Coral juvenile belt transects

Belt surveys were conducted to determine coral juvenile densities and size frequencies within each EcoRRAP monitoring plot. Methods followed AIMS LTMP survey protocols (SOP10: AIMS_LTMP_SOP10v2_Benthic-surveys-photography_2020_DOI.pdf). Briefly:Methods:     Run tape in straight line between plot star pickets. Really big bommies that need to be circumnavigated to pass on the more shallow side on reef slope, others crossed    Survey slate-width belt of 0.34 x 5.00 m along the transect line on the upward side of the tape (=up the reef slope). Skip >1 m patches of sand (ie extend the transect beyond 5 m by the length of the sand patch).    Record all living HC juveniles ≤ 5 cm, to whatever taxonomic resolution possible - at least family, or genus. Estimate size of each to nearest cm. Avoid remnant patches of corals    Record ‘% available substratum’ = estimate % cover of TA+CCA+MA (I also include large rubble as habitable space). This follows LTMP protocol: “proportion of substrate occupied by algae. We used total algal cover as corals do not only settle on coralline algae and we wished to preserve the possible negative effects of macroalgae.”    Record turf algal height (in mm with calliper) at a single point each meter for the first 3 m of the transect. Find nearest turf to each meter mark.    Estimate amount of sediments on surface: 0, none; 1, thin layer; 2, considerable amount of sediment but still removable by fanning, and 3, thick deep layer of sediment.    Estimate the slope of the reef as either 0, 30, 60 or 90 degrees    Photograph unknown juveniles, record time of pic so we can attribute it to plot, and its size.    Transect length 4m in deep, 5m in shallows.

本研究采用样带调查法，测定每个EcoRRAP监测样地内的珊瑚幼体密度与体型频率分布。调查方法遵循澳大利亚海洋科学研究所（AIMS）长期监测计划（LTMP）的调查规程（SOP10: AIMS_LTMP_SOP10v2_Benthic-surveys-photography_2020_DOI.pdf）。具体方法如下：
在样地的固定桩柱间拉直测绳；若礁坡上存在体积过大、需绕行的珊瑚礁丘，则从礁坡较浅一侧绕行，其余情况直接穿越测绳即可。
沿测绳上坡侧（礁坡上坡方向）布设宽度匹配野外调查石板尺寸的0.34m×5.00m样带。若遇到长度超过1m的沙斑，则跳过该区域，将样带延长超出原5m范围，延长长度等于沙斑的长度。
记录所有体长≤5cm的活体硬珊瑚（Hard Coral, HC）幼体，尽可能鉴定至最高分类阶元，至少需至科或属级别；估算每只幼体的体长，精确至1cm；避开残留的珊瑚斑块。
记录"可利用基质占比"：估算基质被藻类覆盖的百分比（包括结壳珊瑚藻（Crustose Coralline Algae, CCA）、草皮藻类（Turf Algae, TA）与大型藻类（Macroalgae, MA），同时将大型砾石视为可栖息空间）。该方法遵循LTMP规程："基质中被藻类占据的比例。本研究采用总藻类盖度，因为珊瑚不仅可在结壳珊瑚藻上附着，且需保留大型藻类可能带来的负面影响。"
在样带前3m范围内，每隔1m选取一个测点，使用游标卡尺测量该点附近的草皮藻类高度，精确至毫米；每个测点需选取距离测绳刻度最近的草皮藻丛。
估算基质表面沉积物含量：0代表无沉积物；1代表存在薄层沉积物；2代表沉积物含量较多，但仍可通过拂扫去除；3代表存在厚层深层沉积物。
估算礁坡坡度，分为0°、30°、60°或90°四个等级。
对无法鉴定的幼体进行拍照，并记录拍摄时间，以便关联对应样地及幼体体长信息。
深水区样带长度为4m，浅水区样带长度为5m。