Edgar Graham J, Stuart-Smith Rick D, Thomson Russell J, Freeman Debbie J
Institute of Marine and Antarctic Studies, Hobart, Tasmania, Australia.
Centre for Research in Mathematics, Western Sydney University, Parramatta Campus, Penrith, New South Wales, Australia.
PLoS One. 2017 May 24;12(5):e0177216. doi: 10.1371/journal.pone.0177216. eCollection 2017.
Through systematic Reef Life Survey censuses of rocky reef fishes, invertebrates and macroalgae at eight marine reserves across northern New Zealand and the Kermadec Islands, we investigated whether a system of no-take marine reserves generates consistent biodiversity outcomes. Ecological responses of reef assemblages to protection from fishing, including potential trophic cascades, were assessed using a control-impact design for the six marine reserves studied with associated reference sites, and also by comparing observations at reserve sites with predictions from random forest models that assume reserve locations are fished. Reserve sites were characterised by higher abundance and biomass of large fishes than fished sites, most notably for snapper Chrysophrys auratus, with forty-fold higher observed biomass inside relative to out. In agreement with conceptual models, significant reserve effects not only reflected direct interactions between fishing and targeted species (higher large fish biomass; higher snapper and lobster abundance), but also second order interactions (lower urchin abundance), third order interactions (higher kelp cover), and fourth order interactions (lower understory algal cover). Unexpectedly, we also found: (i) a consistent trend for higher (20%) Ecklonia cover across reserves relative to nearby fished sites regardless of lobster and urchin density, (ii) an inconsistent response of crustose coralline algae to urchin density, (iii) low cover of other understory algae in marine reserves with few urchins, and (iv) more variable fish and benthic invertebrate communities at reserve relative to fished locations. Overall, reef food webs showed complex but consistent responses to protection from fishing in well-enforced temperate New Zealand marine reserves. The small proportion of the northeastern New Zealand coastal zone located within marine reserves (0.2%) encompassed a disproportionately large representation of the full range of fish and benthic invertebrate biodiversity within this region.
通过对新西兰北部和克马德克群岛八个海洋保护区的岩礁鱼类、无脊椎动物和大型藻类进行系统的珊瑚礁生物调查，我们研究了禁捕海洋保护区系统是否能产生一致的生物多样性结果。对于六个设有相关参照地点的海洋保护区，我们采用对照-影响设计评估了珊瑚礁群落对禁渔保护的生态反应，包括潜在的营养级联效应，还通过将保护区地点的观测结果与假设保护区地点被捕捞的随机森林模型预测结果进行比较来进行评估。保护区地点的大型鱼类丰度和生物量高于捕捞地点，最显著的是笛鲷，其在保护区内的观测生物量相对于保护区外高出40倍。与概念模型一致，显著的保护区效应不仅反映了捕捞与目标物种之间的直接相互作用（大型鱼类生物量更高；笛鲷和龙虾丰度更高），还反映了二阶相互作用（海胆丰度更低）、三阶相互作用（海带覆盖度更高）和四阶相互作用（下层藻类覆盖度更低）。出乎意料的是，我们还发现：（i）无论龙虾和海胆密度如何，各保护区内的昆布藻覆盖度相对于附近捕捞地点都有一致的更高趋势（约20%）；（ii）壳状珊瑚藻对海胆密度的反应不一致；（iii）海胆数量少的海洋保护区内其他下层藻类的覆盖度较低；（iv）相对于捕捞地点，保护区内的鱼类和底栖无脊椎动物群落更具变异性。总体而言，在严格执行保护措施的新西兰温带海洋保护区，珊瑚礁食物网对禁渔保护呈现出复杂但一致的反应。位于海洋保护区内的新西兰东北沿海区域比例很小（约0.2%），却不成比例地大量代表了该区域鱼类和底栖无脊椎动物生物多样性的全部范围。
