Grazing impact of microzooplankton upon phytoplankton

Alterations of freshwater flow regimes and increasing eutrophication can lead to alterations in phytoplankton biomass, composition, and growth in estuaries and adjacent coastal waters. Since phytoplankton is the first trophic level of most aquatic foodwebs, these changes can be propagated to other biological compartments, eventually impacting water quality and ecosystem services. However, phytoplankton responses to environmental changes in abiotic variables (e.g., light, nutrients) are additionally controlled by mortality or removal processes (e.g., grazing, horizontal advection and viral lysis). Grazing exerted by microzooplankton, usually dominated by phagotrophic protists, is considered the most relevant phytoplankton mortality factor in most aquatic systems (see Calbet, Landry 2004). In fact, grazing impact of microzooplankton can prevent phytoplankton accumulation in marine systems despite an overall increase in phytoplankton replication rate. By consequence, microzooplankton grazing may minimize problems associated to increased eutrophication and, ultimately, prevent the occurrence of harmful phytoplankton blooms. Thus, microzooplankton grazing on phytoplankton constitutes a key biological process required to understand and predict relationships between hydrological and biological processes in aquatic ecosystems and to use ecosystem properties to improve water quality and enhance ecosystem services, general principles of the Ecohydrology Concept (Zalewski 2000).

Catchment influences on the hydrological flows to lake terra alta (Linhares, ES, Brazil) and ecohydrology perspectives

Dissertação de mestrado, Ecohidrologia, Faculdade de Ciências e Tecnologia, Universidade do Algarve, 2015

A viabilidade económica da gestão sustentável do montado de sobreiro. Caso de estudo - Aldeia das Amoreiras

Dissertação de Mestrado, Economia do Turismo e Desenvolvimento Regional, Faculdade de Economia, Universidade do Algarve, 2016

A regulation-based classification system for marine protected areas (MPAs)

Marine protected areas (MPAs) are a global conservation and management tool to enhance the resilience of linked social-ecological systems with the aim of conserving biodiversity and providing ecosystem services for sustainable use. However, MPAs implemented worldwide include a large variety of zoning and management schemes from single to multiple-zoning and from no-take to multiple-use areas. The current IUCN categorisation of MPAs is based on management objectives which many times have a significant mismatch to regulations causing a strong uncertainty when evaluating global MPAs effectiveness. A novel global classification system for MPAs based on regulations of uses as an alternative or complementing, the current IUCN system of categories is presented. Scores for uses weighted by their potential impact on biodiversity were built. Each zone within a MPA was scored and an MPA index integrates the zone scores. This system classifies MPAs as well as each MPA zone individually, is globally applicable and unambiguously discriminates the impacts of uses. (C) 2016 The Authors. Published by Elsevier Ltd.