Seasonal nutrient loadings in four monsoonal micro/meso tidal tropical estuaries, west coast of India.

Nutrient concentrations were studied seasonally along estuarine and fluvial regions of four micro/meso tidal rivers from Karnataka and Maharashtra, west coast of India. This study was performed to assess the pathway of nutrients across the salinity gradients and evaluate the impacts of weathering and human activity on nutrient concentrations. The rivers of Maharashtra had phosphate concentrations several orders of magnitude higher than the rivers of Karnataka.

Fresh and recirculated submarine groundwater discharge zones along the central west coast of India.

The study area receives an average of 2840.0 mm of rainfall within four months every year. A portion of the rainwater is flown to the sea as surface water, and the other part is percolated into the bottom as groundwater.

Major and trace metals in suspended and bottom sediments of the Mandovi and Zuari estuaries, western India: distribution, source, and pollution.

Major elements and trace metals in suspended sediments along transect stations of the Mandovi and Zuari estuaries showed three types of distribution: (a) high concentrations of most metals (Al, Fe, Mn, Cr, Pb, Cu, Ni, Zn, Co, Sc, Mo, and U) in the upper estuary and their decreasing concentrations seaward in every season, (b) lower concentrations of some metals (Mg, Cr, Zr, V, Al, Th) in the upper estuary and bay and their increased concentrations in the lower estuary, and (c) higher concentrations of some metals (Cu, Ni, Zn, Pb, and Cr) in the upper estuary and bay and their decreased concentrations in the lower estuary. Mn was the most significant pollutant in both the estuaries. The Zn, Cr, Fe, and Mo in Mandovi during the monsoon and post-monsoon and, Pb, Ni, and Cr in Zuari during the post- and pre-monsoons were in the range "moderately to heavily polluted.

Iron ore pollution in Mandovi and Zuari estuarine sediments and its fate after mining ban.

Iron ore was mined from the banded iron formations of Goa, India, and transported through the Mandovi and Zuari estuaries for six decades until the ban on mining from September 2012. Here we focus on the environmental magnetic properties of sediments from the catchment area, upstream and downstream of these estuaries, and adjacent shelf during peak mining time. Magnetic susceptibility (χ lf) and saturation isothermal remanent magnetization (SIRM) values of sediments were highest in upstream (catchment area and estuaries), decreased gradually towards downstream (catchment area and estuaries), and were lowest on the adjacent shelf.

Magnetic properties of sediments in cores from the Mandovi estuary, western India: Inferences on provenance and pollution.

Magnetic properties of sediments were investigated in 7 gravity cores recovered along a transect of the Mandovi estuary, western India to understand their provenance and pollution. The maximum magnetic susceptibility of sediments was at least 6 times higher in the upper/middle estuary than in lower estuary/bay. The χfd% and χARM/SIRM of sediments indicated coarse, multi-domain and pseudo-single domain magnetic grains, resembling ore material in the upper/middle estuary and coarse stable single domain (SSD) to fine SSD grains in the lower estuary/bay.

Geochemistry of the suspended sediment in the estuaries of the Mandovi and Zuari rivers, central west coast of India.

The geochemistry of the suspended particulate matter (SPM) collected during the monsoon was determined to identify the sources of SPM and to understand the physicochemical processes in the Mandovi and Zuari river estuaries. The concentrations of SPM decrease seaward in both estuaries, but are relatively high at bay stations. Kaolinite is the most dominant clay mineral in the upstream of both rivers.