Mangroves in the southwest and southeast of the country that covers four states: Karnataka, Tamil Nadu, Kerala and Andhra Pradesh will be in the most vulnerable condition. These coastlines will submerge and the mangroves in the area will degrade more as compared to other areas. Certain regions like Chilika and Sundarbans along the east coast and Dwarka and Porbandar along the west coast of India is likely to see less reduction and landward shift by 2070 due to the differential response to precipitation and sea level change in different parts of the Indian coastline, said the study.
A team of five researchers led by BSIP senior scientist Jyoti Srivastava carried out the research on two mangrove species namely Rhizophora mucronata and Avicennia officinalis which are dominating India’s coastline. The research has been published in a renowned science journal, Elsevier: Ecological Informatics.
“In our study, we took two mangrove species that are dominating the Indian coastline and then we projected and mapped the distribution of these plant species in our country’s coastline in past, present and future climate change scenarios,” said senior scientist Jyoti Srivastava who led the research.
BSIP first collected all the available mangrove fossils records that included a collection of pollen records of the two species from around 6,000 years ago to know how these species survived and what its distribution was. The scientists modelled the distribution of these plants in the past with the help of past climate data and validated it through several techniques. Going through the model projection and past records, they found the two mangrove species had comparatively widespread distribution in the Indian coastline and were flourishing well.
Thereafter, the team compared it with present mangrove data that was collected through field surveys in mangrove areas along the Godavari, Kaveri and Mahanadi deltas. After analyzing both present and past data in the wake of the climate change situation, the scientific institute found out that at present there is too much mangrove degradation. On the basis of it, the team projected the future mangrove distribution using several future climate change scenario data that indicated that under the highest global warming scenario by 2070, around 50% of mangroves will either vanish or shift from the coastline.
“Decline in mangroves at present in comparison to the past is due to the rise in temperature with a decline in precipitation. A decline in temperature leads to high saline conditions along the coastlines making mangroves vulnerable,” said Srivastava.
She said, “We took these two mangrove species for research as they are amongst the most dominant species that protect our coastline from eroding during natural calamities, like cyclones and tsunamis. If they are reduced, the natural infrastructure that protects our coast and villages located on the coast will be washed away.”
These mangroves also have a great socio-economic importance as they provide a multitude of goods and services to the coastal population, especially fishermen helping them earn their livelihood.
BSIP’s study can help identify highly suitable areas for conservation and management and develop restoration strategies to facilitate the growth of these mangrove species in the future.