Large Marine Producers and Plants Includes Algae, angiosperms, and seaweeds

Algae Collective term for autotrophs processing chlorophyll and capable of photosynthesis but lacking vessels to collect sap. Diatoms and dinoflagellates are classified as unicellular algae Seaweed is the informal name for large, marine multicelluar algae Seaweed such as Kelp can reach over 200 feet in length!

Structure of Seaweeds Blades: Structure that resemble leaves Stipes: Stemlike structures Holdfast: root-shaped jumble at the base that holds the seaweed in place. Gas bladders: assist many species in reaching strongly illuminated surface water. Thallus: the body of the seaweed comprised of the blades, stipes, and holdfast.

Classification of Seaweeds Chlorophytes: Green Algae Live at or near the surface Related to land plants Phaeophytes: Brown Algae Largest algae Include Kelps that can reach heights of 200 feet! Can grow 20 inches per day! Can grow in deeper water (about 100 feet deep) Live in temperate and polar climates mostly Make up the Pacific Ocean’s giant kelp beds (California)

Classification of Seaweeds Continued Rhodophytes: Red Algae Most abundant Smaller and need less sunlight Can live in very deep water: down to 900 feet Some may be hundreds of years old and they grow very slowly

Marine Angiosperms Angiosperms Flowering, vascular plants with seeds Include sea grasses and mangrove trees Not considered seaweeds Descended from land ancestors and all live in shallow coastal water Most live at the surface

Sea Grasses Not true grasses Have leaves, stems, and roots Found on the coast of North America, Atlantic coast of Europe, Eastern Asia, Australia, and South Africa Form broad gray or green submerged meadows Reproduce by putting pollen in the water Most common type is Eelgrass (found the Chesapeake Bay!) Provide food for marine grazers such as sea turtles, manatees, and dugongs. Provide habitat for organisms such as blue crabs and fish

Sea Grass Meadow

Mangroves Trees that thrive in sediment-rich lagoons, bays and estuaries. Found in the Indo-Pacific, tropical Africa, and the tropical Americas Distribution depends on rainfall, temperature, and currents Mangrove forests assist the stabilization and expansion of deltas and other coastal wetlands. The complex root structure also forms a barrier and safe haven for organisms at the base of the tree.

Mangrove Forest

Commercial Importance Algin: from Algae Stiffens fabrics Make adhesives Salad dressings Prevents gritty crystals in ice cream Clarifies beer and wine Helps to make soaps and shaving cream Carageenan: A seaweed extract Replaces fat in hamburgers Prevents fire-extinguishing foams from dispersing Prevent chocolate milk from separating