Long-term effects of major climatic events on the resilience and capacity for recovery of a tropical seagrass habitat

In the summer of 2010/2011 Queensland experienced severe Tropical Cyclone Yasi and some of the worst floods on record. Cyclones and plumes associated with flooding have the potential to negatively impact seagrass habitats physically and/or physiologically. Many seagrass communities on the east coast of Queensland were already in decline prior to the floods due to strong La Niña conditions for several years meaning that these communities were likely to be less resilient to further impacts and have a reduced capacity for recovery. Significant losses of coastal and deep water seagrasses near Bowen and Abbot Point were observed after the floods and TC Yasi. Results of long-term seagrass monitoring have shown evidence of recovery of deep water seagrass however, the coastal inshore meadows have not recovered. Experimental investigations of the potential for seagrass recovery at Abbot Point indicated that coastal seagrass species have a strong reliance on vegetative growth for recovery, while deep water species at Abbot Point recover through both vegetative growth and seeds within the sediment seed bank. Seed bank assessments of the coastal species at Abbot Point only found a very small store of seeds in the sediment. The lack of seeds combined with the complete loss of inshore adult plants may mean that the potential for these coastal species to recover may be restricted. The scale and longevity of the 2010/11 La Niña events were unprecedented and may have potentially resulted in a state change for Abbot Point coastal seagrasses