Marine Ecosystems Quiz

Marine Ecosystems

• Marine ecosystems include oceans, salt marshes, intertidal habitats, estuaries, lagoons, mangroves, coral reefs, and the deep sea and sea floor.
• They are contrasted with freshwater ecosystems, which have a smaller salt content.

Characteristics of Marine Ecosystems

• Considered ecosystems because plant life supports animal life and vice-versa.
• Provide fish habitat, food, shelter from predators and competitors, migration routes, and reproduction cues.
• Critical habitats include salt marshes, intertidal ecosystems, lagoons, estuaries, mangroves, beaches, coral reefs, and seagrass beds.

Salt Marsh Ecosystem

• Transitional area between land and salty or brackish water (e.g., sloughs, bays, estuaries).
• Dominated by halophytic (salt-tolerant) herbaceous plants.
• Considered one of the most biologically productive habitats on the planet, rivaling tropical rainforests.
• Tidal surges bring in nutrients, which tend to settle in plant roots, and natural chemical activity of salty water and algae blooms allow for great biodiversity.

Intertidal Ecosystem

• Study of intertidal ecosystems involves interactions between organisms and their environment, as well as between different species within a community.
• Organisms live between low and high tide lines, with exposure at low tide and immersion at high tide.
• Vertical zonation is a key characteristic of intertidal ecosystems.

Lagoons, Estuaries, and Bays

• Shallow, semi-enclosed, and sheltered littoral bodies of water.
• Lagoons: semi-enclosed coastal basins with limited freshwater input, high salinity, and restricted circulation.
• Estuaries: semi-enclosed coastal basins where freshwater from rivers mixes with saline water from the ocean.
• Bays: more open littoral basins with flow not as restricted and salinity levels approaching the open sea.
• Favorable conditions in these ecosystems include a wide range of salinity, near total light penetration, large quantities of organic nutrients, and high rates of vertical mixing.

Uses and Threats to Lagoons, Estuaries, and Bays

• Uses: harbors, disposal sites, recreation, science and education, aquaculture, transport, fishing, sand mining, seed fish and shrimp collection, ornamental fish collection, gleaning, and desalination.
• Threats: pollution from domestic sewage waste, domestic solid waste, sediments from erosion and construction, mine tailings, industrial organic and toxic wastes, agricultural chemicals, oil and fuel leaks, and landfills.