Sea-level rise and vertical range shifts

Megan I Saunders (1)

1 ARC Centre of Excellence for Environmental Decisions & The Global Change Institute, The University of Queensland, QLD, 4072,, @saunders_meg

Sea-level change causes vertical range shifts of organisms occupying intertidal marine regions. Predicted sea-level rise of up to a meter or more by 2100 will cause a re-distribution of valuable coastal habitats, such as seagrass, mangroves, and coral reefs. Identifying locations where habitats are at risk of being lost, and location where habitats may potentially occur in the future, is important for management of coastal resources. Using field data and species distribution models I examined how coral reef, seagrass and mangrove habitats would re-distribute vertically in response to changing sea-level. In instances where migration to newly inundated areas is possible there is potential for habitat areas to expand in future. Conversely, in cases where natural or man-made features prevent migration losses of habitat extent are likely. In highly developed urban areas seawalls and levees are built to prevent inundation and to protect valuable infrastructure, which precludes habitat migration. Interactions between ecosystems will occur as sea levels rise, for instance, when the response of one ecosystem to sea-level rise causes changes in abiotic conditions in adjacent communities. There may be interactive effects on between local stressors and sea-level rise. For example, seagrass occurring in turbid water will be at higher risk from sea-level rise than seagrass occurring in clear water. In such cases mitigation of the local stressor can improve the response of coastal habitats to sea-level rise, providing a management opportunity to minimize impacts of climate change.