RESUMEN
Mercury distribution and bioaccumulation in aquatic ecosystems of tropical Australia is poorly characterised. Barramundi (Lates calcarifer), a widespread high-order predator in both fresh and coastal marine waters of the region, fulfils requirements for a bio-indicator of mercury contamination. In a study of the Mary River system of the Northern Territory, total mercury in the muscle tissue of 300 specimens gathered over four years (2013-2017, across both wet and dry seasons) was determined by direct combustion-atomic absorption spectrometry. Source of nutrition and trophic position of barramundi in the food web was also estimated via carbon and nitrogen isotopes (δ13C and δ15N), respectively, in tissue by stable isotope mass spectrometry, and determination of strontium isotopes (87Sr/86Sr) in otoliths by laser ablation-ICPMS differentiated between freshwater and saltwater residence. Results showed that fish moving into freshwater floodplain wetlands concentrated mercury in muscle tissue at approximately twice the level of those that remained in saline habitats. Resolving life histories through otolith analyses demonstrated diversity in mercury bioaccumulation for individual fish of the same migratory contingent on the floodplains. Although trophic level (δ15N), capture location, source of nutrition (δ13C), and age or size partly predicted mercury concentrations in barramundi, our results suggest that individual variability in diets, migration patterns and potentially metabolism are also influential. Using a migratory fish as a bio-indicator, and tracking its life history and use of resources, proved valuable as a tool to discern hot spots in a coastal waterway for a contaminant, such as mercury.
Asunto(s)
Rasgos de la Historia de Vida , Mercurio , Perciformes , Contaminantes Químicos del Agua , Animales , Bioacumulación , Ecosistema , Monitoreo del Ambiente , Peces/metabolismo , Cadena Alimentaria , Mercurio/análisis , Isótopos de Nitrógeno/análisis , Perciformes/metabolismo , Contaminantes Químicos del Agua/análisisRESUMEN
The author describes her struggle with depression and borderline personality disorder, self-harm, and suicidality. She first reviews the long years during which she did not respond to any of the numerous antidepressant medications that were prescribed. She then describes how she finally achieved healing and good functioning as a result of long-term caring psychotherapy in the context of a strong therapeutic relationship in combination with medications that were found to be effective for her symptoms.
Asunto(s)
Trastorno de Personalidad Limítrofe , Conducta Autodestructiva , Femenino , Humanos , Salud Mental , Psicoterapia , Trastorno de Personalidad Limítrofe/psicología , Antidepresivos , Conducta Autodestructiva/terapiaRESUMEN
Sustained observations of microbial dynamics are rare, especially in southern hemisphere waters. The Australian Marine Microbial Biodiversity Initiative (AMMBI) provides methodologically standardized, continental scale, temporal phylogenetic amplicon sequencing data describing Bacteria, Archaea and microbial Eukarya assemblages. Sequence data is linked to extensive physical, biological and chemical oceanographic contextual information. Samples are collected monthly to seasonally from multiple depths at seven sites: Darwin Harbour (Northern Territory), Yongala (Queensland), North Stradbroke Island (Queensland), Port Hacking (New South Wales), Maria Island (Tasmania), Kangaroo Island (South Australia), Rottnest Island (Western Australia). These sites span ~30° of latitude and ~38° longitude, range from tropical to cold temperate zones, and are influenced by both local and globally significant oceanographic and climatic features. All sequence datasets are provided in both raw and processed fashion. Currently 952 samples are publically available for bacteria and archaea which include 88,951,761 bacterial (72,435 unique) and 70,463,079 archaeal (24,205 unique) 16 S rRNA v1-3 gene sequences, and 388 samples are available for eukaryotes which include 39,801,050 (78,463 unique) 18 S rRNA v4 gene sequences.