MARINE AND COASTAL BIODIVERSITY
Marine and coastal biodiversity:
The oceans cover 70% of the planet’s surface area, and marine and coastal environments contain diverse habitats that support an abundance of marine life. Life in our seas produces a third of the oxygen that we breathe, offers a valuable source of protein and moderates global climatic change. Some examples of marine and coastal habitats include mangrove forests; coral reefs; sea grass beds; estuaries in coastal areas; hydrothermal vents; and seamounts and soft sediments on the ocean floor a few kilometres below the surface
Marine biodiversity: Marine biodiversity is an aggregation of highly inter-connected ecosystem components or features, encompassing all levels of biological organization from genes, species, populations to ecosystems. The marine environment has a very high biodiversity because 32 out of the 33 described animal phyla are represented there.
Biodiversity includes four main components:
- Genetic diversity refers to the genetic variation that occurs among members of the same species.
- Species diversity (taxonomic diversity) refers to the variety of species or other taxonomic groups in an ecosystem.
- Ecosystem diversity refers to the variety of biological communities found on earth. With ecosystem diversity we generally consider its two levels, that is, communities and ecosystems.
- Functional diversity refers to the variety of biological processes, functions or characteristics of a particular ecosystem.
Marine habitats are habitats that support marine life. Marine life depends in some way on the saltwater that is in the sea (the term marine comes from the Latin mare, meaning sea or ocean).
Marine habitats can be divided into coastal and open ocean habitats. Coastal habitats are found in the area that extends from as far as the tide comes in on the shoreline out to the edge of the continental shelf.
Importance of marine biodiversity: Healthy marine ecosystems are important for society since they provide services including food security, feed for livestock , raw materials for medicines, building materials from coral rock and sand, and natural defenses against hazards such as coastal erosion and inundation.
Coastal biodiversity: The coastal ecosystems occur where the land meets the sea and that includes a diverse set of habitat types like the mangroves, coral reefs, seagrass beds, estuaries and lagoons, backwaters etc. affect the functioning of biogeochemical cycles of these coastal ecosystems.
The coast, also known as the coastline or seashore, is defined as the area where land meets the ocean or as a line that forms the boundary between the land and the ocean or a lake.
Rocky shores: Rocky shores are usually found along exposed coasts and provide habitat for a wide range of sessile animals (e.g. mussels, starfish, barnacles) and various kinds of seaweeds. Along tropical coasts with clear, nutrient-poor water, coral reefs can often be found between depths of 1 – 50 m.
Mudflats: Mudflats are coastal wetlands that form when mud is deposited by tides or rivers. They are found in sheltered areas such as bays, bayous, lagoons, and estuaries. Mudflats may be viewed geologically as exposed layers of bay mud, resulting from deposition of estuarine silts, clays and marine animal detritus.