Sea grass Survey Article

Figures of bent people over the muddy shores was a sight to see one early morning (7th June). Those bent figures were community members of Lovu, Vadravadra and Yadua villagers taking part in seagrass surveys led by 4 marine field team of WWF. The sites surveyed included Vadravadra, Levuka-i-Gau, Sawaieke and Nakobuna Bay.

A typical day of surveying involved waking up at 5 to be greeted by the chill in the

morning and completing a day’s work at dusk. And then there’s the odd day of taking very long walks eg. from Lovu our camp site to Vadravadra village, all capped to an inspiring experience of laughter, great food and companionship with all the hard survey work!

Our team of 14 (10 males+4 females) was split into smaller teams of 4 people with the goal of scoping a large area of shoreline within a limited time frame and possibility of bad weather. The survey design of 50m replicate transects were laid at the seagrass area with 25 m2 quadrat sampling every 5m point on the line transect. Transects placed at 100m intervals along the shoreline where seagrass grows. Observations on percentage cover of the different seagrass species and algae component of the quadrat were recorded based on a standard ID guide. Other measurements include seagrass blade length with a 30cm ruler, a function of canopy height of seagrass meadow. Texture of sediment from fingering it to determine grain size class and the count of marine organisms found within the quadrat was also recorded. Apart from the field biological community surveys, spatial mapping of the seagrass, mud flats and beach area was done using initially a Global Positioning Systems Unit to mark the extent of each habitat type along the coast before being plotted onto a map.

Four species of seagrass were identified throughout the district coastline which included Syringodium isoetifolium (Si), Halophila ovalis (Ho), Halodule uninervis (Hu), and Halodule pinifolia (Hp). Survey results indicate that extent of seagrass growth was most prominent at Vadravadra and Nakobuna with the highest count of marine organisms like sea cucumber, crabs, starfish, brittle stars were noted at Lovu

and Nakobuna Bay. This rather undisturbed shore environment showcases the web of life and food links amongst the seagrass, beach and local mangroves. We may not realize it but the local fishers and their communities recognize the value of keeping this natural balance in check for more fish food for their future.

The beach profiling is an addition to our usual business of marine/ coastal surveys. Beach profiling is conducted at 4 key beach areas by placing 3-6 segments on the cross section of beach, with initial measurements of its slope using a clinometer instrument. Other measurements of salinity using a refractometer, thermometer to determine air temperature and a magnifying glass to describe the beach sand composition. Wave counts every hour were carried out to determine the waves’ characteristics. Debris present on the beach was also noted and was sorted during time spent on the beach. Reference points to mark extent of beach were measured and recorded for the purpose of annual beach monitoring.

In summary, with evenings to discuss and reflect on the day’s events our lasting impressions were that of understanding better the seagrass area and its community of life. The beach cleanup and sorting the debri provoked thoughts of its source and journey to the beach. Another realization by the community group is the lasting consequences of debri to the marine life contained within the beach, seagrass grass meadows, mud shores and the lagoon that could directly affect some of the food sources gleaned from their shores, thus creating awareness outreach during such surveys.