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. The Earth has around 620,000 kilometres (390,000 mi) of coastline. Coasts are important zones in natural ecosystems, often home to a wide range of biodiversity. On land, they harbor important ecosystems such as freshwater or estuarine wetlands, which are important for bird populations and other terrestrial animals. In wave-protected areas they harbor saltmarshes, mangroves or seagrasses, all of which can provide nursery habitat for finfish, shellfish, and other aquatic species. Rocky shores are usually found along exposed coasts and provide habitat for a wide range of sessile animals 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.
The Gulf of Mannar is a large shallow bay forming part of the Laccadive Sea in the Indian Ocean with an average depth of 5.8 m (19 ft). It lies between the southeastern tip of India and the west coast of Sri Lanka, in the Coromandel Coast region. The chain of low islands and reefs known as Adam's Bridge, which includes Mannar Island, separates the Gulf of Mannar from Palk Bay, which lies to the north between India and Sri Lanka. The estuaries of Thamirabarani River and Vaippar River of South India and the Malvathu Oya of Sri Lanka drain into the Gulf. The dugong is found here.
Southeast Asian coral reefs have the highest levels of biodiversity for the world's marine ecosystems. They serve many functions, such as forming the livelihood for subsistence fishermen and even function as jewelry and construction materials. Coral reefs are developed by the carbonate-based skeletons of a variety of animals and algae. Slowly and overtime, the reefs build up to the surface in oceans. Coral reefs are found in shallow, warm salt water. The sunlight filters through clear water and allows microscopic organisms to live and reproduce. The Indian Ocean holds 60% of the world's coastal reefs, 25% are in the Pacific and 15% are in the western Atlantic. There are coral reefs in the Persian Gulf, Madagascar, the Philippines, Hawaiian Islands and off Southeast Asia. Coral reefs have been preserved and identified in rocks over 400 million years old. Coral reefs are actually composed of tiny, fragile animals known as coral polyps. Coral reefs are significantly important because of the biodiversity. Although the number of fish are decreasing, the remaining coral reefs contain more unique sea creatures. The variety of species living on a coral reef is greater than anywhere else in the world. An estimation of 70-90% of fish caught are dependent on coral reefs in Southeast Asia and reefs support over 25% of all known marine species. However, those sensitive coral reefs are facing detrimental effects on them due to variety of factors: overfishing, sedimentation and pollution, bleaching, and even tourist-related damage.
Blast fishing, fish bombing, or dynamite fishing is a destructive fishing practice using explosives to stun or kill schools of fish for easy collection. This often illegal practice is extremely destructive to the surrounding ecosystem, as the explosion often destroys the underlying habitat that supports the fish. The frequently improvised nature of the explosives, and undetonated charges, used means danger for fishermen and divers as well, with accidents and injuries.
Marine conservation, also known as ocean conservation, is the protection and preservation of ecosystems in oceans and seas through planned management in order to prevent the over-exploitation of these resources. Marine conservation is informed by the study of marine plants and animal resources and ecosystem functions and is driven by response to the manifested negative effects seen in the environment such as species loss, habitat degradation and changes in ecosystem functions and focuses on limiting human-caused damage to marine ecosystems, restoring damaged marine ecosystems, and preserving vulnerable species and ecosystems of the marine life. Marine conservation is a relatively new discipline which has developed as a response to biological issues such as extinction and marine habitats change.
The environment of Sri Lanka is unique in being one of the world's bio-diversity hot-spots.
Marine ecosystems are the largest of Earth's aquatic ecosystems and exist in waters that have a high salt content. These systems contrast with freshwater ecosystems, which have a lower salt content. Marine waters cover more than 70% of the surface of the Earth and account for more than 97% of Earth's water supply and 90% of habitable space on Earth. Seawater has an average salinity of 35 parts per thousand of water. Actual salinity varies among different marine ecosystems. Marine ecosystems can be divided into many zones depending upon water depth and shoreline features. The oceanic zone is the vast open part of the ocean where animals such as whales, sharks, and tuna live. The benthic zone consists of substrates below water where many invertebrates live. The intertidal zone is the area between high and low tides. Other near-shore (neritic) zones can include mudflats, seagrass meadows, mangroves, rocky intertidal systems, salt marshes, coral reefs, lagoons. In the deep water, hydrothermal vents may occur where chemosynthetic sulfur bacteria form the base of the food web.
The Belize Barrier Reef is a series of coral reefs straddling the coast of Belize, roughly 300 meters (980 ft) offshore in the north and 40 kilometers (25 mi) in the south within the country limits. The Belize Barrier Reef is a 300-kilometer (190 mi) long section of the 900-kilometer (560 mi) Mesoamerican Barrier Reef System, which is continuous from Cancún on the north-eastern tip of the Yucatán Peninsula through the Riviera Maya and down to Honduras, making it the second largest coral reef system in the world after the Great Barrier Reef in Australia. It is Belize's top tourist destination, popular for scuba diving and snorkeling and attracting almost half of its 260,000 visitors. It is also vital to the country's fishing industry.
A wild fishery is a natural body of water with a sizeable free-ranging fish or other aquatic animal population that can be harvested for its commercial value. Wild fisheries can be marine (saltwater) or lacustrine/riverine (freshwater), and rely heavily on the carrying capacity of the local aquatic ecosystem.
The Coral Triangle (CT) is a roughly triangular area in the tropical waters around Indonesia, Malaysia, Papua New Guinea, the Philippines, the Solomon Islands and Timor-Leste. This area contains at least 500 species of reef-building corals in each ecoregion. The Coral Triangle is located between the Pacific and Indian oceans and encompasses portions of two biogeographic regions: the Indonesian-Philippines Region, and the Far Southwestern Pacific Region. As one of eight major coral reef zones in the world, the Coral Triangle is recognized as a global centre of marine biodiversity and a global priority for conservation. Its biological resources make it a global hotspot of marine biodiversity. Known as the "Amazon of the seas", it covers 5.7 million square kilometres (2,200,000 sq mi) of ocean waters. It contains more than 76% of the world's shallow-water reef-building coral species, 37% of its reef fish species, 50% of its razor clam species, six out of seven of the world's sea turtle species, and the world’s largest mangrove forest. In 2014, the Asian Development Bank (ADB) reported that the gross domestic product of the marine ecosystem in the Coral Triangle is roughly $1.2 trillion per year and provides food to over 120 million people. According to the Coral Triangle Knowledge Network, the region annually brings in about $3 billion in foreign exchange income from fisheries exports, and another $3 billion from coastal tourism revenues.
The fishing industry in the Maldives is the island's second main industry. According to national tradition in the words of former President Maumoon Abdul Gayoom, "Fishing is the lifeblood of our nation, it is inborn. From the soil on which we live, to the sea around us, it remains an integral part of our existence. Fishing, and our country and its people, [are] one and shall remain inseparable forever." The Maldives has an abundance of aquatic life and species of fish. Common are tuna, groupers, dolphin fish, barracuda, rainbow runner, trevally and squirrelfish and many more. Aside from being of essential importance to the economy, fishing is also a popular recreational activity in the Maldives, not only among locals but by tourists. The islands have numerous fishing resorts which cater for these activities.
Hikkaduwa National Park is one of the three marine national parks in Sri Lanka. The national park contains a fringing coral reef of high degree of biodiversity. The area was declared a wildlife sanctuary on May 18, 1979, and then on August 14, 1988, upgraded to a nature reserve with extended land area. The growth of the number of visitors in the next 25 years increased the degradation of the coral reef. To reduce the effects to the ecosystem, the reef was declared a national park on September 19, 2002.
Kalpitiya is a coastal town located in western region of, Puttalam District. The Kalpitiya peninsula consists of a total fourteen islands. It is developing as a tourist destination.
Mangrove ecosystems represent natural capital capable of producing a wide range of goods and services for coastal environments and communities and society as a whole. Some of these outputs, such as timber, are freely exchanged in formal markets. Value is determined in these markets through exchange and quantified in terms of price. Mangroves are important for aquatic life and home for many species of fish.
Climate change in Sri Lanka is an important issue, and its effects threaten to impact both human and natural systems in Sri Lanka. Roughly 50 percent of its 22 million citizens live in low-lying coastal areas in the west, south, and south-west of the island, and are at risk of future sea level rise. Climate change also threatens the island's biodiversity, including its marine ecosystem and coastal coral reef environments. Sea-level rise due to climate change has the potential to affect the overall abundance of endemic species. Sri Lanka's coastal regions, such as the Northern Province and the Northern Western Province, are considered major hotspots and extremely vulnerable to climate change. These maritime provinces are the most densely populated. In addition to being a threat to Sri Lanka's biodiversity, climate change may cause disastrous consequences on various levels in such areas. Such consequences include: Affecting agricultural productivity, causing natural disasters like floods and droughts, increasing the spread of infectious illnesses, and finally undermining the living standards.
The resilience of coral reefs is the biological ability of coral reefs to recover from natural and anthropogenic disturbances such as storms and bleaching episodes. Resilience refers to the ability of biological or social systems to overcome pressures and stresses by maintaining key functions through resisting or adapting to change. Reef resistance measures how well coral reefs tolerate changes in ocean chemistry, sea level, and sea surface temperature. Reef resistance and resilience are important factors in coral reef recovery from the effects of ocean acidification. Natural reef resilience can be used as a recovery model for coral reefs and an opportunity for management in marine protected areas (MPAs).
Coastal hazards are physical phenomena that expose a coastal area to risk of property damage, loss of life and environmental degradation. Rapid-onset hazards last over periods of minutes to several days and examples include major cyclones accompanied by high winds, waves and surges or tsunamis created by submarine earthquakes and landslides. Slow-onset hazards develop incrementally over longer time periods and examples include erosion and gradual inundation.
Environmental issues in Sri Lanka include large-scale logging of forests and degradation of mangroves, coral reefs and soil. Air pollution and water pollution are challenges for Sri Lanka since both cause negative health impacts. Overfishing and insufficient waste management, especially in rural areas, leads to environmental pollution. Sri Lanka is also vulnerable to climate change impacts such as extreme weather events and sea level rise.
The East African coral coast is a marine ecoregion along the eastern coast of Africa. It extends along the coasts of Kenya, Tanzania, and northern Mozambique, from Lamu in Kenya to Angoche in Mozambique. It adjoins the Northern Monsoon Current Coast ecoregion to the north, and the Bight of Sofala/Swamp Coast ecoregion to the south.
Sri Lanka is a relatively small continental island, it exhibits a remarkable diversity of forest types, which are among the biologically one of richest forests in Asia. In these forests plant species show extraordinary patterns of localized distribution. Sri Lanka's forest became one of highest density of species diversity in the world. Sri Lanka natural forest cover about 12,493 km2 29.46% According to the National Red List said, Sri Lanka counts 253 land species, 245 species of butterflies, 240 birds, 211 reptiles, 748 evaluated vertebrates and 1,492 invertebrates. Forest coverage is about 70% tropical dry monsoon forests, 15% tropical moist monsoon forests and 5% tropical lower montane forests. By the dawn of the 19th century, Sri Lanka's forest cover was estimated at up to 70% of the total land area. Since then, the forest cover has decreased progressively over time. Significant loss of Sri Lanka's forest cover was first reported in the 19th century, with the introduction of plantation agricultural crops such as tea and vegetables. Commercial timber extraction policy of colonial rulers (British colonial time also led to clearing of forests in the dry zone. Irrigation development and agricultural expansions have been identified as key drivers of forest cover change.
