As global warming threatens corals, scientists search for reefs that can take the heat
As global warming threatens corals, scientists search for reefs that can take the heat
随着全球变暖威胁珊瑚，科学家们寻找能够抵御高温的礁石
MAJURO, Marshall Islands—Perched on the bow of an aluminum landing craft, Anne Cohen gazed a few yards ahead of the vessel toward a yellow robot gliding across the emerald Majuro lagoon. The unmanned surface vehicle, called Yellowfin, was quickly becoming one of the coral researcher’s most dependable guides in these Central Pacific waters. 马绍尔群岛，马朱罗——安妮·科恩（Anne Cohen）站在一艘铝制登陆艇的船头，凝视着前方几码处，一艘黄色机器人正滑行在马朱罗环礁翡翠色的泻湖上。这艘名为“黄鳍金枪鱼”（Yellowfin）的无人水面航行器，正迅速成为这位珊瑚研究员在这些中太平洋水域中最可靠的向导。
“She’s the best dive buddy,” said Cohen, a tenured scientist at the Woods Hole Oceanographic Institution in Cape Cod. Programmed to navigate to a precise set of coordinates, the robot cut through small swells like a tiny sailboat without a mast, directing Cohen toward a destination she had traveled thousands of miles to revisit. “它是最好的潜水伙伴，”科恩说，她是科德角伍兹霍尔海洋研究所（Woods Hole Oceanographic Institution）的一名终身科学家。该机器人被编程为导航至一组精确的坐标，像一艘没有桅杆的小帆船一样切开细小的波浪，引导科恩前往她不远万里前来重访的目的地。
When the robot finally paused, hovering in place, Cohen recognized it as her cue. Somewhere below should be a patch of reef she’d been observing over the last few years, and she was eager to see how it was faring. Each visit carried a growing weight of uncertainty. 当机器人最终停下并悬停在原地时，科恩意识到这是给她的信号。在下方某处，应该就是她过去几年一直在观察的一片礁石，她急切地想看看它的状况。每一次造访都带着日益沉重的不确定性。
Since 2023, record-breaking marine heat waves have swept through the tropics, fueling the most severe global coral bleaching event ever recorded. More than 80 percent of the world’s reefs have been impacted in at least 83 countries and territories. Corals have been so stressed by the extreme temperatures, they’ve expelled the tiny algae living inside their tissues that provide them with food and their brilliant hues, leaving them pale, ghostly and struggling to survive. Many have not recovered. 自2023年以来，破纪录的海洋热浪席卷了热带地区，引发了有记录以来最严重的全球珊瑚白化事件。在至少83个国家和地区，超过80%的全球珊瑚礁受到了影响。珊瑚因极端温度而承受巨大压力，它们排出了生活在组织内、为其提供食物和绚丽色彩的微小藻类，导致珊瑚变得苍白、如幽灵般，并在生存边缘挣扎。许多珊瑚至今未能恢复。
Cohen hoped the reef beneath her might be different. She yanked on her black and yellow snorkel fins, spit into her mask so it wouldn’t fog underwater and slid off the boat, her slight frame barely making a splash. Within seconds of peering into the blue, she let out a squeal muffled by her snorkel, astonished at the scene unfolding beneath her. 科恩希望她下方的礁石能有所不同。她穿上黑黄相间的浮潜脚蹼，往面罩里吐了口唾沫以防在水下起雾，然后滑入水中，她瘦小的身躯几乎没有激起水花。在凝视深蓝几秒钟后，她通过呼吸管发出了一声闷响，对眼前展现的景象感到震惊。
Towering pinnacles of chestnut-colored tabletop corals rose from the sandy seafloor like trees, their broad plate-like canopies sheltering fish hiding in their shadows. Dense thickets of staghorn corals stretched in every direction, their golden antler-like branches twisting across a sprawling reef extending as far as the eye could see, bursting with shades of mustard yellow, pink and lavender pastels. 栗色的桌面珊瑚像树木一样从沙质海底拔地而起，高耸入云，它们宽阔的盘状冠层为躲在阴影中的鱼类提供了庇护。茂密的鹿角珊瑚丛向四面八方延伸，它们金色的鹿角状枝条在广袤的礁石上交织，一眼望不到边，绽放出芥末黄、粉红和淡紫色的柔和色彩。
“It’s like a wonderland,” Cohen said, popping her head above the surface, beaming. “I feel like Alice.” “这就像仙境一样，”科恩将头探出水面，满脸笑容地说道。“我觉得自己就像爱丽丝。”
In today’s oceans, the scene felt almost surreal, said Cohen, 62, who has spent the last 30 years studying coral reefs and the impacts of climate change on marine environments. But it was a confirmation of something she had long believed: that even as hotter temperatures devastate coral reefs, some still possess an extraordinary ability to endure. She was determined to find out how. Unlocking the secrets behind their resilience, she said, could one day help scientists and conservationists restore, or even cultivate, reefs better equipped to survive a warming planet. 62岁的科恩在过去30年里一直致力于研究珊瑚礁以及气候变化对海洋环境的影响。她说，在今天的海洋中，这一幕显得近乎超现实。但这证实了她长期以来的一个信念：即使高温正在摧毁珊瑚礁，一些珊瑚仍然拥有非凡的忍耐力。她决心找出原因。她说，解开它们韧性背后的秘密，有朝一日可以帮助科学家和环保人士修复，甚至培育出更能适应变暖地球的珊瑚礁。
Searching for super reefs
寻找“超级珊瑚礁”
Over the last decade, a significant part of Cohen’s research has focused on tracking down these reefs that are somehow defying the odds. In 2018, she started a project dedicated to this search called Super Reefs, named after a number of reefs she’d encountered around the world that seemed to be thriving even while others nearby蝴蝶效应. 在过去十年中，科恩研究的重要部分集中在追踪这些以某种方式打破常规的礁石上。2018年，她启动了一个专门从事这项搜索的项目，名为“超级珊瑚礁”（Super Reefs），这个名字源于她在世界各地遇到的一些礁石，它们在附近其他珊瑚礁白化或死亡时，似乎依然生机勃勃。
“We saw these corals that were behaving as if there was no heat wave at all,” she recalled. “I kind of felt like there was Superman or Superwoman coming in there and flexing their muscles, being super, super strong.” “我们看到这些珊瑚的表现，就好像根本没有热浪一样，”她回忆道。“我感觉就像超人或女超人来到那里展示肌肉，变得超级、超级强大。”
Three years later she launched a joint global initiative with The Nature Conservancy and Stanford University aimed at not only finding heat-tolerant communities, but also protecting them. Even the hardiest of reefs are not invincible, she said. Coastal development projects such as ports or harbors that require dredging can bury corals beneath sediment. Agricultural runoff, sewage and plastic pollution introduce harmful pathogens and excess nutrients that spark coral disease or toxic algal blooms that suffocate the tiny animals. 三年后，她与大自然保护协会（The Nature Conservancy）和斯坦福大学联合发起了一项全球倡议，旨在不仅寻找耐热的珊瑚群落，还要保护它们。她说，即使是最顽强的礁石也不是不可战胜的。需要疏浚的港口或码头等沿海开发项目可能会将珊瑚掩埋在沉积物之下。农业径流、污水和塑料污染引入了有害病原体和过量营养物质，引发珊瑚疾病或有毒藻华，使这些微小的动物窒息。
Bottom trawling—a fishing method that drags weighted nets across the seafloor—can crush entire reefs, while dynamite fishing can shatter centuries-old coral colonies in seconds. “That would be like taking a sledgehammer to crush a hermit crab,” Cohen said. 底拖网捕捞——一种在海底拖拽加重网的捕鱼方法——可以摧毁整个礁石，而炸药捕鱼可以在几秒钟内粉碎数百年历史的珊瑚群落。“那就像是用大锤去砸碎一只寄居蟹，”科恩说。
Already, the world has lost more than half of its coral reefs to the combined pressures of climate change and other human activity. Some scientists warn that without significant intervention, more than 90 percent of tropical reefs could disappear in the next 25 years. 目前，由于气候变化和其他人类活动的共同压力，世界已经失去了超过一半的珊瑚礁。一些科学家警告说，如果没有重大的干预措施，未来25年内，超过90%的热带珊瑚礁可能会消失。
The goal of the new Super Reefs initiative was to specifically identify coral strongholds in places where governments had already demonstrated an invested interest in creating marine-protected areas—designated zones in the ocean where human activities are limited or prohibited to safeguard critical ecosystems. Belize, Hawaii, and the Marshall Islands fit the bill. All had plans to create or strengthen already established marine-protected areas when the project launched. 新的“超级珊瑚礁”倡议的目标是专门确定那些政府已经表现出投资兴趣、致力于建立海洋保护区的珊瑚据点——即海洋中限制或禁止人类活动以保护关键生态系统的指定区域。伯利兹、夏威夷和马绍尔群岛符合这一条件。在项目启动时，这些地方都有计划建立或加强已有的海洋保护区。
This was important, Cohen said. She didn’t want to collect data just for the sake of it. She wanted to make sure the research her team conducted could inform practical decisions related to where and how to protect super reefs. The next challenge was narrowing their search. Not every reef that shows signs of resilience is a super reef. By definition, Cohen said, super reefs have to have scientifically proven capabilities of surviving hotter temperatures over time, either because they have genetically adapted to extreme heat or because local ocean conditions like cooler currents have shielded them. They also have to be able to potentially reseed other reefs. 科恩说，这一点很重要。她不想仅仅为了收集数据而收集数据。她希望确保其团队进行的研究能够为有关在哪里以及如何保护超级珊瑚礁的实际决策提供依据。下一个挑战是缩小搜索范围。并非每一个表现出韧性迹象的礁石都是超级珊瑚礁。科恩说，根据定义，超级珊瑚礁必须具备经科学证明的、随时间推移在更高温度下生存的能力，这要么是因为它们在基因上适应了极端高温，要么是因为较冷洋流等局部海洋条件保护了它们。它们还必须具备潜在地为其他礁石重新播种的能力。
“If we can protect these more climate-resilient reefs and make sure that they are protected from other human impacts like pollution or dredging or other things, then we’re securing those more heat-r “如果我们能保护这些更具气候韧性的礁石，并确保它们免受污染、疏浚或其他人类活动的影响，那么我们就能保护那些更耐热的……”