The Vembanad Lake (also known as the Cochin backwaters), which constitute the second largest wetlands in India, is one of the most productive ecosystems. It also sustains a large variety of fishery and is a cradle for many economically important migratory species. The evolutionary history of this region shows that Vembanad Lake plays an important role in the ecology and economy of the southwest coast of India. The remote forcing of the lake, influencing the formation of mud banks and other coastal processes invite scientific curiosity in characterizing the behavior of the lake with respect to physical and chemical properties and, the associated biological productivity.

The Vembanad Lake is presently undergoing severe environmental degradation due to increased human intervention. Recognizing the socio-economic importance of this water body, it has recently been scheduled under “vulnerable wetlands to be protected” (Ramsar site no.1214). The anthropogenic influence in the Cochin backwaters increased in the second half of 19th century and remains high to the present day. The construction of salinity barriers in the upstream of the estuary to support agricultural activities during 1970’s further deteriorated the situation, resulting in diminished flushing and increased sedimentation. Likewise, issues related to the health of the estuary and its capacity to withstand such interventions have become prominent.

Work Plan:

a) Approach:

1. Long-term environmental data collection (physical, chemical, microbial and biological) from the selected locations in the Vembanad Lake on a monthly basis and from  adjacent near shore region on a seasonal basis.
2. Preparation of a digitized map of the study region including bathymetry
3. Development of a hydrodynamic model for the Vembanad Lake.
4. Development of a water quality model for the Vembanad Lake.
5. Development of an ecosystem model for the Vembanad Lake.

b) Work Module:

• Preparation of digitized map for the study region (Vembanad Lake)
  • Shoreline mapping and bathymetry
  • Sediment texture
  • Estimation of nutrient loading in to the lake from rivers, seepage from   domestic sector, agricultural and aquaculture fields, industries and other anthropogenic activities on an annual basis using terrestrial model.
• Development of a hydrodynamic model to the Vembanad Lake
  • Time-series measurements of tides, currents, temperature, salinity and suspended materials at selected stations in the lake.
  • Harmonic analysis of tide data to derive constituents
  • Development, calibration and validation of the hydrodynamic model
• Development of a Water Quality Model
  • Data from the above locations for different chemical (nutrients), microbial (bacteria) and biological (nano and micro plankton) parameters.
  • Development and calibration of a 2D water quality model constituting of four interacting systems: oxygen, nitrogen, phosphorus and carbon
  • Input data for the model,  Dissolved oxygen, Phytoplankton, CBOD, NH4-N, NO3-N, PO4-P, DOP, DON
  • Benthic production and sediment-water interaction (benthic chamber experiments).
  • Carbon biogeochemistry (DIC, DOC, pCO2, POC, SOC).
  • Estimation of different environmental coefficients by experiments in the field and in the laboratory.
• Development of Ecosystem Model
  • Micro and meso zooplankton – Species diversity, seasonal abundance and distribution
  • Growth/grazing experiments for micro/meso zooplankton
  • Extension of the WQ model by including the standing stock, growth rate,
  • feeding, respiration and mortality rates to predict meso zooplankton abundance (copepod).
  • Develop an ecosystem model predicting the abundance of mesozooplankton (copepod) in the lake