Data from: Ocean warming expands habitat of a rich natural resource and benefits a national economy

Geographic redistribution of living natural resources changes the access and thereby harvesting opportunities between countries. Internationally shared fish resources can be sensitive to shifts in the marine environment and this may have great impact on the economies of countries and regions that rely most heavily on fisheries to provide employment and food supply. Here we present a climate change related biotic expansion of a rich natural resource with substantial economic consequences, namely the appearance of Northeast Atlantic mackerel (Scomber scombrus) in Greenlandic waters. In recent years, the summer temperature has been record high in the Irminger Current and this development has expanded the available and realized mackerel habitat in time and space. Observations in the Irminger Current in East Greenland in 2011 of this temperature sensitive epipelagic fish were the first records so far north-west. This change in migration pattern was followed by a rapid development of a large-scale fishery of substantial importance for the national economy of Greenland (23% of Greenland's export value of all goods in 2014). A pelagic trawl survey was conducted in mid-summer 2014 and the results showed that the bulk of ~1 million tonnes of mackerel in the Irminger Current in SE Greenland were located in the relatively warm (>8.5ºC) surface layer. Mackerel was also observed in SW Greenland. Finally, 15 CMIP5 Earth System Model projections of future marine climate were used to evaluate the epipelagic environment in Greenland. These projections for moderate and high CO2 emission scenarios (RCP 4.5 and 8.5) suggest how the available mackerel habitat may expand further in space and time. Overall, our results indicate that, if the stock remains large, productive and continues its current migration pattern, then climate change has provided Greenland with a new unique opportunity for commercial exploitation. However, positive cases like this should not be cherry-picked and misused as arguments against timely and effective mitigation of climate change.

活体自然资源的地理再分布，会改变各国间的资源获取途径，进而影响捕捞机遇。国际共享鱼类资源对海洋环境变化极为敏感，这对于高度依赖渔业保障就业与粮食供给的国家和地区而言，可能造成显著的经济冲击。本研究聚焦于与气候变化相关的、具有重大经济影响的丰富自然资源的生物分布扩张现象，具体表现为东北大西洋鲭（Scomber scombrus）现身格陵兰海域。近年来，伊尔明厄海流（Irminger Current）的夏季水温屡破纪录，这一变化使得鲭鱼的适宜栖息与实际活动范围在时空维度上均得到拓展。2011年，科研人员在格陵兰东部海域的伊尔明厄海流中观测到这一对水温敏感的上层洄游鱼类，这是该鱼种在西北海域的首次正式记录。这种洄游模式的转变随后催生了规模化捕捞产业，其对格陵兰国民经济的贡献极为显著——2014年，该渔业产值占格陵兰所有商品出口总额的23%。2014年仲夏，研究团队开展了上层拖网调查，结果表明，格陵兰东南部海域伊尔明厄海流中约100万吨鲭鱼的主体种群栖息于水温高于8.5℃的表层水域。此外，格陵兰西南部海域也有鲭鱼的观测记录。最后，本研究采用15个耦合模式比较计划第五阶段（CMIP5）的地球系统模式，对格陵兰海域未来海洋环境进行预估，以此评估该区域的上层水域环境。针对中等与高强度二氧化碳排放情景（典型浓度路径RCP 4.5与RCP 8.5）的预估结果显示，鲭鱼的适宜栖息范围有望在时空维度上进一步扩张。总体而言，研究结果表明：若鲭鱼种群仍维持现有规模与生产力，并延续当前洄游模式，那么气候变化将为格陵兰带来全新的商业化开发机遇。但需注意，此类正向案例不应被选择性截取并滥用，作为反对及时有效开展气候变化减缓行动的论据。