Entry for:NZMSS Student Awards
Seagrasses are important, highly productive, primary producers that provide a range of ecosystem services. Globally, increasing anthropogenic pressure in coastal regions has resulted in severe seagrass losses. As a result of seagrass losses in New Zealand, Zostera muelleri is recognised as a declining species. Many of New Zealand’s estuaries and coastal waterways suffer from sedimentation events, which has the potential to impact seagrasses via smothering and light attenuation. This study examined the response and resilience of Z. muelleri to catastrophic sedimentation events (isolated and cyclic).
A mesocosm experiment was used to test the effects of isolated and cyclic burial events (5, 10 and 15 days durations)on Z. muelleri. Morphometric and physiological seagrass parameters, including sucrose content, were quantified to assess acute and chronic impacts. An additional experiment was conducted in situ at three sites in Tauranga Harbour (New Zealand) over 66 days to assess the spatial variation in responses to isolated and cyclic burial events. Morphometric and physiological parameters were compared in order to identify indicators of stress. The outcomes will enable quantification of tolerable changes in sedimentation levels and identification of areas that are at high-risk of losing seagrass due to sedimentation.