Macroalgal blooms pose a threat to coastal ecosystems worldwide, especially in highly eutrophic environments. Excess nutrients often facilitate the proliferation of opportunistic algae, but in some systems grazing activity counterbalances its effects. I evaluated the regulating role of mesograzers associated with eelgrass (Zostera marina) in Elkhorn Slough, a eutrophic estuary where Ulva spp. blooms are frequent during the upwelling season. I monitored recruitment and transplant success of Ulva spp. along transects placed across the edge of the largest Z. marina bed. Changes in abundance of Ulva spp. on transplants differed spatially and seasonally, and were significantly correlated with density of both small and large invertebrate groups. Grazing affected not only adult Ulva spp. but also its early developmental stages, leading to decreased Ulva spp. abundance on transplants and minimal recruitment inside the Z. marina bed.

巨藻水华对全球沿海生态系统构成威胁，尤其是在高度富营养化的环境中。过多的养分通常会促进机会藻类的繁殖，但是在某些系统中，放牧活动会抵消其作用。我评价与大叶藻（相关mesograzers的调节作用叶藻）在埃尔克霍恩斯劳，富营养化河口，石莼属。上升季节经常开花。我监测了Ulva spp的募集和移植成功。沿着横穿最大Z. marina床边缘的样条线。乌尔瓦丰度的变化spp。移植物在空间和季节上都不同，并且与小型和大型无脊椎动物组的密度显着相关。放牧不仅影响成年乌尔瓦人种。而且还处于早期发育阶段，导致Ulva spp减少。Z. marina床内的移植物丰富且募集到最少。