Global warming promises to change fish and shrimp farming
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by Roy Rosen, Development Scientist and Benedict Standen, Product Manager, Biomin, Austria limate change is a reality that threatens food security and requires us in the aquaculture industry to adapt in numerous ways. According to the World Health Organisation (WHO) in 2018, “In the last 130 years, the world has warmed by approximately 0.85oC. Each of the last three decades has been successively warmer than any preceding decade since 1850. Sea levels are rising, glaciers are melting, and precipitation patterns are changing. Extreme weather events are becoming more intense and frequent.” We have a recently reached a turning point where policy, legislation, industrial growth and technology have been challenged. Increased awareness and concern have manifested in many demonstrations: eg Fridays for Future, often led by youth around the world. Indeed, in the mainstream population we now understand the scientific, economical and often personal detail that climate change influences with us all. Climate change is a direct threat to food security. Indeed, one of the most pressing challenges we face is how to feed an ever-increasing population without increasing our ecological or environmental footprint. This is where aquaculture comes in. Aquaculture has grown and, consequently, it is more in the public spotlight as to how it may affect climate change. Generally public opinion now realises that aquaculture is one of the most sustainable solutions for healthy nutrition. Yet, it is also pertinent to consider how climate change will affect the aquaculture industry.
We all must eat
There are many points where climate change ’meets’ aquaculture, from water temperature to algal blooms, global changes in sea levels and regional or local level extreme climate events. Regardless of cultured species, every animal must eat, so we must first consider the implications of climate change, directly or indirectly, on aquafeeds. A common trend now in aquafeeds is reformulating with more sustainable ingredients, with lower reliance on marine lipid and protein sources. As well as emerging novel ingredients (eg insects, single cell proteins, etc.), many formulations currently rely on materials of plant origin. Consequently, the influence of climate change on related agricultural commodities such as soy, wheat, corn, rice and others will directly affect aquatic production. Since aquatic species are generally poikilothermic, their metabolism also changes with temperature. This is one reason why some feed manufactures produce feeds for specific seasons, and these may become more popular if we see more extreme weather.
Weather, fungi and toxins
A major outcome of changing weather patterns on crops used in the aquafeed industry is the increased growth and change of distribution patterns of harmful fungi and moulds, which not only affect the crop directly, but also produce secondary toxic metabolites known as mycotoxins. Among the major toxigenic fungi to contaminate crops are members of the genera Aspergillus (producing aflatoxins, ochratoxins,) Claviceps (ergot alkaloids) Penicillium (ochratoxin,
24 | September 2020 - International Aquafeed