Epiphytes on seagrass (Zostera marina) growing in the lower intertidal were examined along an estuarine gradient within Yaquina Bay, Oregon over a period of 4 years. The Yaquina Estuary receives high levels of nutrients from the watershed during the wet season and from the ocean during the dry season. Mean epiphyte biomass per unit seagrass leaf surface area (epiphyte load) peaked during the summer, and thus epiphyte load was higher during dry season than wet season in both marine and riverine dominated regions. Epiphyte load was greater in marine than in riverine dominated areas in both wet and dry seasons, although only dry season differences were significant. There was no evidence that grazers controlled epiphyte load differences. Annual DIN concentration was inversely related to epiphyte load, principally because of elevated wet season dissolved inorganic nitrogen from river inputs. While there was a positive annual relation of epiphyte load to PO₄ concentration, it is not clear that phosphorus becomes a limiting nutrient for epiphyte growth. Water column light attenuation tends to increase linearly with distance from the estuary mouth, while both epiphyte load and Z. marina biomass tend to decrease. Both seagrass and seagrass epiphytes may be increasingly light limited in the upper estuary, and thus, epiphyte loads may have proportionally more impact on seagrass occurrence in this estuarine region.

对俄勒冈州亚奎纳湾河口梯度生长在潮间带下部的海草（大叶藻）上的附生植物进行了为期 4 年的检查。亚奎纳河口在雨季从流域吸收大量营养物质，在旱季从海洋吸收大量营养物质。单位海草叶表面积的平均附生生物量（附生植物负荷）在夏季达到峰值，因此在海洋和河流为主的地区，旱季附生植物负荷高于雨季。在雨季和旱季，海洋中的附生植物负荷均高于河流为主的地区，尽管只有旱季差异显着。没有证据表明食草动物控制附生植物负荷差异。年度 DIN 浓度与附生植物负荷呈负相关，主要是因为雨季河流输入中溶解的无机氮增加。虽然附生植物负荷与 PO ₄浓度呈正相关，但尚不清楚磷是否成为附生植物生长的限制性养分。水柱光衰减趋于随着距河口距离的增加而线性增加，而附生植物负荷和Z. marina生物量趋于减少。在河口上部，海草和海草附生植物都可能受到越来越轻的限制，因此，附生植物负荷可能对该河口区域的海草发生产生相应更大的影响。