A partnership with:

Seagrass Project

Principal Investigator: Susantha Udagedera

Project Partner & Funder: Project Seagrass.

Location: Island-wide

Current Status: Completed.


Twelve species of Seagrass have been recorded from Sri Lanka, ranging from North, South, Southwest, West and Northwest coastal areas. The Puttalam lagoon has an extensive Seagrasses meadow, which in the early and mid-1990s covered approximately 24% of the total lagoon area. The lagoon is a large 327 km2 lagoon in the Puttalam District of western Sri Lanka and is both economically and ‪‎ecologically important to the 250,000 people who live in the area.  Seagrass habitat in Puttalam lagoon supports fisheries productivity and importantly food supply in such areas.

However, Seagrasses are subjected to a magnitude of threats, and have declined rapidly in the last two decades, with many severe environmental impacts. With an estimated loss of 110 km2 a year, and a loss of 29% of the Seagrass area that was believed to have existed at the beginning of the twentieth century (Serrano et al., 2016; Cullen-Unsworth and Unsworth, 2013). Decline of the standing crop of Seagrasses ecosystems in northern, eastern and western parts of the Negombo Lagoon (~100 km away from Puttalam lagoon) is estimated as 96% from 1997 to 2004 (only seagrass decline data available for Negombo Lagoon ( De Silva and Amarasinghe, 2007). The risk is that such widespread seagrass loss will result in food insecurity and economic instability among resource dependent communities living around the Puttalam lagoon.

This collaborative research was undertaken as part of a wider project investigating  links between Seagrass meadows and food security, using Sri Lanka as a pilot case study. The aim of the study was to evidence links between seagrass associated fauna and local food security. In the Sri Lanka pilot, we used a baited underwater video system for rapid habitat assessment and visual fish census,  conducted two hundred household surveys (socio-economic) along the Puttalam Lagoon, carried out two hundred fisheries landings surveys and conducted market assessments (two market).


Research Team:

  1. Dr. Leanne C. Cullen-Unsworth, Sustainable Places Research Institute, Cardiff University and Project Seagrass
  2. Dr. Richard R.K.F Unsworth, Seagrass Ecosystems Research Group, Swansea University.
  3. Susantha Udagedara, Blue Resources Trust, Sri Lanka
  4. Benjamin L. Jones, Sustainable Places Research Institute, Cardiff University and Project Seagrass

Sorting seagrass

Conducting surveys

Project Sponsors