Tracking changes in intertidal and subtidal seagrass meadows in the Andaman archipelago

Team members: Elrika D’Souza, Evan Nazareth, Rajeswari B.T., Rohan Arthur, Siddhi Jaishankar, Teresa Alcoverro, and Wenzel Pinto

Alumni: Rachana Rao

Project timeline: 2019 - Present

Seagrasses are the only true marine flowering plants with over 65 species that form extensive meadows and occupy less than 0.2% area of the world’s ocean. They occur in all coastal waters except Antarctica, from intertidal beds to depths of upto 90 m in the sea. Seagrasses are amongst the most valued ecosystems and play an important role in carbon storage, along with other coastal ecosystems, at rates greater than many terrestrial ecosystems. They help in coastal protection, support fisheries and other biodiversity.

Despite the enormous services they provide, seagrasses have largely been overlooked and face extreme threats due to climate change and more so due to human disturbances. The rate at which we are losing seagrass cover has only accelerated from 0.9% in the 1940s to 7% since the 1990s, making it close to a loss of 10 million football fields worth the area. This has further affected a myriad of species dependent on this system, including humans.

The bulk of this knowledge of seagrasses comes from the temperate meadows, which are typically single-species. Tropical meadows, that show both monospecific and multi-species assemblages. Through this long-term monitoring study, we assess how tropical seagrass systems respond to abiotic and biotic factors over time given the threats they face due to the global climate crisis and human disturbances. 

Project objectives:

• To track changes in seagrass species composition and distribution over time

• To track species phenology (shoot density, root density, flowering, fruiting, seed presence across seasons) along the abiotic gradients

• To track species morphological traits (leaf length, leaf width, biomass) across seasons along the abiotic gradients