Status and the potential for extinction of the largetooth sawfish Pristis pristis in the Atlantic Ocean

1. Sawfishes currently are among the most threatened elasmobranchs in the world. Only two species inhabit Atlantic waters: the largetooth sawfish (Pristis pristis) and the smalltooth sawfish (Pristis pectinata), both having suffered dramatic declines in their ranges. 2. The goal of this study was to evaluate the status of P. pristis in the Atlantic, and estimate local extinction risk based on historical and recent occurrence records. In order to accomplish these goals, a thorough search for historical and recent records of P. pristis in the Atlantic was conducted, by reviewing scientific and popular literature, museum specimens, and contacting regional scientists from the species’ historical range. 3. In total, 801 P. pristis records (1830–2009) document its occurrence in four major regions in the Atlantic: USA (n =41), Mexico and Central America (n =535), South America (n=162), and West Africa (n =48). Locality data were not available for 15 records. 4. Historical abundance centres were the Colorado-San Juan River system in Nicaragua and Costa Rica (and secondarily Lake Izabal of Guatemala), the Amazon estuary, and coastal Guinea-Bissau. 5. Currently, the species faces drastic depletion throughout its entire former range and centres of abundance. It appears to have been extirpated from several areas. The probability of extinction was highest in the USA, northern South America (Colombia to Guyane), and southern West Africa (Cameroon to Namibia). 6. Currently, the Amazon estuary appears to have the highest remaining abundance of P. pristis in the Atlantic, followed by the Colorado–San Juan River system in Nicaragua and Costa Rica and the Bissagos Archipelago in Guinea Bissau. Therefore the protection of these populations is crucial for the preservation and recovery of the species.

Organic-walled dinoflagellate cysts in recent sediments from the Guadiana river estuary, South-East Portugal

Dissertação de Mestrado, Biologia Marinha, Faculdade de Ciências do Mar e do Ambiente, Universidade do Algarve, 2007

Simulation of economic benefits achieved by water quality improvement for recreational and professional users, within the SPICOSSA SSA (SPICOSSA System Approach) 11 - Guadiana estuary ecosystem sic

Dissertação de Mestrado, Gestão da Água e da Costa, Faculdade de Ciências e Tecnologia, Universidade do Algarve, 2010

Successional dynamics in inland dune shrub communities drive changes in functional diversity

Communities can be defined as assemblages of species coexisting under particular environments. The relationship between environment and species are regulated by both environmental requirements –which ultimately determine the species capacity to establish and survive in a particular environment– and the ecological interactions occurring during assembly processes –which also determine community composition by conditioning species coexistence. In this context, plant functional traits are attributes that represent ecological strategies and determine how plants respond to environmental factors and interact with other species. Therefore, the analysis of how traits vary through the dynamics of communities, such as along successions, can give insights about how environmental requirements and species interactions may determine the composition and functional structure of these communities. The xerophytic shrub communities inhabiting inland sand dunes in SW Portugal are characterized by successional processes that are mainly driven by local (edaphic gradients and human disturbance) and regional (climate) processes. Therefore, they constitute an appropriate system for studying species interactions and environmentcommunity co-variations based on functional terms. Using these communities as a model, we evaluate the hypothesis that successional community changes in species composition of xerophytic shrub communities can result in concurrent changes in functional diversity