Climate Adaptation and Integration into Aquaculture Planning

(9/13/2019 12:00:00 AM)

Climate 101

The earth is warming at rates unprecedented in our known history (IPCC 2014).  The current warming trend is highly likely to be caused by humans, through the burning of fossilized plants that release old Carbon into the atmosphere (IPCC 2014).  The current level of Carbon Dioxide (CO2) in the atmosphere has passed 400 parts per million (ppm), are exceeding any geological records of CO2 known to exist (IPCC 2014).  CO2 is an important part of the Earth’s atmosphere, allowing energy from the sun to pass through to the earth, while capturing some of the radiated heat making the earth habitable and without massive temperature swings.  We are now adding much more CO2 to the atmosphere, leading to potential changes in the ecosystem that may not be well understood (IPCC 2014).  The Intergovernmental Panel on Climate Change (IPCC), an international body focused on developing an objective, scientific view of climate change, uses models and scenarios to project future climate change impacts.  The model outputs across the various IPCC scenarios suggest that actual temperature change is moving above even the highest scenario projections (IPCC 2014).  Changes in precipitation patterns are also likely to occur as a result of climate change (IPCC 2014). 

Impacts to Southeast Asia

Warming trends and increasing temperatures have already been observed across most of SE Asia (Hijoka et al. 2014).  Precipitation changes are not as consistent across the region, with some areas seeing more yearly rainfall with other receiving less.  Water scarcity is expected to be an important issue in the region due to increased demand and lack of good management (Hijoka et al. 2014).  Food production and food security in the region will vary with most areas expected to experience a decline in productivity (Hijoka et al.  2014).  Coastal and marine systems are under increasing stress from both climate and non-climatic drivers with projected sea level rise to result in significant impacts to coastal ecosystems (Hijoka et al. 2014).  Due to projected sea level rise, approximately 1 million or so people along the coast of SE Asia are at risk from flooding.  Extreme climate events will have an increasing impact on human health, security, livelihoods and poverty that will vary across the region (Hijoka et al. 2014).

Adaptation

Development of approaches that allow systems, species and people to adapt to a changing environment will be critical to continuity in delivery of nature’s benefits.  Successful approaches to adaptation incorporate the notion of vulnerability, identify and manage around uncertainty and build in complexity to the decision process (Stein et. al. 2014).  Actions that increase either the resistance or resilience of natural systems to the likely impacts of climate change will be important for adaptation management (Stein et al. 2014).  Tools to increase resilience may include reducing existing non-climate stressors, managing the system for function, protecting refugia and increasing habitat connectivity and implementation of proactive management and restoration plans (Stein et al. 2014).  Identification of the most vulnerable landscapes or species help the manager prioritizes the areas/species for adaptation (Stein et al. 2014).  Vulnerability is defined as the combination of potential impact to the system plus the adaptive capacity of the system (Stein et al. 2014).  Potential impact is a combination of how long a system/species is exposed to the stressor and the sensitivity of the system/species to the stressor (Stein et al. 2014).  Most vulnerability studies have good information on potential impacts but understanding of adaptive capacity lags behind (Thompson et al. 2015). 

Climate and Aquaculture

Coastal wetlands and seagrass beds sequester more carbon per unit area than most land-based ecosystems (Laffoley and Grimsditch 2009).  Further carbon emissions from aquaculture facilities compared to wild fish and other foods is significantly lower (Hall et al. 2011).  However, the global greenhouse gas contribution of fisheries, aquaculture and their supply chain is poorly studied, albeit relatively small compared to global emissions (Cochrane et. al. 2011).  Farmed aquatic organisms do no emit methane (a global greenhouse gas), but some parts of the aquaculture system can emit GHG (Hall et al. 2011).  Globally aquaculture production direct energy use is relatively low, but aquaculture can contribute to GHG emissions indirectly through the use of inputs such as feeds and inorganic fertilizers (Hall et al. 2011).  The modification of land for aquaculture facilities can have some contributions to GHG emission as a result in changes in soil, water and waste management (Hall et al .2011).  Transportation of aquaculture products does contribute to GHG emissions (Hall et al. 2011).  As best we can tell the aquaculture estimate of CO2 emissions is about 1% of the global total and about 7% of the agriculture total (Hall et al. 2011).  Some aquaculture systems have use significant amounts of energy, such eel aquaculture with warm water recirculation and high intensity shrimp farming, with aeration and pumping, contributing relatively higher amounts of CO2 emission (Hall et al. 2011).  Depending on the type of systems that is being cultured, the impacts that contribute to emissions, may include land change, feed, pond preparation and pumping (Hall et al. 2011).  Whether the impacts of climate on various cultured systems could include decrease in survival rate leading to lower yield (Hall et al. 2011). 

Adaptation and Mitigation

Within the vulnerability framework, the following measures could be taken to adapt aquaculture systems to climate change.  First, reduce the expose of the system to climate impacts by implementing measures such as raising pond dykes, upgrade pumps and sluices, maintain natural habitat or relocate to more favorable areas (UN-FAO 2013).  Second, reduce the sensitivity to the system, but farming more tolerant species, reduce dependence on wild caught seed, fishmeal and fish oil and diversify product range and livelihoods (UN-FAO 2013).  Finally, increase the adaptive capacity of the system through better weather forecasting, improved disease surveillance systems and for associations and networks to pass along best management practices and processes (UN-FAO 2013).  Biotechnology may offer some solutions in the future including improved breeds and pathogen free/tolerant species (UN-FAO 2013).  However, many of these technologies are still relatively expensive and not generally available to the rural farmer (UN-FAO 2013). 

Key Messages

Southeast Asia has a huge dependence on aquatic systems for food and job security (Taylor et al. 2016).  Climate stress is already here, with sea level rise, rising temperatures, changes in precipitation patterns and shifts in species ranges (IPCC 2014).  Climate change will cause disruptions to aquatic systems, to minimize the risk of climate impacts, we should identify vulnerable systems, and develop adaptation strategies.  Negative impacts are expected on productivity and viability of aquaculture operations and other related agriculture sectors (DeSilva and Soto 2009; UN-FAO 2013).  Climate impacts will be helped through adaptation and mitigation approaches.  In the short-term non-climate related drivers have larger impacts (UN-FAO 2013).  Current poor practices in aquaculture undermine the health of the system by reducing resiliency to climate change impacts (UN-FAO 2013).  Flexibility in management of aquaculture systems is necessary as no prescriptive advice is available (UN-FAO 2013).  Aquaculture’s footprint is relatively small, but still changes can help, such as transition to energy efficient approaches, elimination of practices that reduce ability to sequester Carbon, and look for synergies with other water use sectors (UN-FAO 2013).  Development of policy that favor climate smart approaches are likely to help in mitigates potential impacts from climate (UN-FAO 2013).

Guidance on use of climate data and projections

Climate data and projections are critical components to adaptation planning, however using these data and projections properly are the key to making informed decisions.  First, incorporate uncertainty when estimating future changes, i.e. do use projections for multiple future projections and acknowledge that scenarios encompass a range of possible outcomes (IPCC 2014).  Do not average across scenarios or assign likelihoods to the outcomes of any one scenario.  Second, not all general circulation models at the global scale are equal and represent different drivers of climate systems (Stoner et al. 2009).  About 1/3 of the models are relatively good everywhere, and about 1/3 are relatively poor everywhere (Stoner et al. 2009).  In selecting models to use choose multiple models and produce ensemble averages, resist the temptation to identify the best model and eliminate poor models from the pool (IPCC 2014).  Remember it is impossible to predict the natural variability in the climate system but is possible to identify the trends.  Finally, a caution on downscaling, not all downscaled model output is created equally, be cautious about the choice of downscaling and the use to assure it meets the scale and scope of your adaptation planning (Stoner et al. 2009). 

VIFEP (USAID workshop )