黄石湖夏日清晨，身穿胶鞋、穿着救生衣的工人拉起刺网，试图扭转多年的生态破坏。据美国国家公园管理局（NPS）称，到10月，这项季节性捕捞作业通常会告一段落，此前已投放数千英里长的刺网。目标是一种入侵鱼类：湖鳟，该鱼于1994年首次在湖中被发现。
During summer mornings at Yellowstone Lake, workers in rubber boots and life jackets pull up gillnets in an effort to reverse years of ecological damage. By October, the seasonal fishing operation typically winds down after deploying thousands of miles of gillnets, according to the National Park Service (NPS). The target is an invasive fish first detected in the lake in 1994: lake trout.
影响远不止渔业。据NPS称，到2000年代中期至晚期，在溪流中产卵的黄石切喉鳟数量已降至1970年代末水平的5%至10%。垂钓者捕获的鱼变少，护林员在湖边看到的动物也变少，一些钓鱼向导在受影响地区减少了旅游团。这种下降威胁到几种本土野生动物的重要食物来源。为何湖鳟成为问题黄石切喉鳟是该湖的本土鱼类，是灰熊、鱼鹰、白头海雕和河狸的重要食物来源。
The effects extended beyond the fishery. By the mid-to-late 2000s, the number of cutthroat trout spawning in streams had fallen to just 5% to 10% of late-1970s levels, according to the NPS. Anglers caught fewer fish, park rangers saw fewer animals around the lake, and some fishing guides reduced tours in affected areas. The decline threatened a vital food source for several native wildlife species. Why lake trout became a problemYellowstone cutthroat trout are native to the lake and an important food source for grizzly bears, ospreys, bald eagles, and river otters.
相比之下，湖鳟于20世纪80年代被引入黄石湖，其存在于1994年首次得到证实。湖鳟改变了食物网，因为它们栖息在较深的水域，许多以切喉鳟为食的捕食者难以到达那里。NPS估计，一条湖鳟每年可捕食多达41条切喉鳟。托德·科尔（Todd Koel）及其同事于2020年在《鱼类》（Fishes）杂志上发表的一项研究还记录了这种入侵鱼类的繁殖潜力。
Lake trout, by contrast, were introduced to Yellowstone Lake in the 1980s, with their presence first confirmed in 1994. They altered the food web because they inhabit deeper waters, where many predators that feed on cutthroat trout cannot easily reach them. The NPS estimates that a single lake trout can consume up to 41 cutthroat trout annually. A 2020 study published in Fishes by Todd Koel and colleagues also documented the invasive fish's reproductive potential.
一条重达5公斤的雌性湖鳟在一次产卵事件中可产下6000至8000枚卵。研究人员还发现，黄石湖中的幼年湖鳟存活率似乎是其原生范围内幼鱼的四到六倍。
A female lake trout weighing 5 kilograms can produce 6,000 to 8,000 eggs in a single spawning event. The researchers also found that young lake trout in Yellowstone Lake appeared to survive at rates four to six times higher than those of young fish in their native range.
研究人员报告称，2012年年度刺网作业量超过46800个100米网夜，达到了科学审查小组推荐的基准。随着抑制力度加大，估计的湖鳟生物量从2012年的432017公斤下降到2019年的196675公斤。
The researchers reported that annual gillnetting effort exceeded 46,800 100-meter net-nights in 2012, meeting a benchmark recommended by a scientific review panel. As suppression intensified, estimated lake trout biomass declined from 432,017 kilograms in 2012 to 196,675 kilograms in 2019.
下降主要由成鱼数量减少79%所驱动。恢复的进展与局限大规模清除工作仍在继续。国家公园管理局报告称，工作人员在2024年捕获了26.4万条湖鳟，累计清除数量达到490万条。该机构还估计，成年湖鳟种群数量已从高峰下降了约90%。负责领导黄石公园本土鱼类保护计划的科尔报告称，黄石鳟正在返回产卵溪流，熊和秃鹰又开始在附近觅食。
The decrease was driven primarily by a 79% reduction in adult fish. Progress and limits of the recoveryLarge-scale removal efforts have continued. The NPS reported that crews caught 264,000 lake trout in 2024, bringing the cumulative number removed to 4.9 million. The agency also estimated that the adult lake trout population had declined by about 90% from its peak. Koel, who leads Yellowstone's Native Fish Conservation Program, has reported that cutthroat trout are returning to spawning streams and that bears and bald eagles are feeding near them again.
鱼鹰也开始出现在该地区。然而，恢复仍未完成。在《鱼类》研究中，2019年黄石鳟的丰度仍低于管理目标。研究人员发现，体长超过400毫米（约16英寸）的大鱼变得更常见，单条鱼的体重也翻了一番。他们认为，食物及其他资源的竞争减少可能解释了这些变化，表明幸存鳟鱼的生存条件有所改善，尽管种群尚未完全恢复。
Ospreys have also begun appearing in the area. However, recovery remains incomplete. In the Fishes study, cutthroat trout abundance was still below management targets in 2019. Researchers found that larger fish, exceeding 400 millimeters (about 16 inches), had become more common and that individual fish weights had doubled. They suggested that reduced competition for food and other resources could explain these changes, pointing to improved conditions for surviving trout even though the population had not fully recovered.
该研究还考察了减少湖鳟繁殖的努力。2019年10月，研究人员使用直升机在卡林顿岛附近的一个湖鳟产卵场撒布了1.8万公斤有机颗粒。该处理旨在减少发育中鱼卵可获得的氧气。次年春天设置的陷阱未捕获到任何湖鳟鱼苗。研究人员将该结果解读为证据，表明该处理可能杀死了该地点的胚胎，但该发现并未确定该方法在整个湖泊范围内是否有效。
The study also examined efforts to reduce lake trout reproduction. In October 2019, researchers used a helicopter to spread 18,000 kilograms of organic pellets over a lake trout spawning site near Carrington Island. The treatment was intended to reduce oxygen available to developing eggs. Traps set the following spring caught no lake trout fry. The researchers interpreted the result as evidence that the treatment likely killed embryos at the site, but the finding did not establish whether the method would be effective across the entire lake.
2019年，另一种潜在威胁出现，当时工作人员捕获了一条非黄石湖本土鱼类——湖白鲑。研究人员怀疑它是被非法引入的。
Another potential threat emerged in 2019, when crews caught a cisco, a fish not native to Yellowstone Lake. Researchers suspected it had been illegally introduced.
如果大头鲑建立起来，它们可能会与切喉鳟鱼争夺食物，同时也会为湖鳟鱼提供另一种猎物来源。抑制项目继续依赖资金、实地工作和监测。根据国家公园管理局的说法，黄石永恒基金会每年向本土鱼类保护贡献约100万美元，而志愿钓鱼者帮助研究人员采集鱼类并记录数据。科尔将湖鳟鱼控制与道路维护和锅炉维修进行了比较，将其描述为需要持续关注的必要工作。
If cisco become established, they could compete with cutthroat trout for food while also providing another prey source for lake trout. The suppression program continues to rely on funding, fieldwork, and monitoring. Yellowstone Forever contributes approximately $1 million annually to native fish conservation, according to the NPS, while volunteer anglers help researchers collect fish and record data. Koel has compared lake trout control with maintaining roads and repairing boilers, describing it as essential work that requires ongoing attention.
尽管已经清除了数百万条入侵性鱼类，但在2020年研究评估的最新一年里，切喉鳟鱼的数量仍低于管理目标。需要进行监测和随后的种群估计，以确定本土鳟鱼接近这些目标的程度。
Despite the removal of millions of invasive fish, cutthroat trout abundance remained below management targets in the latest year assessed by the 2020 study. Monitoring and subsequent population estimates will be needed to determine how closely the native trout are approaching those targets.