By Hannah Lochan, Research Officer at the Institute of Marine Affairs, Trinidad and Tobago, and Member of Ecoseas Caribbean
What inspired you to specialize in coral ecology and marine conservation at the Institute of Marine Affairs (IMA) Trinidad & Tobago?
My journey in marine biology began during a summer field course during my undergraduate university days. I was aiming for a general Biology degree but felt uncertain about my future. Then, I saw a flyer for a week-long course on coral reefs in Toco, Trinidad, and decided to join. That experience changed everything. Seeing the coral reef system up close, learning about its incredible biodiversity, and being guided by inspiring mentors solidified my passion for marine biology. From that moment, I knew this was the path I wanted to follow.
After completing my degree, I started an internship with the coral restoration team at the Cape Eleuthera Institute (CEI) in the Bahamas. This experience gave me an insight into diving and the various restoration techniques used to rehabilitate coral reefs. What was supposed to be a five-month internship quickly turned into a year, as I fell in love with the work and location!
Can you explain coral bleaching and its impact on your work? How do corals show resilience?
Corals are fascinating immobile invertebrate animals with a mutualistic relationship with zooxanthellae, tiny algae that photosynthesize and provide nutrients. Zooxanthellae also give corals their color. This relationship depends on specific conditions (25–28°C), but prolonged temperatures above 29.4°C cause coral bleaching, where corals expel zooxanthellae, turning white. Bleached corals can recover if zooxanthellae return within weeks.
The Caribbean has experienced eight mass coral bleaching events in three decades. Tobago’s most severe was in 2010, causing ~38% coral loss (Alemu & Clement, 2016), with little recovery since. Coral cover now averages ~14.5%. Bleaching occurred again in 2023 and 2024, with over 50% of corals at eight Tobago sites showing heat stress (Ganase, 2024). It was heartbreaking to witness, but our work isn’t over, we will soon return to assess coral mortality and the potential for recovery.
After bleaching, coral disease outbreaks are common. For Trinidad and Tobago, a major threat is the highly transmissible Stony Coral Tissue Loss Disease, which has devastated reefs in The Bahamas and Florida. Though not yet detected in Tobago, we are working to strengthen our defenses as much as possible. This involves regular monitoring of reefs to identify early signs of disease to enable a swift response.
A 2006 valuation estimated Trinidad and Tobago’s coral-related tourism at $101 to $130 million (Burke et al., 2008). But their true value goes far beyond dollars, coral reefs are the frontline defense against coastal erosion and storms, the backbone of fisheries that sustain food and livelihoods and a driving force behind tourism that sustains local economies. Coral reefs are not just important for the environment, they also hold cultural significance for many coastal communities. Protecting them helps preserve both nature and heritage for future generations.
What are some of the biggest scientific and logistical challenges in coral restoration efforts?
One of the most pressing challenges is addressing climate change, with frequent mass bleaching events and the aggressive Stony Coral Tissue Loss Disease posing severe threats to reef survival. During the Reef Futures Conference 2024, Professor Pete Mumby presented projections from the Great Barrier Reef, showing that if we stay within the 1.5°C warming limit, reefs will remain as they are now by the end of the century. However, we have already exceeded this threshold. In a more extreme scenario of a 3°C temperature rise, projections suggest substantial reef degradation, with coral cover dropping to an average of just 5%, though this impact will vary across different reefs.
This bleak outlook is exacerbated by the fact that high loss of coral cover, leads to significant declines in genetic diversity, loss of wild genotypes, and ultimately a reduction in coral reef recovery, with limited juvenile corals to regenerate new populations. Research by Mumby in Palau showed that coral colonies less than 0.5 m apart had an average fertilization rate of 30%. However, as colonies were spaced farther apart, fertilization success dropped to 10% at 10 m, and nearly 0% at 15 m (Mumby et al., 2024). Furthermore, disturbances in already restored areas also present a challenge, as they undermine the considerable efforts, labor, and resources invested in conservation.
Logistically, more funding is needed to support restoration activities, which can be very costly, with projects having a median cost of USD $400,000 per hectare (Bayraktarov et al., 2019). Funding is needed not only for short-term or pilot projects but also for a sustainable financing model to ensure long-term continuity of activities and jobs.
In addition to cost, scaling up restoration efforts has been challenging. Many restoration projects are short-term, with varying success. Challenges stem from working with delicate, slow-growing living organisms that take years to grow and may have high mortality rates, making restoration a slow process. Insufficient funding, labor, improper site selection, ineffective methodologies, and limited access to efficient tools can all slow down the scalability of projects.
What emerging technologies or scientific methods are aiding coral recovery and conservation?
Innovation is essential! Scientists and marine managers recognize that business as usual isn’t enough. New technologies, methods, and AI tools are being used to protect coral reefs and improve coverage globally.
One key effort is the creation of gene banks to preserve coral genetic diversity. At CARMABI Research Station in Curacao, scientists have perfected cryopreservation of coral sperm, keeping it viable in liquid nitrogen for years. This sperm can later be used to fertilize coral eggs. The team is also working on preserving coral larvae, maintaining a full coral in its swimming state.
Scientists at the University of Miami are working to restore declining elkhorn coral populations in Florida by importing corals from Tela, Honduras. These colonies will be monitored ex-situ for coral spawning, and the resulting baby corals will be grown in the lab while permits are sought for outplanting them on Florida reefs. While controversial, principal investigator Professor Andrew Baker emphasizes the need for drastic solutions to address the severe decline of coral populations.
The need for biobanking has become clear, with many countries setting up ex-situ systems to protect remaining coral genotypes from harsh conditions in the wild, as species extinction becomes a growing threat. This approach helps safeguard corals from bleaching and disease while also allowing colonies to spawn in lab settings.
The MARIN project at the Institute of Marine Affairs is using assisted fertilization and coral seeding to restore Tobago’s reefs, with guidance from SECORE International. The process involves collecting eggs and sperm from different corals of the same species to increase genetic diversity in fertilization. The larvae are then allowed to settle on ceramic substrates, which are later placed back on the reef. While many larvae may not survive, the goal is to increase the number of baby corals that can be outplanted compared to what occurs naturally. In July 2024, the team outplanted the first batch of boulder brain juvenile corals at Hermitage Reef in Tobago, and we are excited to monitor their success and growth.
Engaging the local community is crucial. The MARIN Tobago project has established the Marine Resilience Network (MRN), which includes key government and community stakeholders to ensure the sustainability of restoration and resilience efforts beyond the project’s timeline. So far, some network members have been trained in restoration activities. Additionally, the MRN has been vital in reporting disturbances like fish kills and coral bleaching around the island.
How can policymakers, institutions and individuals support coral conservation efforts?
Legislation, enforcement, and proper management are crucial for protecting marine resources. There is often a disconnect between the value of tourism and the environment that supports it. We need leaders who have the will and determination to uphold their responsibility to implement the action plans that will help to mitigate pollution, regulate land clearing and coastline development and to recognise the need to support sustainable management of natural resources in the long term.
Private sector support is vital. Companies should invest in the environment and restoration programs, boosting both ecological and human resilience. This involvement can also scale projects and support innovation. A co-management approach can improve regulation enforcement and foster a sense of ownership in the community.
To gain individual support, continuous community engagement is essential. Raising awareness through social media, art, and digital storytelling helps shift perspectives on the environment.
What advice would you give to young women pursuing careers in marine science and ecological research?
Believe in yourself and your abilities! Work hard and stay open to opportunities that would allow you to build your network and keep you connected to people in the marine space. Do not be afraid to reach out to people, to get involved in what interests you. Volunteering and joining groups with like-minded people can open doors and even provide more direction as you traverse your career. Also, explore and develop your skills. For example, photography or blog writing are great ways to share your passion while also building your capacity. It is not an easy road, but your passion and your presence is so important in contributing to a healthier marine environment and ultimately a healthier society!
Stay informed! Follow IMA for the latest updates on their efforts to protect and restore coral reefs in Trinidad and Tobago!
If you’re inspired by this guest blog, join the movement and sign up to RISE UP and be part of the push for bold ocean action!
This is a guest blog and may not necessarily represent the views of other RISE UP network members or RISE UP as a whole. It is only through open dialogue and a diversity of ideas that we will arrive at the solutions necessary to restore Ocean health.
References
Alemu, J. B., I., & Clement, Y. (2014). Mass coral bleaching in 2010 in the Southern Caribbean. PLoS ONE, 9(1), e83829. https://doi.org/10.1371/journal.pone.0083829
Bayraktarov, E., Stewart‐Sinclair, P. J., Brisbane, S., Boström‐Einarsson, L., Saunders, M. I., Lovelock, C. E., Possingham, H. P., Mumby, P. J., & Wilson, K. A. (2019). Motivations, success, and cost of coral reef restoration. Restoration Ecology, 27(5), 981–991. https://doi.org/10.1111/rec.12977
Burke, L., Greenhalgh, S., Prager, D., & Cooper, E. Coastal Capital. World Resources Institute.
Ganase, A. (2024). 2024 Mass Coral Bleaching: Tipping Point for Tobago’s Reefs?. Living World Journal of the Trinidad and Tobago Field Naturalist Club.Mumby, P. J., Sartori, G., Buccheri, E., Alessi, C., Allan, H., Doropoulos, C., Rengiil, G., & Ricardo, G. (2024). Allee effects limit coral fertilization success. Proceedings of the National Academy of Sciences, 121(52). https://doi.org/10.1073/pnas.2418314121