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. It 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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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.  They have also been observe 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.

In recent years, the impact of boats has been driven by the accelerated development of activities in the coastal zone, 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. For this reason, we evaluate potential marine traffic regulations within the marine reserve, especially in areas that represent critical habitats for sea turtles. Our work relies on both scientific research and participatory work with local authorities and direct users, to assess 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 mating 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, resting, swimming or mating 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.

Similarly, this study seeks to understand the mechanisms of reaction of the sea turtles to the approach of the boats, and the external factors that intervene in their detection. One example of these external factors is the level of noise in the environment. This data will be key in designing conservation strategies that avoid the negative impact of marine traffic on the species.

At the same time, we are working with local captains and crew to determine the human capacity to detect animals in the water during navigation. Thanks to their participation, we 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. Then, the captains navigate at different speeds through this 1km section, notifying to the investigator the time of each detection. This data is helping us to 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.

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.

Video of a datalogger multicanal located on a marine turtle

Promoting sea turtle conservation amongst the local community in the Galapagos Islands

As part of the project, we partake in outreach activities aimed at different audiences. We work with the local community with the objective of increasing interest in knowing the life strategies of sea turtles, including the different threats they face both inside and outside the Galapagos Marine Reserve. As part of the activities, talks are held with different sectors of the community; including students from local schools, authorities, park rangers, naturalist guides, and the community in general. In addition, we are carrying out workshops with students from Isla Isabela, in order to give them field experience. Through these workshops, we teach the students about different species that can be found in the island, their life cycles and threats they face within the Galapagos Marine Reserve. Following, the group visit a sea turtle feeding site, to perform an underwater census together with the members of the project. In practice, students learn to identify species, stages of life (adults or juveniles), genders, as well as different body marks such as cuts or fractures caused by vessel impacts in the turtles present in the area.

 

Talk to students from Puerto Villamil
Talk to students from Puerto Villamil
Workshop with park rangers from Puerto Villamil, Isabela Island.
Workshop with park rangers from Puerto Villamil, Isabela Island.
Lecture at a local school in Puerto Villamil, Isla Isabela
Lecture at a local school in Puerto Villamil, Isla Isabela.
Explaining about sea turtle migration strategies to students from Puerto Ayora, Santa Cruz Island
Explaining about sea turtle migration strategies to students from Puerto Ayora, Santa Cruz Island.
Sea turtle feeding site and students from Puerto Villamil - Isabela Island.
Sea turtle feeding site and students from Puerto Villamil - Isabela Island./figcaption>

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

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The mission of the Charles Darwin Foundation and its Research Station is to tackle the greatest threats and challenges to Galapagos through scientific research and conservation action, in order to safeguard one of the world’s most important natural treasures.

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