Pollution Issues in Coastal Lagoons in the Gulf of Mexico

The coastline of the Mexican Gulf of Mexico is an area of paramount importance. It poses valuable biological and ecological resources such as coastal lagoons, rivers, estuaries, wetlands and swamps. It poses 206 coastal systems including 73 coastal lagoons with high biological richness. Their study shows the physicochemical characteristics and pollution levels into the four more productive lagoons of Tampamachoco, Mandinga, Alvarado in the Veracruz state and Terminos Lagoon in Campeche state, México, have the present characteristics. The lagoons show a wide interval in physiochemical parameters (temperature: 18–32°C, salinity: 11–38 ups, and nutrients: oxygen 1.8–9.0 mg/L, total phosphorus 2.6–123 μM total nitrogen 5–70 μM, and chlorophyll 10–50 mg/m3). All of them oscillated between normal to eutrophication condition. The presence of PAHs and some of the high toxicity as anthracene, and chrysene, as well as naphthalene and its methyl derivatives has been reported. Also, chlorinated hydrocarbons used for agriculture purposes and malaria control (DDT, lindane, endosulfan) have been identified in these lagoons. Metals as Cr, Pb, Ni, Cd, and V among others were recently reported in the lagoons considered in this study. Concentrations of pollutants also show significant variations depending on the time and the type of lagoon, or estuary

Avian movements in a modern world - cognitive challenges

Different movement patterns have evolved as a response to predictable and unpredictable variation in the environment with migration being an adaptation to predictable environments, nomadism to unpredictable environments and partial migration to a mixture of predictable and unpredictable conditions. Along different movement patterns different cognitive abilities have evolved which are reviewed and discussed in relation to an organism’s ability to respond to largely unpredictable environmental change due to climate and human-induced change and linked to population trends. In brief, migrants have a combination of reliance on memory, low propensity to explore and high avoidance of environmental change that in combination with overall small brain sizes results in low flexibility to respond to unpredictable environmental change. In line with this, many migrants have negative population trends. In contrast, while nomads may use their memory to find suitable habitats they can counteract negative effects of finding such habitats disturbed by large-scale exploratory movements and paying attention to environmental cues. They are also little avoidant of environmental change. Population trends are largely stable or increasing indicating their ability to cope with climate and human-induced change. Cognitive abilities in partial migrants are little investigated but indicate attention to environmental cues coupled with high exploratory tendencies that allow them a flexible response to unpredictable environmental change. Indeed, their population trends are mainly stable or increasing. In conclusion, cognitive abilities have evolved in conjunction with different movement patterns and affect an organism’s ability to adapt to rapidly human-induced changes in the environment

Distribution and habitat suitability index model for the Andean catfish Astroblepus ubidiai (Pisces: Siluriformes) in Ecuador

In conservation biology there is a basic need to determine habitat suitability and availability. Astroblepus ubidiai (Siluriforms), the only native fish in the highlands of Imbabura province in the Ecuadorian Andes, was abundant in the past in the Imbakucha watershed and adjacent drainages, but currently it is restricted to a few isolated refuges. Conservation actions are needed if this unique fish is to persist. A Habitat Suitability Index (HSI) for the species has been developed in order to aid management decisions. In this HSI model biomass density (B) was selected as a better indicator of habitat quality than either abundance or density.A population well-being index (PI) was constructed with the combination of B and an indicator of fish health (proportion of fish in the population with parasites and deformities). Based in other models of benthic fish the habitat variables current velocity, flow, depth, width, cover, invertebrate composition, vegetation type, terrestrial vegetation, land use, substrate, temperature, pH, TDS, oxygen, altitude, and slope were included in the analysis. An anthropogenic perturbation index (H) and a fragment isolation index (FII) were developed and included as habitat variables as well. The HSI model was applied to refuges and a sample of 15 aquatic bodies without fish populations within the study region. From the sampled sites without A. ubidiai 26.6% presented low quality, andthe remaining 73.3% had medium quality according to the HSI estimated. Good quality habitat for dispersal, escape or translocations is rare in the region. The low HSIs estimated in some of the refuges suggests that current populations are not settled in the most favorable habitat but in the habitat least favorable to the agents of decline. Astroblepus ubidiai (Siluriformes), el único pez nativode las alturas de Imbabura, en los Andes Ecuatorianos,era un recurso abundante en el pasado. Actualmente sudistribución está limitada a unos cuantos refugios aislados.Se necesitan acciones de conservación para que estaespecie perdure. Se desarrolló un modelo para estimar elíndice de calidad de hábitat (ICH) que ayude en futurasdecisiones de manejo. En este ICH la densidad de biomasa(B) fue seleccionada como un mejor indicador de calidadde hábitat, comparada con el uso común de abundanciao densidad incorporado en otros modelos. Se generó uníndice de bienestar poblacional (IP) basado en B y en unindicador de salud poblacional (SP) derivado de la proporciónde peces en la población con parásitos y malformaciones.Diecinueve variables físicas, biológicas y geográficasfueron evaluadas dentro del modelo, el cual fue aplicadoa una muestra de 15 sitios sin poblaciones de A. ubidiaidentro del área de estudio. De esta muestra, 26.6% de lossitios presentó baja calidad de hábitat, y el restante 73.3%presentó calidad media de acuerdo a la evaluación con elmodelo. En la región hay escasos hábitats de buena calidadpara dispersión, escape y reubicación de este pez

Zooplankton variability in the Strait of Georgia, Canada, and relationships with the marine survivals of Chinook and Coho salmon.

The Strait of Georgia, Canada, has complex interactions among natural and human pressures that confound understanding of changes in this system. We report on the interannual variability in biomass of 12 zooplankton taxonomic groups in the deep (bottom depths greater than 50 m) central and northern Strait of Georgia from 1996 to 2018, and their relationships with 10 physical variables. Total zooplankton biomass was dominated (76%) by large-sized crustaceans (euphausiids, large and medium size calanoid copepods, amphipods). The annual anomaly of total zooplankton biomass was highest in the late 1990s, lowest in the mid-2000s, and generally above its climatological (1996-2010) average after 2011, although many individual groups had different patterns. Two latent trends (derived from dynamic factor analyses) described the variability of annual biomass anomalies underlying all zooplankton groups: a U-shaped trend with its minimum in the mid-2000s, and a declining trend from 2001 to 2011. Two latent trends also described the physical variables. The variability represented by these four latent trends clustered into two periods: 1996-2006, with generally declining zooplankton biomass and increasing salinities, and 2007-2018, with increasing zooplankton biomass and decreasing salinities. ARIMA modelling showed sea surface salinity at Entrance Island in the middle Strait of Georgia, the Pacific Decadal Oscillation, and the peak date of the spring phytoplankton bloom were significantly related to the two latent zooplankton trends. ARIMA models comparing zooplankton and physical variables with the marine survivals of four salmon populations which enter the Strait as juveniles (Chinook: Cowichan River, Puntledge River, Harrison River; Coho: Big Qualicum River) all included zooplankton groups consistent with known salmon prey; prominent among the physical variables were sea surface salinity and variables representing the flow from the Fraser River. These regressions explained (adjR2) 38 to 85% of the annual variability in marine survival rates of these salmon populations over the study time period. Although sea temperature was important in some relationships between zooplankton biomass and salmon marine survival, salinity was a more frequent and more important variable, consistent with its influence on the hydrodynamics of the Strait of Georgia system