Aquaculture in a changing climate

Editor's Notes

1. When I started working on the impacts of climate change on fisheries and aquaculture, in 2005, there was already a lot of academic research on climate variability, marine and aquatic ecology and fish production, but that research had little traction in the world of policy and management and was entirely unconnected with the world of climate adaptation and mitigation, of the IPCC and the climate conferences. There was no climate change policy, position statement or agenda from any national or international organization working with the sector, and none of the major climate change policies had given consideration to the sector – or even to the oceans. It took 15 years before the words ocean and fish were mentioned in UNFCCC conferences. So, as well as doing some research on vulnerablity and adaptation options, With my colleagues, we have worked hard over the last 7 years to bring climate change policy issues – impact, adaptation and mitigation – into the policy arena. Some of the steps we’ve taken and the initiatives I’ve led or been involved in include FAO’s first publication on climate change, fisheries and aquaculture Started a climate change research programme at the WorldFish Center Brought fish to COP15 – Copenhagen and hit on the idea of oceans day – like forest day and agriculture day… Helped to found the Partnership on Climate Fisheries and Aquaculture
2. Arrive here at a time when you’ve just had the largest climate-change related political demonstration in the US
3. NE US and Canada will get wetter, southern part of he country, central America and chile and much of Brazil will get dryer, as will the mediterranean, Sahel, India and Australia. SE Asia and the western Pacific will get more rain, as will scotland ,scandinavia and the soviet union
4. IPCC not over-pessimistic in its assessments…
5. The insurance company Munich Re, however, found an increase in extreme weather events (and not just cost of insurance and value of payouts)
6. Simple pathway…
7. More complicated….
8. In a 4 degree warmer world, you’d only be safe for six months of the year, instead of the 9.5 now.
9. Winners, losers and sustainability
10. Main point: ‘No regrets”
11. ! Energy use/ GHG emissions due to aquaculture can vary strongly between species, systems and regions In general LCA studies indicate that the farming stage is the most important one concerning energy use and greenhouse gas emissions, however, more studies involving the whole value chain are necessary Within the aquaculture production stage feed is most commonly the most important source of greenhouse gas emissions in aquaculture (in case the system depends on feed). On farm electricity and fuel use has a substantial impact in case of a high degree of mechanization (e.g. aeration, water exchange systems). In certain extensive systems fertilizers contribute to greenhouse gas emissions and energy use as well.
12. Results for GWP given in kg CO 2 e for the production of one live-weight tonne of fish I chose these two systems because they are from the same authors and the methodology is similar. Both analysis went up to the farm-gate (Tilapia study went beyond, but also gave results for up to farm-gate) Salmon: Pelletier et al. 2009 ( Not All Salmon Are Created Equal: Life Cycle Assessment (LCA) of Global Salmon Farming Systems) Tilapia: Pelletier & Tyedmers 2010 (Life Cycle Assessment of Frozen Tilapia Fillets From Indonesian Lake-Based and Pond-Based Intensive Aquaculture Systems)
13. Make sure the comparisons are from methodologically similar or robust studies (eg Pelletier). Good to see some more comparisons with global fisheries. Is the source correct?
14. Reduction of energy and fuel use: R educed machinery use and use of energy efficient machinery; Energy efficient lighting; Use of low carbon and/or recycled building materials; Local sourcing of inputs; Improved command and control processes; Reduction in inorganic fertilizer and other chemical inputs Renewable energy use and generation On site generation of power and/or heat from renewable sources ( solar, wind, geothermal, water, tide, wave, and biomass ); Use of biomass crops; Sourcing of renewable energy supplies ( electricity from renewable sources; run vehicles, boats, machinery and generators on biofuels ) Adoption of best management practises Efficient conversion of feed to animal biomass: enhanced through good site selection, adopting optimal feeding strategies (e.g. concerning feed presentation, feeding rate and frequency), ensuring good husbandry, selective breeding programs, switch to more energy-efficient feeds as well as improved dosage forms (e.g. better pellet size, palatability and digestibility) Improved soil, water and waste management: Avoid excessive accumulation and mineralization of organic carbon in ponds. Yet accumulating carbon (in wastewaters, sediments/sludge), however, can be captured and utilized to produce biogas or biomass (production of sea cucumbers, shellfish, detrivorous fish, algae and various plants using aquaculture waste has been successfully tested – however, species composition needs to be chosen very carefully )
15. Landscape level: Integration of the aquaculture within the wider ecosystem (e.g. farming landscape or wetlands) Farming landscape: Most of the world’s soils used for agriculture have been depleted of organic matter due to conventional farming practices (e.g. ploughing or hoeing before every crop). This degradation process is reversible: the formation of carbon stocks in soils can be achieved through increased carbon inputs and the adoption of certain agricultural practices, e.g. reduced tillage, use of cover crops. This is not only beneficial for mitigating climate change, but also enhances food security (increased yields). Sludge and wastewater from aquaculture can be used as fertilizer for agricultural crops or as a type of soil conditioner for degraded sites  The carbon in the sludge/wastewater is conserved. However, not all tested systems concerning fertilization of agricultural crops have been proven successful. Mangrove-friendly aquaculture: Various integrated systems have emerged, especially in Southeast Asia, including mangrove-shrimp, mangrove-crab or mangrove-fish systems Ways to enforce these measures include (organic) certification or integration of carbon credit schemes. However, GHG emissions and sequestration that occur as a result of the management of coastal and marine habitats are currently not accounted for and therefore not included in international climate change mechanisms (e.g. REDD; Laffoley et al. 2009). Example: Shrimp farmers striving for organic certification in Ecuador are obliged to replant at least 50% of any mangrove forest cleared to establish the farm (Bunting et al, 2009). Mangroves: long-term rate of carbon accumulation in sediment 139 gC m -2 yr -1  sequestration of carbon by means of conservation and restoration has high potential Synergies: Besides mitigation of climate, aquaculture will also need to adapt it its impacts - both mitigation and adaptation are essential in reducing the risks of climate change. The implementation of an ecosystem approach to aquaculture is one of the most relevant adaptations to climate change and also has mitigation potential  pursuing this strategy might for now be the most appropriate action