This study was conducted in the Jardines de la Reina National Park, Cuba. The health of the communities of corals and crustose coralline algae was studied in the years 2001, 2012 and 2017. The probable effect of hurricanes and sea surface temperature on these communities was also assessed. The area was only affected by three hurricanes and a tropical storm from 2000 to 2017. Sea surface temperature showed an increasing trend (by 0.03
Este estudio se realizó en el Parque Nacional Jardines de la Reina, Cuba. Se estudió la salud de las comunidades de corales y algas coralinas costrosas en los años 2001, 2012 y 2017. También se evaluó el probable efecto de los huracanes y la temperatura superficial del mar sobre dichas comunidades. La zona solo ha sido afectada por tres huracanes y una tormenta tropical en este siglo (desde 2000 hasta 2017). La temperatura de la superficie del mar mostró una tendencia creciente (en 0.03°C). El mayor porcentaje de Mortalidad Antigua se registró en 2001 (74% en arrecife frontal y 53% en crestas del arrecife) y el más bajo de Mortalidad Reciente en 2012 (0.03% en arrecife frontal y 0.17% en crestas del arrecife). La cobertura de coral aumentó en el arrecife frontal en 2017, entre 3% y 2%, respecto de 2001 y 2012. En las crestas del arrecife, el mayor porcentaje de cobertura se registró en 2001 (14.8%). A diferencia de los factores de estrés locales, se determinó que los huracanes y la temperatura de la superficie del mar probablemente hayan afectado negativamente a los arrecifes de coral, particularmente a las crestas del arrecife. Ambos hábitats han mostrado resistencia y/o capacidad de recuperación de los impactos sufridos después de 2001, lo que sugiere cierto nivel de resiliencia.
Coral reefs are biodiverse and productive ecosystems, but they are threatened by local stressors, and by global stressors such as climate change (
The structure of Cuba’s coral reef is quite variable. Unlike the ones located to the north of the mainland, reef ecosystems in the south are separated from the island by keys and large, deep lagoons with reef patches, which reduce the effect of global and local stressors on the health of these systems. Among the southern reefs, those of the Jardines de la Reina archipelago stand out particularly because of their conservation status (health) (
In the JRNP, there are no indications to suggest that coral reefs are being affected by local stressors (
During the present century, the JRNP has been affected by four tropical cyclones, but studies have focused on the effects of only two of these storms (
No comprehensive study of the effects of global stressors on the coral reef of the JRNP and their potential resilience has been published. Undoubtedly, research on coral reefs distant from human settlements, such as those of the JRNP, provides a unique opportunity to determine how resilient these ecosystems are to climate change, a phenomenon that is already causing probably irreversible damage to them (
The Jardines de la Reina archipelago (21°21’16’’N 79°75’5’’W-20°87’16’’N 78°54’66’’W) is formed by 661 keys and islands and extends along 360 km, paralleling the southern coast of the Cuban provinces of Camaguey, Ciego de Ávila and Sancti-Spiritus. The waters of the Gulf of Ana María are to the northwest of the archipelago and those of the Caribbean Sea to the south. In 1996, the Cuban Ministry of Fisheries proclaimed approximately 950 km2 of the archipelago a “zone under special regime of use and protection”. This management category is equivalent to the internationally recognized Marine Reserve. The entire area, from Cayo Breton to Cayo Cabeza del Este, was established as a National Park in 2010 on account of its ecological values and conservation status, according to the Cuban Council of Ministers.
Based on the experience gathered from over 15 years of work in the study area, and on research done between 2008 and 2019 (
Sampling sites per year. Zones of the JRNP (EWR, Westernmost Reserve; WR, Western Reserve; CR, Central Reserve; ER, Eastern Reserve and EER, Easternmost Reserve). Horqueta, Anclitas and Macao: sites where average monthly temperature was measured.
To determine the effects of tropical cyclones on the JRNP, historic chronology (from 1851 to 2017) was considered, using the database from the Institute of Meteorology of Cuba and published papers on tropical cyclones (
Three sites, Horqueta (21°06’6’’N 79°41’71’’W), Anclitas (20°78’6’’N 78°93’81’’W) and Macao (20°53’975’’N 78°40’88’’W), were chosen to document SST variations in the JRNP (
To assess normality, data were processed using the Shapiro-Wilk and Bartlett tests. For data that did not meet normality standards, the nonparametric Kruskal-Wallis test was used. Temperature trend analysis was performed using the Mann-Kendall test. All statistical analyses were performed using the XLSTAT Program Version 2016.02.28451.
Reef crests (1-3 m deep) and fore reef (8-15 m deep) (
Fore reefs | ||||
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Reserve zones | Years | Quadrats | Transects | Coral colonies |
EER | 2001 | 28 | 6 | 75 |
ER | 2001 | 78 | 18 | 213 |
CR | 2001 | 94 | 22 | 271 |
WR | 2001 | 112 | 24 | 359 |
EWR | 2001 | 81 | 18 | 212 |
EER | 2012 | 24 | 8 | 64 |
ER | 2012 | 57 | 38 | 415 |
CR | 2012 | 81 | 46 | 522 |
WR | 2012 | 72 | 45 | 430 |
EWR | 2012 | 81 | 48 | 452 |
EER | 2017 | 298 | 60 | 792 |
ER | 2017 | 150 | 30 | 445 |
CR | 2017 | 200 | 40 | 690 |
WR | 2017 | 250 | 50 | 846 |
EWR | 2017 | 268 | 60 | 718 |
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CR | 2001 | 47 | 12 | 78 |
WR | 2001 | 78 | 20 | 191 |
EWR | 2001 | 25 | 7 | 77 |
CR | 2012 | 54 | 31 | 179 |
WR | 2012 | 78 | 49 | 222 |
EWR | 2012 | 27 | 16 | 57 |
CR | 2017 | 199 | 39 | 300 |
WR | 2017 | 250 | 50 | 336 |
EWR | 2017 | 300 | 60 | 417 |
To know the historical status of the coral reef of the JRNP and whether it is resilient, health indicators between years (2001, 2012 and 2017) and between reserves per zone year were compared. These ecological indicators (OM, RM, live coral cover, coral recruit density and CCA cover) were selected taking into account that coral mortality could be a consequence of ocean warming and other climate events, such as the increasing number and frequency of strong hurricanes (
To assess normality, the data (OM, RM, live coral cover, recruit density and CCA cover) were processed using the Shapiro-Wilk W and Bartlett tests. The data did not meet normality standards, so the nonparametric Kruskal-Wallis test was used. When significant differences were documented, the Wilcoxon test was used to determine the elements showing the differences. For normal results, ANOVA was used (mean monthly SST). Statistical analyses were carried out with the R software version 3.1.2 (
The area was only affected by three hurricanes and a tropical storm from 2000 to 2017 (
Tropical cyclone | Year | Category | Date |
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Dennis | 2005 | Hurricane, Category 4 | 8 July |
Fay | 2008 | Tropical Storm | 17 August |
Ike | 2008 | Hurricane, Category 1 | 8 September |
Paloma | 2008 | Hurricane, Category 3 | 8 November |
Monthly mean SST was studied at three sites of the JRNP, but no significant differences between sites were found. The mean SST value for the whole study area (using the SST of the three sites) was used for every statistical analysis. Mean SST had a value of 28.69±1.59°C during the period studied (2003-2017). Significant differences of annual mean SST between years were not found (p>0.05) (
A. The horizontal black line shows annual mean value and coloured vertical bars show incidence of El Niño and La Niña events. WNo (Weak Niño); MNo (Moderate Niño); VSNo (Very Strong Niño); WNa (Weak Niña); MNa (Moderate Niña); SNa (Strong Niña); ND (No data). The boxes represent mean±SE and the vertical bars represent mean±SD. B. The red line represents temperature tendency.
Mean monthly SST showed a rather seasonal behaviour; January, February and March (the cold, dry season) showed no differences, and July, August and October (the warm, wet season) showed similar values. The highest monthly mean SSTs were in September (31.01±0.44°C) and August (30.50±0.43°C) (
The boxes represent mean±SE and the vertical bars represent mean±SD The letters represent the differences recorded
OM showed significant differences between the years surveyed on the fore reef and on the reef crests (
A: OM (df=2, p-value <2.2e-16), RM (df=2, p-value <2.2e-16), live coral cover (df=2, p-value=9.802e-06). B: OM (df=2, p-value=2.058e-12), RM (df=2, p-value <2.2e-16), live coral cover (df=2, p-value=5.169e-07)
RM showed significant differences between the years surveyed on the fore reef in 2001 (3.1%), 2012 (0.03%) and 2017 (2.7%) and on the reef crests in 2001 (3.6%), 2012 (0.17%) and 2017 (7%) (
On the fore reef and reef crests, coral cover showed significant differences between the three years surveyed. On the fore reefs, the lowest coral cover was in 2001 (15.2%), followed by 2012 (16.2%), and the highest in 2017 (18.8%) (
The highest recruit density on the fore reef was recorded in 2012 (11.2 colonies m-2), followed by 2017 (7.7 colonies m-2) and 2001 (2.6 colonies m-2) (
A, recruit (df=2, p-value=5.578e-07), cover (df=2, p-value < 2.2e-16). B, recruit (df=2, p-value=0.000634), cover (df=2, p-value=0.00712).
CCA cover was significantly different in the years 2001 (18%) and 2012 (26.5%) in comparison with 2017 (4%) on the fore reefs, and in the years 2001 (10.6%) and 2017 (12%) in comparison with 2012 (18.7%) on the reef crests (
Several studies on coral reefs suggest that the decline of this ecosystem is caused by climate-induced stress resulting from events such as El Niño and intense hurricanes (
The JRNP is a good place for studying the resistance and recovery of coral communities to climate change. In this marine protected area (MPA) there is no evidence of a negative impact from local stressors on the reef of the park (
In the JRNP, annual average SST showed no significant differences between the 14 years surveyed. However, SST increased by 0.03°C in the entire period. This behaviour must be monitored because, according to
All climatic and oceanographic variables (SST, rain and storm frequency anomalies) resulting from El Niño and La Niña events could have influenced the behaviour of coral communities in the JRNP. The OM percentage was higher in 2001, which could have resulted from the severe 1998 El Niño event (
El Niño | La Niña | |||||
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Weak-10 | Moderate-7 | Strong-5 | Very Strong-3 | Weak-10 | Moderate-4 | Strong-7 |
1952-53 | 1951-52 | 1957-58 | 1982-83 | 1954-55 | 1955-56 | 1973-74 |
1953-54 | 1963-64 | 1965-66 |
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1964-65 | 1970-71 | 1975-76 |
1958-59 | 1968-69 | 1972-73 |
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1971-72 | 1995-96 | 1988-89 |
1969-70 | 1986-87 | 1987-88 | 1974-75 |
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1976-77 | 1994-95 | 1991-92 | 1983-84 |
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1977-78 |
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1984-85 |
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1979-80 |
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Red bars, Niño; Blue bars, Niña.
Not only El Niño events could be the cause of high OM in the JRNP in 2001; a period of 73 years without hurricanes (from the Hurricane of Santa Cruz del Sur in 1932 to Hurricane Dennis in 2005), could be another cause. Hurricane frequency in the JRNP is regarded as low, taking into account that the area has only been affected by three hurricanes and a tropical storm in this century. Although hurricanes are largely deemed as destructive and catastrophic events, they can also benefit tropical and subtropical marine ecosystems, because they absorb energy from surface waters through transference of latent heat, thus reducing SST. They can also bring to the surface cooler deep waters, which together with their cloud systems lower surface temperatures. This cooling process depends on the characteristics of the hurricane and of depth-related temperature variations at each site (
Bleaching and sea temperature rise are two of the most serious and imminent threats to coral reef (
From 2001 to 2012, moderate El Niño events prevailed during the years 2002 and 2003, while weak El Niño events prevailed from 2004 to 2007, which could have influenced the decrease in the OM in 2012, as high temperatures did not prevail in this period. During the same period, La Niña events were weak in 2008 and 2009, strong in 2010-2011 and moderate in 2012 (
The RM indicator is considered the most important evidence of the reef condition during the past year. A positive sign of reef recovery would be an average regional RM value of ≤2% (
A live coral cover of 15% to 20% would be a good parameter for assessing reef health and recovery (
On the reef crests, coral cover was lower in 2012 than in 2001, which coincided with results from a previous study (
An average regional recovery of five colonies m-2 could be a promising indicator of transitional reef recovery (
Before 2017, there was a strong El Niño event (2015-2016) (
In 2017, the percentage of RM was higher than in 2001 and 2012, which could be related to the strong La Niña events that occurred before 2001 and 2012 (1999-2000 and 2010-2011, respectively) (
In 2017, coral cover in this habitat showed high values, even higher than those of 2012, but lower than those of 2001. The reef crests of the JRNP are formed by huge populations of
CCA are an important component of the benthos in tropical seas (
The significant differences between the zones of reserve showed the same result pattern for most indicators for the different years. However, these results confirm that although there is a protection gradient from the central zone to the east and west ends of the park, its influence on the status of coral and CCA communities is not clear (
The results of the present study show that the occurrence of hurricanes and SST behaviour could be the most probable causes of impacts on coral reefs in the JRNP in the study period. These negative effects on corals and CCA were more visible on the reef crests of the JRNP. Although the coral community may be totally different in its structure and functioning, it showed resistance and/or recovery capacity from the impacts suffered after 2001, suggesting some resilience between 2001 and 2012 (in a period of approximately 10 years), because it was mostly recovered after the disturbances that occurred in this period of time, which became evident until 2017, particularly for the coral cover.
The results of the present study could be used by decision makers, authorities and researchers as useful information for future management and monitoring strategies in the JRNP. The evidence that climate change is acting on coral communities has been documented by many authors cited in this study. The condition of an MPA does not, per se, reduce the effects of SST anomalies and hurricane frequency on coral communities, but it is an important tool for protection from other stressors, such as fishing, overexploitation of tourism and local stressors such as water pollution and wastewater discharges.
This study was financed by the project “Diversidad biológica y conectividad entre el archipiélago Jardines de la Reina y golfo de Ana María, Cuba”, code P211LH005-031, of the National Programme of Conservation of Cuban Biodiversity (Ministry of Science, Technology and Environment of Cuba). We express our gratitude to the participants in the joint expedition CUBAGRRA II (August 2001), to the technicians and specialists of the Institute of Oceanology of Cuba, the Centre for Marine Research of the University of Havana, the Centre for the Research of Coastal Ecosystems, the Ocean for Youth vessel and the Jardines de la Reina Marlin branch. Our special thanks are due to Eduardo del Sol, Evelio A. Alemán, Roy Phillips, Claudia Bustamante, Noel López and Fabián Pina, and also to Vicente Osmel Rodríguez for his support with the English. IdeaWild org is thanked for equipment support.