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Tenth Plan Activities and Achievements

During the 10 th Five Year Plan Period (2002-07), the following R&D projects were undertaken:

Marine Ecotoxicology

The Government have prescribed marine disposal standards for effluents arising from municipalities and a variety of industries. In order to ensure that the resultant seawater quality, as a result of discharge of these wastes is not detrimental to marine organisms, limits on the load of chemical and biological substances that will be disposed into the sea have to be set. These limits are often decided by prescribing safe limits of these chemicals to marine organisms. They are generally termed as Ambient Seawater Quality Standards. These standards vary from organism to organism and may vary for each type of habitat. In India, the Central Pollution Control Board (CPCB) has prescribed Primary Water Quality Criteria for different uses of seawater. They are for the basic parameters like dissolved oxygen, bacteria, and heavy metals for seawater in and around ecologically sensitive areas. These limits are based on expert opinions derived from conventional experiments. However, attempts are yet to be made to prescribe standards for harmful heavy metals, pesticides, etc. for other areas as they reach the marine environment through industrial and agricultural sources. To facilitate development of such standards using modern experimental techniques, the ICMAM-PD has launched a marine eco-toxicology project. The main objective of the project is to determine habitat specific water quality standards for heavy metals, pesticides, oil residues for coastal waters, estuaries and habitats like coral reefs to facilitate better management of water quality in these areas by the State Pollution Control Boards. The task is being carried out by ICMAM-PD, in association with Madurai Kamaraj University ( Madurai), ALM PGIBMS, University of Madras (Chennai) and Institute for Ocean Management, Anna University (Chennai). Experiments are conducted using various groups of animals ranging from planktonic larvae up to marine fishes under a continuous flow system (Fig. 9). Draft safe limits for copper,Cadmium and mercury based on results

obtained using 6 organisms have been determined. These values have been referred to the Central Pollution Control Board for notification

Ecosystem Modelling approach for Area Management

Recent experiences in studying the coastal and marine ecosystem revealed the need for a holistic approach to understand the bio-geomorphological changes that are prevalent in the ecosystem and the resultant impact on their productivity. In order to demonstrate the use of this concept for management of the ecosystem model, areas such as Vedaranyam lake (Tamil nadu), Chilka Lake (Orissa) and Kochi Backwaters (Kerala) have been selected. The project activities are being carried out by ICMAM-PD in association with Centre for Environmental Studies, Anna University (Chennai), Andhra University, Visakhapatnam (Andhra Pradesh), Chilka Lake Development Authority (Orissa) and Regional Centre, National Institute of Oceanography, Kochi (Kerala). Studies conducted jointly by ICMAM-PD and Central Environmental Studies, Anna University for nutrients and productivity at Vedaranyam Lagoon indicate low productivity despite favourable nutrient concentration which is as a result of turbidity. Increase of tidal flow through different options of opening new mouths were explored using computer based modeling techniques. It has been found that it would increase the tidal flow by 30cm, which would enrich the biomass and considerably reduce the turbidity to enhance the productivity of the lagoon. The suggestion has been communicated to the State Government for necessary action.

Hydrobiological investigations conducted at Chilka Lake to select a zone suitable for modelling resulted in the selection of middle zone for this purpose, as it shows dynamic changes in hydrological conditions. The results obtained indicated that the hydrodynamics especially inflow of the seawater has profound impact on biology and productivity of the lake. The project activities will be continued in the 11 th plan towards development of an Ecosystem model. Kochi backwaters, a zone opposite to Regional Centre, NIO, Kochi has been selected for modelling. Extensive data on tides, currents, nutrients and productivity have been collected during November 2003 and March 2004. Preliminary analysis of data has indicated preference of nitrate over ammonia for phytoplankton production. A water quality model has been developed to understand the quantitative relationship between hydrodynamics and the nutrient concentration and distribution. A preliminary biological model has been developed to determine the chlorophyll productivity against nutrient concentration. As the results desired demand development of Kochi backwaters specific coefficients on key parameters, they are being developed at present. The project will be continued during the 11 th plan for development of an Ecosystem model for the entire backwaters.

Shoreline Management

The developmental activities like construction of ports and harbours, shore protection measures, expansion of beaches for tourism activities etc., have caused changes in the geomorphology of the coastal areas, resulting in periodical erosion of the beaches and loss of human habitats like fishermen villages. These problems are prominent at most of the locations along the coasts of Kerala, Tamil Nadu, Andhra Pradesh, Karnataka, Orissa, West Bengal and Maharashtra. To begin with, these problems will be investigated at selected locations along Kerala (Kayamkulam to Munambam), Tamil Nadu (Ennore) and Orissa (Paradip) coasts. The problem of shoreline changes of Ennore coast is already described in the ICMAM Plan for Chennai

Shoreline management plan for Ennore coast

It is well known that the shoreline along Chennai coast is subjected to oscillations due to natural and man made activities. Impact of the construction of Ennore port, 16 km North of Chennai port, another erosion problem was emerged and details have already been mentioned under the ICMAM plan of Chennai . If, no intervention is planned, there will be a threat of erosion to the beaches of fishing village located north of the port

Since the available information on Ennore coast is not sufficient for working out suitable measures, a research project entitled “Shoreline Management along Ennore” was formulated to conduct detailed field and model investigations on various dynamical aspects (water level variations, currents & circulation, tides, waves, bathymetric variations, sediment transport, shoreline changes etc) of Ennore coast covering Ennore creek to Pulicat mouth. The objective of the project is to develop hindcast, nowcast and forecast models on shoreline changes in priority areas for identification of vulnerable areas of erosion/ accretion to arrive at remedial measures for protection of coastline from natural and human perturbations. After intensive field observations to estimate erosion (Fig.10) and modeling, a viable solution of deployment of submerged geotubes at a depth of 5 m has been suggested (Fig.11). The Ennore port authorities are in the process of implementing the solution.

Shoreline changes along the Orissa coast

Gahirmatha, an Internationally known nesting ground of Olive Ridley Turtles, is located about 20 km north of the Paradip Port. The nesting area extends approximately along 35-40 km stretch of the coastline Wheeler island (Fig.12) About 0.2 to 0.7 million Olive Ridley Turtles visit this beach during December - April for mass nesting every year. Rushikulya, about 25 km north of Gopalpur is another mass nesting site. The mass nesting occurs due to the availability of suitable nesting environment like sandy beaches, elevation, soil texture, presence of wetland, backwater and brackishwater and mangrove vegetation along the coasts. However, in the last 20 years, large-scale mortality and shifting of nesting ground towards north especially at Gahirmatha has been observed.

Preliminary observations made during the 9 th plan period indicate that the unique topography, shoreline, beach profile and sediment texture of this area are continuously changing. The beach width has been reported to be severely reduced due to erosion processes. The nesting area is also reported to be under serious threat from the erosion process.

The ICMAM-PD initiated a Shoreline Management programme for Orissa coast especially to study the nesting zones at Rushikulya and Gahirmatha with an aim to suggest measures for protection and development of the coastline to suit the nesting of turtles

Fig.12. Turtle mass nesting locations along the Orissa coast.

After 4 years of study in the area, especially measuring beach profiles at both the locations, it was found that the locations where mass nesting of turtles occur have distinct profiles of steep coast leading to berm, wide backshore, medium to large grain sized sands and lack of thick vegetation. It was also found that when these profiles change at these locations due to changes in sediment transport pattern or wave conditions, the turtles do not perform mass nesting. Few beach profiles showing these features are indicated below: (Fig.13). These results reveal that beach profiles and characteristics play an important role in the selection of sites for mass nesting by turtles. In order to clearly understand the causes of shoreline changes, project to study the coastal circulation pattern along the Gopalpur-Chilika and Paradip to Dhamra coasts which harbour both of the above turtle nesting sites has been developed by the Govt of Orissa with the help of ICMAM PD and the project has been submitted to the World bank for funding through the Ministry of Environment and Forests

Fig.12. Turtle mass nesting beach profile at Rushikulya and non-nesting beach profile at Gahirmatha

Shoreline management of Kerala coast

The Kerala coast experiences severe erosion and accretion, which has led to loss of several acres of coastal land and accretion at river mouths/creek mouths. This phenomena is more pronounced between Munambam and Kayamkulam stretch in the Kerala coast. In order to study the physical and geological processes that are responsible for causing erosion/accretion, a project was sanctioned to Centre for Earth Science Studies, Trivandrum. The project aimed to determine the extent of erosion and accretion along the stretch and also the areas more vulnerable for such damages. It suggested remedial measures like construction of T groins as shore protection measures at Kayankulam stretch after taking into consideration the effect of these structures on the adjoining stretches of the coastline in causing erosion/accretion

Coastal Engineering strategy for Shore Protection for Kerala -A Pilot Project

Different types of coastal protective measures have been implemented along the Kerala coast during the last sixty years. Of the various protective measures adopted so far, construction of seawalls is the most commonly used method. Various designs of seawall have been attempted along different stretches of the coast covering about 75% of Kerala’s coastline of about 570 km. In spite of this, erosion is continuing even at many locations that have been protected by seawalls. The maintenance cost is enormously high since the seawalls get damaged very often. One of the major concerns of the Government of Kerala in dealing with the issue of coastal erosion is the protection of the eroding “protected shorelines”. This pilot project is for developing an appropriate strategy and design for coastal protection along the Panathura coast. Centre for Earth Sciences Studies, Trivandrum and IIT Madras were involved in the project. After collecting field data and performing modeling, the project has suggested construction of T groins to protect the shore (Fig.14)

Fig.14. T-groins suggested as shore protection measure at Panathura

Management of Tidal inlets

Mangalore (Nethravathi river)

Historically, the Nethravathi river (Mangalore) inlet was of migrating nature leading to navigational hazards to fishing community and old Mangalore port since several decades. Two rubble mound breakwaters (river training jetties) were built during 1994 to guide the flow for safe navigability of fishing boats. Due to breakwaters, the migration of river mouth has stalled. But, it leaded to severe coastal erosion at south of south breakwater since 1996 during the monsoons. (Fig.15) . The site of erosion is a barrier spit over a length of 1.4 Km connected to main land at southern end. This erosion has potential threat during monsoon to open another mouth to which will lead to operational hazards for fishing community and old Mangalore port. State Govt. has implemented some solutions including rubble mound revetments and Gabion Revetments, which have not yielded useful results for shore protection in the lack of proper study of the coast. Therefore, a scientific understanding of the local coastal process around inlet was undertaken to investigate the cause of problem and to provide the technical solution for protecting the coastal erosion as well as to minimize adverse impact on adjacent coast. After performing modeling studies based on field measurements, construction of groins, submerged reefs etc were suggested ( Fig.16 ). The Central Water Commission is also exploring funding from the Asian Development Bank for implementing the solution.

Vellar Estuary

The inlet of Vellar estuary, Tamilnadu located south of Cuddalore faces siltation during non-monsoon months. Due to narrow mouth, the fishing vessels are unable to navigate inside the estuary. As a result these vessels anchored nearby fishing harbours posing enormous hardship to fishing community. An extensive study was conducted by ICMAM PD and IIT Madras. It has suggested dredging as the only viable option to keep the mouth open, as the other alternatives such as training jetties will cause severe erosion on the northern side of the mouth.