Oceanography-Chapter 8_Marine Ecosystem_Logoon, estuaries, Bays.pdf

Marine ecosystems Marine ecosystems among earth's aquatic ecosystems. Include oceans, salt marsh, intertidal habitat, estuaries and lagoons, mangroves and coral reefs, the deep sea and the sea floor. contrasted with freshwater ecosystems, which have a smaller salt content. considered ecosystems beca...

Marine ecosystems Marine ecosystems among earth's aquatic ecosystems. Include oceans, salt marsh, intertidal habitat, estuaries and lagoons, mangroves and coral reefs, the deep sea and the sea floor. contrasted with freshwater ecosystems, which have a smaller salt content. considered ecosystems because the plant life supports the animal life and vice-versa. ◼ ◼ Fish habitat ◼ Food ◼ Shelter from predators, competitors, current, natural disturbances ◼ Migration routes ◼ Reproduction cues Place or environment where aquatic plants or animals naturally live and grow Critical habitats ◼ ◼ ◼ ◼ ◼ ◼ ◼ Salt marsh Intertidal ecosystem Lagoons, estuaries and bays Mangroves Beaches Coral reefs Seagrass beds Salt marsh transitional intertidal between land and salty or brackish water (e.g.: sloughs, bays, estuaries). dominated by halophytic (salt tolerant) herbaceous plants. treated as "wastelands", along with other wetlands. one of the most biologically productive habitats on the planet, rivaling tropical rainforests. tidal surges bring in nutrients, which tends to settle in roots of the plants within the salt marsh. natural chemical activity of salty (or brackish) water and the tendency of algae to bloom in the shallow unshaded water also allow for great biodiversity. Intertidal ecosystem Intertidal ecology is the study of intertidal ecosystems, where organisms live between the low and high tide lines. At low tide, the intertidal is exposed (or ‘emersed’) whereas at high tide, the intertidal is underwater (or ‘immersed’). Intertidal ecologists therefore study the interactions between intertidal organisms and their environment, as well as between different species of intertidal organisms within a particular intertidal community. Vertical zonation Lagoons, Estuaries and Bays Shallow, semi-enclosed and sheltered littoral bodies of water Lagoon – semi-enclosed coastal basin with limited fresh water input, high salinity, and restricted circulation; lagoons often lie behind sand dunes, barrier islands, or other protective features, such as the coral reef of an atoll lagoon. Estuaries – semi-enclosed coastal basin in which fresh river water entering at its head mixes with saline water entering from the ocean; usually associated with a river’s intersection of the coast. It is more diluted than lagoons (Malampaya Sound) Bays – more open littoral basins and flow is not as restricted; salinity levels approaching the open sea (Manila Bay, Batan Bay, San Miguel Bay) Favorable conditions: Wide range of salinity Near total light penetration Large quantity of organic nutrients from flora and marine inputs High rate of vertical mixing Proximity to other critical habitats such as mangroves and seagrasses Estuary semi-enclosed coastal body of water with one or more rivers or streams flowing into it, and with a free connection to the open sea. often associated with high levels of biological diversity. tidal mouths of rivers (aestus is Latin for tide), characterized by sedimentation or silt carried in from terrestrial runoff and, frequently, from offshore. made up of brackish water. Estuaries are often given names like bay, sound, fjord, etc. The terms are not mutually exclusive. under threat from human activities such as pollution and overfishing. Grouped by structure rather than circulation, there are other types of estuaries. Bar-built estuaries are effectively synonymous with barrier island lagoons. Tectonic estuaries form when the sea floods a geologically subsident region. Coastal plain estuaries are flooded river valleys, and fjords are submerged glacier-eroded valleys. Sandbar between St. Agnes and Gugh on the Isles of Scilly off the coast of Cornwall, Great Britain A tidal sandbar connecting the islands of Waya and Wayasewa of the Yasawa Islands, Fiji Lagoons, Estuaries and Bays: Uses Non-extractive Extractive Transformation Harbors Disposal sites (sewage and industrial effluents) Recreation Science and education Aquaculture Transport Fishing Sand mining Seed fish and shrimp collection Ornamental fish collection Gleaning Desalinization Landfill Aquaculture Lagoons, Estuaries and Bays: Pollution Domestic sewage waste from coastal cities, municipalities, and ships Domestic solid waste dumped along shoreline areas or rivers Sediments from upland and coastal erosion, construction sites, and poor agriculture practices Mine tailings and sediments from quarrying and mining in coastal and upland areas Industrial organic and toxic wastes Chemicals from agriculture and aquaculture Oil and fuel leaks and spills on land and from