Seabirds redistribute nutrients between different ecosystem compartments and over vast geographical areas. This nutrient transfer may impact both local ecosystems on seabird breeding islands and regional biogeochemical cycling, but these processes are seldom considered in local conservation plans or biogeochemical models. The island of Stora Karlsö in the Baltic Sea hosts the largest concentration of piscivorous seabirds in the region, and also hosts a large colony of insectivorous House martins Delichon urbicum adjacent to the breeding seabirds. We show that a previously reported unusually high insectivore abundance was explained by large amounts of chironomids—highly enriched in δ¹⁵N—that feed on seabird residues as larvae along rocky shores to eventually emerge as flying adults. Benthic ammonium and phosphate fluxes were up to 163% and 153% higher close to the colony (1,300 m distance) than further away (2,700 m) and the estimated nutrient release from the seabirds at were in the same order of magnitude as the loads from the largest waste-water treatment plants in the region. The trophic cascade impacting insectivorous passerines and the substantial redistribution of nutrients suggest that seabird nutrient transfer should be increasingly considered in local conservation plans and regional nutrient cycling models.

海鸟在不同的生态系统区域和广阔的地理区域之间重新分配营养。这种养分转移可能会影响海鸟繁殖岛上的当地生态系统和区域生物地球化学循环，但这些过程很少在当地保护计划或生物地球化学模型中考虑。波罗的海的 Stora Karlsö 岛栖息着该地区最大的食鱼海鸟，并且还栖息着一大群食虫海鸟Delichon urbicum，与繁殖海鸟相邻。我们表明，先前报道的异常高的食虫动物丰度是由大量摇蚊 - 高度富含δ ^{15 来解释的}N——以海鸟残骸为食，幼虫沿着岩石海岸，最终成为飞行的成虫。靠近群落（1,300 m 距离）的底栖铵和磷酸盐通量比远离群落（2,700 m）高 163% 和 153%，并且估计来自海鸟的营养释放量与来自群落的负荷处于同一数量级该地区最大的污水处理厂。影响食虫雀类的营养级联和营养物质的大量重新分配表明，在当地保护计划和区域营养循环模型中应该越来越多地考虑海鸟营养转移。