 Approximately 200 species of marine plants  Salinity greatest challenge  Exposure to salt water dehydrates most plants  Adaptations for marine plants  Include waxy coverings  Protection that reduces water loss and prevents dehydration

 Submergent plants  Live entirely underwater.  Example: Seagrasses  Emergent plants  Live with their roots submerged but with a significant portion of the plant growing above the surface  Example: Mangrove Trees  Both produce oxygen via photosynthesis  Emergent plants release oxygen into the air  Submergent plants release oxygen into the seawater

 Grow close together forming mangrove swamps or communities along tropical shores  Have prop roots  Anchor the mangrove trees into the muddy sand  Exposed during low tide, covered during low tide  Roots act as a net to trap organic debris brought in by the tides  Biological Productivity  Provide shelter and food for many organisms  Enriched with nutrients carried in by the tides  Considered “nurseries” of the sea  Young fish and other small animals hide to avoid being eaten by bigger organisms

 Lower Beach: area closer to the water  Does not have any plants  High tides and heavy surf prevent plants from taking root  Salty conditions in the sand and misty air creates inhospitable conditions for plant growth  Upper Beach  Dunes : Small hills formed by wind moving sand  Held in place by the roots of beach plants  Are very delicate and can be easily destroyed by human encroachment  Beach grass Ammophilia  Has long underground stems and deep roots that help hold the sand in place  stabilizes dunes  Beach grasses are widely spaced to minimize competition with each other

 High temperatures (>37o C)  Conditions resemble desert conditions  Adaptations include:  Thick waxy covering to minimize water loss from evaporation (example prickly pear cactus, Opuntia compresa )  Plants store water in their stems (example seaside goldenrod)  Plants grow the side of the dunes that face away from the ocean  Dunes provide shelter from winds and mist from ocean  Trees often grow only as tall as the dune

 Grow along the sandy beaches of calm bays  Reed Grass  Example Phragmites  Identified by fluffy brown tassels  Cordgrass  Found along the intertidal zone  Can be covered by water during high tides  can tolerate changes in salinity and temperature  Provide ecosystems for organisms such as fiddler crabs and mussels  Has the ability to break down industrial pollutants  Releases chemicals as harmless gas

 Adaptations  Special glands located in the leaves allow cordgrass to excrete excess salt  Glasswort (pickle weed) has short, thick wazy stems that store fresh water that the plant needs to survive

 Grass that grows underwater  Example: Eel Grass, Zostera marina  Found in cooler waters along the Atlantic and Pacific Coasts  Lives in protected bays and inlets of the subtidal zone  Grow close together forming beds which provide hiding places for mollusks, arthropods, and fish  Example: Turtle grass, Thalassia  Found in bays and inlets of warmer water along Florida and the Gulf of Mexico  Have underground stems called rhizomes  Form interlocking mat that helps stabilize the sandy seafloor  Provide a shelter and food for fish and marine invertebrates