Reducing the Threats for Sea Turtles

Reducing the Threats for Sea Turtles

Reducing the threat of boat strikes on Green Turtles in Galapagos

This project is currently Active

The Galapagos Islands are a key site for the conservation of the green turtle (Chelonia mydas), as they are host to the second most important nesting colony in the region, and also provide numerous feeding sites for this specie throughout the archipelago.

Despite the protection provided by the "Marine Reserve" status, there are still some threats to the species in Galapagos, where interaction with fisheries and the impact of boats are the most problematic.

Like many Central and South American Countries, economic development in the Galapagos Archipelago is oriented towards ecotourism, and its potential continues to grow. In the last decade the number of visitors to the islands has increased dramatically, and in turn generating an increase in marine traffic as a product of tourism demand, and hence an increased interaction between boats and marine fauna.

Our Research Team

Macarena Parra Díaz

Principal Investigator

Macarena worked first at CDRS as a field volunteer on sea turtle monitoring in 2006 and as assistant in the same project in 2007. She later joined the vertebrate program and supported as a curator...

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Sofía M. Green Iturralde grew up alternating between life in the Galapagos and in mainland Ecuador. She is a graduate in Conservation Biology and Equine Sciences and is volunteering for some time in...

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Diana Loyola

Volunteer

Diana Loyola graduated as a Biologist with a minor in Ecology and Management from the University of Azuay in the city of Cuenca. She was a local student scholarship holder of the Charles Darwin...

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Other collaborators:

Dr. Jonathan Houghton, Dr. Hansjoerg KuncByron Delgado (FCD).

Project Details

The Galapagos Islands provide nesting beaches for the second most important green turtle nesting colony in the region.
The Galapagos Islands provide nesting beaches for the second most important green turtle nesting colony in the region. Every year, from December to May, the archipelago receives nesting females that migrate from Costa Rica, Salvador, Colombia, Continental Ecuador, Peru, Chile, among other countries.

At present, the boat strikes injuries have been observed in more than 19% of green turtles (Chelonia mydas) in some feeding sites near populated areas and also in 12% of females nesting on the main nesting beach (Quinta Playa) of the archipelago. Added to this, there are numerous reports of turtle mortality due to injuries related to vessel collisions, reports registered from 2002 to the present.

The Galapagos archipelago is of great importance at the regional level for green turtles.
The Galapagos archipelago is of great importance at the regional level for green turtles, not only for their nesting sites, but also for providing feeding spots distributed throughout the archipelago.

The impact of boats has been driven by the accelerated development of activities in the coastal zone observed in recent years, activities mainly focused on marine transport and tourism. With this project we expect to reduce the incidence of injured and dead sea turtles due to boat strikes in the Galapagos Marine Reserve, though the evaluation of potential marine traffic regulations within the marine reserve, especially in areas that represent critical habitats for sea turtles. It will be relying on both scientific research and participatory work with local authorities and direct users, to assess both their perception of the impact of marine transit on the islands, and to discuss possible restrictions to mitigate the impact.

Turtles look for sheltered and shallow areas to rest.
Turtles look for sheltered and shallow areas to rest. In these areas it is common to see them sleeping underwater, or very close to the shore with the carapace exposed to the sun. Shallow areas may represent a risk in the case of transit of small boats, such as pangas or zodiacs, as there is not enough depth for the turtles to swim to the bottom to avoid an impact.

The main goal of this project is to develop an economically sustainable solution to reduce threats to sea turtles related to marine transit, through community participation, scientific research and improvement of marine transport and tourism practices, combining the economic expectations of the community with conservation priorities.

The specific objectives of our project are:

  1. Evaluate the efficacy of different changes in navigation practices within the Galapagos Marine Reserve, such as
    1. Determine speed limits for navigation in areas that represent critical habitats for sea turtles.
    2. Evaluate changes in navigation routes, to avoid navigating through critical habitats of sea turtles.
    3. Asses the effectiveness of the use of propeller protectors.
  2. Identify potential areas where new navigation and tourism practices can be applied to reduce sea turtle mortality.
  3. Define socio-economic challenges and solutions.

Our results

Turtle equipped with multi-sensory device, on a nesting beach. The device has a camera that allows to obtain data of the turtle's natural behavior.
Turtle equipped with multi-sensory device, on a nesting beach. The device has a camera that allows to obtain data of the turtle's natural behavior.

In 2018, a study of the surface behaviour of female green sea turtles was initiated during the breeding season. This study will identify those activities that make them more vulnerable to being impacted by boats, how often these behaviours occur and where. For example, these included resting, swimming or breeding on the surface, which puts them at a greater risk of collision.

Image taken underwater, using the device installed in the turtle carapace. It shows the turtle resting on the sandy bottom, the morning after having deposited a nest on a nearby beach.
Image taken underwater, using the device installed in the turtle carapace. It shows the turtle resting on the sandy bottom, the morning after having deposited a nest on a nearby beach.

At the same time, we are also working with local captains and crew to determine the human capacity to detect animals in the water during navigation. Thanks to their participation, the researchers are conducting experiments to detect objects in the water. The experiments consist of randomly distributing mock carapaces of sea turtles within a section of 1km navigation, and subsequently the captains navigate at different speeds through this 1km section, notifying to the investigator the time at which each detection occurs. This data is helping us calculate distances of detection to the objects in the water from the boat, under different speeds scenarios. Combining these results, with the time for reaction of the turtles to approaching boats, it will be possible to calculate appropriate navigation speeds within critical habitats to avoid collisions with sea turtles.

The image shows the time when the turtle comes to the surface to breathe.
Sea turtles need to swim frequently to the surface to breathe, rest and reproduce, making them vulnerable to being hit by boats traveling at high speed. The image shows the time when the turtle comes to the surface to breathe. The image was captured by the device installed in its carapace.

The researchers are also working with the authorities and the local community to evaluate and take into account the socio-economic implications of any proposed management measures. An attempt will be made to generate a holistic plan to facilitate conservation actions by the Directorate of the Galapagos National Park, without affecting the aspiration of economic growth of the local community.

Keywords: Chelonia mydas, sea turtles, green turtle, marine transit, boat strikes

Current Donors

The Leona M. and Harry B. Helmsley Charitable Trust, Prince Albert II of Monaco Foundation.

The “Charles Darwin Foundation for the Galapagos Islands”, in French “Fondation Charles Darwin pour les îles Galapagos”, Association International sans but lucratif (“AISBL”), has its registered office located at Drève du Pieuré 19, 1160 Brussels, and is registered under the trade registry of Brussels under the number 0409.359.103.

© 2019 Charles Darwin Foundation. All rights reserved.