Tuesday, June 22, 2010

Global Warming and Turtles

The effects of global warming/climate change will most likely have enormous impacts on turtles and other wildlife, mainly because the rate at which the climate is changing far exceeds the abilities of animals to adapt naturally to such dramatic environmental changes. In fact, scientists predict that many species will go extinct as a result of climate change.

With regards to turtles, a number of key climate change impacts have been identified:

Loss of nesting beaches: Sea level rise from the melting of polar ice is already contributing to the loss of beach and turtle nesting habitat. Weather extremes, also linked to climate change, mean more frequent and severe storms which alter nesting beaches, cause beach erosion, and inundate or flood turtle nests.

Seasonal beach erosion becoming more pronounced each year, photo Elke Talma

Reduced hatchling survival rates: Hotter sand from increasing temperatures results in decreased hatching rates or complete nest failure.

Month old turtle embryo dies in nests, photo Elke Talma

Imbalance in sex ratios: Increased sand temperatures will affect hatchlings by altering natural sex ratios, with hotter temperatures producing more female hatchlings.

Turtles gather at breeding sites and fight for mates, photo unknown

Change in their geographic distribution: Turtles use ocean currents to travel and find prey. Warming ocean temperatures influence migratory species by altering currents and impacting the distribution and abundance of prey species. This can result in southerly species being found in more northerly regions, well outside of their normal range.

Young leatherback hatchling at the mercy of the current, photo unknown

Loss of foraging grounds: Warmer water temperatures affect coral reefs through coral bleaching which are vital to the survival of species like the hawksbill.

Hawksbill turtle feeding on sponges, photo Pierre Andre Adam

While nothing can be done to stop changes in current flow, we can do our utmost to mitigate impacts to our coastline by making sure there is adequate beach vegetation to minimise sand erosion thus protecting the nesting platform and maximise shade cover to provide cool areas under vegetation to maximise or maintain egg survival rates as temperatures rise. This can be further enhanced through controlled coastal development. On a personal level, everyone should try to reduce their carbon footprint.

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