaries These estuaries form where land sank or subsided. e.g. San Francisco Bay.
Hint: Think viking. Anyone know the last type of estuary?e
Fjords! Created when retreating glaciers cut deep into the earth.
