Relationship of litterfall anomalies with climatic anomalies in a mangrove swamp of the Yucatan Peninsula, Mexico.

Among the set of phenological traits featuring mangrove ecosystems, litterfall production stands out with marked intra-annual and longer-term variation. Furthermore, mangrove forests resilience is one of the most important ecological attribute, reconciling the juxtaposed terrestrial and marine environment such transitional systems occupy. However, world's mangroves are nowadays facing recurrent climatic events, reflected in anomalies depicted by major drivers, including temperature and precipitation. This physical-environmental setting may either constrain or favor overall forest productivity. A combination of time series analysis (spectral density and cross-correlation techniques) and statistical model fitting (General additive model) was implemented to explore trends in total litterfall of a well-developed mangrove forest in southeastern Gulf of Mexico (Celestun Lagoon, SE Mexico) and potential association with the varying behavior of temperature (°C) and precipitation (mm month-1), highlighting their anomalies. The results are consistent with a synchronous response between litterfall production and climatic variables (mean monthly temperature and total monthly precipitation). Concurrent peak litterfall production in Celestun lagoon with high temperatures and precipitation occurred during June and October, featuring a two-month time lag for the response time. More than half of the litterfall anomalies (53.5%) could be reflecting either multiple sources of climatic anomalies (maximum, minimum, and monthly average temperature and monthly total precipitation) or single point events (cyclone landfall). This relationship dynamics showed an interannual persistence (1999-2010). The structure portrayed by the litterfall time-series was not unequivocally related to climatic anomalies. Arguably, climatic anomalies behave with different intensities and even may exhibit complex interactions among them. The study of anomalies provides a baseline for a better grasp of: i) mangrove anomalies responses and ii) their vulnerability to these extremes.

Tourists perceptions of Caribbean islands facing environmental threats before the COVID-19 health crisis: Holbox Island and Archipelago of Bocas del Toro.

Knowledge gaps exist in the socio-ecological systems of small touristic islands in Latin America. Understanding tourists' perceptions of their environmental knowledge can help plan actions to prevent natural capital loss necessary for local economies. Tourists' perceptions of a touristic hotspot, Holbox Island, were documented. Surveys demonstrated that tourists are aware of their environmental impacts and are interested in minimizing these. Results were compared with results on Bocas del Toro, Panama. Tourists' perceptions had similarities among sites driven by similarities in tourists' populations with a common geographic origin. Tourists lack site-specific knowledge to steer them towards environmentally conscious decisions in both regions. Findings suggest the need to promote local actions to gain tourists' understanding about their destination and support education programs on island conservation. Addressing these needs can help build resilience to overcome the adverse socio-environmental effects of tourism, environmental disasters, and health crises as COVID-19 on small islands.

Assessment of the bacterial community structure in shallow and deep sediments of the Perdido Fold Belt region in the Gulf of Mexico.

The Mexican region of the Perdido Fold Belt (PFB), in northwestern Gulf of Mexico (GoM), is a geological province with important oil reservoirs that will be subjected to forthcoming oil exploration and extraction activities. To date, little is known about the native microbial communities of this region, and how these change relative to water depth. In this study we assessed the bacterial community structure of surficial sediments by high-throughput sequencing of the 16S rRNA gene at 11 sites in the PFB, along a water column depth gradient from 20 to 3,700 m, including five shallow (20-600 m) and six deep (2,800-3,700 m) samples. The results indicated that OTUs richness and diversity were higher for shallow sites (OTUs = 2,888.2 ± 567.88; H' = 9.6 ± 0.85) than for deep sites (OTUs = 1,884.7 ± 464.2; H' = 7.74 ± 1.02). Nonmetric multidimensional scaling (NMDS) ordination revealed that shallow microbial communities grouped separately from deep samples. Additionally, the shallow sites plotted further from each other on the NMDS whereas samples from the deeper sites (abyssal plains) plotted much more closely to each other. These differences were related to depth, redox potential, sulfur concentration, and grain size (lime and clay), based on the environmental variables fitted with the axis of the NMDS ordination. In addition, differential abundance analysis identified 147 OTUs with significant fold changes among the zones (107 from shallow and 40 from deep sites), which constituted 10 to 40% of the total relative abundances of the microbial communities. The most abundant OTUs with significant fold changes in shallow samples corresponded to Kordiimonadales, Rhodospirillales, Desulfobacterales (Desulfococcus), Syntrophobacterales and Nitrospirales (GOUTA 19, BD2-6, LCP-6), whilst Chromatiales, Oceanospirillales (Amphritea, Alcanivorax), Methylococcales, Flavobacteriales, Alteromonadales (Shewanella, ZD0117) and Rhodobacterales were the better represented taxa in deep samples. Several of the OTUs detected in both deep and shallow sites have been previously related to hydrocarbons consumption. Thus, this metabolism seems to be well represented in the studied sites, and it could abate future hydrocarbon contamination in this ecosystem. The results presented herein, along with biological and physicochemical data, constitute an available reference for further monitoring of the bacterial communities in this economically important region in the GoM.

Comparative Molecular and Morphological Variation Analysis of Siderastrea (Anthozoa, Scleractinia) Reveals the Presence of Siderastrea stellata in the Gulf of Mexico.

The genus Siderastrea exhibits high levels of morphological variability. Some of its species share similar morphological characteristics with congeners, making their identification difficult. Siderastrea stellata has been reported as an intermediary of S. siderea and S. radians in the Brazilian reef ecosystem. In an earlier study conducted in Mexico, we detected Siderastrea colonies with morphological features that were not consistent with some siderastreid species previously reported in the Gulf of Mexico. Thus, we performed a combined morphological and molecular analysis to identify Siderastrea species boundaries from the Gulf of Mexico. Some colonies presented high morphologic variability, with characteristics that corresponded to Siderastrea stellata. Molecular analysis, using the nuclear ITS and ITS2 region, corroborated the morphological results, revealing low genetic variability between S. radians and S. stellata. Since the ITS sequences did not distinguish between Siderastrea species, we used the ITS2 region to differentiate S. stellata from S. radians. This is the first report of Siderastrea stellata and its variability in the Gulf of Mexico that is supported by morphological and molecular analyses.

Oocyte distribution within and between ovary lobes is largely homogeneous in Lachnolaimus maximus (Perciformes: Labridae) / La distribución de los ovocitos en y entre los lóbulos ováricos de Lachnolaimus maximus (Perciformes: Labridae) es generalmente homogénea

Abstract:In fish reproduction, previous information of ovary oocyte distribution is necessary, when oocytes quantitative estimates are required to estimate batch or annual fecundity. Heterogeneous oocyte distribution requires a standardized sampling protocol to prevent bias in estimates, whereas homogeneous distribution, allows sampling of any portion of gonads with no risk of bias. We studied gonad oocyte distribution patterns in the hogfish Lachnolaimus maximus population from Southern Gulf of Mexico. For this, 23 mature females were selected from a total of 47 individuals exhibiting visible oocytes in the ovaries. These females were classified by reproductive phase and sub-phase (early developing-ED, developing-D, spawning capable-SC and actively spawning-AS). Six histological sections were taken from the anterior, middle and posterior regions of the left and right ovary lobes of each individual. Digital image processing (AxioVision and Image ProPlus programs) was used to estimate oocyte density per unit area, and for different development stages. Contingency tables were used to analyze oocyte distribution frequencies between the regions of each lobe, and between the lobes of each ovary. This was supported with a Pearson's χ2 test for goodness-of-fit and a replicated G test to confirm distribution heterogeneity. Oocyte stage distribution was homogeneous in almost all 23 females regardless of the ovary lobe. In the left ovary lobe, oocyte distribution was uniform in all three regions sampled regardless the female phase or sub-phase. In the right ovary lobe, oocyte frequencies were similarly uniform for the ED, D and AS phase and sub-phases; nevertheless, during SC phase, some heterogeneity was observed in tertiary vitellogenesis-Vtg3 oocytes, especially in samples from middle and posterior regions of this lobe. Females in AS sub-phase are normally used to estimate batch fecundity in fish such as L. maximus, which has shown to have asynchronous oocyte development and batch spawning. Given the homogeneous oocyte distribution pattern within and between the ovary lobes in females in AS sub-phase, no systematization is required of the gonad histological sampling protocol to estimate species batch fecundity. Nevertheless, due to the heterogeneous Vtg3 oocytes distribution in the right ovary lobe of females in the SC phase, it is best to systematically take sections of any region in the left ovary lobe when conducting a study encompassing all of a species' reproductive aspects. Rev. Biol. Trop. 65 (1): 293-303. Epub 2017 March 01.

ResumenPara el estudio de la reproducción de los peces es necesario, un conocimiento previo sobre la distribución de los ovocitos en el ovario, así como estimaciones cuantitativas del número de ovocitos para estimar la fecundidad por lote o anual. Una distribución heterogénea exige tener un protocolo de muestreo estandarizado para prevenir sesgos en las estimaciones, mientras que una distribución homogénea permite utilizar muestras de cualquier parte de las gónadas sin riesgo de sesgo. Nosotros estudiamos el patrón de distribución de los ovocitos de la población de la doncella de pluma Lachnolaimus maximus del sur del Golfo de México. Para este propósito, 23 hembras maduras fueron seleccionadas de un total de 47 individuos que presentaron ovocitos observables a simple vista en los ovarios. Estas hembras fueron clasificadas según su fase o sub-fase reproductiva (desarrollo temprano-DT, desarrollo-D, aptitud para desovar-AD y desove activo-DA). Seis secciones histológicas fueron realizadas de las regiones anterior, media y posterior de los lóbulos derecho e izquierdo del ovario de cada individuo. Un procesamiento digital de imágenes (AxioVision e Image ProPlus) fue utilizado para estimar la densidad de los ovocitos, en diferentes estadios de desarrollo, por unidad de área. Las frecuencias de distribución de los ovocitos fueron analizadas entre regiones de un mismo lóbulo y entre lóbulos de cada ovario por medio de tablas de contingencia. Este análisis involucró la aplicación de la prueba de bondad de ajuste del χ2 de Pearson y de la prueba de G replicada en el caso de observar una distribución heterogénea. La mayoría de las 23 hembras analizadas presentó una distribución homogénea de los diferentes estadios de ovocito, en cualquier lóbulo considerado. En el lóbulo ovárico izquierdo, la distribución de los ovocitos fue similar en las tres regiones muestreadas, en cualquier fase o sub-fase de las hembras. En el lóbulo ovárico derecho, las frecuencias de los ovocitos fueron semejantes para las hembras en fase y sub-fases de DT, D y DA; sin embargo, durante la sub-fase de AD, una heterogeneidad en el desarrollo de los ovocitos en vitelogénesis terciaria-Vtg3 fue observada, especialmente en las muestras de las regiones media y posterior de este lóbulo. Las hembras en sub-fase de DA son usualmente utilizadas para estimar la fecundidad por lote en las especies de peces como L. maximus, la cual presenta un desarrollo asincrónico de los ovocitos y realiza desoves sucesivos por lote. Debido al patrón de distribución homogéneo de los ovocitos en y entre los lóbulos ováricos de las hembras en sub-fase de DA, no se requiere estandarizar un protocolo de muestreo histológico de las gónadas para estimar la fecundidad por lote de la especie. Sin embargo, debido a la distribución heterogénea de los ovocitos en Vtg3 en el lóbulo ovárico derecho de las hembras en fase de DA, es preferible tomar sistemáticamente secciones de cualquier región del lóbulo ovárico izquierdo cuando se realiza un estudio que incluye todo los aspectos reproductivos de la especie.

Impact of Autocidal Gravid Ovitraps on Chikungunya Virus Incidence in Aedes aegypti (Diptera: Culicidae) in Areas With and Without Traps.

Puerto Rico detected the first confirmed case of chikungunya virus (CHIKV) in May 2014 and the virus rapidly spread throughout the island. The invasion of CHIKV allowed us to observe Aedes aegypti (L.) densities, infection rates, and impact of vector control in urban areas using CDC autocidal gravid ovitraps (AGO traps) for mosquito control over several years. Because local mosquitoes can only get the virus from infectious residents, detecting the presence of virus in mosquitoes functions as a proxy for the presence of virus in people. We monitored the incidence of CHIKV in gravid females of Ae. aegypti in four neighborhoods-two with three AGO traps per home in most homes and two nearby neighborhoods without AGO mosquito control traps. Monitoring of mosquito density took place weekly using sentinel AGO traps from June to December 2014. In all, 1,334 pools of female Ae. aegypti (23,329 individuals) were processed by real-time reverse transcription PCR to identify CHIKV and DENV RNA. Density of Ae. aegypti females was 10.5 times lower (91%) in the two areas with AGO control traps during the study. Ten times (90.9%) more CHIKV-positive pools were identified in the nonintervention areas (50/55 pools) than in intervention areas (5/55). We found a significant linear relationship between the number of positive pools and both density of Ae. aegypti and vector index (average number of expected infected mosquitoes per trap per week). Temporal and spatial patterns of positive CHIKV pools suggested limited virus circulation in areas with AGO traps.

Oocyte distribution within and between ovary lobes is largely homogeneous in Lachnolaimus maximus (Perciformes: Labridae).

Studies of fish reproductive biology often involve quantitative estimates based on histological sections of the ovaries. Prior characterization of gonad oocyte distribution patterns in females is fundamental to these studies. Heterogeneous distribution requires a standardized sampling protocol to prevent bias in data such as fecundity estimations. In contrast, homogeneous distribution allows sampling of any portion of the gonads with no risk of bias. A preliminary study was done of gonad oocyte distribution mode in a hogfish Lachnolaimus maximus population in the southern Gulf of Mexico. A total of 23 sexually-active females were selected and classified by reproductive stage. Six histological sections were taken from the anterior, middle and posterior regions of the left and right ovary lobes of each individual. Digital image processing (AxioVision and Image ProPlus programs) was used to estimate oocyte density per unit area in different development stages. Contingency tables were used to analyze oocyte distribution frequencies between the regions of each lobe and between the lobes of each ovary. This was supported with a Pearson's χ2 test for goodness-of-fit and a replicated G test to confirm distribution heterogeneity. Oocyte type distribution was homogeneous in almost all the females regardless of ovary region or lobe. This was particularly the case for females in the actively spawning reproductive subphase. Females in this subphase are normally used to estimate batch fecundity in fish species such as L. maximus, which have asynchronous oocyte development and batch spawning. However, heterogeneity was present in tertiary vitellogenesis oocytes in the right lobe of females in the spawning capable reproductive phase. In these cases, it is preferable to take histological sections from any region of the left ovary lobe to ensure unbiased estimation of fecundity and adequate characterization of this species' sexual cycle.

Epidemiological and clinical observations on patients with dengue in Puerto Rico: results from the first year of enhanced surveillance--June 2005-May 2006.

From June 2005 to May 2006, a clinic-based enhanced surveillance system for dengue was implemented in a Puerto Rican municipality to provide a population-based measure of disease incidence and clinical outcomes. We obtained demographic and clinical information from suspected cases and performed serologic and virologic testing. We used World Health Organization (WHO) criteria to classify cases and applied a simplified case definition for severe dengue illness. There were 7.7 laboratory-positive cases of dengue per 1,000 population. The highest incidence, 13.4 per 1,000, was among 10 to 19 year olds. Of the 156 laboratory-positive cases, three patients (1.9%) met WHO criteria for dengue hemorrhagic fever, and 30 patients (19.2%) had at least one severe clinical manifestation of dengue infection. Our data suggest that in a community with endemic dengue, enhanced surveillance is useful for detecting symptomatic infections. Furthermore, the simplified case definition for severe dengue may be useful in clinic-based surveillance.

Epidemic dengue and dengue hemorrhagic fever at the Texas-Mexico border: results of a household-based seroepidemiologic survey, December 2005.

A dengue-2 epidemic causing dengue hemorrhagic fever (DHF) occurred in the contiguous border cities of Matamoros, Tamaulipas (Mexico), and Brownsville, TX, in 2005. In December, we conducted a household-based epidemiologic survey to determine the incidence and seroprevalence of dengue infection among Matamoros and Brownsville residents and to identify risk factors associated with infection. Antibodies to dengue were measured in 273 individuals. The estimated incidence of recent dengue infection was 32% and 4% among Matamoros and Brownsville participants, respectively. The estimated prevalence of past dengue infection was 77% and 39% among Matamoros and Brownsville participants, respectively. The Breteau index was 28 in Matamoros and 16 in Brownsville, reflecting an abundant winter population of Aedes mosquitoes. Discarded waste tires and buckets were the two largest categories of infested containers found in both cities. Our results underscore the risk for epidemic dengue and DHF in the Texas-Mexico border region.