Functional changes in benthic macrofaunal communities along a natural gradient of hypoxia in an upwelling system.

Increasing global concern has been raised about the expansion of hypoxia in coastal waters and its potential to impact benthic ecosystems. Upwelling areas offer opportunities to study the effects of hypoxia on benthic communities under natural conditions. We used a biological trait-based approach and estimated functional diversity indices to assess macrobenthic community functioning along a depth gradient associated with naturally increasing hypoxia and concentrations of organic matter in the upwelling zone of northern Chile (South-East Pacific) over two years. Our results highlighted the increasing dominance of opportunistic biological traits associated with hypoxia and high organic matter content. Habitat filtering was the main process affecting the studied communities. Functional diversity patterns were persistent overtime despite the occurrence of a pulse of oxygenation. This study contributes to our understanding of how natural hypoxia impacts macrobenthic communities, providing useful information in the context of increasing eutrophication due to human influence on coastal areas.

Teorias subjetivas de docentes sobre a inserção laboral de seus alunos cegos / Teorias subjetivas de docentes sobre la inserción laboral de sus alumnos con ceguera / Teachers' subjective theories about the employment integration their blind students

La inserción laboral de las personas con ceguera ha sido investigada, pero no existen trabajos que indaguen sobre lo que piensan y conocen los docentes que forman a estas personas y sobre las dificultades de sus estudiantes para insertarse laboralmente después de su educación. El objetivo de esta investigación cualitativa fue comprender las teorías subjetivas de seis docentes de un establecimiento educacional de La Serena, Chile. El método de recolección de datos utilizado fue la entrevista en profundidad y el estudio de los datos se realizó a través de los procedimientos de codificación de la grounded theory y el análisis del contenido de las teorías subjetivas. Se encontró, como principal resultado que, para los participantes la educación inadecuada del ciego es la principal causa de la dificultad para la inserción laboral. Esta investigación puede aportar información valiosa para aquellos encargados de las políticas públicas entorno a la discapacidad visual.

A inserção laboral das pessoas com cegueira foi pesquisada, mas não existem estudos que perguntem sobre o que pensam e conhecem os docentes que formam estas pessoas e sobre as dificuldades de seus estudantes para inserir-se no mercado laboral depois de sua educação. O objetivo desta pesquisa qualitativa foi compreender as teorias subjetivas de seis docentes de um estabelecimento educacional de La Serena, Chile. O método da coleta de dados utilizado foi a entrevista em profundidade e o estudo dos dados realizou-se por intermédio dos procedimentos de codificação da grounded theory e a análise do conteúdo das teorias subjetivas. Encontrou-se, como principal resultado, que para os participantes a educação inadequada do cego é a principal causa da dificuldade para a inserção laboral. Esta pesquisa pode aportar informação valiosa para aqueles encarregados das políticas públicas entorno à incapacidade visual.

Even though research has been conducted on the employment integration at blind people, studies have failed to consider what teachers think and know about their blind students' difficulties entering the workforce after completing their education. The aim of this qualitative study was to understand the subjective theories of six teachers from a school in La Serena, Chile. In-depth interviews were used to collect data, which were subsequently studied using grounded theory coding procedures and subjective theory content analysis. The main finding of this study was that participants regarded the inadequate education of blind people as the key reason for their employment difficulties. This study can provide valuable information for policymakers focusing on visual impairment.

Macrobenthic communities in a shallow normoxia to hypoxia gradient in the Humboldt upwelling ecosystem.

Hypoxia is one of the most important stressors affecting the health conditions of coastal ecosystems. In highly productive ecosystems such as the Humboldt Current ecosystem, the oxygen minimum zone is an important abiotic factor modulating the structure of benthic communities over the continental shelf. Herein, we study soft-bottom macrobenthic communities along a depth gradient-at 10, 20, 30 and 50 m-for two years to understand how hypoxia affects the structure of shallow communities at two sites in Mejillones Bay (23°S) in northern Chile. We test the hypothesis that, during months with shallow hypoxic zones, community structure will be much more dissimilar, thereby depicting a clear structural gradient with depth and correlated abiotic variables (e.g. organic matter, temperature and salinity). Likewise, during conditions of deeper hypoxic zones, communities will be similar among habitats as they could develop structure via succession in conditions with less stress. Throughout the sampling period (October 2015 to October 2017), the water column was hypoxic (from 2 to 0.5ml/l O2) most of the time, reaching shallow depths of 20 to 10 m. Only one episode of oxygenation was detected in June 2016, where normoxia (>2ml/l O2) reached down to 50 m. The structure of the communities depicted a clear pattern of increasing dissimilarity from shallow normoxic and deep hypoxic habitat. This pattern was persistent throughout time despite the occurrence of an oxygenation episode. Contrasting species abundance and biomass distribution explained the gradient in structure, arguably reflecting variable levels of hypoxia adaptation, i.e. few polychaetes such as Magelona physilia and Paraprionospio pinnata were only located in low oxygen habitats. The multivariable dispersion of community composition as a proxy of beta diversity decreased significantly with depth, suggesting loss of community structure and variability when transitioning from normoxic to hypoxic conditions. Our results show the presence of semi-permanent shallow hypoxia at Mejillones Bay, constraining diverse and more variable communities at a very shallow depth (10-20 m). These results must be considered in the context of the current decline of dissolved oxygen in most oceans and coastal regions and their impact on seabed biota.