Seasonal migrations of fish populations can have large effects on lake nutrient budgets and food web dynamics, but the addition of a migrating non‐native species may alter these dynamics. The Round Goby (Neogobius melanostomus) arrived in Lake Ontario (USA/Canada) about 20 years ago with a documented history of annual offshore–inshore migrations in its native range. Here we combined nearshore, fixed‐plot video with offshore trawl data to document the annual migration of this population over multiple years. This behaviour was correlated with seasonal, nearshore temperature changes. The population size structure and mean fish length of returning fish were smaller than those of out‐migrating fish. The out‐migrating population contained an estimated 37.7 metric tonnes of phosphorous; and we estimated roughly 20 metric tonnes were translocated to and remained in offshore waters over the winter months, representing an important nutrient subsidy to a variety of offshore piscivorous fish. Lake Sturgeon (Acipenser fulvescens) have incorporated Round Goby extensively into their diet and consume a size range of fish matching the size range of missing Round Goby that fail to return to the nearshore. We conclude Round Goby are an important prey within the food web of Lake Ontario and translocate roughly 6.5% of the monthly total phosphorous load entering from surface waters. Further investigations of the nutrient content, population size structure and fate of migrating Round Goby in Lake Ontario are warranted to clarify the extent of this prey and nutrient subsidy in ongoing assessments of lake condition.

中文翻译：

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圆虾虎鱼（Neogobius melanostomus，帕拉斯1814）的季节性迁徙动态及其对安大略湖食物网的影响

鱼类种群的季节性迁移可能对湖泊养分收支和食物网动态产生很大影响，但是增加非本地物种的迁移可能会改变这些动态。圆虾虎鱼（Neogobius melanostomus）大约20年前到达安大略湖（美国/加拿大），该文件记录了其本国范围内每年的近海-近海迁徙历史。在这里，我们将近海固定地块视频与近海拖网数据相结合，以记录该人口在过去几年中的年度迁移。这种行为与季节性的近岸温度变化有关。返乡鱼的种群规模结构和平均鱼长小于迁徙鱼的种群。移居国外的人口估计含磷37.7公吨；我们估计在冬季，大约有20公吨被转移到并留在海上水域，这是对各种海上食鱼鱼类的重要营养补贴。St鱼湖（Acipenser fulvescens）已将Round Goby广泛地纳入其饮食中，并食用了一定大小的鱼，其大小与缺少的Round Goby的大小范围相同，无法返回近岸。我们得出结论，环虾虎鱼是安大略湖食物网中的重要猎物，可以转移约每月从地表水进入的总磷负荷的6.5％。有必要对安大略湖中来回虾虎鱼的营养成分，种群大小结构和结局进行进一步调查，以在正在进行的湖泊状况评估中阐明这种猎物和营养补贴的程度。