Marine Ecosystems

Marine ecosystems are among the largest of Earth's aquatic ecosystems. They include oceans, salt marshes, intertidal zones, estuaries, lagoons, mangroves, coral reefs, the deep sea, and the sea floor. They can be contrasted with freshwater ecosystems, which have a lower salt content. Marine waters cover two-thirds of the surface of the Earth. Such places are considered ecosystems because the plant life supports the animal life and vice versa.

Diversity of Marine Ecosytem Marine ecosystems are home to a host of different species ranging from tiny planktonic organisms that comprise the base of the marine food web (i.e., phytoplankton and zooplankton) to large marine mammals like the whales. In addition, many fish species reside in marine ecosystems including flounder, scup, sea bass, monkfish, squid, mackerel, butterfish, and spiny dogfish. Birds are also plentiful including shorebirds, gulls, wading birds, and terns. Some marine animals are also endangered including whales, turtles, etc. In summary, many animal species rely on marine ecosystems for both food and shelter from predators.

Salinity Water salinity based on dissolved salts Fresh waterBrackish waterSaline waterBrine < 0.05%0.05–3%3–5%> 5%

Ocean coasts support plant and animal life Habitat – an environment that has all necessary requirements for an organism to live. Intertidal Zone – the habitat at the edge of the ocean. Estuaries – the place where fresh water from rivers and streams mixes with salt water from the ocean. Wetlands – wet, swampy areas that are often flooded at the edge of estuaries.

ECOLOGICAL ADVANTAGES Climate moderation Climate moderation CO 2 absorption CO 2 absorption Nutrient cycling Nutrient cycling Waste treatment and dilution Waste treatment and dilution Reduced storm impact (mangrove, Reduced storm impact (mangrove, barrier islands, coastal wetlands) Habitats and nursery areas for marine and Habitats and nursery areas for marine and terrestrial species Genetic resources and biodiversity Genetic resources and biodiversity Scientific information Scientific information

ECONOMIC ADVANTAGES Food Food Animal and pet feed (fish meal) Animal and pet feed (fish meal) Pharmaceuticals Pharmaceuticals Harbors and transportation routes Harbors and transportation routes Coastal habitats for humans Coastal habitats for humans Recreation Recreation Employment Employment Offshore oil and natural gas Offshore oil and natural gas Minerals Minerals Building materials Building materials

Types of Marine Ecosystems Estuaries Salt marshes Rocky shores Sandy Shores Coral reef Mangrove swamp Barrier islands

Estuaries An area in which fresh water from a river mixes with salt water from the ocean; a transition area from the land to the ocean. Other names: bay, sound, lagoon, harbor, or bayou. River bringing freshwater to the sea The Ocean Area where fresh and salt water mix

Characteristics of Estuaries Water is brackish : a mixture of freshwater and saltwater There is a gradual increase in salinity as you go from the river (0-5ppt) to the middle of the estuary (5-25ppt), to the ocean (>25 ppt). (ppt = parts per thousand, a unit for salinity) Pollutants are absorbed in estuaries.

Characteristics of Estuaries Very nutrient rich ecosystems leads to high productivity and high biodiversity. Fast-moving rivers and waves carry nutrient-rich particles. Sediment settles out in the estuary when the water slows down. Nutrients accumulates on the bottom (benthic zone). Great place for plants to grow!

Estuary plants Plants must be adapted to salty habitat cordgrass eelgrass glasswort – a succulent

Estuary animals Huge variety including… Blue crab, Stone crab, Fiddler crab, Horseshoe crab, Mosquito, Lobster, Flounder, Stripped bass, Crane, Flamingo, Sea gull, Ibis, Manatee, otters, and many more.

Salt Marshes A low area that is subject to regular, but gentle, tides, dominated by grasses. Salt marshes do not have trees or shrubs Location: Gulf of Mexico and Atlantic coast Texas salt marsh

Mangrove Swamps Coastal wetlands located in tropical and subtropical zones; characterized by salt- tolerant trees and shrubs, such as mangrove trees

Rocky shores Also called rocky intertidal zone – many places to live in this habitat, means high biodiversity Organisms must be adapted to wave action, changing tide levels

Rocky Shores At low tides, there are often tide pools left behind where you can see starfish, anemones, crabs, octopus

Sandy Shores Not as much biodiversity as rocky shores – Why? 1.not much habitat diversity 2.sand dries out at low tide some small things can live in the sand, food for shorebirds

Barrier Islands Narrow islands made of sand that provide a buffer for the mainland from the sea Constantly shifting, especially with storms Ex: North Carolina OuterBanks

Barrier beach Silversides Blue crab Low tide Dwarf olive Clam Beach flea Tiger beetle High tide Ghost shrimp Mole shrimp Sandpiper Peanut worm White sand macoma Sand dollarMoon snail

OceanBeach Intensive recreation, no building Primary Dune No direct passage or building Trough Limited recreation and walkways Secondary Dune No direct passage or building Bay or Lagoon Intensive recreation Back Dune Most suitable for development Grasses or shrubsTaller shrubs Taller shrubs and trees Bay shore No filling Barrier Islands Think about ecological succession as you move away from the ocean. What is the disturbance in this ecosystem?

Coral Reefs Structures in the shallow oceans that are built by animals called corals; serve as a habitat for many diverse organisms Require two things: warm temperatures and sunlight Found between 30°N and 30°S of the equator

Coral Reefs There are many different kinds of corals: Soft corals Hard corals

Coral Reefs Growing on the reef with the corals are other animals, such as sponges, worms, shrimps, crabs, mollusks Living in and around the reef are fish, sea turtles, sea snakes, marine mammals

Coral Reef Destruction 1. Coral bleaching – when temperatures go above normal, the algae in the coral can be rejected, the coral turns a whitish color and dies. Natural and/or manmade causes: El Nino, Global warming

Coral Reef Destruction 2. Physical damage Ships, anchors, tourist divers Dynamite fishing - reefs are damaged by physical destruction that may occur when people collect fish

Coral Reef Destruction 3.Land development and pollution – loss of mangrove forests means more nutrients and sediments flow out to the sea; coral may die from sediment or algal blooms 4.Fish and coral trade 5.Increased exposure to UV due to ozone depletion

Human Interactions Effect Shorelines Half of coastal wetlands lost to agriculture and urban development Half of coastal wetlands lost to agriculture and urban development Over one-third of mangrove forests lost since 1980 to agriculture, development, and aquaculture shrimp farms Over one-third of mangrove forests lost since 1980 to agriculture, development, and aquaculture shrimp farms About 10% of worlds beaches eroding because of coastal development and rising sea level About 10% of worlds beaches eroding because of coastal development and rising sea level Ocean bottom habitats degraded by dredging and trawler fishing boats Ocean bottom habitats degraded by dredging and trawler fishing boats

UPWELLING Winds blowing across the ocean surface push water away. Water then rises up from beneath the surface to replace the water that was pushed away.