Detección de anticuerpos séricos de influenza aviar tipo A, enfermedad de Newcastle y bronquitis infecciosa y laringotraqueitis infecciosa en aves acuáticas silvestres de tres lagunas andinas del Ecuador

The aim of this study was to determine the presence of serum antibodies against four respiratory pathogens (avian influenza [AI], Newcastle disease [NDV], avian infectious bronchitis [IBV] and avian infectious laryngotracheitis [ILT]) that could affect migratory aquatic and resident birds of three high Andean lagoons of Ecuador. Blood samples (n=153) were collected from birds of seven species in the Andean lagoons of Colta, Yambo and Yahuarcocha. The presence of antibodies (Ab) against IBV and ILT was detected by an indirect ELISA (ELISAi) and by the haemagglutination inhibition test (HI); and NDV and avian influenza (H5N1 and H7N3) were detected by an ELISAc and HI. Seropositivity to NDV was 3.2% (5/153), with three cases in Yahuarcocha in the Neotropical cormorant (Phalacrocorax brasilianus), one case in Colta in the Andean coot (Fulica ardesiaca) and one in Yambo in the Andean reddish duck (Oxyura ferruginea). The seropositivity against AI was 13% (20/153), mainly in the Andean reddish duck and the Southern silvery grebe (Podicceps occipitalis) in Colta, and in the yellow-billed pintail (Anas georgica), Andean coot and Andean reddish duck in Yambo. Likewise, serum Ab was found against IBV in two cormorants in Yahuarcocha. No antibodies against ILT were found.El objetivo del estudio fue determinar la presencia de anticuerpos séricos frente a cuatro patógenos respiratorios (influenza aviar [AI], enfermedad de Newcastle [NDV], bronquitis infecciosa aviar [IBV] y laringotraqueítis infecciosa aviar [ILTV]) que podrían afectar a las aves acuáticas migratorias y residentes de tres lagunas altoandinas del Ecuador. Se colectaron 153 muestras de sangre de aves de siete especies en las lagunas andinas de Colta, Yambo y Yahuarcocha. La presencia de anticuerpos (Ac) contra IBV e ILTV se detectó por un ELISA indirecto (ELISAi) y por la prueba de inhibición de la hemoaglutinación (HI); para NDV e influenza aviar (H5N1 y H7N3) se usó un ELISAc e HI. La seropositividad a NDV fue de 3.2% (5/153), habiendo tres casos en Yahuarcocha en el cormorán neotropical (Phalacrocorax brasilianus), un caso en Colta en la focha andina (Fulica ardesiaca) y uno en Yambo en el pato rojizo andino (Oxyura ferruginea). La seropositividad contra AI fue de 13% (20/153), mayormente en el pato rojizo andino y el zambullidor plateado (Podicceps occipitalis) en Colta, y en el ánade piquiamarillo (Anas georgica), focha andina y pato rojizo andino en Yambo. Asimismo, se encontró Ac séricos contra IBV en dos cormoranes en Yahuarcocha. No se encontraron anticuerpos contra ILTV

Recent dynamics and condition of coral reefs in the Colombian Caribbean

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% (Rosario) hasta 53.3% (San Andrés). La cobertura coralina fluctuó considerablemente entre 10.1% (Santa Marta) y 43.5% (Urabá). Los arrecifes estudiados han permanecido relativamente estables durante el periodo evaluado en términos de algas y corales. El único cambio significativo en la cobertura se detectó en algunas parcelas de monitoreo del Tayrona, y pocas especies coralinas explicaron la tendencia de disminución. En Rosario se detectó una tendencia significativa de incremento para las algas en la mayoría de las parcelas. En San Andrés y Urabá las tendencias temporales (aumento y disminución respectivamente) se presentaron en ciertos niveles de profundidad. En estas dos áreas las tendencias en la cobertura de las algas fueron explicadas principalmente por cambios en los tapetes algales. En general las causas de los patrones observados no pudieron identificarse. Los programas de monitoreo deben evaluar no solo las tendencias generales de algas y corales sino también las de sus componentes (especies de coral y grupos funcionales de algas). Así mismo, deben enfocarse en evaluar los mecanismos involucrados en los cambios, en especial aquellos relacionados con la recuperación coralina y la resiliencia arrecifal, de manera que se pueda enfrentar el deterioro arrecifal en el actual contexto de cambio climático

Temporal patterns in coral reef, seagrass and mangrove communities from Chengue bay CARICOMP site (Colombia): 1993-2008

Few monitoring programs have simultaneously assessed the dynamics of linked marine ecosystems (coral reefs, seagrass beds and mangroves) to document their temporal and spatial variability. Based on CARICOMP protocol we evaluated permanent stations in coral reefs, seagrass beds and mangroves from 1993 to 2008 in Chengue Bay at the Tayrona Natural Park, Colombian Caribbean. Overall, the studied ecosystems showed a remarkable stability pattern over the monitoring period. While there were annual variations in coral reefs (coral cover) and mangroves (litterfall) caused by hurricane Lenny in 1999, particular trends in seagrass (leaf area index and leaf productivity) appear to reflect the natural variability in this ecosystem. We suggest that monitoring sites at the three marine ecosystems had in general a healthy development in the last 16 years. Our results are critical to locally improve the management strategies (Tayrona Natural Park) and to understand the long-term dynamics of closely associated marine ecosystems in the Caribbean. Copyright © 2011 Elsevier B.V. All rights reserved

Enemies with benefits: parasitic endoliths protect mussels against heat stress

Positive and negative aspects of species interactions can be context dependant and strongly affected by environmental conditions. We tested the hypothesis that, during periods of intense heat stress, parasitic phototrophic endoliths that fatally degrade mollusc shells can benefit their mussel hosts. Endolithic infestation significantly reduced body temperatures of sun-exposed mussels and, during unusually extreme heat stress, parasitised individuals suffered lower mortality rates than nonparasitised hosts. This beneficial effect was related to the white discolouration caused by the excavation activity of endoliths. Under climate warming, species relationships may be drastically realigned and conditional benefits of phototrophic endolithic parasites may become more important than the costs of infestation

First approach to the trophic ecology and diet of the rainbow runner, elagatis bipinnulata (quoy and amp; gaimard, 1825) (pisces: carangidae), in the central colombian caribbean

The rainbow runner (Elagatis bipinnulata) scores high in trophic level (4.24) but it is not a voracious fish (Q/B = 10.8). Its diet is dominated by the dwarf herring (Jenkinsia lamprotaenia), eats more in the dry season, than in the rainy season and significantly more in the afternoon that in the morning suggesting preference for daylight feeding. Primera aproximación a la ecología trófica del salmón, Elagatis bipinnulata (Quoy y Gaimard, 1825) (Pisces: Carangidae), en el Caribe central colombianoEl salmón (Elagatis bipinnulata) marca alto en nivel trófico (4,24) pero no es un pez voraz (Q/B = 10,8). Su dieta está dominada por la sardina enana (Jenkinsia lamprotaenia), come más en la época seca que en la época de lluvia y come significativamente más en la tarde que en la mañana, lo cual sugiere preferencia por la alimentación diurna

Recent Region-wide Declines in Caribbean Reef Fish Abundance

Profound ecological changes are occurring on coral reefs throughout the tropics, with marked coral cover losses and concomitant algal increases, particularly in the Caribbean region. Historical declines in the abundance of large Caribbean reef fishes likely reflect centuries of overexploitation. However, effects of drastic recent degradation of reef habitats on reef fish assemblages have yet to be established. By using meta-analysis, we analyzed time series of reef fish density obtained from 48 studies that include 318 reefs across the Caribbean and span the time period 1955–2007. Our analyses show that overall reef fish density has been declining significantly for more than a decade, at rates that are consistent across all subregions of the Caribbean basin (2.7% to 6.0% loss per year) and in three of six trophic groups. Changes in fish density over the past half-century are modest relative to concurrent changes in benthic cover on Caribbean reefs. However, the recent significant decline in overall fish abundance and its consistency across several trophic groups and among both fished and nonfished species indicate that Caribbean fishes have begun to respond negatively to habitat degradation

Spatial Patterns of Parrotfish Corallivory in the Caribbean: The Importance of Coral Taxa, Density and Size

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