Adaptation to Climate Change in Marine Turtles

Developing an approach for adaptation to climate change in the insular Caribbean - the hawksbill turtle as an indicator species

Future climate change may alter atmospheric circulation, potentially changing temperatures, weather cycles, wind and ocean currents. Coastal species, such as sea turtles, that use shorelines and other coastal marine ecosystems could therefore be greatly impacted.

Climate and local non-climate stressors may act synergistically to further damage the health and sustainability of coastal ecosystems. Sea turtles are excellent indicator species for considering climate change conservation planning because of their interdependence on terrestrial and marine resources.

The health of beaches as well as mangrove, sea grass beds, coral reefs and deep ocean ecosystems can be gauged by the presence of sea turtles that use these areas for nesting, foraging, rookeries and migrations. Climate changes in the ocean and along coastal interfaces will exert strong effects on sea turtles.

For example, sea level rise will decrease nesting beaches and feeding habitats, increase sand temperature which can alter the sex ratio or potentially result in mortality, increase sea surface temperature effects on coral and sea grasses will also affect the foraging habitats of sea turtles, and changes in ocean currents will lead to alteration of migration paths.

The World Wildlife Fund, through a grant from the MacArthur Foundation is working to develop an approach for adaptation options for endangered marine turtle management to climate change. Activities include:

1. Identification of the relevant topics in climate change and biodiversity as they pertain to the vulnerability of the hawksbill turtle, i.e. ambient temperature at nesting sites, beach morphology and resilience, pertinent dynamics of water tables, mangrove, sea grass beds, coral reefs, ocean ecosystems and currents.
2. Sources, types and availability of existing information.
3. Known and potentially unknown information gaps and best ways to fill them.
4. Best approach to organize and process the information to be gathered during the following months.

Through a preliminary workshop, which included international experts who have published data and results on climate change and marine turtle science, an initiative was formed. ACT (Adaptation to Climate change in the marine Turtles) is an international initiative with an open door policy, operating as a network of interested specialists. Members may join multiple task groups. Membership in task groups is unlimited and unrestricted. The initiative is coordinated by Lucy Hawkes (lhawkes@wwfca.org) and consists of 8 tasks groups, each with specific aims and missions. Each group leader will be the focus point for coordinating the group’s work.

• ACT 1: nest site selection and adaptive capacity
• ACT 2: the genetic units of climate change impact
• ACT 3: Sex ratios baselines and adaptation measures
• ACT 4: Climate change as a driver of depensation effects
• ACT 5: Foraging sites and plasticity
• ACT 6: Coastal planning for climate change
• ACT 7: Communications and outreach
• ACT 8: Providing links to climate change science