Tobago’s coral reefs analysed with new tech

Divers from the Institute of Marine Affairs at Mt Irvine reef, Tobago. -

The Institute of Marine Affairs (IMA), together with a research team from Coastal Dynamics Ltd (CDL), is using advanced computer models to gain new insights into Tobago’s coral reef ecosystems.

These models help scientists understand how ocean currents interact with coral structures and how coral larvae move through the water.

In a media release on December 9, the IMA said this research could greatly improve coral restoration efforts by showing how different reef systems are connected and how coral larvae spread.

The findings, published in a recent study,A Numerical Modelling Approach to Coral Restoration and Management: Understanding Tobago’s Hydrodynamics and Reef Connectivity, shed light on how water movement shapes the health and growth of coral reef ecosystems around Tobago.

By understanding these underwater patterns, the scientific team aims to better protect and restore the reef structures that are vital to the island’s marine life and coastal communities.

Tobago’s coral reef ecosystems play a crucial role in protecting the island’s coastlines. Acting like natural barriers, these reef structures help shield shorelines from the impact of waves and storms, reducing damage to property and the environment.

Beyond coastal protection, Tobago’s coral reef communities support local livelihoods through fishing and tourism, which are vital to the island’s economy. They also provide homes for countless marine species, contributing to a healthy and thriving ocean ecosystem.

However, these coral ecosystems face growing threats from human activities and climate change. Rising sea temperatures are causing more frequent marine heatwaves, which lead to coral bleaching – a condition that makes corals more vulnerable to disease and less able to withstand environmental changes. When coral reefs suffer, so do the services they provide to the community.

Restoring coral reef systems

Dr Anjani Ganase, coral reef ecologist at the Institute of Marine Affairs (IMA), highlighted the importance of reef connectivity and management in coral restoration.

Ganase also writes regular features for Newsday on Tobago's reefsand other spects of its environment.

She said, “Understanding the interactions between ocean currents and coral reef systems is crucial for effective restoration efforts. It allows us to predict larval dispersal patterns and identify areas that may be more resilient to environmental changes. By integrating this knowledge with ongoing monitoring, we can develop more targeted strategies that enhance the recovery of our reef communities.”

These restoration efforts are part of the Marine Resilience Initiative (MARIN) Tobago, a project supported by bpTT. The initiative focuses on coral reef and seagrass restoration, while building a network for Tobago’s marine resilience.

Using tech to help reefs recover

Similar to video games, the scientists use computer simulations through advanced modelling techniques to mimic real-life scenarios, which helps them study how ocean currents around Tobago transport coral larvae. The models can even extend to explore connections with nearby islands such as Grenada, Barbados, and St Vincent and the Grenadines.

-

The project uses two main types of models. The first, hydrodynamic modelling, simulates ocean conditions such as water flow, tides, temperature, and salinity (satiness) levels. The second, known as an agent-based model, tracks how coral larvae drift with the currents until they eventually settle on the reef systems.

Medina Ishmael-Lalla, an oceanographer and numerical modeller at Coastal Dynamics Ltd, said. “Numerical modelling is a cost-effective way to explore Tobago’s ocean dynamics and reef connections. By simulating these conditions, we can develop targeted strategies for coral reef preservation and restoration, especially following coral bleaching events.

"This approach helps us evaluate different scenarios, including the impacts of climate change.”

In October 2024, Coastal Dynamics presented a scientific paper at the International Coastal Conference (ICS) in Doha, Qatar, showcasing the essential role of these modelling techniques in Tobago’s coral-reef restoration.

Monitoring coral health

In addition to modelling, IMA does annual coral monitoring to assess the health of Tobago’s reef structures. This programme measures factors including the amount of living coral, types of coral and fish species, and any signs of disease or damage.

Data collected through the Coral Reef Early Warning System (CREWS) at Buccoo and Speyside helps monitor water quality, as changes in temperature and salinity can affect coral health.

By combining both modelling and monitoring, the IMA said it is taking a dynamic, comprehensive approach to coral reef restoration. These efforts aim to enhance the resilience of coral communities, ensuring they continue to provide essential benefits for Tobago’s people and marine life for generations to come.