Coastal environments under pressure
More than 60% of the human population now live on or near a coastline (source: IUCN), and this proportion goes up to 85% in Australia. These areas, at the interface between land and sea, are of considerable socio-cultural and economic importance (e.g. tourism). They also host extraordinary biodiversity that supports many significant services to humankind such as maintenance of fisheries, water purification or carbon sequestration (“blue carbon”). The increasing human population (and associated activities) are having pronounced deleterious effects on the ecological condition of the world’s coastal environments and their biodiversity.
Stressors of different nature are affecting coastal ecosystems: water pollution and eutrophication, urban development and habitat degradation, introduction of alien species, climate change and its associated effects (water temperature increase, ocean acidification, sea-level rise etc). Yet their combined impacts on coastal biodiversity are poorly understood, mainly for two reasons. Firstly, traditional approaches for assessing the impacts of human activities on coastal biodiversity present multiple constraints that limit observations to a small number of taxa. Secondly, studies often focus on the impact of a single stressor, ignoring their interacting effects.
To efficiently improve the health of coastal environments and provide informed decisions for their sustainable development, we need
- to improve the in situ description of coastal biodiversity; and
- better understand the interactions between stressors and their combined effects on biological communities.
Combining environmental DNA (eDNA) biomonitoring technics to get comprehensive biodiversity survey with Bayesian Networks to disentangle effects of human stressors on coastal biodiversity and build ecological risk assessment (ERA) models. This will further allow to identify the main stressors affecting local biodiversity, test different management scenarios and recommend priority actions. We are currently developing this approach in Northern Queensland (Australia), focusing on the impacts of land-based contaminants and invasive species in estuarine ecosystems to develop a template applicable to the management of the majority of world’s coastal systems.