Leatherback Turtles and Submarine Cables in the Caribbean

And What Is This Map For?

The objective is to visualize all cable routes alongside various sightings of leatherback turtles. In some areas, the animals pass very close to where submarine cables are laid. Turtles heading to nesting sites on the beaches may travel many nautical miles. The map alternates between two views: the first focuses on turtle sightings closest to beaches with submarine cables, and the second offers a broader view of turtle trajectories and cable routes across the sea. This dual visualization highlights how the movements of these animals can seem to echo the paths traced by technological infrastructures beneath the ocean.

Background

I chose leatherback turtles because Cuban authorities mentioned them during the installation of the Arimao cable. Specifically, they stated that the timing of female turtles nesting on Cienfuegos beach would be respected. They also indicated that the protection of this marine ecosystem has been taken into account to avoid impacts in areas with high concentrations of marine vegetation.

Therefore, we have a proven case showing that both the installation and removal of submarine infrastructure can affect not only this species. It would be advisable to assess each case individually when deciding how and when to lay or remove cables in these sensitive environments.

The process of connecting a submarine cable is preceded by studies conducted by an oceanographic vessel. This vessel maps the seafloor along various routes, and based on those results, the cable is designed and ordered from manufacturers. So, during this process, it would be possible to assess whether a vital seabed is going to be impacted or not. The same applies when deciding whether to remove a portion of unused cable.

“It is an infrastructure that lies on the seafloor for thousands of kilometers without any particular surveillance. The cables are inevitably pulled up by anchors, trawl nets, underwater earthquakes, etc. That's why at least two cables are needed. With one cable, the situation is not satisfactory; it's when you have two that you start to breathe easier. Three cables are even better.”

“Once that is done, we have to lay the cable, and for this, we have a special tool, which is a fleet of ships grouped in a company called Orange Marine.”
—Luc Vuillemin, President of International Networks at Orange S.A., Outremers360 (2019).

Environmental Impact of Obsolete Submarine Cables

The key risks should be separated between impacts in deep waters and those in shallow waters. In deep waters, the risk of contamination is reduced. Often, cables are found to be “clean” when recovered for recycling.

Sources from the University of Berkeley who have studied the area noted that telecommunications cables do not harm biodiversity to the same extent as many other oceanic activities, mainly because they are fixed infrastructures.

In fact, when Caribbean government officials were interviewed about this, they stated that drone-based monitoring of submarine lines generates a huge amount of data on local biodiversity. Interestingly, much of this data can be uploaded to virtual archives—"the cloud"— which could travel through these very same cables.

According to the International Cable Protection Committee (ICPC):

Peer‐reviewed scientific research confirms submarine cables are neutral to benign in the marine environment.
✓ Modern cables and installation techniques prevent sea animal entanglement.
✓ Fish bites caused less than 0.5% of all faults between 1959 and 2006, with no such faults reported since.
✓ Cable sheathing made of high-grade polyethylene is chemically inert.
✓ Electrical fields are shielded; weaker than that of a laptop.
✓ No plowing or burial of cables in the deep ocean.
✓ Survey frequencies are above the hearing range of most marine animals.
✓ Cables are routed away from seamounts and hydrothermal vents.

The ICPC also cites other UN-affiliated organizations:

UNEP/WCMC–ICPC Cable Report 2009: "Environmental impact of fibre‐optic cables is neutral to minor."
UNCLOS Report of the UN Secretary General 2015: "Low carbon footprint and small relative impact."
UN World Ocean Assessment 2016: "Very limited environmental impacts."

In short, the main principle should be not to disturb marine life. Therefore, cables in coastal areas whose removal would affect species and plants should be left in place. Deep-sea cables could be recycled if the net environmental benefit is positive. Each decision should be made in coordination with local stakeholders.

“Research into the recovery of the seabed following protective burial of submarine communications cables shows that physical recovery is controlled mainly by the availability of sediment and the potential of that sediment to be eroded, transported and deposited. In that context, recovery is most rapid on the inner continental shelf, becoming less rapid with increasing water depth and distance from shore.”
—Kraus, Christoph and Lionel Carter, 2018. Ocean Engineering 157, 251–261.

Out of Service Cables

A submarine cable system that has been decommissioned or taken out of service is collectively referred to as an "OOS Cable".

Reasons for Recovery of OOS Cables

An OOS Cable may be recovered for reasons that may include the following:

To clear a path for a new cable in a burial area.
To prevent interference with a new cable route running parallel to an OOS Cable.
To comply with government permits requiring cable recovery at the end of its useful life.
To release cable owners from liability for leaving the OOS Cable on the seabed.
For a cable recycling company to recover materials for economic value.

Planning Considerations

Drafting new system development and governance documents should include provisions for the recovery of limited lengths of the cable after it has been taken out of service.
When constructing a new cable near an OOS Cable, arrange for the recovery of sections of the OOS Cable that are required to be clear for installation on the new route.
Follow the above principle when approached by other seabed users who wish to install subsea plants or extract seabed material in the vicinity of an OOS Cable.
Plan all cable recovery operations to minimize future interference to other seabed users by leaving the remaining cable in no worse condition than it was prior to the recovery.

Recovery Considerations

Legal Background

Under UNCLOS and customary international law, there is no requirement for the removal of OOS Cables in maritime zones beyond the territorial sea.
If a coastal state mandates removal of a submarine cable outside its territorial waters, cable owners can request a jurisdictional basis for such a requirement. Without a valid jurisdictional basis, removal requirements may be inconsistent with international law and subject to legal challenges.
Decisions on OOS Cable removal beyond territorial seas are primarily made by cable owners, driven by economic incentives like recycling valuable materials.
Cable owners and recovery service providers must be aware of maritime law principles to ensure compliance and mitigate legal risks.
The conflict dynamics are influenced by environmental considerations and potential disputes over resource ownership. Stakeholders must balance economic interests with environmental stewardship and legal compliance for sustainable OOS Cable management.
Ownership rights, responsibilities, and obligations do not change because a cable is an OOS Cable. Third-party recovery companies have no title to the cable or right to recover any cable without the permission of the legal owners.
Cable owners considering recovery offers should negotiate a recovery contract with a reputable recovery company that ensures proper equipment and trained crew are used, and all cable components are recycled and/or disposed of in an environmentally sound manner.
Unauthorized or incompetent recovery actions, such as leaving "bird cages," can expose cable owners to indemnity claims for damage to anchors, fishing gear, or the marine environment. Bird caging occurs when an armored cable is damaged, causing the tightly wound armor wire to spread out, increasing the risk of fishing gear snags. This can be avoided by capping cut cables or attaching clump weights, following standard industry practices.
Cable owners should ensure recovery contracts include: proper equipment and trained crew, documentation and capping of remaining cable segments, environmentally sound recycling/disposal, and liability coverage for third-party claims.
Recovery companies must confirm legal authority for cable removal, especially if not acting on behalf of the original owner, and resolve any ownership disputes prior to recovery operations.
For abandoned cables, successor companies may assume ownership or third parties may obtain title through admiralty proceedings, demonstrating original owners are untraceable or have renounced interest.

Pre-Decision Factors

In deciding whether to remove an OOS Cable, cable owners and third-party recovery companies should generally consider the following factors, among others:

Any potential effect on the safety of surface navigation or other uses of the sea.
Present and possible future effects on the marine environment. The comparative environmental impact of leaving the cable in place compared to the disruption caused by attempting to remove the cable should be considered, including consideration of composition and condition of cable materials, burial and sedimentation conditions, and the benthic environment.
The risk that the cable will significantly shift position at some future time.
The costs and technical feasibility associated with removal of cables.
The determination of a new use for allowing the cable or parts thereof to remain on the seabed.
The management of out-of-service cables as part of the cable protection program.
The potential socio-economic benefits of recovering the cable.

Post-Decision Factors

If the decision is to retain a decommissioned cable for future use or to leave an OOS Cable in place, Cable Owners should consider implementation of the following:

Notify all relevant charting authorities that the cable is no longer in service.
Inform local fishermen and other seabed users of the status change, ensuring future claims for sacrificed fishing gear are evaluated on their merits.
Ensure the cable owner remains responsible for the OOS Cable, whether through insurance or other means.
Explore alternative uses for the cable, such as donating it to scientific research bodies.
Update the ICPC Secretariat to facilitate the modification of the cable database.

International Cable Protection Committee. ICPC Recommendation #1, Management of Decommissioned and Out-of-Service Cables, Issue 14A, 12 June 2020.

FAQ: Sea Turtle Conservation & Submarine Cables

Q: How do submarine cables impact sea turtles?

A: Cables can interfere with migration routes and nesting areas, potentially causing disorientation for hatchlings due to artificial light.

Q: What should I do if I see a nesting turtle?

A: Maintain distance, keep quiet, and avoid using any lights that might disturb the turtle.

Q: How does extreme heat affect turtle nests?

A: High temperatures can cause nest failure, deformities in hatchlings, and skewed sex ratios.

Q: How can submarine cable installation be more environmentally friendly?

A: Cable routes should be assessed to avoid disrupting vital marine habitats, especially in coastal areas.

Sea Turtle Nesting Season and Best Practices

Sea turtle nesting season runs from March to October. Unfortunately, rising temperatures, habitat loss, and artificial lights threaten their survival. Experts like Dr. Sarah Milton, Dr. Jeanette Wyneken, and Dr. Annie Page share tips on protecting turtles and hatchlings, including staying away from nests and minimizing light pollution.

Learn More

Regulatory Challenges and Policy Framework

Processes need to be clarified and simplified to ensure that environmental considerations are evaluated on a case-by-case basis. Local stakeholders and environmental concerns must be taken into account.

That is, we wouldn't want to mandate the removal of cables crossing sensitive habitats, but we also wouldn’t want to forbid their removal when doing so would provide environmental benefits.

References

Evans, D., et al. (2021). Identification of the Gulf of Mexico as an Important High-Use Habitat for Leatherback Turtles. Ecosphere. Link
Fossette, S., et al. (2010). Atlantic Leatherback Migratory Paths and Temporary Residence Areas. PLoS ONE. Link

Data Providers

Data downloaded from OBIS-SEAMAP (http://seamap.env.duke.edu/dataset/7) on 2025-04-24. You can download the credits of the data bases from the following link:

Download CSV: Credits