DataSheet_1_Tissue loss disease outbreak significantly alters the Southeast Florida stony coral assemblage.pdf

A stony coral tissue loss disease (SCTLD) outbreak, first widely reported in 2014 in the Southeast Florida Ecosystem Conservation Area (Coral ECA), has continued to impact stony coral communities for more than seven years. Here, we utilize long-term (2012-2020) annual monitoring data from the Southeast Florida Reef Evaluation and Monitoring Project (SECREMP) to assess the impact of the SCTLD outbreak on the stony coral assemblage as well as spatiotemporal and ecological associated variation. SECREMP examines 22 permanent sites distributed along Florida’s Coral Reef from Miami-Dade County north to Martin County, Florida. We expand upon previously documented disease event-related regional impacts. Coral ECA SCTLD prevalence was greatest in 2016 coinciding with significant declines in coral live tissue area (LTA). Even though by 2018 SCTLD prevalence had dropped to < 1% and significant annual LTA declines were no longer recorded, upwards of 59% of stony coral total LTA in the Coral ECA was lost between 2015-2018. In this study, SCTLD was observed across all habitats and affected 11 stony coral species. Colony size did not preclude infection or mortality, with 25% of all infections occurring on colonies 5-14 cm in diameter. The indiscriminate nature of the disease and lack of size refugia has altered the stony coral population structure and assemblage composition. Since 2016, the coral assemblage has shifted towards smaller colonies, with a significant decrease in mean colony size. Juvenile corals, < 4 cm diameter, of many reef building, structurally-complex species were rarely documented, while eurytopic, generalist species dominated juvenile abundance. Although significant losses, altering ecosystem function, were documented, all species recorded prior to the disease event were present, albeit some only as juveniles. Our study adds to the growing body of evidence of the severity of the disease outbreak and precarious state of the stony coral assemblage in the Coral ECA. We show long-term monitoring projects provide invaluable opportunities to capture such spatiotemporal changes in coral assemblages and may identify potential indicators of recovery. While no stony coral species were completely lost from the monitored assemblage, the likelihood of recovery, to even a pre-outbreak state, is limited without immediate action addressing development related local stressors and climate change related global stressors.

2014年首次于佛罗里达东南部生态保护区（Coral ECA）广泛报道的石珊瑚组织损失病（stony coral tissue loss disease, SCTLD）疫情，已持续影响石珊瑚群落超过七年。本研究采用佛罗里达东南部珊瑚礁评估与监测项目（SECREMP）2012-2020年的长期年度监测数据，评估了SCTLD疫情对石珊瑚群落的影响，及其相关的时空与生态变异。SECREMP在佛罗里达珊瑚礁带从迈阿密-戴德县向北至佛罗里达州马丁县的区域内，布设了22个永久性监测点位。本研究拓展了此前已记录的、与疫情相关的区域影响研究结果。2016年，珊瑚生态保护区的SCTLD患病率达到峰值，同期珊瑚活组织面积（live tissue area, LTA）出现显著下降。尽管至2018年时，SCTLD患病率已降至1%以下，且未再记录到珊瑚活组织面积的显著年度降幅，但2015-2018年间，该保护区内石珊瑚总活组织面积已损失逾59%。本研究中，SCTLD在所有生境中均有检出，共影响11种石珊瑚。珊瑚群体大小并未成为感染或死亡的避难因素，25%的感染发生在直径5-14厘米的珊瑚群体上。该疫情的无差别传播特性以及缺乏规模避难所，已改变了石珊瑚的种群结构与群落组成。2016年以来，珊瑚群落向小型群体转变，平均群体规模出现显著下降。许多造礁、结构复杂的珊瑚物种中，直径小于4厘米的幼年个体鲜有记录，而广适性广食性物种占据了幼年个体数量的主导地位。尽管已记录到该疫情造成了严重损失并改变了生态系统功能，但疫情发生前记录的所有物种均仍存在，尽管部分物种仅以幼年个体形式留存。本研究进一步佐证了该疫情的严重程度，以及佛罗里达东南部生态保护区内石珊瑚群落岌岌可危的现状。研究表明，长期监测项目为捕捉珊瑚群落的此类时空变化提供了宝贵契机，或可识别潜在的恢复指标。尽管监测群落中未完全丧失任何石珊瑚物种，但如果不立即采取行动应对与开发相关的本地胁迫因子与气候变化相关的全球胁迫因子，即便恢复至疫情前的状态，其可能性也极为有限。