Coastal Environments Under a Changing Climate—What If Resilience Building Is Not Enough?
Gregory Wilford Fisk, Philip Edward Haines and Beth Frances Toki
Climate change is expected to have a significant adverse effect on coastal and island natural systems (Walther et al. 2002; Hobday and Lough 2011). The intertidal position of mangroves, salt marshes, beaches and tidal flats, make them susceptible to changes in sea level but also other climate change variables such as increasing intense storms, and changes to rainfall patterns that can affect the physiology, ecology and long term stability of these habitats over time (refer Lovelock and Ellison 2007; Commonwealth of Australia 2009; Australian Government 2015).
Freshwater wetlands on the coast such as perched lakes, dune lakes, palustrine swamps and peat swamps, are particularly vulnerable to saline intrusion and will face more periodic tidal incursions as a result of coastal storms. Prolonged periods of high salinity will cause ecological shifts in these communities away from predominantly freshwater flora and fauna communities, favouring instead those estuarine species that can withstand more variable conditions (Neilsen and Brock 2009).
Subtidal habitats such as nearshore coral and rocky reefs and seagrass will be less affected by sea level rise, but will be more exposed to broader scale changes in ocean temperature, acidity and impacts from more intense land based runoff (affecting salinity, nutrient, light penetration and sedimentation rates).
W. Leal Filho (ed.), Climate Change Adaptation in Pacific Countries, Climate Change Management, DOI 10.1007/978-3-319-50094-2_26
Coastal species are also being affected by climate change both locally and at much greater spatial scales. Changes to the distribution of migratory species including usage of habitats for key life cycle stages such as nesting, breeding and roosting are expected for both migratory birds and marine turtles that make use of coastlines as their core habitat.
While there has been considerable effort by scientists to diagnose the effects of future climate change on natural coastal systems, climate change adaptation as a field of study and management practice continues to be heavily focused on the built environment. Many jurisdictions around the world (including all of the States and Territories in Australia) have implemented some form of legislative measure and policy guidance to ensure climate change is considered in future urban development decisions on the coast. Climate change adaptation planning and management for natural environments has been comparatively much slower to evolve.
Well formed climate change strategy documents for natural systems are now only just emerging; usually focused on existing protected areas and reserves. Invariably, these ‘first generation’ climate change strategies highlight a strong research focus and on building the resilience of these natural systems to either withstand or recover from climate change impacts (Hyder 2008; Australian Government 2015). However, there are challenges and differences of opinion amongst land and water managers to the need to start managing these areas differently because of future climate change.
It is widely recognised that climate change is most likely to exacerbate existing and more conventional threats as well as introduce new challenges for coastal managers in the context of how species, ecosystems, infrastructure and human uses are managed. Both these points question the long term effectiveness of a research and resilience building strategy, particularly facing the budget realities of governments with less public money to spend on park and reserve management and broader natural resource management issues.
The paradox of this situation is that many of the natural coastal systems that are most susceptible to climate change are incredibly valuable public assets. They contribute to both national economic growth and well as local subsistence through tourism, recreational use, and fisheries resources. In many cases, the economic benefits we derive from these systems far outweighs private infrastructure on the coast under similar threat (Buckley 2011), which raises a far more fundamental question: Will Governments and their communities seek to actively protect and manage natural assets that are vulnerable to climate change in the same way as the built environment?
If this is the case, it is asserted that a strategic approach to adaptation planning and management—similar to what is currently being developed for urban built environments—needs to start to be considered for coastal natural areas. Like the urban environment, this new management paradigm needs to be both risk and time based.