Data for Downscaled climate change threats to United States freshwater finfish aquaculture

Climate change threatens food production, yet gaps remain in our understanding of these threats to aquaculture, the fastest growing food production subsector. To build climate-resilient practices and policies we need to quantify and map current and future climate threats to aquaculture. Here, we explore how downscaled climate change [SSP 2 (eq. RCP 4.5) and SSP 5 (eq. RCP8.5), CMIP6] threats – including water scarcity, flooding, and increasing temperature – may directly affect United States (US) freshwater farmed fish (N = 7) based on their biological thermal tolerances and indirectly challenge the operations required for production, including to the human workforce. Aquaculture in the US is dominated by catfish, trout, and tilapia production and is widespread, with some form of finfish aquaculture present in every state and nearly half of all counties across the country. Given the current location of catfish, tilapia, bass, and carp in the US and their tolerance to warmer conditions, we find increasing temperatures are less likely to biologically impact these species negatively. In contrast, current trout, sturgeon, and perch production will be biologically threatened by rising temperatures. With respect to operational needs for facilities, increases in ‘wet bulb’ temperatures in the Southeast will regularly challenge human physiological limits and constrain worker capacity. Drought in the Southwest will also limit an intrinsically water dependent system, affecting nearly all taxa. While current areas of aquaculture will tend to become increasingly challenging for farmed fishes, new potential habitats will open up for nearly all species. Overall, in the absence of immediate greenhouse gas mitigation, there are several non-mutually exclusive climate adaptations, yet these adaptations can be extremely costly. Ultimately, freshwater aquaculture in the US is going to be under intense climate pressure, which may drive out small operations and cause the country to further increase dependence on international aquatic food imports.气候变化正威胁粮食生产，但我们对气候变化给水产养殖业（aquaculture）——这一增长最快的粮食生产子行业——带来的这类威胁的认知仍存在缺口。为构建气候适应型的实践模式与政策体系，我们需要量化并绘制水产养殖业当前及未来面临的气候威胁图谱。本研究探讨了降尺度气候变化情景[SSP 2（等效于RCP 4.5）与SSP 5（等效于RCP 8.5），CMIP6]所带来的威胁——包括水资源短缺、洪涝灾害与气温上升——如何基于美国（US）7种淡水养殖鱼类的生物热耐受特性，对其产生直接影响，并间接制约养殖生产所需的各项运营活动，包括对劳动力群体的影响。美国水产养殖业以鲶鱼、虹鳟与罗非鱼养殖为主，分布极为广泛，全美各州以及近半数县域均存在不同类型的有鳍鱼类养殖活动。鉴于美国境内当前鲶鱼、罗非鱼、鲈鱼与鲤的养殖区位及其对高温环境的耐受能力，本研究发现气温上升不太会对这些物种产生负面生物学影响。相比之下，当前的虹鳟、鲟鱼与河鲈养殖将受到气温上升的生物学层面威胁。就养殖设施的运营需求而言，美国东南部地区湿球温度的升高将持续突破人类生理极限，进而制约作业人员的生产能力。美国西南部的干旱同样会制约本就高度依赖水资源的养殖系统，对几乎所有养殖物种类群造成影响。尽管当前的水产养殖区域对养殖鱼类而言将愈发艰难，但几乎所有物种都将获得新的潜在适宜栖息地。总体而言，若不立即开展温室气体减排行动，尽管存在多种互不排斥的气候适应方案，但这些方案的实施成本将极为高昂。最终，美国淡水水产养殖业将面临严峻的气候压力，这可能会迫使小型养殖企业退出市场，并导致美国进一步提升对国际水产食品进口的依赖度。