Conservationists raise alarm over vanishing coastal ecosystems in Raigad

Nearly 55 hectares of coastal ecosystemsmdashan area equivalent to 10 Wankhede stadiumsmdashnear Devghar in Raigad district has submerged over the past three decades shows a study Punebased Srushti Conservation Foundation SCF a nonprofit organisation conducted the study close to the mouth of Bankot Creek which has a 15kmlong beach using satellite images Information from the locals about erosion prompted the studyPreliminary statistics show there was a total loss of around 55 hectares of coastal habitats between 1990 and 2022 including mangroves creeklets mudflats and sandy coastlines and erosion of over 300 metres of shoreline ldquoIt clearly indicates a worrying sign of coastal inundation and extreme shoreline erosion which has prompted concerns about the effects of climate changerdquo the researchers saidA satellite image showing the erosion over the yearsExplaining their findings SCF Managing Director Dr Deepak Apte said ldquoIt was observed that the satellitederived shoreline unsupervised classificationbased water body boundary had now shifted 300500 metres towards land Besides it was clear that mangrove and Casuarina plantations were also not able to withstand the loss of sediment and eventually they got uprootedrdquoAlso Read Mumbai Chhagan Bhujbals son nephew seek dropping of PMLA proceedings in view of SC guidelinesA change in the sediment profile from a claysilty to a coarsesand dominant seascape has also been observed ldquoLarge expanses of mangroves are already on the verge of extinction most likely as a result of a change in sediment structure from muddy to sandy nature Some of these areas are now beginning to recoverrdquo said Apte In 2020 the landfall of Cyclone Nisarga close to the coast of Devghar saw the death of trees shrubs and approximately five hectares of mangrove speciesLessons learntThe study concluded that there is a need for a systematic examination of how the shoreline is changing like in various parts of the state For instance in many places saltwater intrusion is causing mangroves to grow on agricultural lands and in many others sediment loss results in significant erosionldquoClimate changerelated sealevel rise will further worsen the situation The government should commission a study to seek solutions to deal with the changing seascape We are currently doing ad hoc interventions which will only worsen the situationrdquo Apte said He added ldquoIt will not only erode our natural barrier but will also facilitate erosion in the long runrdquoThe SCFrsquos studies on the impact of Cyclone Nisarga on mangrove and nonmangrove areas show that mangroves are crucial during storm surges and cyclones ldquoUnregulated construction of seawalls is another case where the problem of erosion is shifted from one place to another These may be temporary fixes for severely deteriorating shorelines but they cannot and should not be the only optionsrdquo explained ApteSand mining threatSand mining has allegedly been taking place in the vicinity of Devghar beach near Bankot Creek Although the effect of sand mining on erosion in the Devghar region is still unknown studies have found that unrestricted sand mining is accelerating erosion in various locations along the Maharashtra coastline For instance several areas between Alibaug and Mandwa have seen illegal sand mining entirely erode beachesldquoWhile on one side sea level is increasing and on the other side sand mining on beaches is flattening natural shore gradients facilitating coastal inundation In the case of sand mining in the creeks these are getting deeper and deeper facilitating erosion and largescale saltwater inundation in nearby areas as it increases its water carrying capacity during high tides and storm surges Though deepening of creeks is necessary and essential in many cases to facilitate storm water drainage especially in the rainy season it is very sitespecific and needs to be done in a very careful mannerrdquo said ApteIn the case of Devghar an increase of erosion coincides well with the construction of bridges and related activities the study found Sumaira Abdulali the convenor of Awaaz Foundation which has pioneered and led the antisand mining campaign in India since 2004 told midday that after climate change sand mining is another major contributor to the problem ldquoWe have found evidence of a longterm effect of sand mining on our coastline which has submerged and shrunkrdquoSCFrsquos suggested solutions to the stategtgt Focus on developing a shore management policy keeping climate change in mindgtgt Launch communitybased climate resilience adaptation and awareness programmesgtgt Start scientific management across creeks to maintain optimal depth and water levelgtgt Review the Kharland Bund Policy as construction of bunds to prevent saltwater ingress will only shift the problem from one place to another It is facilitating largescale mangrove mortalitygtgt Review the efficacy of sea walls and their impact on shore erosion in nearby areas