Coral Health in Bocas del Toro (2023-2024)

Paula Sills, M.A.

Ankay Conservation

Paling Brain Coral

Abstract

Coral reefs are essential ecosystems that provide biodiversity and coastal protection.

However, rising ocean temperatures and human activities threaten their survival. This study assesses

coral health in Bocas del Toro, Panama, comparing 2023 and 2024 data based on standardized transect

surveys. Findings indicate a slight improvement in some indicators, such as reduced degradation

levels, but an increase in coral mortality. Understanding these trends is crucial for guiding

conservation efforts.

Introduction

Coral reefs face increasing threats from climate change, pollution, and habitat destruction

(Hughes et al., 2017). Key indicators of coral health include degradation levels, bleaching severity,

and disease prevalence (Darling et al., 2019). This study evaluates coral health in Bocas del Toro by

analyzing degradation, mortality, and environmental stressors between 2023 and 2024.

Methods

The data was collected using a 30-meter transect survey with a 120-point intercept

method. This technique records the frequency of coral health indicators, including degradation levels,

bleaching severity, and the presence of coral diseases. The key metrics analyzed in this study are:

– Degradation levels: Mild degradation (DGM: 10-50%) and heavy degradation (DGH: >50%).

– Bleaching severity: Paling (PA), partially bleached (PB), and fully bleached (FB).

– Coral diseases: Yellow Band Disease (YBD), White Band Disease (WBD), and Black Band Disease

(BBD).

Results

Key findings based on the yearly average found per transect survey:

– Healthy Corals (HE): Decreased from 3.17 in 2023 to 2.07 in 2024, indicating a decline in coral

resilience.

– Mild Degradation (DGM): Decreased from 3.00 in 2023 to 2.01 in 2024, suggesting some

recovery.

– Heavy Degradation (DGH): Decreased slightly from 2.45 in 2023 to 2.23 in 2024.

– Dead Coral (DE): Increased from 1.83 in 2023 to 2.53 in 2024, signaling a rise in coral mortality.

– Bleaching Trends: Paling (PA) and partially bleached (PB) corals decreased in 2024, while fully

bleached (FB) corals remained stable.

– Coral Disease: BBD and WBD were recorded in 2023 but absent in 2024, suggesting reduced

disease prevalence.


Figure 1: Dead Coral Observations per 30m Transect (2023 vs 2024) The following figure represents the average number of dead coral (DE) points recorded per 30-meter transect using a 120-point intercept survey method. The increase in 2024 suggests worsening coral mortality conditions.

Discussion

The decrease in mild (DGM) and heavy (DGH) degradation levels at a first glance could

suggest some localized recovery in coral conditions. However, the increase in dead coral (DE) levels

is concerning, as it most probably indicates that the degraded corals have transitioned to dead corals

and that environmental stressors are negatively affecting coral survival. Likewise, the absence of

recorded coral disease in 2024 seems like a positive sign, once again, it could be to the fact that those

diseases were the cause of the currently dead corals, but are not currently affecting new live coral.

These findings highlight the complexity of coral health assessment. Monitoring long-term trends and

implementing targeted conservation efforts will be essential to mitigating further coral loss.

Conclusion

While the data indicates a slight improvement in some coral health indicators, the increase in

mortality underscores that the worsening of their health led to their death. The positive news is that

there are less corals with new degradation. Future studies should focus on tracking some specific

corals to be able to determine causality of deaths and/or recovery.

References

1. Darling, E. S., et al. (2019). Coral reef resilience and climate change . Science Advances, 5(4).

2. Hughes, T. P., et al. (2017). Global warming and recurrent mass bleaching of corals. Nature, 543(7645), 373-377.