THE RESILIENCE OF TROPICAL SEAGRASSES TO CHRONIC STRESS AND PHYSICAL DISTURBANCES

Abstract

Seagrasses are marine angiosperms that grow in the sheltered coastal waters and are considered one of the most valuable ecosystems on earth. Despite the recognition of their significant economic and ecological value, the past five decades has seen substantial loss and degradation of seagrass meadows worldwide, largely driven by declining water quality from human activities such as coastal modification, runoff and eutrophication. Seagrasses are sensitive to changes in water quality and possess a variety of mechanisms for coping with low light. However, little is known about how acclimation to turbid environments affects their overall resilience, and how recovery is affected when stressors are combined. This thesis tests the effects of chronic light reduction and physical disturbance on seagrass resilience. It also examines how frequent disturbances can impact resilience in the long term and whether an improvement in abiotic conditions necessarily results in recovery of the system to its original state.