Plankton, Algae, and Plants

Plankton Plankton: the mass of mostly microscopic organisms that float or drift freely in the waters of aquatic (freshwater and marine) environments. (Algae, phytoplankton, zooplankton, jellyfish). The basis of all life in the ocean. Make oxygen for us to breath.

Collecting and Studying Plankton Plankton Nets: Conical nets made of nylon threads woven in a fine interlocking pattern. Hauled behind a ship or set to a certain depth and then reeled in. Analyze plankton by counting how many there are, the types, and an estimate of the sample volume of water. Plankton per unit volume of water. Why Study Plankton? Plankton can tell us about the amount of dissolved oxygen, carbon dioxide, pH, temperature, and light intensity of the ocean at the time and place of sampling.

Phytoplankton: The Autotrophs Generate sugar (glucose) by photosynthesis. Make oxygen for us to breathe. 75% of Earth’s oxygen comes from phytoplankton in the ocean. Live in Photic zone Critical to marine life and life on Earth Primary producers and bottom of food web Generate oxygen

Types of Phytoplankton Diatoms: Dominant and most productive. Appeared in Cretaceous about 100 million years ago. Contributed to Earth’s current atmospheric oxygen. More than 5,600 known species! Made of Silica Dinoflagellates: Some live in corals. Others are free drifters. Have flagella to propel them forward and rotate around. Can move vertically but not side to side. Reproduce by division Some are bioluminescent: Chemical reaction transformed into light (they glow!) Numerous bioluminescent dinoflagellates cause “red tides” or harmful algal blooms. Usually occurs in spring: Can reach 29 million organisms per gallon!

Red Tide

Types of Phytoplankton Coccolithophores and Silicoflagellates: Coccolithophores: Covered in disks of calcium carbonate (calcite). Live near surface in brightly lit areas. In Mediterranean, they make the water look milky because they are so abundant Make up the famous White Cliffs of Dover in England (chalk) Silicoflagellates: made of silica (quartz) One or two flagella to move Little is known about them Picoplankton: Extremely small Contribute a lot of oxygen

Upwelling Upwelling: the movement of deep, cold, and nutrient-rich water to the surface. Organisms sink when they die. But these dead organisms are nutrient rich. They must be brought to the surface for other organisms to have food. Sunlight is also a key factor.

Zooplankton: The Heterotrophs Planktonic organisms that eat the primary producers Most numerous primary consumers in the ocean Eat diatoms, dinoflagellates, and other phytoplankton

Types of Zooplankton Copepods: Tiny shrimp-like animals related to crabs, lobsters, and shrimp which are all crustaceans. Make up 70% of zooplankton in the ocean Jellyfish: Considered macroplankton because they are larger than 1 centimeter across. Krill: Considered the keystone to the Arctic ecosystem. A shrimp-like crustacean that is eaten by seabirds, squids, fishes, and whales. Travel in schools Foraminifera (forams): Calcium Carbonate (calcite shells) Related to amoebas