Germination and growth evaluation of Tall-Stilt Mangrove (Rhizophora apiculata) propagules in Tropical Peninsular India

Abstract

Mangrove forests are one among the most productive ecosystems and offer a wide range of resources and services including shoreline stabilization, habitat, nursery and breeding ground for many commercial fin and shell fish species and other fauna. In order to conserve and restore the fast diminishing mangroves patches along the coasts of tropical peninsular India, especially of Kerala due to anthropogenic developmental activities as well as pollution, holistic investigations must be carried out to find the reasons and suitable environmental factors that can support the germination and growth of propagules of different mangrove species. A preliminary attempt has been carried out to evaluate the germination and growth characteristics of tropical Tall-Stilt mangrove, Rhizophora apiculata Blume, propagules in situ along with water and sediment characteristics at a natural and private owned mangrove cum fish farm, ‘Mangrove Isle’, Kayamkulam, Alappuzha District of Kerala state (India). Monthly water and sediment samples were collected and physico-chemical parameters were analyzed following standard procedures and morphometric growth studies in situ of the mangrove during the three seasons, pre-monsoon, monsoon and post-monsoon were assessed for a year during 2017-2018. Water quality parameters like total dissolved solids, hardness and nitrate registered significant (P<0.01) difference and clay as well as silt content of sediment also showed significant (P<0.05) seasonal variation. A total of 11 morphometric parameters of plant were recorded to assess growth  seasonally up to one year from the germination of propagules and the results were discussed in relation to water and sediment quality. Conservation, propagation and cultivation of indigenous mangrove species along the Kerala coast is the need of the hour to save the coast of Kerala from natural disasters like beach erosion, tsunami, flood and other anthropogenic hazards.