Keywords

1 Introduction

India has a vast coastline that stretches over nine states and four union territories, including two group of islands (Krishnan et al. 2018). The coastlines of India are on both its eastern and western shores. Indian coastline consists of 5422 km of mainland shore with 2344 km of islands in Indian jurisdiction (Andaman and Nicobar Islands and Lakshadweep islands). This double archipelago total length is 2094 km. Western Indian coast includes Gujarat, Maharashtra, Karnataka, Goa and Kerala, whereas eastern India includes Odisha, West Bengal, Tamil Nadu and Andhra Pradesh. Daman and Diu on the west coast and Puducherry on the east coast are union territories. Andaman and Nicobar Islands (ANI) are located in the Bay of Bengal and Lakshdweep islands in Arabian Sea. Eighteenth longest overall coastal length in the globe. In coastal regions, valuable resources, fertile habitats and high biodiversity contribute greatly to the nation’s economy. As a result of rising population, urbanisation, industry and climate change, coastal areas must be looked at and examined in greater depth (Panigrahy and Mohanty 2012; Bhomia et al. 2016).

This chapter examines the coastal states and islands of Indian territory, particularly the coastal ecosystems and wetlands. We also summarise numerous laws and regulations implemented to conserve these ecosystems.

2 The Coastal States, Union Territories and Islands of India

2.1 Gujarat

The western state of Gujarat has the longest coastline of 1600 km. There are 41 ports, both big and little, located along Gujarat’s coastline. Gujarat’s well-known beaches include Diu, Dwarka and Porbandar. The Gulf of Khambhat and the Gulf of Kachchh are located in Gujarat. Coastal zones include mangroves, coral reefs, seagrasses and salt marshes. Second, to West Bengal, Gujarat has the second greatest mangrove coverage. The Gulf of Kachchh, Kachchh Bay and Saurashtra have a greater density of mangroves (including the Gulf of Khambhat-Dumas Ubharat areas). A maximum of 71.5% mangrove cover exists in the Gulf of Kachchh. The Gulf of Kachchh, Saurashtra and South Gujarat include some mangrove habitats. The Rann of Kachchh is a very rare environment with salt marsh as the primary plant. The GRK base looks like a table with numerous little peaks at ground level, or “islands”, some of which are dubbed “bets”. In geological time, it’s considered an area of instability due to transgression. This body of water has shallow water depth ranging from 0.5 to 1.5 m. During October and November, the area goes through a dry period and is soon overrun by an ocean of salt crystals (Stansley 2004). A quiet stretch of coast in Gujarat is home to mangroves, salt marshes and coral reefs. Coral reefs are abundant throughout the Gujarat coast; however, they are only found in the abundance Gulf of Kachchh, and their diversity is very low in other areas. Gujarat, where reef-forming corals (scleractinian) are few, has coral reefs that have a low variety compared to other main regions of India.

2.2 Maharashtra

Maharashtra is the third largest state in India area-wise. It is flanked by the Western Ghats in the east and the Arabian Sea in the west. The Konkan coast has a length of 720 km. Maharashtra features several waterways, tidal mudflats, salt marshes and mangroves. The 720 km coastline along the Konkan area of Maharashtra houses the Great Mumbai Region (GMR). Because of its urban setting, the GMR was chosen as a unique instance when drafting the revised Coastal Regulation Zone (CRZ) notification of 2011. Mangroves in the Mumbai region require monitoring and protection, especially to control coastal pollution and solid waste management (Krishnamurthy et al. 2014). “The Sahyadri” mountain range in Maharashtra has an average elevation of 1000–1200 m above mean sea level (MSL). The Sahyadri hills have numerous offshoots spreading eastwards (Satmala, Ajanta, Harishchandra, Balaghat and Mahadeo). The Konkan coastal strip is a tiny stretch of coastal land that is only 50 km long. Branching rivers from the Sahyadri hills, which join the coastline, bisect the coastline. Konkan comprises four main creeks: Terekhol, Rajapuri, Vijaydurg and Raigad. Mumbai is in the top 20 cities with exposure to extreme sea level and tropical cyclones.

2.3 Goa

Goa is the smallest state in India. It is characterised by long sandy beaches well-known for tourism. Goa is known worldwide for its spectacular beaches. Goa is surrounded by Maharashtra on north, Karnataka on the east and the Arabian Sea on the west. Mangrove patches and lush western ghat forest line the state’s shoreline.

2.4 Karnataka

Karnataka’s coastline extends for 320 km, into three districts: Dakshin Kannada (62 km), Udupi (98 km) and Uttara Kannada (160 km). Konkan Peninsula adjoins the Arabian Sea to the west, while the Western Ghats join it to the east, and Kerala plateaus are in the north. Several ridges and branches of the Western Ghats link this region to the ocean. Coastal Karnataka is peppered with rivers, waterfalls, peaks and hill ranges. The coastal plain is 50–80 km in breadth.

2.5 Kerala

Kerala’s coastline measures 580 km, being the fifth-longest in India. The Malabar coast in Kerala is well renowned. The Arabian Sea and the Western Ghat mountain range separate Kerala from the east. Malabar’s backwaters, beaches and tea and coffee plantations are all well-known. The Kerala coast spans from Manjeswaram in the north to Pozhiyur in the south. The beach infrastructure along the Cochin-Alleppey coast is developed.

2.6 Andhra Pradesh

Andhra Pradesh’s coastline runs the second-longest in India for 974 km on the eastern coast. Andhra Pradesh’s coastline lies between the Eastern Ghats and the Bay of Bengal. The coastline is home to two large rivers, the Godavari and Krishna, and smaller river deltas with agricultural land. India’s second-largest lagoon and India’s largest mangrove ecosystem are other key coastal ecosystems. The mangroves of the Godavari estuary (Krishna Delta and Machilipatnam) and Pulicat lagoon are critical coastal habitats in Andhra Pradesh. The largest lagoon in India is connected to the Bay of Bengal and houses both permanent and migratory birds. Seagrass beds and mangrove patches are seen in the lagoon as well.

2.7 Tamil Nadu

Tamil Nadu has a coastline of 1076 km, which is the third longest in the country. The Coromandel Coast is well-known. Every ocean on the Indian subcontinent touches the Tamil Nadu coastline. It runs from the Bay of Bengal to the Arabian Sea. Kaveri Delta is in the east, while the Western Ghats occupy the south, and Utkal plain lies in the north. The state’s coastal districts include Ramanathapuram, with 237 km of shoreline, and Chennai, which has 19 km of coastline. The Gulf of Mannar extends for 365 km, Palk Bay extends for 294 km, and the west coast of Tamil Nadu stretches between Kanyakumari and Neerody (60 km). Major seaports such as Chennai and Tuticorin, together with various marine ports, marinas and harbours, are located along the coast of Tamil Nadu. Gulf of Mannar has beautiful seagrass meadows, mudflats and salt marshes. The pichavaram mangroves, Muthupet mangroves, Pulicat lake and Kaliveli backwaters are ecologically vulnerable locations on the Tamil Nadu coast (GIZ Report 2013)

2.8 Odisha

Coastal Odisha is also known as Utkal plains and measures 485 km. The shores of the Mahanadi and Brahmani-Baitarni rivers are almost entirely depositional (Ajai et al. 2012a). The lower Ganges plain spans north to south, whereas the Tamilnad lowlands are south of the Bay of Bengal. This area has six main estuaries (including Bhitarkanika and Mahanadi mangroves), a big brackish water lagoon (Chilika Lake), enormous mudflats and sandy beaches. Gopalpur and Chandipur beaches are widely recognised. Nesting grounds for Olive Ridley turtles are located just south of the Bhitarkanika mangroves.

2.9 West Bengal

West Bengal’s coastline is roughly 157 km in length. The West Bengal shoreline is found in Purba Medinipur and the South 24 Parganas districts. The Sundarbans is on the Ganga-Brahmaputra and Meghna riverbanks, which makes about 40% of the total mangrove coverage in the globe. Sundarbans offers a great diversity of flora, having several species. Sundarbans is famous for the Royal Bengal tiger feeding on fish. The coastline’s principal features are mudflats, creeks and tidal flats. West Bengal experiences significant storm activity.

2.10 Union Territories of India: Coastal Regions

2.10.1 Puducherry

Union Territory of India, situated on the coromandel coast in the east, was originally known as Puducherry. It is confined by land on three sides, with the Bay of Bengal on the eastern side. The eastern coastal plain of Puducherry is parallel to the Bay of Bengal. The plain is 400–600 m broad, with sand dunes along the coastline.

2.10.2 Daman and Diu

Daman and Diu are a Union Territory (UT) of India located on the west coast of the Arabian Sea. Daman and Diu is India’s smallest federal division, which covers just 112 km2. The territories of Daman and Diu are divided by the Gulf of Khambhat, not one continuous province. The UT is bounded by the state of Gujarat and the Arabian Sea. Daman and Diu feature extensive salt marshes and plentiful fisheries. Daman and Diu were amalgamated with Dadra and Nagar Haveli, an Indian UT, on January 26, 2020.

2.10.3 Andaman and Nicobar Islands (ANI)

Andaman and Nicobar Islands (UT of India) consists of 572 islands, of which 38 are inhabited. East of the archipelago is the Andaman Sea, while west of it is the Bay of Bengal. The capital of the territory is Port Blair. The entire landmass of the islands is 8249 km2. Ten Degree Channel separates the Andaman Islands from the Nicobar Islands (Bandopadhyay and Carter 2017). ANI is home to the most pristine and vulnerable island ecosystems in the world. This environment has evolved in isolation from the mainland over time, resulting in various flora and fauna. Isolated islands mean many endemic species of flora and wildlife. The majority of the Sundaland biodiversity hotspot includes sections of ANI (Sridhar 2018). Mangroves, coral reefs and seagrasses characterise ANI’s rich coastal ecosystems. The whole coastline of the ANI islands is 1962 km, which comprises the huge Exclusive Economic Zone of India. With 96 approved wildlife sanctuaries, ANI manages 9 national parks and biosphere reserve in Great Nicobar. The isolation and remoteness of ANI Islands favour the evolution of endemism of both vegetation and animals.

2.10.4 Lakshadweep Islands

Lakshadweep archipelago is located between 400 and 600 km off the coast of Kerala. It comprises 12 atolls, 3 atoll reefs and 5 coral banks (Nobi et al. 2011; Dalia et al. 2014). Lakshadweep has various ecosystems consisting of mangroves, corals, seagrasses, dunes and seaweeds. The ecosystems of the Lakshadweep islands are rich in biodiversity and productivity. The islands’ terrestrial ecosystems are protected from the powerful ocean waves (Robin et al. 2012). The Lakshadweep coral atoll system features enormous shallow lagoons and coral reefs. The island lagoon covers 4200 km2, and their Exclusive Economic Zone (EEZ) is 4,000,000 km2 (www.lakshadweep.gov.in). The Lakshadweep Sea is full of fishing resources, especially tuna (Gopi et al. 2021).

3 India’s Coastal Ecosystems

3.1 Mangroves

Indian coastal states and Indian territorial islands are rich, diversified mangroves. Indian mangroves occupy only 3.3% of the total mangrove cover of the world. However, when it comes to mangrove species richness, 56% of the global mangrove species are found in India (Ragavan et al. 2019). Salt-tolerant, hardy, and long-lived trees can grow in environments with high salinity and regenerate and proliferate. Through their robustness, these trees give protection against storm surges, stabilise coastline and safeguard coasts. Mangrove forests play a vital role in the carbon, nitrogen, phosphorus and sulphur nutrient cycle. Ecosystems trap organic carbon, debris and sediments that bring along them organic matter from the coastal and river catchments, producing plentiful nourishment for the system. Mangroves provide abundant estuarine and coastal fisheries by harming the nearby oligotrophic systems (Singh et al. 2005; Ranjan et al. 2010). Mangroves provide marine ecosystems with much-needed nutrients because of the deposition of organic-rich, very fine sediments. Mangroves serve as nurseries for the young of marine fish, crabs and shrimp. They offer a wide variety of forest products, helping the local community. Locally used by locals as fuel and fodder, the robust tree wood has several medicinal uses.

Mangrove forest deforestation is one of the main causes of mangrove loss (Ajai et al. 2012b). The deep green mangrove forest with a sufficient food supply also provides habitat for numerous tiny and large creatures. These woodlands are bird species-rich. Some help crocodiles and deer (Bhitarkanika mangroves). Sundarbans mangroves are known for fish-fed tigers. These dense mangrove forest with evergreen trees and tiny rivers has tremendous recreational possibilities. People visit for boating, sightseeing, bird viewing and fishing in mangroves wetland. It has recently been largely valued as a carbon storage and carbon sink. Mangroves in India became important following the 2004 Tsunami because many fringes near mangroves protected from the waters and storm surges because of their immobility.

Around 43,000 km2 of coastal wetlands include estuaries, lagoons, mangroves and mudflats. These wetlands help slow down runoff, buffer against storm surge, the barrier against storm surge, and shield against tsunami (Bassi et al. 2014). Bees found in mangroves can produce up to 100 pounds of honey per hive in a year. Mangroves on the west coast are considerably less established due to higher coastline and few main rivers moving west (Selvam 2003). East coast Mangroves occupy almost 60% of the mangrove cover, 23% is found on west coast and 17% in ANI . Because of the different geographic locations and rivers that flow east, east coast mangroves are significantly more floristically rich and biodiverse (Nayak et al. 2016; Kathiresan 2018).

This mangrove forest of Sundarbans lies in India and Bangladesh. India’s Sundarbans is part of the Ganga-Brahmaputra Delta in the state of West Bengal. The second largest mangrove patch is in Gujarat, followed by Tamil Nadu and Andhra Pradesh (Selvam 2003). ANI islands contain the most variety and rich mangroves, second in number only to Gujarat’s.

3.1.1 Sundarbans Mangroves (West Bengal)

Sundarbans mangrove forests are the world’s largest lying in India and Bangladesh. The Sundarbans is the result of the merging of the Ganga, Brahmaputra and Meghna rivers before meeting Bay of Bengal. The tidal flooding of the Brahmaputra and Ganga rivers has provided a stable and ideal habitat for mangroves to flourish. Approximately 4100 km2 of the Sundarbans’ mangrove swamp is forested, of which approximately 2125 km2 are mangrove swamp and 1781 km2 are water. Over the last three decades, the Sundarbans has been safeguarded by numerous methods. Included are biosphere reserve, national park and wildlife sanctuary (Gopal and Chauhan 2006). Sundarbans mangroves are a UNESCO World Heritage site. West Bengal has India’s greatest mangrove cover, followed by Gujarat and ANI (Ajai et al. 2012b). The Sundarbans supplies a vital livelihood to the locals, yet settlements place unwelcome stresses on this ecology. Several risks have grown alongside the local population: increased tourism, aggressive fishing, loss of mangrove trees for cultivation and overfishing (Saha et al. 2006; Kumar and Ramanathan 2015).

3.1.2 Maharashtra, Karnataka, Kerala and Goa Mangroves

In Maharashtra, 27,092.14 ha of mangrove vegetation exists. Thane, Mumbai, Raigarh, Ratnagiri and Sindhugarh have mangroves (Mugade and Sapkale 2014). Avicennia, Sonneratia and Rhizophora are Maharashtra’s main mangrove genus. Mangroves occupy 663 ha in Kerala. Much of Kerala’s mangrove region is Valapattanam, Kunhimangalam, Kasargod-Nileshwar, Kavvayi and Puthuvypin. Mangrove forest covers 3463.36 ha in Goa. Mapusa and Zuari rivers all flow through somewhat dense regions of mangroves. Chorao Sanctuary with good mangrove stretches along the Mandovi River. Major mangrove species Avicennia, Sonneratia and Rhizophora are found along the rivers Zuari, Mapusa and Mandovi and cover major mangroves area.

3.1.3 Mangroves Pichavaram and Muthupet (Tamil Nadu)

Mangroves are important in ecologically vulnerable regions along the Tamil Nadu coast. The state mangrove cover area is 5565 ha. The most prominent mangroves in Cauvery Delta are Pichavaram and Muthupet. The Pichavaram mangroves, which have 1100 ha, are constrained by the Vellar and Coleroon rivers. Forty percent of the total area is taken up by waterways and the rest by mangrove vegetation placed in the middle (Ranjan et al. 2010; Sappal et al. 2014). A 75% loss of mangrove forest coverage has been seen in the Pichavaram mangroves (Kathiresan 2002; Ranjan et al. 2010). The 2004 Tsunami damaged the Pichavaram mangroves (Ranjan et al. 2008). Muthupet, meaning “Pearl Land”, is part of the Point Calimere Wildlife Sanctuary, Tamil Nadu’s only Ramsar site. Both Pichavaram and Muthupet mangroves receive freshwater from October to November, especially during the northeastern monsoon season. This leads to mangroves experiencing a long dry season and very high water salinity. Besides these two large mangrove patches, most estuaries and backwater system along the Tamil Nadu coast have mangrove forests in patches. The dominant mangrove species present throughout the Tamil Nadu coast is the Avicennia marina. Other significant species detected include Rhizophora, Excoecaria and Acanthus ilicifolius (Kathiresan 2000).

3.1.4 Andaman and Nicobar Mangrove (ANI)

ANI contains about 572 islands, islets, creeks, beaches and rocky outcrops with abundant mangrove forest. These islands harbour 34 real mangrove species of 15 genera, 10 orders and 12 families, 50% of the global mangrove species (Ragavan et al. 2015). According to the 2013 India Forest Survey, total mangrove land of 604 km2 occurs in ANI, which is third in extent after West Bengal and Gujarat. Favourable climate circumstances, including short dry season, heavy rainfall and high tidal amplitude, cause lush green mangrove trees in ANI (Sridhar 2018).

3.1.5 Mahanadi and Bhitarkanika (Odisha)

Mangrove forests on India’s east coast are more diversified, healthier, denser and floristically rich than the west coast (Dasgupta and Shaw 2013, 2016). Mangrove patches of Odisha’s east coast are located along the Mahanadi, Brahmani, Baitarni, Dhamra and Devi delta. The primary districts with mangroves are Kendrapara, Jagatsinghpur, Bhadrak and Balasore. Bhitarkanika is India’s second-biggest mangrove forest. It has rich in plants, birds and animal species. Mangrove comprises about 300 plant species, 174 bird species, 31 animal species and 29 reptile species (Badola and Hussain 2003; Bhomia et al. 2016; Kadaverugu et al. 2021). Bhitarkanika also houses the endangered saltwater crocodile (Crocodylus porosus). Bhitarkanika mangroves underwent considerable deforestation pressure during 1951–1961 due to population growth around the forest resulting in human habitation, aquaculture and agriculture mangrove destruction. In 1975, to conserve the surviving mangroves, the Odisha government declared an area of 672 km2 bounded by Dhamra and Brahmani rivers as Bhitarkanika Wildlife Sanctuary under the 1972 Wildlife (Protection) Act. In 1998, a core area of 145 km2 was declared as Bhitarkanika National Park within the sanctuary.

3.2 Salt Marshes

Salt marshes are halophytic plants growing in marshy environments near the seas and oceans. These plants grow in high saline environment and form an important ecosystem of coastal areas supporting species diversity and providing important ecosystem services. Salt marshes grow in the upper tidal zone and are subject to tidal inundations regularly. The salt marshes vegetation may be herbs, shrubs or grasses which thrive when supplied with saltwater. The salt marshes area in Odisha and West Bengal is yet to be explored. Salt marsh plants are useful in several forms. They are often used as bedding and thatching material and animal fodder by coastal communities. They also help improve the quality and stability of coastal habitats of many aquatic species by stabilising the surrounding environment from various natural forces like storm surge. They help in pollution abetment and water clarity by reducing the quantity of suspended solids in the water column through filtration services (Gopi et al. 2019; Unsworth et al. 2019). The salt marshes like other coastal wetlands are under natural and anthropogenic pressures. In the recent decades, several pressures, increasing salinity and temperature and introduction of exotic species have rendered the natural salt marshes as non-resilient halophytic plants. The salt marshes are vulnerable to sea-level rise as a consequence of climate change which threatens their significant contribution to coastal protection, fisheries support, biodiversity conservation and carbon sequestration. Until few years back, salt marshes have been almost unexplored in India in terms of net area occupied, species diversity, ecological dynamics and ecosystem services they provide (Jagtap and Rodrigues 2004; Patro et al. 2017). According to Viswanathan et al. (2020), the overall area of salt marshes in India is about 1611 km2 with Gujarat having maximum area of 1443 km2. Salt marshes have been categorised as one of the Ecologically Sensitive Areas (ESA) under the Coastal Regulation Zone (CRZ) Notification 2019. In India 14 salt marsh species have been reported; while all the 14 are found on the western coastline, 13 species have been reported on the east coast (Patro et al. 2017; Viswanathan et al. 2020).

3.3 Seagrasses

Seagrasses are angiosperms growing in shallow coast in estuaries, lagoons and bays. They are considered to be the keystone species as they provide wide range of ecosystem services from food, shelter to carbon storage (Duarte et al. 2013; Stankovic et al. 2021). The seagrass beds are one of the most ecologically important producers in the marine environment as they are the primary producers and provide shelter and food to various organisms, also providing nutrients to coral reefs and storing carbon (Mishra and Apte 2021) Mangrove plants and the seagrass meadows supply a large part of the diets of many large and small marine organisms, including dugongs, sea turtles, fishes and small invertebrates (Thangaradjou et al. 2007; Gopi et al. 2020; Mishra and Apte 2020). Seagrass meadows are the only angiosperms growing under the saline water and exhibit high primary production rates which is closely linked to high fish production of the associated fisheries (Nobi et al. 2011). They are found in shallow isolated coastal ecosystems like lagoons, estuaries and bays. India has reported 16 seagrass species in the coastal areas along the Indian coast with rich seagrass meadows in Palk Bay and Gulf of Mannar coastal areas in Tamil Nadu having 14 species, ANI has 12 species and Lakshadweep Islands have 10 species, and Odisha and Gujarat have 8 species (Bharathi et al. 2014; Thangaradjou and Bhatt 2018; Gopi et al. 2020). Two of the islands in Lakshadweep Agathi and Kadamath have six and five species of seagrasses, respectively, and support large number of green turtles for feeding and nesting (Nobi et al. 2011; Nordlund et al. 2018) Though being one of the most important primary producers in the coastal ecosystems, seagrasses are highly threatened ecosystems owing to several natural causes like cyclones, tsunami, intensive grazing, dieback disease and anthropogenic reasons like illegal fishing, nutrient enrichment, pollution, siltation and dredging techniques. Natural causes for seagrass decline are pollution, nutrient enrichment, intense high waves, cyclones and tsunami, intensive grazing and infestation of fungi and epiphytes (Jagtap and Rodrigues 2004; Nobi and Kumar 2013; Patro et al. 2017). Seagrasses have also been used as heavy metal biomonitors in coastal ecosystems, and there are studies from several locations in India (Thangaradjou et al. 2010; Nobi et al. 2011; Selvaraj et al. 2020). Seagrass meadows in ANI and Lakshadweep islands have been studied well and also in Palk Bay and Gulf of Mannar region in Tamil Nadu coasts which are well documented; however, there are any major studies from states like Gujarat, Andhra Pradesh and Odisha which also have dominant and minor seagrass areas (Thangaradjou and Bhatt 2018).

3.4 Coral Reefs

Coral reefs are an important ecosystem in coastal regions as they provide many services and play a significant role in many tropical and subtropical countries (De Kalyan et al. 2017). They exhibit plentiful diversity, present beautiful picturesque sight and hence a great tourist attraction, form food and habitat for several marine species and provide protection against storms and tsunamis. All the three major reef types, i.e. atoll, fringing and barrier reefs, occur in India, and the region includes some of the most extensive, diverse and least disturbed reef areas of the Indian Ocean. Though being rich and diverse, these reefs have not been studied in detail (Venkatraman 2011; Patterson et al. 2020). Not counting the island territories, India has two well-defined mainland coastal areas containing reefs in the states of Gujarat and Tamil Nadu: the Gulf of Kachchh on the northwestern coast and Palk Bay and Gulf of Mannar on the southeastern coast. Apart from these two main regions, there are patches of reef growth on the West Coast, at Malvan and Redi in Maharashtra coast (Venkatraman 2011; De et al. 2017). The ANI have fringing reefs around many islands and a long barrier reef (329 km) on its western coast. There is very limited study on the ANI reefs, which may be the most diverse and pristine reef building corals in India. Extensive reefs have also been observed in Lakshadweep islands, but again these have been poorly explored.

3.5 Lagoons

Coastal lagoons are shallow water bodies that run along a shoreline but remain separated from the ocean by sand bars/spits, coral reefs and barrier islands and have one or several restricted connections with the sea (Mahapatro et al. 2013; Amir et al. 2019). India has several lagoons. India has the largest lagoon, Chilika lake, in Asia lying on the east coast of India in the state of Odisha. The second largest lagoon in India, Pulicat lake, also lies on the east coast shared between the states of Andhra Pradesh and Tamil Nadu connected to the Bay of Bengal (Sahu et al. 2014; Nazneen and Raju 2017). Other prominent lagoons on west coast of India are Vembanad Lake and Ashtamudi Lake. Lagoons are fragile ecosystem owing to their shallow depth and restricted connection with the sea. The high productivity encountered in a lagoon is due to the varied salinity regime existing within the ecosystem. However, the mouth of the lagoons tends to close over time, and the inflow of only freshwater can turn them into freshwater ecosystems solely. In the case of Chilika lagoon, the same condition was observed when this lagoon was put under Montreux record of threatened wetlands under the Ramsar Convention. Later with help of Chilika Development Authority (CDA), this lagoon could be revived (Nazneen et al. 2019a, b). Vembanad Lake (Lat. 9° 30′–10° 10′ N and Long. 76° 10′–76° 25′ E) is the largest brackish water system in the state of Kerala on the southwest coast of India. The 96 km-long lake is a major water fowl habitat supporting unique assemblage of marine, brackish and freshwater species and also has mangroves in patches (Selvam et al. 2012).

4 India’s Coastal Policies

India is one of the world’s mega-biodiversity nations, meaning India is rich in terrestrial biodiversity and rich in marine biodiversity. The three metropolitan cities of Mumbai, Kolkata and Chennai are coastal cities, and the coasts live a substantial population. This section emphasises India’s coastal policies for protecting and managing its large coastline with numerous unique, diversified coastal ecosystems. India has a wide coastline characterised by numerous complex ecosystems, with large dependent populations in India’s coastal zones. Other Indian beaches suffer natural and manmade issues. Urbanisation, industrialisation and commercial activity and natural disasters directly affecting the coastal ecosystem and marine environment pose a big problem for India (Panigrahy and Mohanty 2012). With increasing human population in India’s coastal regions and constant pressure from storms and cyclones, the frequency of which is worsened by climate change, sound policies are needed to manage its wide coast. Marine and coastal deterioration increases pressure on terrestrial and marine natural resources as terrestrial pollution finally finds its way into the oceans and seas.

On the other hand, rising population near the oceans, establishing industries and increasing tourists in coastal areas are primary causes of poor coastal health (Rani et al. 2015). Bay of Bengal and Arab Sea are both dynamic seas with regular cyclones and streams. In recent years, East India has had annual cyclones Phailin, Hudhud, Titli, Phani, Amphan, Tauktae and Yaas (Rani et al. 2015; Barik et al. 2017; Nazneen et al. 2019b; Kumar et al. 2021). Recent yearly cyclonic storms and rising temperatures plainly show that coastal towns like Mumbai and rural communities along the Indian coastline are highly vulnerable to floods, tropical cyclones and tsunamis, causing considerable loss of human life and property devastation (Sindhu and Unnikrishnan 2012). India’s coastal wetlands have been protected under various international and national laws and treaties: Convention on Biological Diversity (CBD), Environmental Protection Act 1986, Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES), Ramsar Convention 1972 and United Nations Convention on the Laws of the Seas (UNCLOS) to name a few (Kumar and Saluja 2019). Some of these statues have been mentioned below.

4.1 Global Conventions and Coastline Protection Treaties

Several global conventions and treaties described below preserve marine and coastal environments. The Meeting of the United Nations on Environment and Development (UNCED) held in Rio de Janeiro in Brazil (also known as the Earth Summit or Rio Summit) in 1992 was an international conference attended by 172 countries, and some of the historic environmental agreements were made here. Three Earth Summit Framework Conventions are relevant to coastal and marine biodiversity. They are the Convention on Biological Diversity (CBD), the UN Framework Convention on Climate Change (UNFCCC) and the UN Convention on Desertification (UNCCD). These agreements cover marine and coastal habitats for protection, management and conservation (Saravanan et al. 2013).

4.1.1 Convention on Biological Diversity (CBD)

India’s marine and coastal environment contains dynamic geomorphological features that preserve and represent unique, diverse biodiversity. Country’s coastal area sustains a considerable amount of the country’s population, imposing tremendous pressure on its coastal and marine resources. Maritime Protected Area Network (MPAN) is a tool to manage natural marine resources for biodiversity conservation and resource-dependent people’s well-being. The other laws and provisions include Wildlife (Protection) Act 1972, Environment (Protection) Act 1986, Coastal Regulation Zone Notification 1991, National Biodiversity Act 2002 for the protection and conservation of coastal and marine environment (Saravanan et al. 2013). MPAs cover nearly 7% of the Indian coastline, but most of them are in ANI and fewer on the Indian coast. MPAs in mainland India are 24 in number with around 8214 km2 area. This represents 4.92% of the total area covered throughout the protected area network. It includes mangroves, estuaries, lagoons, coral reefs, marshes, mudflats, coastal dunes, near-shore ecosystems, gulf waters, creeks, seagrass beds and salt marshes. Most of these MPAs are wildlife sanctuaries, while four are marine parks. Gulf of Mannar National Park, Sundarbans National Park, Bhitarkanika Wildlife Sanctuary and Coringa Wildlife Sanctuary are some of the peninsular India’s major MPAs. India is one of the 17 mega-biodiversity countries, and it is well-known that, apart from its land, coastal and marine analogues are rich in biodiversity. There are only a limited number of marine and coastal regions recognised as MPAs. Many marine and coastal ecosystems with great biodiversity along the shoreline are yet unrepresented and identified for conservation actions. A separate, long-term research endeavour is necessary to build a mechanism for identifying sites and prioritising significant conservation areas.

4.1.2 The Convention on the Conservation of Migratory Species of Wild Animals (CMS)

This convention strives to preserve terrestrial, aquatic and migratory bird species throughout their natural range, from many countries to even continents. Under the auspices of the United Nations Environmental Program (UNEP), an international pact was established on the global conservation of migratory wildlife and their habitats (Kumar and Saluja 2019). The convention secretariat is in Bonn, and the decision-making body is the COP.

4.1.3 The Convention on International Trade in Endangered Wildlife (CITES)

CITES is an international agreement between states to ensure wildlife trading does not harm their survival. CITES exercises some degree of supervision in animal and plant trading across countries and borders. CITES secretariat is based in Geneva, Switzerland, and UNEP manages the administration. CITES regulates international trade in numerous marine species to help preserve their wildlife existence, including dolphins, marine tortoises, corals, queen conch, clams, sea horses and whales (Saravanan et al. 2013; Kumar and Saluja 2019). Thus, CITES protects from unregulated trade and use of endangered and rare marine species that would otherwise be extinct.

4.1.4 Ramsar Convention on International Important Wetlands

Ramsar Convention is a treaty between governments that provides the framework for government action and international cooperation on the conservation and wise use of wetlands and their resources. The treaty was born in 1971 in Ramsar, Iranian city. In a broader sense, the definition of wetlands includes lakes and rivers, estuaries, deltas and tidal flats, peatlands, marshes, mangroves, coral reefs and human-made ecosystems such as agricultural fields, ponds, reservoirs and salt pans (Kumar and Saluja 2019; Ragavan et al. 2020). India is a signatory to the Ramsar Convention and currently has 42 Ramsar-declared wetlands. Ramsar Convention in India ensures wetland management to conserve biodiversity and wise use. The scope of the Ramsar Convention extends to a wide variety of habitats, including rivers and lakes, mangroves, coastal lagoons, peatlands, coral reefs and numerous human-made wetlands such as fish and shrimp ponds, farm ponds, irrigated agricultural land, salt pan reservoirs, gravel pits, sewage farms and canals. Ramsar Wetlands in India include Chilika Lake, Sundarbans Mangroves, Ashtamudi Wetland, Vembanad Kol Lake, Bhitarkanika Mangroves, Kolleru Lake, Point Calimere Wildlife and Bird Sanctuary.

4.1.5 Biosphere Reserves

Biosphere reserve is part of the natural environment representing enormous areas of terrestrial, marine or coastal ecosystems, sometimes comprising both terrestrial and marine ecosystems. In 1971, UNESCO introduced the concept of Biosphere Reserve under its Man and Biosphere Programme. Biosphere reserves are country-specific locations identified under UNESCO’s Man and the Biosphere (MAB) Programme without any special legal force. The goal behind classifying a natural area as Biosphere Reserve is to stimulate the engagement of local populations based on sustainable development, coupled with scientific efforts. The objective of forming the biosphere reserve is to preserve all types of life in situ and its natural environment and support system to serve as a small model system for monitoring and analysing changes in natural ecosystems. In the broader resource management and development planning approach, it is regarded from the biodiversity conservation perspective. India was split into ten biogeographic zones, including coasts. The Indian government has now recognised 18 Biosphere Reserves. India’s maritime reserves include Tamil Nadu’s Gulf of Mannar Biosphere Reserve and West Bengal’s Sundarbans Biosphere Reserve and ANI’s Great Nicobar Biosphere Reserve. A biosphere reserve often has national parks and sanctuaries within its boundaries. Mannar Marine Park is part of GOM Biosphere Reserve. In 1986, a Tamil Nadu government declaration under the Wildlife Protection Act, 1972, declared the Gulf of Mannar region a marine national park. Mannar National Park Gulf (GOMNP) is 560 km2. It has 21 islands surrounding Tuticorin and Ramanathapuram, Tamil Nadu. The GOM harbours around 3600 flora and wildlife, making it Asia’s biologically richest coastal regions (Arisekar et al. 2021). Although it was declared 20 years ago, there was no fishing ban until 2002. Certain limits have been put in place and maintained by the forest department to avoid overfishing and resource depletion. In addition to other developmental initiatives that pose concerns to the area’s biodiversity, such as the impending Sethusamudram canal project and other industrial developments on the Tuticorin coast, extensive fishing is regarded one of the greatest threats to GOM marine resources. These development buildings are not immediately present in the park region; nevertheless they threaten the park’s coral reefs and seagrass environment.

4.1.6 Biodiversity Act, 2002

The Biodiversity Act was created in 2002 to preserve and use biological resources sustainably. The statute was developed primarily to fulfil India’s CBD responsibilities. The legislation provides provisions enabling a fair and equitable sharing of benefits from the utilisation of biological resources and knowledge. Section 37 of this Act recognises and declares Biodiversity Heritage Sites (BHS). Protecting coastal habitats such as mangroves, coral reefs and seagrasses is provision under this act (Ramesh et al. 2018).

4.1.7 Indian Coastal Zone Regulations

Coastal zone is the area of terrestrial and marine interaction. The phrase coastal zone means coastal seawater, diverse coastal wetlands and marine-influenced coastal lines. The coastal zone comprises the area from high to low tide, up to 10 nautical miles from high tide to sea and up to 20 km from high tide to land. In Indian Coastal Regulation Zone (CRZ), the Ministry of Environment and Forests (MoEF) introduced the Environmental Protection Act of 1986 in 1991. CRZ guidelines prohibit activities, including human exploration and near-coastal industrial activities, to protect vulnerable and fragile ecosystems. They restrict activities that can cause hazard to delicate coastal environments (Panigrahy and Mohanty 2012).

Activities such as establishing new industries, mining, large buildings, storing or disposing of hazardous materials, reclamation and bundling—within a particular distance from the coastline are prohibited. After implementing the Environmental Protection Act in 1986, CRZ rules were first framed in 1991. Before this law came into existence, India had dispersed several. It extended laws and ordinances to oversee near-coast activities, but CRZ 1991 was the first comprehensive policy guideline to manage India’s extensive and dynamic coastline harbouring multiple unique and endangered ecosystems. A High Tide Line (HTL) 500 m physical barrier to land was demarcated. This was further separated into four zones specifying either authorised or prohibited activities in these four zones. The entire coastal zone of the country has been classified into four areas: CRZ-I (ecologically sensitive near-shore area where future development activities are not permitted), CRZ-II (an urban coastal area already developed), CRZ-III (a significantly underdeveloped rural or urban coastal area where certain activities are allowed) and CRZ-IV (a special category includes island coasts including the entire Andaman and Nicobar and Lakshadweep islands). With the Ministry of Environment and Forests consent, some vital activities may be permitted (Krishnamurthy et al. 2014). Coastal Regulation Zone (CRZ-I) covers environmentally sensitive, near-shore areas significant from a biodiversity and ecological perspective. These areas include mangroves, coral reefs, marine parks and sanctuaries, reserve forests, wildlife habitats, areas close to fish breeding and spawning grounds, areas of natural beauty, historically important and heritage areas and areas with diverse flora and fauna with abundant genetic diversity areas that are likely to be inundated by rising sea levels as a result of global warming.

Coastal Regulation Zone II (CRZ-II) already covers near-shore metropolitan areas. The region is inside municipal boundaries and was created responsibly with enough roadways, drainage and water supply infrastructure. Coastal Regulation Zone III (CRZ-III) encompasses places that may or may not develop. These areas are also within municipal limits of a not established city or town or other legally declared urban regions. Coastal Regulation Zone IV (CRZ IV) includes Indian island territory. Under CRZ-IV, coastal parts of the Andaman and Nicobar, Lakshadweep and other tiny islands were bounded for their protection and development. Due to its top-down approach, CRZ 1991 notification was modified in 2011 and CRZ notification in 2011 as compared to CRZ 1991 had other faults and met local resistance. The change came into effect, taking into account local communities and stakeholders; however, this resulted in some erosion of their powers. After disasters like the very severe cyclone hitting the Odisha coast in 1999 and the Indian Ocean tsunami in 2004 causing massive property damage and loss of several thousand lives, CRZ had a big influence, and the regulations were seriously followed (Chinnasamy and Parikh 2020). Indian shoreline systems were battered on both east and west coastlines, leading to massive loss of life and infrastructure resulting in harming economy. Post these tragedies, coastal zone protection needs were recognised through stricter restrictions. Integrated Coastal Zone Management (ICZM) concept was taken into account and adjustments made in CRZ 2011 were notified. This included adding policies utilising bottom-up as a strong mechanism of governance. Following CRZ 2011, India increased its potential for disaster management, coastal management and several community-based field projects to enhance stakeholder involvement (Panigrahy and Mohanty 2012; Krishnamurthy et al. 2014). The CRZ also emphasises ecosystem protection including mangroves, coral reefs and seagrasses. In India, seagrass is an “ecologically sensitive area” (ESA) under the Coastal Regulation Zone 2011. States are expected to develop a Coastal Zone Management Plan to defend these regions (Griffiths et al. 2020). Also, ESA includes salt marshes. Coastal Regulation Zone was further altered, and CRZ 2018 was created, resulting in further adjustments. In CRZ 1991, more attention was paid to the safety and livelihood of local fishing communities, but this is lost in CRZ 2018 (Ishan 2019; Chinnasamy and Parikh 2020).

5 Conclusion

This chapter highlights India’s large coastline zone including nine states and four Union territories, and two island groups. India’s coastal zone has enormous geomorphological features such sandy beaches, mudflats, sand dunes, mangroves, seagrass meadows, lagoons and coral reefs. Mangroves and coral reef ecosystems are well investigated in India; however, seagrasses and salt marshes were not explored. India has increased mangrove cover on the eastern coast due to huge rivers flowing eastwards and building massive deltas. The area beneath the mangrove cover is declining for less awareness of past relevance. Mangrove forests were removed for human habitation, farming, livestock grazing and wood. India also has 14 of South Asia’s 16 seagrasses. India’s seagrass ecosystems have not been extensively studied, reporting new places with seagrass meadows. The least studied environment is salt marshes. Their multiple critical roles in carbon sequestration, shoreline protection and habitat supply were not examined. India agrees with various international treaties and coastal ecosystem preservation and conservation agreements. Also, India nationally has various laws and policies to safeguard coastal areas by protecting biodiversity laws and other regulations. Coastal Zone Regulation emphasises a comprehensive plan to protect the coastal zone, which divides coastal communities based on their proximity to the sea.