Sea surge on Kerala coast

Sea surge on Kerala coast

Subject : Environment

Context : Kerala’s 590-kilometre-long coastline — one of the most densely populated in India and exposed to rogue waves — has for long been susceptible to large-scale sea erosion.

Concept :

• A recent study has flagged the possibility of coastal areas in the state witnessing an increasing trend of sea surge in the coming years, mainly due to the rise in sea surface temperature.
• The scientists have advocated for nature-based solutions, in such a case, involving active participation of residents of the coastal communities.
• He added that the most impacted communities in Kerala — bordered by the Western Ghats on the east and the Lakshadweep Sea on the west — live at the ecotone of land and the sea. This calls for urgent intervention of the state government.

Ecotone

• An ecotone is a zone of junction or a transition area between two biomes (diverse ecosystems).
• Ecotone is the zone where two communities meet and integrate.
• For e.g. the mangrove forests represent an ecotone between marine and terrestrial ecosystem.
• Other examples are grassland (between forest and desert), estuary (between fresh water and salt water) and riverbank or marshland (between dry and wet).

Characteristics of Ecotone

• It may be narrow (between grassland and forest) or wide (between forest and desert).
• It has conditions intermediate to the adjacent ecosystems. Hence it is a zone of tension.
• Usually, the number and the population density of the species of an outgoing community decreases as we move away from the community or ecosystem.
• A well-developed ecotone contains some organisms which are entirely different from that of the adjoining communities.

Ecocline

• Ecocline is a zone of gradual but continuous change from one ecosystem to another when there is no sharp boundary between the two in terms of species composition.
• Ecocline occurs across the environmental gradient (gradual change in abiotic factors such as altitude, temperature (thermocline), salinity (halocline), depth, etc.).

Edge Effect – Edge Species

• Edge effect refers to the changes in population or community structures that occur at the boundary of two habitats (ecotone).
• Sometimes the number of species and the population density of some of the species in the ecotone is much greater than either community. This is called edge effect.
• The organisms which occur primarily or most abundantly in this zone are known as edge species.
• In the terrestrial ecosystems edge effect is especially applicable to birds.
• For example, the density of birds is greater in the ecotone between the forest and the desert.