Climate Change
How will climate change impact turtles at sea? The oceans, where sea turtles spend most of their lives, are warming and are expected to absorb 80% of the excess heat trapped on our planet.
Scientists know that sea turtle nests are highly susceptible to climatic variations. Under natural conditions, primary sex determinations are dependent on temperature with lower incubation temperatures resulting in male turtles and higher temperatures resulting in female turtles. In moderate climate change scenarios, rising temperatures are likely to skew primary sex ratios. In more severe climate change scenarios, rising temperatures will result in widespread hatchling mortality as nests exceed temperature thresholds conducive to healthy embryonic development.
Changes in ocean temperature are likely to have a wide range of effects on the survival and behavior sea turtles. Female turtles may not be able to find sufficient prey in warming oceans to consume enough calories to meet the resource requirements of nesting. Even if prey is available in the same quantities but distributed more diffusely, turtles may expend more energy in search of prey. Ecological conditions may then impact physiological conditions resulting in less frequent nesting and production of fewer offspring.
As climate change advances and our oceans continue to warm, hard-shelled sea turtles are following warm water corridors into new areas where they can be “cold-stunned” by rapid seasonal drops in temperature and may become unable to swim in this hypothermic state. Ocean warming trends also contribute to large-scale harmful algal blooms which can affect the health of sea turtles as well as people and other marine wildlife, including sea otters and sea lions.
Changing oceanic currents resulting from climatic shifts are also likely to impact hatchling dispersal as well as hatchlings’ ability to avoid predators in the dispersal phase. Hatchlings typically engage in a frenzied swim to escape coastal waters during the first hours or days after hatching until they become entrained in eddies and currents taking them to zones offshore with lower densities of predators where they can grow and decrease risk of predation. Changes in intensity and location of ocean currents, are likely to negatively impact hatchling survival rates in this critical life history phase.
Take Action for Sea Turtles:
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• Walk, ride your bike or use public transportation whenever possible. If driving is a necessity, consider carpooling!
• Source clean energy for your home and office.
• Reduce your consumption of animal products and other consumer goods with high carbon footprints.
• Support businesses with carbon negative or carbon neutral policies.
• Advocate for legislative solutions (e.g., carbon tax).