REJUVENATION OF LAGOONS ALONG THE EAST COAST OF INDIA, MANAGEMENT: ANTHROPOCENE APPROACH.

drift and the paucity of sediment inflow to deltas. Present study envisages about lagoons, its classification, a comparative study of major lagoons along the east coast of India in changing CC, SLR and seismic activities as ESS unit. The causes, effects and ameliorating measures to combat 21 st -century natural and anthropogenic scenario of lagoons are analysed.


ISSN: 2320-5407
Int. J. Adv. Res. 7(1), 688-714 690 According to morphology, topography, the lagoon can be estuarine lagoon and coastal lagoon . Estuary lagoon: is partially bounded deep coastal form of brackish water with faster inland flow from drainage channels/rivers with only one inlet to open sea with least residence time. Lagoons are wetlands whose major axis is generally coast parallel, shallow, brackish, with sluggish water exchange, and separated from ocean or bay by a spit or reefs with a higher resident time. These lagoons are formed during mid-Holocene sea level rise (≈5000 to 6000 years BP) in gentle sloping, progradation coasts during marine transgression (either submergence or emergence) where the tidal amplitude of adjacent ocean system is 2m-4m Kejerf B 1986 [4] , and 94 [5] . In addition there are saline coastal marshes consisting of prawn aquaculture ponds, potholes, part of past tidal channels and rotten spots in the rims which were included in lagoon in past and are formed due to episodic events like erosion, subsidence, biological processes or anthropogenic acts Miller al al., 1950 [6] ; Mariotti et al 2013 7 ; Schepers et al. 2017 [9] . Miththapala S., 2013 [3] classified lagoons based on water balance (positive, inverse and low inflow), based on geomorphology (coastal plains, a barrier built and tectonic estuaries) and based on stratigraphy (Salt wedge, strongly stratified, weakly stratified and vertically mixed). Koleru, Bendi, Nizmabad, Mundel, RekawaLagoon (Sri Lanka), the Song khla Lake in Thailand, Lagoa dos Patos, de Ara ruama Brazil, Fosu (Ghana) Lagoo Lake St. Lucia (South Africa), Lake Nokoue, Benin, Coorong (Aust ralia), Songkla Lake (Thailand) One shallow inlet, Diffusion only, No tidal current and less water level change (high-density gradient to low-density gradient, wind circulation, Long residence time, Tidal Sway reduced by 5%, May become saline or hypersaline arid/ or subarids.
non-estuarine river-mouth lagoons (hapua) near sea-river interface of a river estuary by a storm spit (usually seasonal and breaching of spit occr they are in low or spasmodic rainfall region.

Global scenario of lagoons:
Wetlands contribute 45% of the globe's productivity and its contribution to the ecosystem is estimated to be 20 trillion dollars, wetland atlas 2012 [11] . The lagoons are universal wetlands in the globe along with the coastline from tropics to poles but the numbers are less in higher latitudes. The percentage of the lagoonal system of the continent vs. the world statistics are Africa (17.9%, & 18.7%), North America (17.6%, & 33.6%) , Asia (13.8%, & 22.2%), South America (12.2%, & 10.3%), Australia (11.4%, & 6.8%) Europe -(5.3% & 8.4%) Barnes R. S. K., 2010 [12] . The gulf coast of America is the longest lagoon with the length of 2800km. New Caledonia, situated in South Pacific is the largest saline/brackish water lagoon followed by the Great Barrier Reef, Australia. The New Caledonia lagoon have water spread area of 23,000 Km 2 with ≈ 9000 IUCN identified with rare/endemic species within six marine clusters. Some prominent freshwater lagoons are Murray mouth Lagoon, Australia, Kalametiya lagoon, southern Sri Lanka. The brackish coastal lagoons are Chilika Lake, India, Jubho Lagoon, Sindh, Pakistan and 691 Bundala lagoon in southern Srilanka. The hypersaline lagoons are Mundel Lagoon, Sri Lanka, Coorong, South Australia, and Laguna Madre, USA, and Hapua, New Zealand. Sri Lanka, a small island has a number of lagoons (8 lagoons >100ha and total 89Ha) comprising of area 7589 Ha ranging from 3ha to 1000ha in its south, southeast and east coast where there is less inland drainage Balsurya A., 2018 [13] .

Review of literature
Hutton James, 1788 [14] reported that the earth is unstable and transactions are continuous due to the interaction of geologic, biologic activities and biogeochemical evolutions. These evolutions manifest in form of different physical ecosystems including the lagoons. Depending upon their characteristics, lagoons can be classified as estuarine, intermittently closed and open lagoons (ICOLs) and closed Nicholas et al., 1981 [15] . The other compartmentalization made by Kjerfve B, 1994 [5] was leaky, restricted and choked.
The climate was warm, dry and drought situation was prevailing in ancient India from 2000yrs BP to 3500years BP (fall of Harappan civilization). From 3500yrs BP to 5000 years BP monsoon was strong, dry and warm (>approximately present). The sea level changed 6m lower than the present level whereas during post-Younger Dryas period i.e. 5000yrs to 9000yrs the monsoon activities were very strong and the MSL was 40m lower than the Anthropocene period. Since the last 1200 years, India has witnessed sea level rise (2mtrs), including changes in vegetation and climate whereas Naidu P.D. 1999 [16] , Mishra et. al., 2018 [17] . coastal areas are thickly populated, vulnerable to major landfills of the earth. Woodroffe et al 2005 [16] mentioned about the discrepancy of formation age, timing and degree of the MHHS (Mid-Holocene High Stand) and the characteristics of post-Holocene sea level fall which favored formation of lagoons. Clark et al., 1978 [97] recognized 6 sea-level historical patterns/ proxies along coastline either emerged or submerged, or both in transitional regions. The sea-level curve, which proposes two Holocene high stands at 5000 and 2800, 14C yrs BP and Woodroffe et al, 2005 [18] mentioned from microfossil records about an MHHS after 3000 BP (14C yrs) of at least 0.5 m. Lagoons (from Italian word Laguna) are larger brackish water bodies separated from sea or bay or gulfs by a spit made of sandbars, coral reefs, barrier reefs, or other natural/artificial barriers (Kennish et al., 2010 [20] ; Kjerfve, 1986 [4] &1994 [5] . Ponton et al., 2012 [21] have mentioned the act of aridification and salinization in Bay of Bengal between 3000 to 1700 years BP.
The beach profile, an effective natural mechanism, causes the wave to break and dissipate their energy. The shoreline change occurs when breakwaters upset the natural equilibrium between beach sediment and the littoral drift pattern confirming a new equilibrium,   [22] . One of the causes are XENs (xeno-ecological niches due to landfills, urban population, industrial activity, mining, and farmland) have altered the ecosystem in last few decades from 1900 (300 KT/day to 3 Gigatons [Gt] /day in 2012 and may increase to 6 GT by 2050 Hoornweg et al., 2013 [23] . Tamil Nadu coast has more accretion during the Dec Tsunami 2004 so that the coastal sand has increased to 34.24% from 32.31% and the water bodies reduced from 49.66% to 45.83% indicating the estuaries and the lagoons along TN coast is reducing in dimension. The Chilika barrier spit (south Odisha coast) has increased the number of tidal inlets and the water spread area has increased after the Tsunami 2004 Mishra et al 2017 [24] . Odisha has 480Km coastline out of which sandy (57%), muddy (33%), marshy (10%) and have least rock coastline and having water depth 10m-15m in the offshore region and longshore sediment transport @ 997594m3/year Sanil Kumar et al., 2006 [25] .
The east coast of India is vulnerable to rise in MSL @ 0.76mm / year (Visakhapatnam) and shall submerge the coastline due to large storms striking the coast and flat continental slope Shetye et. al.,1990 [26] Unnikrishnan et al 2008 [27] . During the pre-Holocene epoch (11700 to 7000 years BP), continental shelves remained dry during the last glaciation and became flooded in mid-Holocene owing to heavy rainfall. The inundation filled up the coastal low lands, modification of sedimentary landforms and eroded some topographic highs which resulted in the formation of the sand barriers along the coastal front and finally the lagoons Davis et al., 2004 [28] .
The end Holocene epoch (≈11700 years old) was reported and commencement of the Anthropocene epoch was unofficially declared by Cruzen-2000 [29] and, Crutzen et. al., 2002 [30] . Addition of the Anthropocene epoch to global time scale is under research in full swing after a first atomic explosion, 1945, Zalasiewicz et al 2008 [31] , 2017 [32] , 2018 [33] . Some researchers claiming to establish the truth that both the epochs are coeval Elis et al, 2016 [34] and 2018 [35] , Kluiving et al 2016 [36] and the new epoch is yet to be officially stamped.

Reasons for study:
The study is undertaken to analyze the impact of anthropogenic interventions on the lake/lagoon dimensions and characteristics, land use and land cover of the catchment, the pollution rate, salinity, inland flow etc during great acceleration period of the Anthropocene Epoch. The study also highlights the significant changes in biodiversity and ecosystem associated with anthropogenic activities including sensitive issue of degradation of the panoramic lagoons along the east coast of India.

Lagoon characteristics and classifications:
The coastal lagoons are generally formed, maintained and sustained by transported sediment and do not feature in high tide coastal zones (amp>4m) and in steep and rocky coasts. The coastal lagoons become swampy when sea level is low but become sandy and look like a lost bay/gulf at high MSL. The salinity designates the lagoon as freshwater (<0.5%PPT), brackish (0.5% to 30% PPT), saline (30% to 50% PPT) and hypersaline (.50% PPT) depending upon evaporation rate and the basin soil, Miththapala, S., 2013 [3] .
For lagoon characteristics, the Roseby Number ( ) is negligible, https://upcommons.upc. (edu/bitstream) /handle /2099.1/3409/41241-9.pdf The Coriolis force ( F 0 = 2 sin φ where is angular velocity of earth= 7.29 x 10 -5 rad/ sec and φ is the value of Latitude, zero at pole and increases with latitude, which influence the flow direction entering the lagoon and the river mouths, currents to squeeze the right shore line in Northern hemisphere, Poincare waves (oscilatory huge waves of large wave lengths in large lagoons), seiches and shoreline parallel currents and waves (Kelvin waves) Cohen A. S. 2003 [37] , Mishra et al 2016 [38] . The Richardson number ( ) where gravity (g), density (ρ), Angular vel. ( , and Q influx and Velocity (U) which determine the turbidity and density of saline water inside a lagoon (For well vertical mixing the .value is 0.07. The parameters showing morphology of the lagoons is governed by factors in Table 2.  [40] , Benoît .et. [41] al., 2007 Camenon et [42] [51] stated India has drifted away from East Antarctica at the knee-fold lengthways along the east coast, (bight) along NE-SW ridge of Krishna-Godavari Basin and formation related to the Kolleru and the Pulikat lake. But the Chilika Lake was formed as a separate block not related with Mahanadi delta and EGB hills as result of Mesozoic tectonic activities. The Chilika lagoon and a part of SMD were attached to EGB-Rayner block during 694 Indo-Antarctic collision. The Rodania assembly, moving south, collided with Western Australia was a part of EGB-Rayner Block or localized reworking of late Neo-proterozoic-Cambrian event gave rise to Chilika, Chatterjee N., 2008 [52] , Das et al 2012 [635] and Gupta S., 2012 [54] , Mishra et al., 2015 [55] .
The Indian coast is based upon on a plate with the firm base but it consists of variable landform due to storm, swale wave environment, and inland sediment, Sujib Kar, 2018 [39] . Lagoons formed along the EC of India are within sandwiched areas between the EGB Hills and the 85 0 Ridge in the Bay of Bengal, (BoB). The interspace between BoB and EGB hills is occupied by six major large deltas whose apex is extending up to130Km inland formed by east flowing rivers.
These rivers are the Subarnarekha, the river system of Mahanadi tri delta, the Vansadhara, the Godavari, the Krishna, the Pennar, the Cauvery, the Bhaigai and many small rivers. Mostly small river estuaries have lagoons/wetlands for its monsoon flood absorption as the rivers are ephemeral and longshore drift deplete the estuary depth during nonmonsoon. The lagoons/wetlands cover three states i.e. Odisha, Andhra Pradesh (AP) and Tamil [56] . The increase in coastline substantiates more inundation of marginal marine zone and favoring formation of more lagoons, backwaters and bays in low lying areas along the east coast in near future. The states with a high rate of erosion vulnerability along the EC of India are 63% of West Bengal, 57% of Pondicherry and 41% of Tamil Nadu coasts respectively. Odisha coast has been expanded by 50% during 1990 to 2016 (CWC report, GOI, Dec 2016, P-7) [56] .

Lagoons along East Coast of India:
The major lagoons along mainland EC, India are the Chilika, Bemdi, Kolleru, Nizamapatnam, Pennar, Pulikat, Mutukadu, Puducherry, Kaliveli, Muthupet, and Gulf of Mannar lagoons. The lagoons along western coast are Astamudi, paravur, Vembanad, Astamudi, Paravur, Murukmpuzha, Ettikulam, Velli, Talapady and many small lagoons along Bombay coast, Gujarat, Diu, and Lagoons of Lakshadweep.  [57] . Erosion and accretion of coastal landforms are continuous processes. India has 10204 natural coastal wetlands spread over areas of 37039.71Km 2 and 2829 numbers of manmade coastal wetlands with 4361.45Km 2 . Out of 178 numbers (area 2460.44 Km 2 ) natural lagoons along the coastal tract of east and west coast of India, only 17 lagoons are major and rest are of small and of less importance (source: National Wetland Atlas) http://www.iomenvis. in/pdf docu ments/COP11_BOOK_Final.pdf. There are thousands of lagoons having area <1Ha to > 10000Km 2 but average size for consideration of a lagoon is >80Km 2 (median size), Barnes R. S. K., 2001 [12] .
The transformations of Hukitola Bay (Fig-3) and Kakinada Bay formations are similar in nature. The configuration indicates the barrier Island is getting stabilized from the southern fringe. There are continuous making and breaking of the barrier islands along the coast to close the concave intrusion of the sea to the mainland. The Palk bay is different as it is a straight separator between Arabian Sea and Bay of Bengal (The Ram Setu or Adam's Bridge).
The characteristics of lagoons of EC of India has steep sea bed slope (Except Chilika lagoon), the short continental shelf of 20Km, low tidal range (1m to 4.5m), beach consists of fine yellow sand (red sand south TN) and large mud flats. Very high net littoral sediment flow to the north (0.5 MMT at Pulikat and Iskapalli lagoons to 1.5MMT Kolleru lake and Chilika (1.0MMT). The coasts of the lagoons encounter BoB disturbances (CS, SCS, VSCS and supper cyclones) frequently and over washed by Tsunamis in December 2004. Physical features of three major lagoons such as Chilika, Koleru, and Pulikat is submitted as under Table -3:  [69] , Saraswathi et al 2016 [70] Chilika lagoon (Ramsar site 229): The Chilika, Odisha is the largest coastal lagoon in India, (Ramsar site 229) is a shallow, brackish, pear-shaped lagoon lying parallel to shore. Though a gulf in past,the lacustrine area of the Chilika has reduced from maximum 1165km2 and minimum 906 km2 in 1950s to present av. area max. ≈1011 to minimum ≈770 Km2, in 2012) Sterling A. 1846 [65] , Mishra S. P. 2016 [71] . The coastal length has been reduced from 70.81 km to ≈63.4 km, max width from 32.2 km to ≈20 km. The lagoon consists of Northern sector (shallow marshy land), Central sector (Breeding ground for aqua habitats and freshwater flow), Southern sector (Stable and deep) and the outer channel with isles and tidal inlets for hydrodynamic activities. Towards south, a canal (Palur) is running which discharges to Bay via the Rushikulya river. The NS, CS, SS, and OC had depth ranges between 0.5 and 1.5m, 1 to 2.5 m, 2.5 and 4.0 m 2.5 and 5.5 m. respectively. The shallow lagoon has av. depth ≈1.5m in 2015, Mohanty et al., 2015 [72] , and Wikipedia. During monsoon and non-monsoon periods, there is a maximum tidal variation of 1.15m at Sipakuda. A dynamic parallel barrier spit towards the north of sandy ridges is extending ≈32Km of av. width 100 m towards the north, and 1500m in southern coast Panda et al 2012 [73] . The spatial and human changes of 3 major lagoons are in Table -4    The present shallow freshwater swampy/ marshy lake, Kolleru in AP, formed as a coastal lagoon in past (>6000 yrs BP). Kolleru was no longer a lagoon but a lake which is of area 180.19 km2 water spread area and 645.9Km2 covered by pisciculture ponds Fig 4. The loss of lake area was 109km2 between 1967 and 2004 (37yrs) and major loss was due to the conversion of 100≈Km2 from the lake to pisciculture ponds. Present water spread area is ≈308 Km2 (variable), width (10Km) and maximum depth of 3m with numerous parallel beach ridges between 1st (adjacent to Bantumilli village) and the third strand line (Peddapalem and Uralagonditippa villages) with a narrow channel, 70 km2 spread of marine water body called Goguleru Creek and series of relict sandbars Vijayalakshmi et al 2018 [74] . A marshy land of 135Km2 is found around the Upputeru river with beach ridges Eruva Mamata, 2009 [75] . With periodic coastal changes, the Koleru Lake and Gallery creek (Lagoon) lies in the third strand line.   [76] have reported that the endorheic Pulikat lagoon with brackish water has been reduced to av. area ≈300km 2 and av. depth reduced to 1.0m. At present, the shallowest region is Arambakkam jetty and Veynadu Island has depth 0.2m. The water spread area has been reduced from 691. 54 [77] . The lagoon is polluted by the inflow of sewage by Buckingham canal of Ennore city. The average sedimentation rate of the lagoon is ≈1.23 cm/ yr (≈ 1.2 m/Century Ramesh et al 2002 [78] .  (Fig 7). The small brackish water area is between the Vansadhara and Nagavali estuaries palaeontological society.in/vol 35/v4.pdf.The salinity varies from 26ppt to 39.5pptThis tropical high Temp is favorable for the assemblage of low diversity ammonia group of benthic formanifera mostly in winter reported by John Murray in the book -Ecology and applications in Benthic Foraminifera, 1988.

Nizampatnam Lagoon:
Nizampatnam lagoon is backwater of length ≈17 Km and of area 1825 Km2 situated in the south of Krishna delta (Fig 8) and Gundlakama, Romper and Upputeru rivers are feeding to the backwater. The depth varies seasonally from 8m to 15m and the coast is having wave amplitude 1m-1.75m. Holocene transgression followed by progradation is the cause of formation of the stripped lagoon Rao P. S. et al 1990 [79] . The lagoon was an active port in 12th-13th century AD but became nonfunctional due to sediment carried to the lagoon from Krishna delta. Nizampatnam lagoon and its periphery are occupied by mudflats/ beach ridges (224 km 2) , mangroves and backwater (289km 2 ) which is vanishing gradually by erosion in the 21 st century, Ch. Anil Babu et al, 2015 [80] . of Iskapalli, Kurru, and Ponapudi. The lagoon is of Holocene origin (1720 to 2043yrs) is fed by a small river 22Km long Pailderu river and the barrier spit island is Kuratipalem. The lagoon was ≈10 Km2 spread, ≈8 km long and ≈2.5 km wide is of Holocene evolution, U-shaped, circumscribing the Kuratipalem Island with the inland source a drainage rivulet of 22km length Raiders. The lagoon was much wider and extended in past and squeezed at present Seetharamaiah et al 2005 [81] . (Fig-8)

Kaliveli Lagoon
Numbers of coastal water bodies are in Puducherry Union Territory and some of the important lakes like Ousteri Lake and Pondicherry lagoons are connected with Chunnabar River in Tamil Nadu. Kalivelli lagoon (lat. 120 05' to 120 15' N and Long 790 59' to 800 15' E) is located at Marakkanam in the estuary of the Yada-yanthittu river and, 18Km from Pondicherry spreading over an area of 68km2 and TI is at Yedayanthittu estuary opening to BoB near UPPUKali creek. The seasonal brackish water dying lagoon in Coromondal coast, Villupuram district of Tamilnadu and a breeding ground and shelter for ≈20000 birds in winter. The Kaliveli backwater is 2.5 km long and of width 370 m. The pH varies from 6 .95 to 10.11 and salinity 4.27 to 35.5 ppt. Since last 1980, the marshland near the mouth has been converted to salt pans and the shallow lagoon has been encroached for prawn farming and the existence of lagoon is under threat Silambarasan et al, 2017 [99] (Fig 09) BOB (Fig 10) is a shallow estuarine water body of 0.87Km2, of total length 20Km bifurcated in N-S direction after length 3Km, width 800m-1500m, and average depth 1-2m situated in Kanchipuram Dist. of Tamil Nadu having salinity 22.67 to 48.40ppt. with two TI's one dredged and other natural Bharathi et al 2012 [82] , Manakadan R. 2014 [83] Vasudevan et al 2015 [84] , http:// www. Sipcot cuddalore .com/ downloads /cheyyur_power_plant _ 701

Muthupet Lagoon:
The Muthupet lagoon (lat. 100 20' N and Long 790 35') is located in near Cauvery delta within it's five distributaries, in Tiruvarur Dist. of Tamil Nadu (Fig 12) and is the estuary of Muthupetai river covering an area of 13.32Km2 width 1km, depth 0.3 -1.2m and tidal amplitude 0.15-0.3m and the volume of water stored 9.6 x 103 Cum and repletion period (τ) is 1.4days (Fig 11). The TIs opens to Palk Bay. The shallow lagoon has av. the depth of 1m and famous nursery area of Oysters and nursery for marine aquafauna, a shelter for arctic avifauna Khan et al 2013 [86] , Rao N. R., 2016 [87] . The Physicochemical character of the lagoon is pH (8.   Fig -12. The marine seascape is of 10 km band 364.9 Km of coastal landscape of area 10,500 Km2 in Ramanathapuram, Tirunelveli, Tuticorin, and Kanyakumari districts. The Gulf cum lagoon is fed by Vaippar, Gundar, Palar, Kottakkarai Rivers from WGB Hills. The islands vary from 0.25 Ha to 130 Ha with total area 6.23Km 2 with coral reefs around the offshore of islands covered by the sand and vegetation. Mannar Island is the largest area of 126.46 Km 2 . It is connected to the main island of Ceylon Anthony Raj 2013 [88] .

Issues related to lagoons in future perspectives:
The change in the characteristics of a lagoon may be due to natural and anthropogenic factors. The natural factor like climate change plays pivotal role along with phenomena like global warming, MSL rise, wind, tide and calamities like drought, flooding, earth quake, and volcanic eruptions. The anthropogenic causes are inland hydraulic structures resulting in sediment paucity, coastal infrastructures, beach deforestation, demographic urbanization, industrialization, and pollution. Anthropogenic pressure at regional scale, like increase in CO2, GHG emission and deforestation, increased global warming (large-scale ice melt), being aggravated by human actions at the global, regional and local scales and resulting in increasing water spread area of the earth and inducing coastal erosion Tessler et al., 2017 [89] , Lageweg et. al., 2017 [90] , Dornbusch, 2017 [91] Earth System Science (ESS) Earth system science (ESS) is solicitation of earth as a system of science related to cryo, pedo and magnetosphere along with Atmosphere, Geo, Hydro, Biosphere (adding anthroposphere) of the earth using the principle of Uniformitarianism (There are inviolable laws of nature that have not changed in the course of time), the Steno´s Four Stratigraphic Laws for Sedimentary Rocks and Actualism (The Present is the Key to the Past) Johnson et al, 1997 [92] . ESS is the combination of astronomy, geology, meteorology and oceanography. The volcanic and seismic activities of Indian Ocean can correlate the ENSO, monsoon, Bay disturbances and Tsunami activities that affect the East coast, the thalassian/the coastal lagoons. It is used to predict vagaries of future meteorological hazards, climate changes and the natural hazards occurring on the globe. Based on stresses imposed on the Geosphere-Biosphere Programme (IGBP), Committee National Research Council (NRC) and the earth system framework, NASA introduced study of the Earth System Science (in 1987) apply ESS to develop prediction system using complex computational methods such as remote sensing, GIS, Cloud and global databases technology to diagnose hominids as the basic transcendent species of the Earth systems. ESS studies have the objective to comprehend the changes occurring on Earth and the impact on life and developing public indulgence in researches on the issue using NASA aerospace tools, research, and exploration missions https://notendur.hi.is/oi/Historical %20Geology%20pdf/1-,

Global warming and Sea level rise:
Sun-earth geometry regulates the climate change but global warming can be natural or an offspring of the anthropogenic carbon emission. Global warming is the long term warming continuous processes of our earth and world's surface temp. was estimated as increased 0.74 ± 0.18 °C during the 20th century changed the Global sea level rise (GSLR) and regional (RSLR). To address climate, the RSLR along the east coast of India associated with borehole studies reveals that paleo shoreline was at Kanuru from 8420 to 8300 yrs BP which is now 4 to 5Km from the present shoreline Udaykumar P. 2014 [93] (Fig-13 Northern hemisphere average MSLR

Current anomalies related to SLR:
Coastal landform along East Coast India was cyclic (either prograding or eroding or temporarily stable). Satellite observations, however, show that since 1993, the sea level has been increasing at a rate of approximately 3 mm/yr, which is significantly higher than the increase before fifty years. GSLR in the 20th century measured ≈170 mm Bindoff et al. 2007 [94] and predicted to rise exponentially in the 21st century due to rise in SST and upper air temperatures shall continue inducing GSLR to 50-140mm by2050 and 60-330mm by 2100 above the reference year 703 1990, Rahmstorf 2007 [95] . Indian coastline is 34% erosional, 28% depositional inclusive EC of India. The present status of coastline >40% erosion of EC India is West Bengal (63%), Pondicherry (57%), and Tamil Nadu (41% Due to MSLR/RSLR, the lagoon barriers retreat landward and will make the spits steep and narrow and shorter in length and shall affect lagoon-sea exchange. This will make the spit vulnerable to breaching and leading to the formation of more inlets. More inland floods shall affect the flushing frequency and increase in salinity. The ecosystem shall change with species variety due to change of nutrition and contaminations shall lead to eutrophication, nutrient imbalance, and its associated adversities.

Temperature
The temperature study for past 100 yr, global av. SAT has raised by 0.76 °C and is predicted to rise further by more 1.1-6.4 °C by end of 21st century (IPCC report, 2007 [103] & 2013 [104] ). Anthropogenic activities have increased the average temperature towards the fag end of 20 th century and early 21st century, Ring et al 2015 [105] . SST rise shall vary regionally/ sporadically and will be moderated by normal climate deviation, Smith et al. 2011, The greatest warming is expected to occur at high latitudes in winter (IPCC 2007 [103] ). 2°C rise in the average maximum temperature can have dangerous carbon sequestration but it shall be catastrophic when it is projected to 4.0 0 C rise Angus Ian 2015 [106] . Surface Air Temperature (SAT) and Sea Surface Temperature (SST) affect the shallow water bodies and slow-moving water. The rate of SST and SAT anomalies are reflected to change in air temperature strongly which influence the water temperature of slow-moving, shallow water bodies such as coastal lagoons. The carbon sequencetion has been increased which is increasing the SST by 0.3 °C and is likely to continue to increase through the next century (IPCC 2007 [103] ). Long-term data for temperature of coastal lagoons water is unavailable, yet it can be presumed that the shallowness and low flushing rates of coastal lagoons shall store more energy within and the water temperatures shall increase and depletion of DO shall occur affecting species grow in lagoons and estuaries Woodward 1987 [18] , Turner 2003 [107] . Particularly the restricted lagoons with low flushing rates and high nutrient inputs like lagoons of EC India may exhibit hypoxic events and change the species composition D'Avanzo et al, 1994 [108] . 704

Precipitation
There will be an increase in events of extreme rainfall Guhathakurta et al 2008 [109] , along Odisha and Andhra Pradesh coast causing a change in drought-flood cycles, more ET, change in GWT and soil moisture along EC India. The effects of increased rainfall shall increase runoff, include the increased delivery of sediment and nutrients to lagoons Orpin et al. 1999 [110] . Increased nutrient inputs may accelerate the eutrophication of lagoons, especially those with low flushing rates with sea level rise, turbidity will reduce. Light penetration and the photosynthetic activity of submerged aquatic vegetation in shallow lagoons compound the risk of eutrophication as highly nutrient Loret et al. 2008 [111] . In addition, reduced light penetration can inhibit the feeding ability of visual predators Horppila et al. 2004 [112] . Pre-monsoon trend in rainfall and rainy days events along the EC, India (!951 to 2011) exhibits an increasing trend in TN and south Andhra coast whereas there is a decreasing trend in rainfall in rest of east coast lagoon catchments Jain et al., 2012 [113] , Mohapatra et al, 2006 [114] . The heavy rainfall events have increased due to increased low-pressure events (Storms, trough lines and westerly's). There shall be more flushing flows to the lagoons in EC India and fluctuate cyclic salinity of the lagoons and outflux of the aquatic vegetation and maintain the eco-health.

Tsunami effects:
There is no previous record of the devastation caused by Tsunami prior to Dec 1881 when there was an earthquake of M=7.9 at Carnicobar which generated 1m waves followed by a  [115] . According to BMTPC Atlas, the coastal districts along the east coast of India has a high risk of severe cyclones are Nellore, Godawari (East), Srikakulam and Guntur in (AP) Kendrapada, Bhadrak, Jagatsinghpur Puri and Ganjam in Orissa; Kanchipuram in Tamil Nadu along the wetlands/lagoon coasts https://ndma.gov.in/images/ cyclones /cyclonepronedistrict.pdf.
The global warming and warm climate will augment the intensity of tropical cyclones with reduced frequencies globally during the 21 st Century whereas the number of storms in the Indian Ocean and Bay of Bengal would increase particularly in lagoons/major wetlands lying along the east coast of India, Mishra et al 2014 [116] .   [118] , V. Sanil Ku.et al, 2006 [25] , Mohapatra, 2015 [117] , ncrmp.gov.in/cyclones-theirimpact-in-india In the last 200 years, at least 2.6 million people may have drowned due to storm surges and causing a range of other damages and devastations Nicholls et. al., 2006 [119] .

Anthropogenic concerns:
Lagoons along EC India are harnessed for pisci-culture, shrimp and prawn culture, energy sources, biotechnology, tourism, transportation, shipping, and varied anthropogenic usages. These factors with other related activities have put immense stress on the lagoon ecosystem which has been brought out in the subsequent chapters.

Anthropogenic emissions:
Apart from sun-earth geometry, the main cause of global warming is GHG emissions of mainly CO, CO2, CH4, SO2, SF6, oxides of nitrogen (NOX), HFCs (hydro-fluorocarbons), PFCs (perfluorocarbons), and NMVOC (nonmethane volatile organic compounds) due to industrial and commercial activities. The subcategory of anthropogenic GHG gasses are CFC (11,12 and 113), Halon (1211 and 1301), HCFC 22, CCl4 (CTC), Methyl holo is also generated due to industry exhausts and residuals, emissions from the vehicle, electronic appliances, and gadgets. These polluting gases with toxic industry effluents discharged into the lagoon are a threat to the existence of flora, fauna, and avifauna.

Ports and harbors:
Port and harbors, sea walls, fishing jetties along the oceanic front, debonding of mangrove are the anthropogenic activities (like armoring, dredging, sand mining, Seawalls, bulkheads, breakwaters, and erosional wakes) that affect the coastline of a lagoon. The activities augment the longshore sediment transport and transform the spits of the adjacent lagoons.

Embankment stabilization:
Sea level increase and an increase of intensities of storms in 21 st century slamming the lagoon coasts have threatened the low-elevation areas. The lagoons have a numbers of islands within which accommodate mostly the low economic group (fishermen, ecotourism service suppliers, and allied communities). In the 20 th century these islands were not protected by gherry bundhs and there was free flow for smooth discharge of floods. The construction of gherries has changed the hydrodynamics of the flow system of the lagoon, the fluvial status, nutrient inflow, ecosystem and salinity of the lagoons. The flow of additional nutrient from the increased settlement, agriculture, pisciculture firms have altered the pragmatic values associated with fisheries, habitats, real estate, and tacit values. The modern avenues and alertness warnings could not reach the weaker section to evacuate promptly to avoid inundation like new Orleans communities during Hurricane Katrina in 2005 Finch et al 2010. [120] Salt Marsh loss: India is the 3rd largest common salt producer of the world after China and the USA The series of lagoons along the EC India are rimed with salt ponds of the complex low lying countryside of developed coastal settlement areas, profitable waterfronts, agricultural areas. The salt marshes lie in low lying areas with the heavy tidal influence of EC of India. It is mostly associated with estuaries/lagoons that provide prime habitat for a special variety of bioturbation, plant species, crab herbivory, and salt production to augment socio-economic activity. India has 6major areas of salt marshes.

Imprints of Fringing of deltas
Coastal lagoons get terrigenous sediment from inflowing streams/ rivers comprising of flocculated silts and clays and deposited at entry or exit point of the water body. The lagoons also transport sediments by the littoral drift near shore through tides, surges, and waves. When there is an imbalance of exchange in the influent system the reconstruction of the barrier spit occurs. The paucity of Indian deltas positioned along the EC of India due to anthropogenic interventions like the construction of hydraulic structures inland have reduced the flushing floods frequencies and the sediment inflow to the lagoon which triggers the coastal erosion Nageswara Rao et al., 2011 [121] . ruffle the coastline of the Bay of Bengal. Delta building process is hindered for sediment paucity, 707 increased settlements as numbers of dams, barrages are constructed in the inland river restricts flushing flow and corresponding sediment and demographic explosion have tempted people to have new settlement in the rims and within the lagoon area Syvitski, et. al., 2008 [122] , and 2011 [123] .

Longshore Transport (LST) along East coast India
The shock during landfall and slamming/ slashing of the storms and the tsunami surges causes major changes in the barrier island and the tidal inlets of the lagoon. Similarly, drought and excess evaporation due to heat waves in the hinterland induce the spits to deform the lagoon's shape and size. In addition to inland sediments, the longshore drift along the east coast of India plays important role in reconstructing the beach, wetlands, and lagoons along the East coast of India. The direction of net LSTR is south to north and vice versa during the month of November and December but the net LST is towards the north for the whole year. The maximum Longshore Sediment Transport Rate (LSTR) was ≈1×10 6 m 3 /yr along Chilika coast South of Guguleru creek (Kolleru coast) to Chilika northern coast Sanil Kumar et al 2006 [25]   In view of imminent danger to the survival to lagoon ecosystem and its biodiversity, it is imperative on the part of planners and stakeholders to adopt an integrated approach to safeguard and at the same time rejuvenate the lagoons on most immediate basis. These water bodies are lifeline of our survival and any piecemeal or isolationist approach would jeopardize the existence of mankind in the long run. The measures submitted below for rejuvenation of the lagoon ecosystem are to be viewed in the context of constant friction between the issue of -development -and -environment‖.
The author does not claim to prescribe panacea for this complex but significant problem area. The article outlines the intention of the author here to stimulate wide-ranging debate and interest to adopt a practical approach to anticipated rejuvenation of lagoon ecosystems in the East Coast of India in future.

Study of CZ and beach nourishment:
It is high time to consider the entire coastal zone of EC, India as an ESS subsystem of science. By using NASA's tool study is needed for the rhythm of terrestrial and oceanic bionetworks changes and their impacts overexploitation of flora, fauna, avifauna, and aquafauna of the global geo-bionetworks. The identification of flagship effects such as nondisposal of non-bio-degradable wastes, demolition wastes, and prohibition of using coastal wetlands as dump yards should be done on priority.
Coastal instability along the east coast: The erosion and accretion of the shoreline of the east coast have pragmatic impact on the at the interface of land especially the lagoon/waterbody's dynamic geographic features,

Mining/Port/Jetti activities:
The lagoons were the old harbors and ports in past without huge infrastructural activities. The huge concrete structures in the vicinity of port near the lagoons coast are destroying the ecosystem and contaminating the lagoon. Present ports and harbors, mining activities on and offshore , shipping and oil exploration/spills and chemical spills degrading the lagoons nearby.

Management strategies:
To ensure Integrated Coastal Zone Management (ICZM), legislation and regulations for Revise Protected Areas (RPA) adjacent to India's EC territorial water and coastal zone management of lagoons/watersheds and their capacity/resilience to multifaceted ecotones need to strengthen mechanism during its rejuvenation in future under RSLR scenario.

Conclusions:-
The key observations during the study are Lagoons along the east coast of India form in the estuaries of small rivers and the suitable landform is sandy or muddy low-lying coasts under mild soil slope. The Coastline is ever changing and the RSLR along the west coast of BOB are prominent. Capacity building and effective coastal zone management by identifying the constraint zones should be built up as a national policy during its reconstruction in 21 st -century RSLR scenario and EC line erosion and accretion.
The fragile coastal lagoons along the east coast of India have multifaceted challenges of different dimensions to the immediate landform near the ocean (wetlands) as it is the frontline to face climatic glitches. The spectrum of biodiversity anomalies in recent past and future prospect are in the hands of nature but triggered by the Homosapiens. It is high time to evaluate the pragmatic values of future changes and the lagoon managers/stakeholders should take timely suitable action to ameliorate the anticipated impact and threats irrespective of their social, political, economic and anthropogenic influences to save the highly nutrient zone and their fragile ecosystem.