Morphological characteristics of an Amazon floodplain lake (Lake Batata, Pará State, Brazil)

A bathymetric survey of an Amazon floodplain lake adjacent to the Trombetas River, the Lake Batata (Pará State, Brazil), was done in order to characterize the lake morphology. This study serve as a tool for limnological interpretation data and in environmental impact assessment due to the disposal of tailings from bauxite processing. Lake area, volume, shoreline lenght, maximum effective length and width, shoreline development, maximum, relative and mean depth, volume development and a hypsographic curve were calculated. Lake Batata is shallow (mean depth 2.19 m) and its area is approximately 18 km² at low water level. Based on the configuration of the shoreline, the lake can be divided into differents compartments: the main body, the bay, the channel and the outlet. The basin of the lake is slightly convex with a typical U-shaped configuration. The lake is submitted to a significant seasonal variation of its surface area and shoreline lenght. The distribution of maximum effective fetch, at the main body, is coincident with the maximum turbidity values, evidencing the wind effect over the lake

Tube Research and Development

Contains reports on two research projects

Seagrass and submerged aquatic vegetation (VAS) habitats off the Coast of Brazil: state of knowledge, conservation and main threats

Seagrass meadows are among the most threatened ecosystems on earth, raising concerns about the equilibrium of coastal ecosystems and the sustainability of local fisheries. The present review evaluated the current status of the research on seagrasses and submerged aquatic vegetation (SAV) habitats off the coast of Brazil in terms of plant responses to environmental conditions, changes in distribution and abundance, and the possible role of climate change and variability. Despite an increase in the number of studies, the communication of the results is still relatively limited and is mainly addressed to a national or regional public; thus, South American seagrasses are rarely included or cited in global reviews and models. The scarcity of large-scale and long-term studies allowing the detection of changes in the structure, abundance and composition of seagrass habitats and associated species still hinders the investigation of such communities with respect to the potential effects of climate change. Seagrass meadows and SAV occur all along the Brazilian coast, with species distribution and abundance being strongly influenced by regional oceanography, coastal water masses, river runoff and coastal geomorphology. Based on these geomorphological, hydrological and ecological features, we characterised the distribution of seagrass habitats and abundances within the major coastal compartments. The current conservation status of Brazilian seagrasses and SAV is critical. The unsustainable exploitation and occupation of coastal areas and the multifold anthropogenic footprints left during the last 100 years led to the loss and degradation of shoreline habitats potentially suitable for seagrass occupation. Knowledge of the prevailing patterns and processes governing seagrass structure and functioning along the Brazilian coast is necessary for the global discussion on climate change. Our review is a first and much-needed step toward a more integrated and inclusive approach to understanding the diversity of coastal plant formations along the Southwestern Atlantic coast as well as a regional alert the projected or predicted effects of global changes on the goods and services provided by regional seagrasses and SAV