Input-export fluxes of heavy metals in the Cochin estuary, southwest coast of India.

Cochin estuary (CE) is one of the largest tropical estuaries along the southwest coast of India, sustaining rich bio-resources. Several studies enlighten the environmental changes in the CE caused by anthropogenic activities. In the present study, an attempt has been made to quantify the heavy metal (dissolved and particulate) fluxes brought by the six rivers into the CE with their exchange into the coastal ocean through the major inlet at Cochin during a steady flow period (October-November 2015).

Seasonal spreading and transport of buoyant plumes in the shelf off Kochi, South west coast of India- A modeling approach.

We investigated the seasonal spreading and transport of buoyant plume in the shelf off Kochi using Finite Volume Community Ocean Model (FVCOM). The modelled river plume typically consisted of an offshore bulge and a coastal current. The spreading of the bulge extended up to a distance of 19 km from inlet during the summer monsoon to <10 km in the spring inter-monsoon.

Spatio-temporal variability in macrobenthic communities and trophic structure of a tropical estuary and its adjacent coastal waters.

Spatio-temporal distribution of the macrobenthic community (> 500 μm) and the trophic ecology of polychaetes were studied for a year in the Cochin estuary (CE) and its adjacent coastal waters. A profound influence of the southwest monsoon (SWM) was evident in the CE, a tropical monsoonal estuary, during the present study. The sediment texture and macrobenthic density exhibited a pronounced spatial variation in the estuary, while in the coastal waters temporal changes were more prominent.

Residual fluxes of water and nutrient transport through the main inlet of a tropical estuary, Cochin estuary, West Coast, India.

Determining robust values for estuarine material fluxes has been a complex task and an interdisciplinary research challenge. With the advent of acoustic Doppler profilers (ADPs) having bottom-track capability and which provides three-dimensional current velocity profiles, more accurate estimation of cross-sectional fluxes is far accomplished in unsteady and bidirectional flow conditions of estuaries. This paper reports for the first time the discharge measurements conducted across Cochin inlet using ADP to examine the spring-neap variability in residual fluxes of water and nutrients during dry season.

Mesoscale process-induced variation of the West India Coastal Current during the winter monsoon.

This manuscript presents the analysis of current meter records at Kollam and Kannur along the 20-m isobaths during November-December 2005. Currents in the coastal waters are strongly influenced by winds (both local and remote forcing), tides, propagation of coastal Kelvin and Rossby waves, etc. We hypothesize that the mesoscale (spatial scales of 10-500 km and temporal scale of 10-100 days) features in ocean are also competent to alter the characteristics of coastal currents to a large extent.

A comparative study on mesozooplankton abundance and diversity between a protected and an unprotected coastal area of Andaman Islands.

The study was carried out to understand the variability in phytoplankton production (Chlorophyll a) and mesozooplankton diversity from two different shallow coastal regions of south Andaman viz. Port Blair Bay (PBB), the only real urban area among the islands and Mahatma Gandhi Marine National Park, a Marine Protected Area (MPA) at Wandoor. Seasonal sampling was carried out during the Northeast monsoon (NEM--November 2005), Intermonsoon (IM--April 2006), and Southwest monsoon (SWM--August 2006).

Impact of eutrophication on the occurrence of Trichodesmium in the Cochin backwaters, the largest estuary along the west coast of India.

Phytoplankton studies in early 1970s have shown the annual dominance of diatoms and a seasonal abundance of Trichodesmium in the lower reaches of the Cochin backwaters (CBW) and adjacent coastal Arabian Sea during the pre-summer monsoon period (February to May). Surprisingly, more recent literature shows a complete absence of Trichodesmium in the CBW after 1975 even though their seasonal occurrence in the adjacent coastal Arabian Sea continued without much change. In order to understand this important ecological feature, we analyzed the long-term water quality data (1965-2005) from the lower reaches of the CBW.

Mesozooplankton distribution near an active volcanic island in the Andaman Sea (Barren Island).

The study addresses the distribution and diversity of mesozooplankton near the active volcano-Barren Island (Andaman Sea) in the context of persistent volcanic signature and warm air pool existing for the last few months. Sampling was done from the stations along the west and east side of the volcano up to a depth of 1,000 m during the inter monsoon (April) of 2006. Existence of feeble warm air pool was noticed around the Island (Atm.

Recovery of an estuary in the southwest coast of India from tsunami impacts.

Water quality in the Cochin Estuary, southwest coast of India during the tsunami attack was assessed and compared with the pre and post tsunami characteristics. From the results obtained, it is evident that a drastic change in hydrography has been inflicted by the energy transferred through the tsunami, which disturbed the entire estuarine embayment. However, the post tsunami water quality showed normal levels indicating that the region has recovered from the tsunami impacts.