1999-2019

The Cape Rodney-Okakari Point Marine Reserve is New Zealand's oldest no-take marine reserve situated along the Leigh coast (est. 1978; the 'Leigh Marine Reserve' hereafter). Historic information on rocky reef communities in the Leigh Marine Reserve is available from baseline surveys in 1978 (Ayling 1978) and repeated in the 1990s (Babcock et al. 1999). While these provide valuable information on long-term changes in the reserve, they did not include fished reefs outside the reserve that provide a control for the effect of protection. The monitoring program presented here was established in 1999 by N. Shears (University of Auckland) for the New Zealand Department of Conservation and includes four sites inside and four sites outside the Leigh Marine Reserve (Shears and Babcock 2003). At these sites, the reefs are gradually sloping from the intertidal to the reef edge, occurring at ~8–15 m depth. From 1999–2000 the reefs were surveyed in four depth ranges (<2, 4–6, 7–9 and >10 m), but subsequent sampling has focussed on the 4-6 m depth range as this is representative of the depth range where sea urchins (Evechinus chloroticus) are most abundant and can form barren habitat (Shears & Babcock 2003; Shears et al. 2008). This depth range has been sampled sporadically (every 1–3 yr at these sites since 2001; note that only fished sites were surveyed in 2003). The surveys were conducted on SCUBA, and at each site, five 1-m2 quadrats were haphazardly sampled within the 4–6 m depth range. Within each quadrat, the density (the number of individuals per metre square) of sea urchins and all large brown macroalgae were recorded (e.g. Ecklonia radiata, Carpophyllum spp., Cystophora spp. and Sargassum sinclairii). For sea urchins, behaviour was recorded as 'cryptic' (sea urchins found in holes, cracks or crevices) or 'exposed' (sea urchins are out in the open and have a strong impact on macroalgal communities; Spyksma et al. 2017). For all large macroalgae the length of all fronds was measured to the nearest 5 cm using a measuring tape. For E. radiata, measurements were taken for both stipe and total length (i.e. from the top of the holdfast to the meristem and the distal end of the primary lamina, respectively). The percent cover of crustose coralline algae, bare rock, turfing algae (e.g. articulated coralline, red foliose), filamentous algae and sediment was assessed visually in each quadrat. In cases where filamentous algae were recorded as overlaying turf and encrusting algae, such that total cover exceeds 100%, the cover data was standardised to add up to 100%.

科德·罗德尼-奥卡里角海洋保护区（Cape Rodney-Okakari Point Marine Reserve）是新西兰历史最悠久的禁捕海洋保护区，坐落于利（Leigh）沿岸，始建于1978年，下文简称“利海洋保护区（Leigh Marine Reserve）”。该保护区内岩礁群落的历史数据可追溯至1978年的基线调查（Ayling, 1978），并于20世纪90年代重复开展（Babcock et al., 1999）。尽管这些数据为保护区内的长期生态变化提供了宝贵参考，但并未纳入保护区外的捕捞岩礁作为保护效应的对照样地。
本研究呈现的长期监测项目由奥克兰大学（University of Auckland）的N. Shears于1999年受新西兰环境保护部委托发起，共设置8个监测样地，其中保护区内、外各4个（Shears and Babcock, 2003）。上述样地的岩礁呈缓坡状，从潮间带延伸至礁缘，水深约8~15米。1999至2000年的调查覆盖了4个水深区间（<2米、4~6米、7~9米及>10米），但后续采样聚焦于4~6米水深区间——该区间是海胆（Evechinus chloroticus）最为富集的生境，且可形成荒芜礁生境（Shears & Babcock, 2003; Shears et al., 2008）。
自2001年起，该水深区间的采样工作不定期开展（每1~3年一次，需注意2003年仅对捕捞样地开展了调查）。所有调查均通过水肺潜水（SCUBA）完成，在每个样地的4~6米水深区间内，随机布设5个1平方米样方进行采样。
在每个样方中，记录海胆与所有大型褐藻的密度（单位：个体/平方米），例如辐射昆布（Ecklonia radiata）、Carpophyllum spp.、Cystophora spp. 以及辛克莱马尾藻（Sargassum sinclairii）等类群。其中，海胆的行为被划分为“隐蔽型”（栖息于孔洞、缝隙或岩缝中）与“暴露型”（裸露于开阔环境，对大型海藻群落造成显著影响；Spyksma et al., 2017）两类。针对所有大型褐藻，使用卷尺测量所有藻叶的长度，精度至5厘米。对于辐射昆布，需分别测量其柄长与总长度（前者为固着器顶端至分生组织的距离，后者为初级叶状体远端至固着器顶端的距离）。
对每个样方内的结壳珊瑚藻、裸露岩石、垫生藻类（turfing algae，如关节珊瑚藻、红色叶状藻类）、丝状藻类及沉积物的盖度进行目视评估。若丝状藻类覆盖于垫生藻类与结壳藻类之上，导致总盖度超过100%，则需将盖度数据标准化至总和为100%。