Spatial and temporal variations in turbidity on two inshore turbid reefs on the Great Barrier Reef, Australia
Spatial and temporal variations in turbidity on two inshore turbid reefs on the Great Barrier Reef, Australia
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DOI：
10.1007/s00338-012-0965-1
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发表时间：
2013-03-01
期刊：
影响因子：
3.5
通讯作者：
Perry, C. T.
中科院分区：
文献类型：
--
作者：
Browne, N. K.;Smithers, S. G.;Perry, C. T.
本研究描述了自然浊度制度在两个近岸混浊的珊瑚礁中央大堡礁，其中风驱动的波浪是沉积物再悬浮的主要代理人。近岸混浊珊瑚礁上的许多珊瑚已经适应了高浊度和波动浊度，然而，据推测，人为活动，如疏浚，产生更大和更长时间的浊度事件，可能超过这些珊瑚礁的环境容忍度和适应能力。自然浊度制度必须加以描述和理解，以确定是否以及何时近岸混浊珊瑚礁的珊瑚群落处于危险之中，从adhergenically升高浊度，但目前很少有基线研究存在。在这里，我们提出了浊度数据（a）中礁，位于磁岛和汤斯维尔和（B）Paluma浅滩之间的半保护珊瑚礁，暴露于更高能量的风和波浪位于哈利法克斯湾的珊瑚礁。仪器被部署在两个珊瑚礁16天，以测量空间和时间的变化，浊度及其驱动力（波浪，水流，潮汐）。当地驱动的风浪是浊度的主要驱动因素，但这种关系的强度取决于波浪暴露。因此，在各个珊瑚礁中，浊度状况有很大差异，这反映在群落组合分布中，在浊度波动较大（> 100 NTU）的珊瑚礁生境中，异养珊瑚（如Goniopora）丰度很高。使用当地风速数据开发的浑浊度模型分别解释了帕卢马浅滩和中礁浑浊度变化的75%和46%。虽然该模型是基于一个简短的两个星期的观测期，它可靠地预测24小时平均浊度的变化，并确定期间浊度上升超过环境基线水平，提供珊瑚礁管理人员的洞察力浊度响应修改气候和沿海沉积物输送制度。
This study describes the natural turbidity regimes at two inshore turbid reefs on the central Great Barrier Reef where wind-driven waves are the main agent of sediment resuspension. Many corals on inshore turbid reefs have adapted to high and fluctuating turbidity, however, anthropogenic activities such as dredging are speculated to produce larger and more prolonged turbidity events that may exceed the environmental tolerance and adaptive capacity of corals on these reefs. Natural turbidity regimes must be described and understood to determine whether and when coral communities on inshore turbid reefs are at risk from anthropogenically elevated turbidity, but at present few baseline studies exist. Here, we present turbidity data from (a) Middle Reef, a semi-protected reef located between Magnetic Island and Townsville and (b) Paluma Shoals, a reef exposed to higher energy wind and waves located in Halifax Bay. Instruments were deployed on both reefs for 16 days to measure spatial and temporal variations in turbidity and its driving forces (waves, currents, tides). Locally driven wind waves were the key driver of turbidity, but the strength of the relationship was dependent on wave exposure. Turbidity regimes thus vary markedly over individual reefs and this is reflected in community assemblage distributions, with a high abundance of heterotrophic corals (e.g. Goniopora) in reef habitats subjected to large fluctuations in turbidity (> 100 NTU). A turbidity model developed using local wind speed data explained up to 75 % and up to 46 % of the variance in turbidity at Paluma Shoals and Middle Reef, respectively. Although the model was based on a brief two-week observational period, it reliably predicted variations in 24-h averaged turbidity and identified periods when turbidity rose above ambient baseline levels, offering reef managers insights into turbidity responses to modified climate and coastal sediment delivery regimes.