气候变化影响海洋中的氧气.rar

Scientists have warned that climate change and pollution are reducing oxygen in the oceans threatening fish species, including tuna, marlin and sharks. The researchers found that around 700 ocean sites are now suffering from low oxygen compared with 45 in the 1960s. Matt McGrath reports. This study highlights the growing threat from climate change. As the world warms, around 90% of the excess heat goes into the oceans. Warmer waters hold less oxygen. In tropical regions, the losses range up to 40% of the dissolved gas in some locations. The loss of oxygen tends to favor species like jellyfish. But bigger fish, like tuna who need more energy, have to move to shallower waters, where oxygen is more plentiful, making them more vulnerable to overfishing. The best solution, say researchers, is to halt nutrient runoff and curb greenhouse gases.

科学家警告称，气候变化和污染正在减少海洋中的氧气，威胁包括金枪鱼、马林鱼和鲨鱼在内的鱼类物种。研究人员发现，现在约有700处海域缺氧，相比之下，上世纪60年代只有45处。以下是马特·麦格拉思的报道。这项研究强调了气候变化带来的日益严重的威胁。随着世界变暖，大约90%的额外热量进入了海洋。水温越高，含氧量越少。热带地区的一些海域的溶解气体减少了40%。缺氧有利于水母这样的物种。但对大型鱼类不利，比如需要更多能量的金枪鱼，不得不迁移到较浅的水域，那里的氧气更充足，但使它们更容易被过度捕捞。研究人员表示，最好的解决办法是停止养分的流入和控制温室气体。