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Spatial Patterns of Parrotfish Corallivory in the Caribbean: The Importance of Coral Taxa, Density and Size  [PDF]
George Roff, Mary H. Ledlie, Juan C. Ortiz, Peter J. Mumby
PLOS ONE , 2011, DOI: 10.1371/journal.pone.0029133
Abstract: The past few decades have seen an increase in the frequency and intensity of disturbance on coral reefs, resulting in shifts in size and composition of coral populations. These changes have lead to a renewed focus on processes that influence demographic rates in corals, such as corallivory. While previous research indicates selective corallivory among coral taxa, the importance of coral size and the density of coral colonies in influencing corallivory are unknown. We surveyed the size, taxonomy and number of bites by parrotfish per colony of corals and the abundance of three main corallivorous parrotfish (Sparisoma viride, Sparisoma aurofrenatum, Scarus vetula) at multiple spatial scales (reefs within islands: 1–100 km, and between islands: >100 km) within the Bahamas Archipelago. We used a linear mixed model to determine the influence of coral taxa, colony size, colony density, and parrotfish abundance on the intensity of corallivory (bites per m2 of coral tissue). While the effect of colony density was significant in determining the intensity of corallivory, we found no significant influence of colony size or parrotfish abundance (density, biomass or community structure). Parrotfish bites were most frequently observed on the dominant species of reef building corals (Montastraea annularis, Montastraea faveolata and Porites astreoides), yet our results indicate that when the confounding effects of colony density and size were removed, selective corallivory existed only for the less dominant Porites porites. As changes in disturbance regimes result in the decline of dominant frame-work building corals such as Montastraea spp., the projected success of P. porites on Caribbean reefs through high reproductive output, resistance to disease and rapid growth rates may be attenuated through selective corallivory by parrotfish.
Large-Scale Absence of Sharks on Reefs in the Greater-Caribbean: A Footprint of Human Pressures  [PDF]
Christine A. Ward-Paige,Camilo Mora,Heike K. Lotze,Christy Pattengill-Semmens,Loren McClenachan,Ery Arias-Castro,Ransom A. Myers
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0011968
Abstract: In recent decades, large pelagic and coastal shark populations have declined dramatically with increased fishing; however, the status of sharks in other systems such as coral reefs remains largely unassessed despite a long history of exploitation. Here we explore the contemporary distribution and sighting frequency of sharks on reefs in the greater-Caribbean and assess the possible role of human pressures on observed patterns.
Macroalgal-Associated Dinoflagellates Belonging to the Genus Symbiodinium in Caribbean Reefs  [PDF]
Isabel Porto, Camila Granados, Juan C. Restrepo, Juan A. Sánchez
PLOS ONE , 2008, DOI: 10.1371/journal.pone.0002160
Abstract: Coral-algal symbiosis has been a subject of great attention during the last two decades in response to global coral reef decline. However, the occurrence and dispersion of free-living dinoflagellates belonging to the genus Symbiodinium are less documented. Here ecological and molecular evidence is presented demonstrating the existence of demersal free-living Symbiodinium populations in Caribbean reefs and the possible role of the stoplight parrotfish (Sparisoma viride) as Symbiodinium spp. dispersers. Communities of free-living Symbiodinium were found within macroalgal beds consisting of Halimeda spp., Lobophora variegata, Amphiroa spp., Caulerpa spp. and Dictyota spp. Viable Symbiodinium spp. cells were isolated and cultured from macroalgal beds and S. viride feces. Further identification of Symbiodinium spp. type was determined by length variation in the Internal Transcribed Spacer 2 (ITS2, nuclear rDNA) and length variation in domain V of the chloroplast large subunit ribosomal DNA (cp23S-rDNA). Determination of free-living Symbiodinium and mechanisms of dispersal is important in understanding the life cycle of Symbiodinium spp.
Coral diseases and bleaching on Colombian Caribbean coral reefs
Navas-Camacho,Raúl; Gil-Agudelo,Diego Luis; Rodríguez-Ramírez,Alberto; Reyes-Nivia,María Catalina; Garzón-Ferreira,Jaime;
Revista de Biología Tropical , 2010,
Abstract: since 1998 the national monitoring system for the coral reefs of colombia (simac) has monitored the occurrence of coral bleaching and diseases in some colombian coral reefs (permanent stations at san andres island, rosario islands, tayrona, san bernardo islands and urabá). the main purpose is to evaluate their health status and to understand the factors that have been contributing to their decline. to estimate these occurrences, annual surveys in 126 permanent belt transects (10x2m) with different depth intervals (3-6 meters, 9-12 meters and 15-18 meters) are performed at all reef sites. data from the 1998-2004 period, revealed that san andrés island had many colonies with diseases (38.9 colonies/m2), and urabá had high numbers with bleaching (54.4 colonies/m2). of the seven reported coral diseases studied, dark spots disease (dsd), and white plague disease (wpd) were noteworthy because they occurred in all caribbean monitored sites, and because of their high interannual infection incidence. thirty five species of scleractinian corals were affected by at least one disease and a high incidence of coral diseases on the main reef builders is documented. bleaching was present in 34 species. during the whole monitoring period, agaricia agaricites and siderastrea siderea were the species most severely affected by dsd and bleaching, respectively. diseases on species such as agaricia fragilis, a.grahamae, a. humilis, diploria clivosa, eusmilia fastigiata, millepora complanata, and mycetophyllia aliciae are recorded for first time in colombia. we present bleaching and disease incidences, kinds of diseases, coral species affected, reef localities studied, depth intervals of surveys, and temporal (years) variation for each geographic area. this variation makes difficult to clearly determine defined patterns or general trends for monitored reefs. this is the first long-term study of coral diseases and bleaching in the southwestern caribbean, and one of the few long term monitor
Marine Reserves Enhance the Recovery of Corals on Caribbean Reefs  [PDF]
Peter J. Mumby,Alastair R. Harborne
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0008657
Abstract: The fisheries and biodiversity benefits of marine reserves are widely recognised but there is mounting interest in exploiting the importance of herbivorous fishes as a tool to help ecosystems recover from climate change impacts. This approach might be particularly suitable for coral reefs, which are acutely threatened by climate change, yet the trophic cascades generated by reserves are strong enough that they might theoretically enhance the rate of coral recovery after disturbance. However, evidence for reserves facilitating coral recovery has been lacking. Here we investigate whether reductions in macroalgal cover, caused by recovery of herbivorous parrotfishes within a reserve, have resulted in a faster rate of coral recovery than in areas subject to fishing. Surveys of ten sites inside and outside a Bahamian marine reserve over a 2.5-year period demonstrated that increases in coral cover, including adjustments for the initial size-distribution of corals, were significantly higher at reserve sites than those in non-reserve sites. Furthermore, macroalgal cover was significantly negatively correlated with the change in total coral cover over time. Recovery rates of individual species were generally consistent with small-scale manipulations on coral-macroalgal interactions, but also revealed differences that demonstrate the difficulties of translating experiments across spatial scales. Size-frequency data indicated that species which were particularly affected by high abundances of macroalgae outside the reserve had a population bottleneck restricting the supply of smaller corals to larger size classes. Importantly, because coral cover increased from a heavily degraded state, and recovery from such states has not previously been described, similar or better outcomes should be expected for many reefs in the region. Reducing herbivore exploitation as part of an ecosystem-based management strategy for coral reefs appears to be justified.
Recent dynamics and condition of coral reefs in the Colombian Caribbean
Rodríguez-Ramírez,Alberto; Reyes-Nivia,María Catalina; Zea,Sven; Navas-Camacho,Raúl; Garzón-Ferreira,Jaime; Bejarano,Sonia; Herrón,Pilar; Orozco,Carlos;
Revista de Biología Tropical , 2010,
Abstract: long-term monitoring data provide a basis to recognize changes in coral reef communities and to implement appropriate management strategies. unfortunately, coral reef dynamics have been poorly documented at any temporal scale in the southern caribbean. through the "national monitoring system of coral reefs in colombia" (spanish acronym: simac), we assessed 32 permanent plots at different depth levels in six reefs areas of the colombian caribbean from 1998 to 2004. temporal trends in coral and algal cover were evaluated by repeated measures anova. the model included the effect of depth levels (a fixed effect), monitoring plots (a random effect) as a nested factor within depths, and time (repeated factor). we found high spatial variability in major benthic components. overall means indicated that algae were the most abundant biotic component in nearly all areas, ranging from 30.3% at rosario to 53.3% at san andrés. live coral cover varied considerably from 10.1% at santa marta up to 43.5% at urabá. coral and algae cover per se are not always accurate reef indicators and therefore they need supplementary information. temporal analyses suggested relative stability of coral and algal cover along the study but the causes for the observed trends were rarely identified. a significant decrease (p=0.042) in coral cover was only identified for some monitoring plots in tayrona-time x plot (depth level) interaction, and importantly, few coral species explained this trend. significant increase (p=0.005) in algal cover was observed over time for most plots in rosario. temporal trajectories in algal cover were influenced by depth-significant time x depth interaction-in san andrés (increase, p=0.004) and urabá (decrease, p=0.027). algae trends were mainly explained by changes in algal turfs. monitoring programs must focus on the mechanisms mediating the changes, in particular those concerning coral recovery and reef resilience in the current context of climate change. rev. biol. tro
Coral diseases and bleaching on Colombian Caribbean coral reefs  [cached]
Raúl Navas-Camacho,Diego Luis Gil-Agudelo,Alberto Rodríguez-Ramírez,María Catalina Reyes-Nivia
Revista de Biología Tropical , 2010,
Abstract: Since 1998 the National Monitoring System for the Coral Reefs of Colombia (SIMAC) has monitored the occurrence of coral bleaching and diseases in some Colombian coral reefs (permanent stations at San Andres Island, Rosario Islands, Tayrona, San Bernardo Islands and Urabá). The main purpose is to evaluate their health status and to understand the factors that have been contributing to their decline. To estimate these occurrences, annual surveys in 126 permanent belt transects (10x2m) with different depth intervals (3-6 meters, 9-12 meters and 15-18 meters) are performed at all reef sites. Data from the 1998-2004 period, revealed that San Andrés Island had many colonies with diseases (38.9 colonies/m2), and Urabá had high numbers with bleaching (54.4 colonies/m2). Of the seven reported coral diseases studied, Dark Spots Disease (DSD), and White Plague Disease (WPD) were noteworthy because they occurred in all Caribbean monitored sites, and because of their high interannual infection incidence. Thirty five species of scleractinian corals were affected by at least one disease and a high incidence of coral diseases on the main reef builders is documented. Bleaching was present in 34 species. During the whole monitoring period, Agaricia agaricites and Siderastrea siderea were the species most severely affected by DSD and bleaching, respectively. Diseases on species such as Agaricia fragilis, A.grahamae, A. humilis, Diploria clivosa, Eusmilia fastigiata, Millepora complanata, and Mycetophyllia aliciae are recorded for first time in Colombia. We present bleaching and disease incidences, kinds of diseases, coral species affected, reef localities studied, depth intervals of surveys, and temporal (years) variation for each geographic area. This variation makes difficult to clearly determine defined patterns or general trends for monitored reefs. This is the first long-term study of coral diseases and bleaching in the Southwestern Caribbean, and one of the few long term monitoring studies on coral diseases worldwide. Rev. Biol. Trop. 58 (Suppl. 1): 95-106. Epub 2010 May 01. Desde 1998 el "Sistema Nacional de Monitoreo de Arrecifes Coralinos de Colombia" SIMAC, ha observado la ocurrencia de enfermedades coralinas y blanqueamiento en arrecifes colombianos (estaciones fijas en la Isla de San Tayrona, Islas del Rosario, Islas de San Bernardo y Urabá Chocoano). Para estimar la ocurrencia se ha examinado anualmente un total de 126 bandas permanentes (10x2m), dispuestas en diferentes rangos de profundidad en las áreas arrecifales objeto de estudio. El análisis de la inform
Ecosystem-Scale Effects of Nutrients and Fishing on Coral Reefs  [PDF]
Sheila M. Walsh
Journal of Marine Biology , 2011, DOI: 10.1155/2011/187248
Abstract: Nutrient pollution and fishing are the primary local causes of coral reef decline but their ecosystem-scale effects are poorly understood. Results from small-scale manipulative experiments of herbivores and nutrients suggest prioritizing management of fishing over nutrient pollution because herbivores can control macroalgae and turf in the presence of nutrients. However, ecological theory suggests that the opposite occurs at large scales. Moreover, it is unclear whether fishing decreases herbivores because fishing of predators may result in an increase in herbivores. To investigate this paradox, data on the fish and benthic communities, fishing, and nutrients were collected on Kiritimati, Kiribati. Oceanographic conditions and a population resettlement program created a natural experiment to compare sites with different levels of fishing and nutrients. Contrary to theory, herbivores controlled macroalgae in the presence of nutrients at large spatial scales, and herbivores had greater effects on macroalgae when nutrients were higher. In addition, fishing did not increase herbivores. These results suggest that protecting herbivores may have greater relative benefits than reducing nutrient pollution, especially on polluted reefs. Reallocating fishing effort from herbivores to invertivores or planktivores may be one way to protect herbivores and indirectly maintain coral dominance on reefs impacted by fishing and nutrient pollution. 1. Introduction Fishing [1–7] and nutrient pollution [8, 9] or both [10–14] are cited as the most important local causes of coral reef decline. It is difficult, however, to evaluate local fishing and nutrient effects independently because these factors are almost always confounded and large-scale experiments are infeasible. Results from theoretical and small-scale experimental studies (typically <1?m2, four from 50 to 250?m2 [14]) suggest prioritizing management of herbivore populations because herbivores can control the effect of nutrients on macroalgal and turf abundance and nutrient enrichment alone is not sufficient to cause a phase shift from coral to macroalgal and/or turf algal dominance [11, 14, 15]. In order to apply these results and implement ecosystem-based management, information is needed on (1) how fishing and nutrients interactively affect the fish and benthic communities, (2) the mechanisms by which fishing (rather than cages that exclude fish) and nutrients are linked to shifts to macroalgal and turf algal dominance, and (3) whether herbivores can control macroalgae and turf algae when nutrient enrichment
Recent dynamics and condition of coral reefs in the Colombian Caribbean  [cached]
Alberto Rodríguez-Ramírez,María Catalina Reyes-Nivia,Sven Zea,Raúl Navas-Camacho
Revista de Biología Tropical , 2010,
Abstract: Long-term monitoring data provide a basis to recognize changes in coral reef communities and to implement appropriate management strategies. Unfortunately, coral reef dynamics have been poorly documented at any temporal scale in the Southern Caribbean. Through the "National Monitoring System of Coral Reefs in Colombia" (Spanish acronym: SIMAC), we assessed 32 permanent plots at different depth levels in six reefs areas of the Colombian Caribbean from 1998 to 2004. Temporal trends in coral and algal cover were evaluated by repeated measures ANOVA. The model included the effect of depth levels (a fixed effect), monitoring plots (a random effect) as a nested factor within depths, and time (repeated factor). We found high spatial variability in major benthic components. Overall means indicated that algae were the most abundant biotic component in nearly all areas, ranging from 30.3% at Rosario to 53.3% at San Andrés. Live coral cover varied considerably from 10.1% at Santa Marta up to 43.5% at Urabá. Coral and algae cover per se are not always accurate reef indicators and therefore they need supplementary information. Temporal analyses suggested relative stability of coral and algal cover along the study but the causes for the observed trends were rarely identified. A significant decrease (p=0.042) in coral cover was only identified for some monitoring plots in Tayrona-time x plot (depth level) interaction, and importantly, few coral species explained this trend. Significant increase (p=0.005) in algal cover was observed over time for most plots in Rosario. Temporal trajectories in algal cover were influenced by depth-significant time x depth interaction-in San Andrés (increase, p=0.004) and Urabá (decrease, p=0.027). Algae trends were mainly explained by changes in algal turfs. Monitoring programs must focus on the mechanisms mediating the changes, in particular those concerning coral recovery and reef resilience in the current context of climate change. Rev. Biol. Trop. 58 (Suppl. 1): 107-131. Epub 2010 May 01. Este trabajo contiene el primer análisis temporal de la información obtenida por el Sistema Nacional de Monitoreo de Arrecifes Coralinos en Colombia (SIMAC). Entre 1998 y el 2004 se monitorearon un total de 32 parcelas permanentes ubicadas a diferentes niveles de profundidad en seis áreas arrecifales del Caribe colombiano. Los patrones temporales de algas y corales fueron evaluados mediante análisis de varianza de medidas repetidas. Los promedios generales indicaron que las algas dominaron en la mayoría de las áreas evaluadas, variando de 30.3% (Ros
Native Predators Do Not Influence Invasion Success of Pacific Lionfish on Caribbean Reefs  [PDF]
Serena Hackerott, Abel Valdivia, Stephanie J. Green, Isabelle M. C?té, Courtney E. Cox, Lad Akins, Craig A. Layman, William F. Precht, John F. Bruno
PLOS ONE , 2013, DOI: 10.1371/journal.pone.0068259
Abstract: Biotic resistance, the process by which new colonists are excluded from a community by predation from and/or competition with resident species, can prevent or limit species invasions. We examined whether biotic resistance by native predators on Caribbean coral reefs has influenced the invasion success of red lionfishes (Pterois volitans and Pterois miles), piscivores from the Indo-Pacific. Specifically, we surveyed the abundance (density and biomass) of lionfish and native predatory fishes that could interact with lionfish (either through predation or competition) on 71 reefs in three biogeographic regions of the Caribbean. We recorded protection status of the reefs, and abiotic variables including depth, habitat type, and wind/wave exposure at each site. We found no relationship between the density or biomass of lionfish and that of native predators. However, lionfish densities were significantly lower on windward sites, potentially because of habitat preferences, and in marine protected areas, most likely because of ongoing removal efforts by reserve managers. Our results suggest that interactions with native predators do not influence the colonization or post-establishment population density of invasive lionfish on Caribbean reefs.
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