Aoki Lillian R, Ritter Carmen J, Beatty Deanna S, Domke Lia K, Eckert Ginny L, Graham Olivia J, Gomes Carla P, Gross Collin, Hawthorne Timothy L, Heery Eliza, Hessing-Lewis Margot, Hovel Kevin, Koehler Karl, Monteith Zachary L, Mueller Ryan S, Olson Angeleen M, Prentice Carolyn, Rappazzo Brendan, Stachowicz John J, Tomas Fiona, Yang Bo, Harvell C Drew, Duffy J Emmett
Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, New York, USA.
Environmental Studies Program, University of Oregon, Eugene, Oregon, USA.
Ecology. 2025 Jan;106(1):e4532. doi: 10.1002/ecy.4532.
Disease is a key driver of community and ecosystem structure, especially when it strikes foundation species. In the widespread marine foundation species eelgrass (Zostera marina), outbreaks of wasting disease have caused large-scale meadow collapse in the past, and the causative pathogen, Labyrinthula zosterae, is commonly found in meadows globally. Research to date has mainly focused on abiotic environmental drivers of seagrass wasting disease, but there is strong evidence from other systems that biotic interactions such as herbivory can facilitate plant diseases. How biotic interactions influence seagrass wasting disease in the field is unknown but is potentially important for understanding dynamics of this globally valuable and declining habitat. Here, we investigated links between epifaunal grazers and seagrass wasting disease using a latitudinal field study across 32 eelgrass meadows distributed from southeastern Alaska to southern California. From 2019 to 2021, we conducted annual surveys to assess eelgrass shoot density, morphology, epifauna community, and the prevalence and lesion area of wasting disease infections. We integrated field data with satellite measurements of sea surface temperature and used structural equation modeling to test the magnitude and direction of possible drivers of wasting disease. Our results show that grazing by small invertebrates was associated with a 29% increase in prevalence of wasting disease infections and that both the prevalence and lesion area of disease increased with total epifauna abundances. Furthermore, these relationships differed among taxa; disease levels increased with snail (Lacuna spp.) and idoteid isopod abundances but were not related to abundance of ampithoid amphipods. This field study across 23° of latitude suggests a prominent role for invertebrate consumers in facilitating disease outbreaks with potentially large impacts on coastal seagrass ecosystems.
疾病是群落和生态系统结构的关键驱动因素，尤其是当它侵袭基础物种时。在广泛分布的海洋基础物种海草（大叶藻）中，过去，消瘦病的爆发曾导致大规模的草甸崩溃，而致病病原体——海草疫霉，在全球的草甸中普遍存在。迄今为止的研究主要集中在海草消瘦病的非生物环境驱动因素上，但来自其他系统的有力证据表明，诸如食草等生物相互作用会助长植物疾病。生物相互作用如何在野外影响海草消瘦病尚不清楚，但对于理解这个全球有价值且正在衰退的栖息地的动态变化可能至关重要。在这里，我们通过对从阿拉斯加东南部到加利福尼亚南部分布的32个海草草甸进行的纬度实地研究，调查了附生食草动物与海草消瘦病之间的联系。从2019年到2021年，我们进行了年度调查，以评估海草的茎密度、形态、附生动物群落以及消瘦病感染的患病率和病斑面积。我们将实地数据与海面温度的卫星测量数据相结合，并使用结构方程模型来测试消瘦病可能驱动因素的大小和方向。我们的结果表明，小型无脊椎动物的啃食与消瘦病感染患病率增加29%有关，并且疾病的患病率和病斑面积都随着附生动物的总丰度而增加。此外，这些关系在不同分类群之间存在差异；疾病水平随着蜗牛（凹螺属）和艾氏等足类动物的丰度增加而增加，但与双螯虾丰度无关。这项跨越23个纬度的实地研究表明，无脊椎动物消费者在助长疾病爆发方面发挥着重要作用，这可能对沿海海草生态系统产生重大影响。
