Climate Change and Resilient Tamil Nadu: Ecosystem based Adaptation - Coastal Ecosystems

1. Climate Change and Resilient Tamil Nadu
Ecosystem based Adaptation - Coastal
Ecosystems
Dr R Ramasubramanian
M.S. Swaminathan Research Foundation (MSSRF)
Chennai, India
August 7,8 & 10, 2020
Virtual Consultation
Science for Resilient Food, Nutrition and Livelihoods:
Contemporary Challenges

2. Length of coast line (Km) 1,076
Sandy Beach (%) 57
Rocky Coast (%) 5
Mud flats (%) 38
Marshy coast(%) -
Coastal Ecosystems Area (sq km)
Estuaries* 179
Mudflats 223
Mangroves 65
Salt Marshes 138
Coral reefs (Gulf of Mannar) 70
Sandy Beaches/ dunes 579
Sea Grass Beds (Gulf of Mannar) 86
Total 1340
Coastal Ecosystems in Tamil Nadu
The coastal area is endowed with a variety of coastal and marine
ecosystems, which are ecologically sensitive but highly productive.
Source : ISRO (2012); Seagrass Beds - IOM (2008). (*estuaries include creeks and lagoons)

3. Livelihood for small artisanal fishers

4. Climate Change Projection for Tamil Nadu coast
Temperature
The maximum temperature is projected to increase by 1.00C -3.10C for the period
between 2010 and 2100 with reference to the baseline 1970-2000.
Rainfall
The number of rainy days between 1901- 2005 showed marginal reduction
(Guhathakurta et al 2011). However, significant increase in heavy precipitation
events observed (India Meteorological Department).
Sea level rise
The rate of GMSL is 3.3 mm year−1 since 1993; In the NIO region the rise was
between 1.06 and 1.75 mm year−1 from 1874 to 2004 and is 3.3 mm year−1 in the
recent decades (1993–2015).
The Tamil Nadu coast by the end of the century the sea level may rise between
0.19 m and 0.73 m (TNSAPCC). The Cauvery Delta is highly vulnerable to SLR.
Cont..

5. Source: IMD ( www.imd.gov.in/section/nhac/
dynamic/cyclone.htm1)
Cyclones between 1891 and 2006
Cont..
Cyclone projections
The number of cyclones along the east coast including Tamil Nadu is likely to
reduce; however, the intensity i.e., the wind speed of the cyclones may increase.
(The Climate Change and India, MoEF&CC, 2010). The Northern part of Tamil
Nadu (Kanchipuram, Cuddalore, Villupuram and Nagapattinam districts) will be
severely affected.
Source: Priya and Mani, 2015

6. Tamil Nadu State Action Plan for Climate Change in the coastal areas
Strategies:
• Increasing tree cover (Mangroves and coastal vegetation) along the coastal
zone with appropriate trees to reduce the impact of coastal erosion
• Biodiversity Conservation in the coastal zone to reduce the climate change
impact
• Reclamation of saline and Alkaline soils along the coastal area

7. Ecosystem Based initiatives to address the issues of
climate change
Ecosystem-based Adaptation (EbA) involves a wide range
of ecosystem management activities to increase the
resilience of the community and the environment to reduce
the climate change vulnerabilities
I. Conservation and management of mangrove wetlands
II. Integrated farming - Aquaculture
III. Biosaline Agriculture

8. District Total Mangrove Cover (sq km)
Cuddalore 7.73
Nagapattinam 3.05
Thiruvarur 1.9
Ramanathapuram 2.34
Thanjavur 12.25
Thiruvallur 0.91
Thiruvarur 12.85
Tuticorin 3.80
Total 44.83
Extent of Mangroves Indian State of Forest Report (2019)
Global Extent: 18 million ha
Mangroves sinks about carbon =218 ± 72 Tg C yr-1 globally.
Mangrove extent in India: 497,500 ha. (4975 sq km)
Tamil Nadu: 4500 ha (45 sq km)
There is a scope to increase the mangrove cover in the Ramanathapuram
and Thiruvarur districts

9. I. Conservation and management of mangrove wetlands
Causes for mangrove degradation: Both anthropogenic and man
made
• Joint Mangrove Management (JMM) -a science based, community
centered and process-oriented approach to conserve, restore and
sustain mangrove wetlands. Implemented in Tamil Nadu, Andhra
Pradesh, Odisha and Maharashtra. More than 2,500 ha of degraded
mangroves restored.
• Natural regeneration of mangroves is also observed in large areas –
in the newly formed mudflats and also in the elevated areas
• In recent years the mangroves in Tamil Nadu face CC vulnerability

10. Restoration of degraded Mangroves

11. Pichavaram Mangroves

12. Before Gaja Cyclone Sep 2018 - Muthupet
After Gaja Cyclone Dec 2018 - Muthupet
Muthupet Mangrove wetland
Nearly 4 sq km was lost (Thiruvarur and Nagapattinam)

13. Impact of SLR on Mangroves
• The mangrove ecosystem has the ability to cope up the sea level
rise provided that there is a continuous sediment supply and
sedimentation and also increase in the below ground biomass
(SDG – 13 Climate Action)
• However, the mangrove wetlands in Tamil Nadu receive very less
sediment flow.
• Sea level rise will result in shift in the distribution of mangrove
species or the ultimate loss of species and wetland ecosystems
•
The mangrove plants tend to colonize in the new intertidal areas
because of rise in the sea level. However, majority of the land in
the upper reaches are with other land uses and will not able to
colonize leading to loss of mangroves due to submergence.

14. II a. Integrated Mangrove Fishery Farming System
• The Mangroves acts as a barrier and the water spread area helps the
farmers to rear fish. Tidal fed ponds;
• IMFFS farms established in Tamil Nadu and Andhra Pradesh; Suitable
for crabs and sea bass; Blue solutions considered IMFFS as one of
the adaptation strategies for SLR (SDG 2; SDG 13)
• Scope for replication in other states

15. II b. Integrated Fish Farming System
Maximum diversified farm outputs
with minimum financial and labour
costs.
Benefits
• Family level farming
• Provides House hold food Security (SDG 2)
• Increase productivity and profit
• Recycling of wastes
• Diversified income
• Produce fish in combination with agriculture
centered around fish pond.
• Farming sub-systems fish, crop, livestock are
linked to each other.
• The byproducts/wastes from one sub-system
become valuable inputs to another sub-system

16. II c. Cage Culture of Sea Bass
Cage culture of sea bass in Krishna District, Andhra Pradesh to enhance
the adaptive capacity of the coastal community to sea-level rise. (SDG 13
and 14)
Plan to replicate in Ramanathapuram coast

17. III. Biosaline Agriculture – Halophytes
Coastal Saline soils in Tamil Nadu: 15,261 ha (Mandal and Sharma 2009).
Halophyte cultivation
Halophytes are saline tolerant plants which grows luxuriantly in saline
soils. More than 2000 species were recorded globally; In Tamil Nadu and
Andhra Pradesh coast 29 halophyte species identified.
The local community use species like Suaeda sp. and Sesuvium sp. are
used as green leaf vegetable.
Seven species of halophytes were cultivated in the saline soils using saline
water along the coastal areas in Tamil Nadu and Andhra Pradesh.

18. Biosaline Farming of halophytes
Porteresia coarctata Paspalum vaginatum
Suaeda maritima Sesuvium portulacastrum

19. Conclusion
• Ecosystem Based Conservation and management of coastal
resources involving the multiple stakeholders (mangroves,
sea grass beds, coral reefs, sand dunes, TDEFs)
• Climate change adaptation measures like integrated
aquaculture, bio-saline agriculture and coastal biodiversity
conservation are important
• Climate literacy and replicable adaptation measures to
mitigate the impacts of CC

20. Thank You