Why the marine and Coastal Environment Matters

 

Figure 1. Estimated mean value of some marine biomes. An estimation of the financial value of selected different marine areas. Marine biomes are divided between coral reefs, estuaries, and oceans. The marine biome covers 75% of the earth’s surface, and accounts for 90% of the planet’s water.

While the immense importance of marine fisheries is acknow­ledged worldwide, coastal fisheries provide an essential role for the livelihoods and cultures of a large share of the Worlds population. One third of the worlds population live in the coastal zone, which comprises an area of only 4% of the total land surface (UNEP, 2006). However, the vital role of land-based activity for coastal ecosystems has not been given adequate attention.

Coastal vegetation habitats, such as mangrove forests, can serve as buffers to protect the shore line from wind generated storms while at the same time they absorb silt, nutrients, toxic substances and support fisheries, provide construction materials, medicines and a huge range of other goods used by communities. The clearing of coastal forests increases suspended sediments and nutrients in terrestrial run-off, causing direct and indirect effects on algal and coral growth and competition and coral reef resilience and recovery (McCook 1999, Nyström et al. 2000). Even unsustainable watershed management practices far inland may impact coral reefs through increased discharges of silt into the ocean (UNEP, 2004). Areas with extensive natural vegetation and mangroves may have reduced human and property losses following the tsunami event on December 26th, 2004 (UNEP, 2005).

Historical overfishing leading to ecological extinction of entire trophic levels makes ecosystems more vulnerable to other natural and human disturbances such as nutrient loading and eutrophication, hypoxia, disease, storms and climate change (Jackson et al. 2001). 

In relation to area, the coastlines are also economically of outstanding importance not only for tourism, but also for a large share of coastal fisheries and tropical reefs provides a large range of ecological goods and services (Moberg and Folke 1999). They are also essential to the world’s impoverished as they supply a large share of basic free food sources.

 
Figure 2. The percentage of fish to the total human diet from various regions in the world. Based on statistics from 1987 to 1989. Fish is the last wild meal in the human diet, but roughly two-thirds of the world’s major stocks are now fished at or beyond their capacity, and another 10 percent have been harvested so heavily that populations will take many decades to recover.   Figure 3. Figure 3. World fisheries and aquaculture production. Shows the amount, in million tonnes, of fish taken by capture and aquaculture fisheries, between the years 1950-1999. Also included is a diagram showing the percentage of the different types of aquaculture in 1998.

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