Prevalence of microplastics in Peruvian mangrove sediments and edible mangrove species.

Mangrove ecosystems have been hypothesised as a potential sink of microplastic debris, which could pose a threat to mangrove biota and ecological function. In this field-study we establish the prevalence of microplastics in sediments and commercially-exploited Anadara tuberculosa (black ark) and Ucides occidentalis (mangrove crab) from five different zones in the mangrove ecosystem of Tumbes, Peru. Microplastic were evident in all samples, with an average of 726 ± 396 microplastics/kg for the sediment, although no differences between the different zones of the mangrove ecosystem were observed. Microplastic concentrations were 1.6± 1.1 items/g for the black ark and 1.9 ± 0.9 microplastics/g for the mangrove crab, with a difference in the microplastic abundance between species (p < 0.05), and between the gills and stomachs of the crab (p < 0.01). Human intake of microplastics from these species, for the population in Tumbes, is estimated at 431 items per capita per year. The outcomes of this work highlight that the mangrove ecosystem is widely contaminated with microplastics, presenting a concern for the marine food web and food security.

Citizen scientists study beach litter along 12,000 km of the East Pacific coast: A baseline for the International Plastic Treaty.

Anthropogenic Marine Litter (AML) accumulating on beaches causes damage to coastal ecosystems and high costs to local communities. Volunteers sampled AML on 130 beaches along the central and southern East Pacific coasts, with AML densities ranging from 0.46 to 2.26 items m-2 in the different countries. AML composition was dominated by plastics and cigarette butts, the latter especially in Mexico and Chile. The accumulation of AML in the upper zones of the beaches and substantial proportions of cigarette butts, glass and metal pointed mainly to local sources. Statistical modelling of litter sources on continental beaches revealed that tourism, access and related infrastructure (e.g. parking lots) best explained AML densities, while plastic densities were also influenced by the distance from river mouths and national Gross Domestic Product. Large-scale monitoring can be a useful tool to evaluate the effectiveness of public policies that should primarily focus on land sources.

Holocene history of ENSO variance and asymmetry in the eastern tropical Pacific.

Understanding the response of the El Niño-Southern Oscillation (ENSO) to global warming requires quantitative data on ENSO under different climate regimes. Here, we present a reconstruction of ENSO in the eastern tropical Pacific spanning the past 10,000 years derived from oxygen isotopes in fossil mollusk shells from Peru. We found that ENSO variance was close to the modern level in the early Holocene and severely damped ~4000 to 5000 years ago. In addition, ENSO variability was skewed toward cold events along coastal Peru 6700 to 7500 years ago owing to a shift of warm anomalies toward the Central Pacific. The modern ENSO regime was established ~3000 to 4500 years ago. We conclude that ENSO was sensitive to changes in climate boundary conditions during the Holocene, including but not limited to insolation.

Previsión de la temperatura superficial del mar frente a la costa peruanamediante un modelo autorregresivo integrado de media móvil / Forecast of sea surface temperature off the Peruvian coast using an autoregressive integrated moving average model

El evento El Niño conecta globalmente el clima, los ecosistemas y las actividades socioeconómicas. Desde 1980 se ha intentado predecir este evento, pero hasta la fecha los modelos estadísticos y dinámicos aún son insuficientes. Por tal motivo, el objetivo del presente trabajo fue explorar mediante un modelo autoregresivo integrado de media móvil el efecto de El Niño en la temperatura superficial del mar (TSM) frente a la costa peruana. El trabajo comprendió 5 etapas: identificación, estimación, verificación diagnóstica, previsión y validación. Se usaron las funciones de autocorrelación simple y parcial (FAC y FACP) para identificar y reformular los órdenes de parámetros en los modelos, así también los criterios de información de Akaike (AIC) y de Schwarz (SC) para la selección de modelos en la verificación diagnostica. Entre los principales resultados se propuso modelos ARIMA(12,0,11) que simularon condiciones mensuales similares a las observadas en el litoral peruano: condiciones frías a fines del 2004, y condiciones neutrales a inicios del 2005.

El Niño connects globally climate, ecosystems and socio-economic activities. Since 1980 this event has been tried to be predicted, but until now the statistical and dynamical models are insufficient. Thus, the objective of the present work was to explore using an autoregressive moving average model the effect of El Niño over the sea surface temperature (TSM) off the Peruvian coast. The work involved 5 stages: identification, estimation, diagnostic checking, forecasting and validation. Simple and partial autocorrelation functions (FAC and FACP) were used to identify and reformulate the orders of the model parameters, as well as Akaike information criterium (AIC) and Schwarz criterium (SC) for the selection of the best models during the diagnostic checking. Among the main results the models ARIMA(12,0,11) were proposed, which simulated monthly conditions in agreement with the observed conditions off the Peruvian coast: cold conditions at the end of 2004, and neutral conditions at the beginning of 2005.