Climate change and global warming have caused a rise in the sea levels of the planet. Now, we are at a spot where our shorelines have to be fortified beyond just the seawalls. For several years, Kerala has been bracing for impacts of climate change, especially since it has one of the longest coastlines in the country.
The consecutive high tides have caused the sea to encroach into the mainland, and the rogue waves have damaged the granite seawalls, proving these methodologies to be counter-productive. Further strengthening and reconstructing the seawalls will only lead to more quarrying, thereby damaging the landscapes further.
To combat this situation, Grassroute community is bringing forth an alternative, nature-based sustainable solution — erecting biological walls using deep-rooted mangroves and other native tree species. The community which is located in Nayarambalam panchayat in Vypeen did an experimental project on November 12, planting 20 mangrove saplings (praandhan kandal) that are six-month-old each, parallel to the seawall at the northern border of Nayarambalam beach. Since they are only capable of thriving in saline marshes, the members set up an artificial habitat on the beach sand for them to flourish.
“Activities were conducted in the past to plant mangroves on the seaside, but none have tried to create an artificial habitat for them. This is purely an experimental project. If a positive result comes out of it, instead of demolishing the Western Ghats and building seawalls, stronger and sustainable biological seawalls can be grown along the entire coast of Kerala,” says K K Reghuraj, farm superintendent, Kerala University of Fisheries and Ocean Studies (KUFOS).
For this project, a pit that is 10m long, one metre wide and deep was dug. Into this, paddy straws, dry leaves, cow dung, and silt were filled, as mangroves will grow rampantly only if the soil is rich in nutrients and have a high organic carbon content. “We collected the silt from the nearby pokkali field and fish farms. The species is being grown in two parallel rows in the triangle model. Instead of directly planting the mangroves to the soil, we are planting them on silt-filled bamboo pegs,” says IB Manoj, member of the Grassroute community.
Out of the 17 species of mangroves in Kerala, praandhal kandal was chosen as they grow well, and can survive better. “They can defend strong waves, and when sea-level rise happens, mangroves can absorb some of it,” adds Manoj.
Initially, the members of the community were planning to execute the project along 150m. But for that, they needed an investment of one lakh rupees. According to the community members, a 1km seawall will cost the government around Rs 10crores, and the other alternative, tetrapods will cost even more than that.
Before the pilot project, Grassroute community had planted mangrove associates like Indian almond, punna maram, sea hibiscus and portia tree in 150 m length in puthanpally and the second set was planted again on a 150m long stretch in the same area. Mangroves were also planted in the marshy area nearby.
“Over 3,000 saplings of the native species, including seedlings were planted. All of these varieties can grow on beach sands. When its leaves and other litters fall onto the soil this can facilitate to regain the organic structure of the soil, making it suitable for mangroves to grow,” says Reghuraj. Neetu Binod, President, Nayarambalam Panchayath inaugurated the programme. C C Siji, the ward member, 12th Ward Nayarambalam, planted the first seedling. Seed Club students of Bhavans Vidyamandir, Elamakkara, teachers from SBOA School, Chittoor, and Rajagiri Outreach students participated in the project.