Sea turtles were once abundant in tropical and sub-tropical waters. Today, their numbers have drastically declined due to a number of factors including commercial exploitation, incidental catch of turtles in net and loss of habitat. Conservation groups around the world have been spearheading an effort to protect the remaining populations of sea turtles. One of the major hurdles faced is a lack of knowledge regarding the role of sea turtles, and the reasons why they should be conserved.
From a scientific point of view, sea turtles play an important part in the continued health of marine ecosystems. They do this in two ways:
- Some species of sea turtles, especially Green turtles, are grazing animals which feed on sea grass. As is the case with normal lawn grass, sea grass beds need to be regularly cut in order to keep them healthy. Sea turtles do this by feeding on longer blades. A decline in the number of sea turtles may see a related decline in sea grass beds, which can have a human impact. Many commercial species of fish, shellfish and crustaceans use sea grass beds as breeding and developmental grounds. Loss of habitat would reduce the numbers of these species as well, lowering biodiversity and having a potentially negative effect on the fishing industry.
- Beaches and dunes are not very nutrient rich areas. There is typically little vegetation on dunes because sand does not hold nutrients well. As such, there is a high potential for erosion. A single nesting turtle can lay as much as 100 eggs on the beach and lower dune. Not all of these will actually hatch and the remaining eggs are a valuable source of nutrients for existing vegetation. They are able to grow stronger, with much more robust root systems. This helps the overall health of the dune system in that there is less potential for erosion and the dunes are maintained.
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It is clear that sea turtles are an integral component of two major ecosystems - the marine system and the beach/dune system. Many more species would be lost if these ecosystems were to be negatively impacted upon. This would ultimately affect humans since people utilize both of these ecosystems for food, recreation, and a number of other activities.
Even if this were not the case and sea turtles did not actually have a significant contribution to their environments, conservation efforts would still be needed because of their economic value. Sea turtles themselves are a valuable commodity, not in terms of using them as a food source etc., but rather as a catalyst for ecotourism. In recent times, the conservation of sea turtles has been linked more strongly to sustainable development. Many communities, in South and Central America for example, have already benefited from ecotourism development.
