10 research outputs found
Assessing the ecological impact of banana farms on water quality using aquatic macroinvertebrate community composition
In Costa Rica, considerable effort goes to conservation and protection of biodiversity, while at the same time agricultural pesticide use is among the highest in the world. Several protected areas, some being wetlands or marine reserves, are situated downstream large-scale banana farms, with an average of 57 pesticide applications per year. The banana industry is increasingly aware of the need to reduce their negative environmental impact, but few ecological field studies have been made to evaluate the efficiency of proposed mitigation strategies. This study compared the composition of benthic macroinvertebrate communities up- and downstream effluent water from banana farms in order to assess whether benthic invertebrate community structure can be used to detect environmental impact of banana farming, and thereby usable to assess improvements in management practises. Aquatic invertebrate samples were collected at 13 sites, using kick-net sampling, both up- and downstream banana farms in fast flowing streams in the Caribbean zone of Costa Rica. In total, 2888 invertebrate specimens were collected, belonging to 15 orders and 48 families or taxa. The change in community composition was analysed using multivariate statistics. Additionally, a biodiversity index and the Biological Monitoring Working Party (BMWP) score system was applied along with a number of community composition descriptors. Multivariate analyses indicated that surface waters immediately up- and downstream large-scale banana farms have different macroinvertebrate community compositions with the most evident differences being higher dominance by a single taxa and a much higher total abundance, mostly of that same taxon. Assessment of macroinvertebrate community composition thus appears to be a viable approach to detect negative impact from chemical-intensive agriculture and could become an effective means to monitor the efficacy of changes/proposed improvements in farming practises in Costa Rica and similar systems
Differences in physiological response to increased seawater temperature in nearshore and offshore corals in northern Vietnam
Spatial correlation and potential conflicts between sea cage farms and coral reefs in South East Asia
Use of cholinesterase activity as a biomarker of pesticide exposure used on Costa Rican banana plantations in the native tropical fish Astyanax aeneus (Günther, 1860)
IRETIn Costa Rica, thousands of tones of agricultural pesticides have been used for decades and their use is continuously increasing due to intensive and expanding production of coffee, pineapple, rice, ornamental plants and bananas. The objective of this study was to evaluate whether choline esterase (ChE) activity could be used as a biomarker of exposure to pesticides in the Costa Rican native fish Astyanax aeneus (characidae). Three methods used in order to evaluate the ChE biomarker were as follows: Laboratory studies where A. aeneus was exposed to organophosphate pesticide (ethoprophos); In situ 48 hr exposure assessment using caging experiments with fish exposed upstream and downstream of banana plantations and ChE activity estimation of in fish captured directly at sites with different degrees of pesticide exposure. Results from the laboratory studies showed that ChE activity in both brain and muscle tissue was significantly lower in fish exposed to ethoprophos than in controls. Fish from the caging experiments showed no difference in ChE activity neither in brain nor in muscle tissue between the four tested sites and was attributed to the short duration of the exposure. A significant difference in ChE activity was determined in muscle of fish captured from Laguna Madre de Dios compared to fish from Canal Batan. Although our laboratory results revealed that ChE activity in A. aeneus was highly responsive to ethoprophos, results from field experiments were less conclusive and showed that the captured fish showed large variability in ChE activity and that more research is needed before ChE activity can be used as reliable biomarker of pesticide exposure.En Costa Rica, se han utilizado miles de toneladas de pesticidas agrícolas durante décadas y su uso aumenta continuamente debido a la producción intensiva y en expansión de café, piña, arroz, plantas ornamentales y banano. El objetivo de este estudio fue evaluar si la actividad de la esterasa de colina (ChE) podría utilizarse como biomarcador de exposición a plaguicidas en el pez nativo costarricense Astyanax aeneus (characidae). Los tres métodos utilizados para evaluar el biomarcador ChE fueron los siguientes: estudios de laboratorio en los que A. aeneus estuvo expuesta a plaguicidas organofosforados (etoprofos); Evaluación de exposición in situ de 48 horas mediante experimentos de enjaulamiento con peces expuestos río arriba y río abajo de plantaciones de banano y estimación de la actividad de ChE en peces capturados directamente en sitios con diferentes grados de exposición a plaguicidas. Los resultados de los estudios de laboratorio mostraron que la actividad de ChE tanto en el cerebro como en el tejido muscular fue significativamente menor en los peces expuestos al etoprofos que en los controles. Los peces de los experimentos en jaulas no mostraron diferencias en la actividad de ChE ni en el cerebro ni en el tejido muscular entre los cuatro sitios evaluados y se atribuyó a la corta duración de la exposición. Se determinó una diferencia significativa en la actividad de ChE en el músculo de los peces capturados en la Laguna Madre de Dios en comparación con los peces del Canal Batán. Aunque los resultados de nuestro laboratorio revelaron que la actividad de ChE en A. aeneus era muy sensible al etoprofos, los resultados de los experimentos de campo fueron menos concluyentes y mostraron que los peces capturados mostraron una gran variabilidad en la actividad de ChE y que se necesita más investigación antes de que la actividad de ChE pueda usarse como biomarcador confiable de exposición a plaguicidas.Na Costa Rica, milhares de toneladas de pesticidas agrícolas têm sido usados há décadas e seu uso está aumentando continuamente devido à produção intensiva e em expansão de café, abacaxi, arroz, plantas ornamentais e bananas. O objetivo deste estudo foi avaliar se a atividade da colina esterase (ChE) poderia ser usada como biomarcador de exposição a pesticidas no peixe nativo da Costa Rica Astyanax aeneus (characidae). Os três métodos utilizados para avaliar o biomarcador ChE foram os seguintes: Estudos laboratoriais onde A. aeneus foi exposto a pesticida organofosforado (etoprofós); Avaliação da exposição in situ de 48 horas usando experimentos de enjaulamento com peixes expostos a montante e a jusante das plantações de banana e estimativa da atividade de ChE em peixes capturados diretamente em locais com diferentes graus de exposição a pesticidas. Os resultados dos estudos de laboratório mostraram que a atividade ChE no cérebro e no tecido muscular foi significativamente menor nos peixes expostos ao etoprofós do que nos controles. Os peixes dos experimentos de enjaulamento não mostraram diferença na atividade ChE nem no cérebro nem no tecido muscular entre os quatro locais testados e foi atribuído à curta duração da exposição. Uma diferença significativa na atividade de ChE foi determinada no músculo dos peixes capturados na Laguna Madre de Dios em comparação com os peixes do Canal Batan. Embora os resultados do nosso laboratório tenham revelado que a atividade ChE em A. aeneus foi altamente responsiva ao etoprofós, os resultados dos experimentos de campo foram menos conclusivos e mostraram que os peixes capturados mostraram grande variabilidade na atividade ChE e que mais pesquisas são necessárias antes que a atividade ChE possa ser usada. biomarcador confiável de exposição a pesticidas.Department of Systems Ecology, SwedenUniversidad Nacional, Costa RicaInstituto Regional de Estudios en Sustancias Tóxica
Diet quality determines blue mussel physiological status: A long-term experimental multi-biomarker approach
International audienceCyanobacterial blooms have increased worldwide and decreases in spring blooms of diatoms in temperate aquatic ecosystems are increasingly reported. Whether such shifts in the food base positively or negatively affect primary consumer's physiological status, growth, and more broadly, ecosystem functioning, is poorly known. Here, we test how a widespread filter-feeding blue mussel from the genus Mytilus reacts to diatoms, filamenous non-toxic cyanobacteria and a mixture of the two in a 50 day feeding experiment and compare with mussels in the field. We use a multi-tracer approach to assess mussels' nutritional and physiological status. Diatoms had highest relative proportions of the essential fatty acids 20:5ω3 (EPA) and 22:6ω3 (DHA), but cyanobacteria had a high relative proportion of polyunsaturated FAs (PUFAs) especially 18:3ω3, a precursor of ω3 FAs. Bulk and amino-acid-δ 15 N demonstrated assimilation of cyanobacterial N or diatom N by the mussels, while fatty acid (FA) composition and δ 13 C-FA analyses demonstrated assimilation of C and FAs from diatoms. Still, C and N from both food sources were utilized when mussels were fed the mix and condition index, scope for growth (SFG; measure of energy status) and the elemental N:P ratio of mussels where higher in mussels fed cyanobacteria only, indicating better growth status in this treatment. It seems like mussels fed cyanobacteria, a food with low proportions of essential FAs compared to diatoms, were able to cover the dietary requirements through FA biosynthesis from precursor FAs. The FA composition and δ 15 N-results from mussels fed cyanobacteria agreed well with seasonal field measurements of mussels. Our study provides the first feeding experiment investigating how blue mussels utilize N from cyanobacteria and shows the rather positive response to this type of food. Our results suggest that imbalances in the biochemical composition of diet of consumers can be overcome through biosynthesis of essential FAs. In the context of climate change with shifting biogeochemical baselines, it is crucial to understand the biological effects of such changes in the quality of the production base
Physiological performance and general histology of the blue mussel, Mytilus edulis L., from the Baltic and North seas
Variability of heat shock proteins and glutathione S-transferase in gill and digestive gland of blue mussel, <em>Mytilus edulis</em>
Responses to temperature, heavy metal and sediment stress by the giant clam Tridacna squamosa
Ambio fit for the 2020s
Environmental challenges and the way we frame and research them are changing, as are the channels for successful transfer of scientific knowledge into decision-making. In a time when novelty is often the beacon leading funding, research and publication, revisiting the archives and going back to the roots of current discussions offer an opportunity to reflect on what got us to where we are today. Ambio’s 50th anniversary in 2021 gave us a reason to look back at how Ambio’s scope and coverage have changed over time and to start a discussion about how Ambio can remain relevant for science and policy in the future. Ambio is growing steadily, and we see an increasingly broad range of methodological approaches and use of different sources of evidence. This is encouraging; our ambition is to support multi- as well as inter- and transdisciplinary science on the interrelationships between the environment and society. At the same time, the field of sustainability science and applied social-environmental research is growing rapidly and with it comes many potential outlets for publishing work within Ambio’s approximate niche. In this increasingly mixed and busy field, we work constantly to ensure that Ambio remains recognized as a leading forum for high quality science, based on a broad foundation of knowledge and at the interface of society and the environment
Insect community composition and functional roles along a tropical agricultural production gradient
High intensity agricultural production systems are problematic not only for human health and the surrounding environment, but can threaten the provision of ecosystem services on which farm productivity depends. This research investigates the effects of management practices in Costa Rica on on-farm insect diversity, using three different types of banana farm management systems: high-input conventional system, low-input conventional system, and organic system. Insect sampling was done using pitfall and yellow bowl traps, left for a 24-h period at two locations inside the banana farm, at the edge of the farm, and in adjacent forest. All 39,091 individual insects were classified to family level and then morphospecies. Insect species community composition and diversity were compared using multivariate statistics with ordination analysis and Monte Carlo permutation testing, and revealed that each of the management systems were significantly different from each other for both trap types. Insect diversity decreased as management intensity increased. Reduced insect diversity resulted in fewer functional groups and fewer insect families assuming different functions essential to ecosystem health. Organic farms had similar species composition on the farm compared to adjacent forest sites, whereas species composition increasingly differed between farm and forest sites as management intensity increased. We conclude that while organic production has minimal impact on insect biodiversity, even small reductions in management intensity can have a significantly positive impact on on-farm insect biodiversity and functional roles supported