Coral reefs are among the most biodiverse ecosystems on the planet, providing essential services to marine life and coastal communities. However, these fragile ecosystems are facing increasing threats from both global climate change and local human activities.
In Guna Yala, a region renowned for its rich marine biodiversity, we co-launched a new coral reef conservation and research initiative in Guna Yala, Panama, with the support of SENACYT Panama and the active engagement of the Guna Congress’s scientific arm, IIDKY (Instituto de Investigaciones y Desarrollo de Kuna Yala), along with MiAmbiente Panama, that marks the most comprehensive coral reef and fish assessment conducted in the region in over 22 years.
Our team monitoring one of the sites sampled in the Guna Yala. CC: Rachel Graham/MarAlliance
Across the entire monitoring of Guna Yala, the team sampled 23 sites, constituting 115 benthic transects, and 184 fish transects, totaling close to 9 km of reef sampling and over 135 hours of cumulative dive time. Overall, the expedition registered 55 different species of reef-forming coral from 18 different genera. By far the most abundant, diverse, and broadly distributed coral species across the surveyed region were those of the genus Porites, Agaricia, and Millepora, while records of species from the genus Ellisella, Eusmilia, Isophylia were relatively rarer and sparsely distributed. The status of coral species in relation to the current bleaching epidemic, genus Agaricia, Favia, and Mycitophylia were most affected by bleaching (over 50% of occurrences sampled), while genus Colpophylia and Acropora were the most impacted by reef diseases. These records suggest genus and species-specific vulnerabilities to important stressors, which means that each species of coral may face its own set of challenges when it comes to surviving changes in the environment, and that different types of corals are affected by environmental stressors (like temperature changes or diseases) in different ways.
Elkhorn coral (Acropora palmata) CC: Rachel Graham/MarAlliance
Blade fire coral (Millepora complanata) CC: Rachel Graham/MarAlliance
Millepora spp. Bleaching CC: Rachel Graham/MarAlliance
The fish surveys specifically focused on 27 species, those of main commercial and/or ecological relevance for coral reef habitats – such as parrotfishes, wrasses, groupers, and jacks -, as well as those that are well known to exert negative impacts on reefs like the invasive lionfish. Across all transects, the team recorded nearly 6,000 individual fish, representing 26 of the 27 target species from over 15 families, aligning with broader regional monitoring efforts. Our results highlight that members of the Scaridae family (parrot fish) were by far the most abundant, well-distributed, and contributed the most to the estimated biomass, closely followed by Labridae (wrasses) and Haemulidae (grunts). All of these families are herbivorous or low-trophic-level predators. Conversely, species known to be heavily impacted by overfishing, such as Serranidae (groupers), were scarce, and species of the Muraenidae, Monacanthidae (filefish), and Balistidae (triggerfish) families were virtually nonexistent in sampled reefs.
While analyses are still underway, preliminary results have started shedding light on the current status of coral reefs and further provided insight into the ecology of reef communities in Guna Yala. For instance, similar to that observed in different regions of the Caribbean, we find that there is a notable and positive correlation between coral reef diversity and benthic complexity – the variety and structure of the seafloor environment – with fish diversity. While there was strong variability in coral reef health across sites (eg., bleaching status, disease influence, amount of dead reef), coupling of survey data with historical and recent sea surface temperatures and anomalies suggests that reefs have been exposed to very similar temperatures over recent time.
One of the five young Guna women who have undergone rigorous training in SCUBA diving and coral reef and fish survey techniques. CC: Rachel Graham/MarAlliance
While elevated temperatures represent a significant stressor affecting coral reefs both locally and globally, direct human activities – such as poor boating practices, river sedimentation, and pollution – are likely a more important direct threat. Unlike the long-term effects of global warming, these human-induced issues can be addressed and mitigated through targeted conservation efforts and sustainable practices.
