Coral Reef Health Indices <i>versus</i> the Biological, Ecological and Functional Diversity of Fish and Coral Assemblages in the Caribbean Sea

<div><p>This study evaluated the relationship between the indices known as the Reef Health Index (RHI) and two-dimensional Coral Health Index (2D-CHI) and different representative metrics of biological, ecological and functional diversity of fish and corals in 101 reef sites located across seven zones in the western Caribbean Sea. Species richness and average taxonomic distinctness were used to asses biological estimation; while ecological diversity was evaluated with the indices of Shannon diversity and Pielou´s evenness, as well as by taxonomic diversity and distinctness. Functional diversity considered the number of functional groups, the Shannon diversity and the functional Pielou´s evenness. According to the RHI, 57.15% of the zones were classified as presenting a "poor" health grade, while 42.85% were in "critical" grade. Based on the 2D-CHI, 28.5% of the zones were in "degraded" condition and 71.5% were "very degraded". Differences in fish and coral diversity among sites and zones were demonstrated using permutational ANOVAs. Differences between the two health indices (RHI and 2D-CHI) and some indices of biological, ecological and functional diversity of fish and corals were observed; however, only the RHI showed a correlation between the health grades and the species and functional group richness of fish at the scale of sites, and with the species and functional group richness and Shannon diversity of the fish assemblages at the scale of zones. None of the health indices were related to the metrics analyzed for the coral diversity. In general, our study suggests that the estimation of health indices should be complemented with classic community indices, or should at least include diversity indices of fish and corals, in order to improve the accuracy of the estimated health status of coral reefs in the western Caribbean Sea.</p></div

Three-way fully nested and permutational ANOVAs outcomes contrasting biological, ecological and functional diversity of reef fish among different health grades of the RHI and 2D-CHI indices, among zones nested in health grades and among sites nested in zones and health grades.

<p>Three-way fully nested and permutational ANOVAs outcomes contrasting biological, ecological and functional diversity of reef fish among different health grades of the RHI and 2D-CHI indices, among zones nested in health grades and among sites nested in zones and health grades.</p

Linear regression and Pearson correlation.

<p>a) species richness of fish, b) richness of functional groups of fish in relation to the grades of coral health, according to the RHI at the scale of sites. Dotted lines indicate the 95% confidence interval.</p

Grade of reef health estimated with the indices RHI and 2D-CHI in each study zone.

<p><b>a)</b> RHI health grade per zone; <b>b)</b> CHI health grade per zone.</p

Study area with zones of coral reefs in the western Caribbean.

<p>Cancún, Banco Chinchorro, Xcalak, Punta Manabique, Cayos Cochinos Media Luna, Cayos Miskitos.</p

Three-way fully nested and permutational ANOVAs outcomes contrasting the biological, ecological and functional diversity of hermatypic corals among different health grades of RHI and 2D-CHI indices, among zones nested in health grades and among sites nested in zones and health grades.

<p>Three-way fully nested and permutational ANOVAs outcomes contrasting the biological, ecological and functional diversity of hermatypic corals among different health grades of RHI and 2D-CHI indices, among zones nested in health grades and among sites nested in zones and health grades.</p

Coral reef health in sampling sites evaluated with CHI.

<p><b>a) Cancun:</b> Bonanza (Bo), Chitales (Ci), Cuevones (Cu), El Bajito (EB), La Bocana (LB), Manchones (Ma), Punta Nizuc (PN), Radio Pirata (RP); <b>b) Banco Chinchorro:</b> Six sites for Baliza (Ba1, Ba2, Ba3, Ba4, Ba5, Ba6), six sites for Chancay (Ch1, Ch2, Ch3, Ch4, Ch5, Ch6), six sites for Colorados (Co1, Co2, Co3, Co4, Co5, Co6), six sites for Cueva Tiburones (CT1, CT2, CT3, CT4, CT5, CT6), six sites for La Caldera (LC1, LC2, LC3, LC4, LC5, LC6), and six sites for Penelope (Pe1, Pe2, Pe3, Pe4, Pe5, Pe6); <b>c) Xcalak:</b> six sites for Alejandro Reefs (Al1, Al2, Al3, Al4, Al5, Al6), six sites for Hobná (Ho1, Ho2, Ho3, Ho4, Ho5, Ho6), six sites for Bacalar Chico (Bac1, Bac2, Bac3, Bac4, Bac5, Bac6), six sites for Poza Rica (PZ1, PZ2, PZ3, PZ4, PZ5, PZ6), and six sites for Rio Huach (RH1, RH2, RH3, RH4, RH5, RH6); <b>d) Punta Manabique:</b> Piedra de la barracuda (PBA), Bajo del Cabo (BCA), Motaguilla (Mo); <b>e) Cayos Cochinos:</b> three sites for Pelicanos (PL1, PL2, PL3), three sites for Grupera (Gr1, Gr2, Gr3), two sites for Mariposales (Mr1, Mr2), two sites for Salamandinga (Sa1, Sa2), and two sites for Roatan Bank (RB1, RB2); <b>f) Media Luna:</b> six sites for Media Luna (ML1, ML2, ML3, ML4, ML5, ML6) and <b>g) Cayos Miskitos:</b> London Reef (LOR), Nee Reef (NER), Porgee Reef (POR), Lamarka Reef (LAR), Martinez Reef (MAR), Cayo Muerto (MUK). Error bars correspond to standard deviation.</p

Two-way nested and permutational ANOVAs (Model 2) outcomes contrasting the biological, ecological and functional diversity of fish and corals among different health grades of the RHI and 2D-CHI indices and among sites nested in the health indices.

<p>Two-way nested and permutational ANOVAs (Model 2) outcomes contrasting the biological, ecological and functional diversity of fish and corals among different health grades of the RHI and 2D-CHI indices and among sites nested in the health indices.</p

Coral reef health in sampling sites evaluated with RHI.

<p><b>a) Cancun:</b> Bonanza (Bo), Chitales (Ci), Cuevones (Cu), El Bajito (EB), La Bocana (LB), Manchones (Ma), Punta Nizuc (PN), Radio Pirata (RP); <b>b) Banco Chinchorro:</b> Six sites for Baliza (Ba1, Ba2, Ba3, Ba4, Ba5, Ba6), six sites for Chancay (Ch1, Ch2, Ch3, Ch4, Ch5, Ch6), six sites for Colorados (Co1, Co2, Co3, Co4, Co5, Co6), six sites for Cueva Tiburones (CT1, CT2, CT3, CT4, CT5, CT6), six sites for La Caldera (LC1, LC2, LC3, LC4, LC5, LC6), and six sites for Penelope (Pe1, Pe2, Pe3, Pe4, Pe5, Pe6); <b>c) Xcalak:</b> six sites for Alejandro Reefs (Al1, Al2, Al3, Al4, Al5, Al6), six sites for Hobná (Ho1, Ho2, Ho3, Ho4, Ho5, Ho6), six sites for Bacalar Chico (Bac1, Bac2, Bac3, Bac4, Bac5, Bac6), six sites for Poza Rica (PZ1, PZ2, PZ3, PZ4, PZ5, PZ6), and six sites for Rio Huach (RH1, RH2, RH3, RH4, RH5, RH6); <b>d) Punta Manabique:</b> Piedra de la barracuda (PBA), Bajo del Cabo (BCA), Motaguilla (Mo); <b>e) Cayos Cochinos:</b> three sites for Pelicanos (PL1, PL2, PL3), three sites for Grupera (Gr1, Gr2, Gr3), two sites for Mariposales (Mr1, Mr2), two sites for Salamandinga (Sa1, Sa2), and two sites for Roatan Bank (RB1, RB2); <b>f) Media Luna:</b> six sites for Media Luna (ML1, ML2, ML3, ML4, ML5, ML6) and <b>g) Cayos Miskitos:</b> London Reef (LOR), Nee Reef (NER), Porgee Reef (POR), Lamarka Reef (LAR), Martinez Reef (MAR), Cayo Muerto (MUK). Error bars correspond to standard deviation value.</p