CARBON SEQUESTRATION IN THE SEAGRASS MEADOWS OF MALINDI MARINE PARK AND RESERVE, KENYA

Abstract

Seagrass meadows are efficient carbon dioxide (CO2) sinks sequestering about 10% of the annual organic carbon (Corg) burial in the global oceans. Corg sequestered by seagrass beds in Marine Protected Areas (MPAs) in Western Indian Ocean (WIO) region is poorly understood.The purpose of the study was to determine carbon sequestration in living seagrass biomass and sediments in the seagrass meadows of Malindi Marine Park (MMP) and Malindi Marine Reserve (MMR). Seagrass was sampled using 10 cm x 10 cm, 20 cm long corer while sediments was sampled using a PVC corer 2 cm diameter, 20 cm long during South East Monsoon (SEM) and North East Monsoon (NEM). Seagrass biomass was determined and converted into Corg while sediment Corg was determined by loss on ignition (LOI). Results showed that the dominant seagrass species was Thalassodendron ciliatum with over 80% cover. Other seagrass species present in MMP and MMR were Thalassia hemprichii, Enhalus acoroides, Syringodium isoetifolium and Halophila ovalis. There were significant differences in the mean Corg storage in living seagrass biomass between MMP and MMR during SEM for both the exposed are as (t 10 = -3.489, p = 0.006) and NEM (t 10 = -10.677, p < 0.0001) and in submerged areas (SEM t 10 = -2.385, p = 0.038) and (NEM t 10 = -7.95, p < 0.0001). There were no significant differences in the mean sediment Corg between MMP and MMR during SEM (t 6.139 = 2.02, p = 0.089) and NEM (t 10 = 2.112 p < 0.061) in the exposed areas and in submerged areas during SEM (t 10 = 1.908, p = 0.085) and NEM (t 10 = -1.73, p < 0.114). The data provide an insight on factors influencing the potential of seagrass meadows to significantly sequester Corg in MPAs. Therefore, there is need for an integrated ecosystem approach to seagrass management for improved livelihoods to coastal communities and global climate change mitigation.