Effects of UV radiation on community establishment: a global perspective

Increased ultraviolet radiation (UV-A and/or UV-B) may impact on the establishment and structure of a shallow water benthic invertebrate assemblages. A global experiment in more than 8 countries, using an identical methodology (transparent UV filters) will add significantly to our understanding of the impacts of anthropogenically induced global change on natural systems. To appraise the effects of increased UVR on shallow marine benthic assemblages, five experimental rafts were deployed in protected bays west of Shirley Island near Casey Station, Antarctica (66.16oS 110.30oE). Each raft consisted of eight experimental units, each of which contained a colonization panel (ceramic tile) positioned horizontally and submerged 4-6 cm underwater. Irradiation treatments were randomly assigned to each unit with the use of UV cut-off filters. The treatments were as follows: No UVR (transmits photosynthetically active radiation or PAR, 400-700nm), No UVB (transmits PAR + UVA, 320-700nm), Perspex (full spectrum, 280-700nm, procedural control), or No filter (full spectrum, treatment control). In addition there were three levels of consumer treatments: With consumption (container sides removed), without consumption (container sides perforated with 4 mm holes), and a control (3 sides perforated, 1 side removed). After seven weeks tiles were removed to the laboratory for examination. All tiles were dominated by diatoms and no sessile invertebrates were apparent. The first trial has been completed, but several other panels are still in place. A conference will be held in early 2002 between participating countries to discuss results and findings.The 2001\2002 summer season consisted of experimental designs divided up into three separate projects.The aims were all to provide a corrollary to the previous seasons data.Project 1 consisted of the extraction and redeployment of settlement depth arrays situated in Geoffrey's Bay and Hollin Island Channel. Due to prevailing weather conditions resulting in limited boating hours and diving program, only one array was retrieved. On inspection of the array it was decided to deploy further replicates to gain a better temporal understanding of the communities.Projects 2 and 3 consisted of a similar experimental design, however monitoring the shallower depths of settlement (depths of 1m and 2m below sea level) for a period of one month. Project 2 consisted of arrays with two depths and 2 panels per depth, triple replicated, under the icesheet in O'Brien Bay and Shirley Channel, with a substrate depth of 20m. Diatom samples are to be analyzed in Australia. Project 3 was of a similar design to project 2 though it was measuring recruitment in shallow open water. The two sites consisted of Noonan Cove and Geoffrey's Bay at substrate depths of 5m. These tiles are also to be analyzed on return to Australia.There were 5 rafts used in this study - they are listed as R1 to R5 there were two factors in the design -(i) predator access: Caged (C) Half caged (H) and Open (O) and ii) UV exposure: Perspex (P), Macrolon (M), No filter (N) and Film + perspex (F).A list of the diatoms found on the settlement panels is provided at the URL below.The fields in this dataset are:SpeciesSample

增强的紫外线辐射（ultraviolet radiation, UVR，涵盖UV-A和/或UV-B）可能会影响浅水底栖无脊椎动物（benthic invertebrate）群落的建立与结构。一项在8个以上国家开展、采用统一实验方法（透明紫外滤膜，transparent UV filters）的全球实验，将极大增进我们对人为诱导的全球变化如何影响自然生态系统的认知。

为评估增强的紫外线辐射（UVR）对浅海底栖群落的影响，研究团队在南极洲凯西站（Casey Station）附近雪莉岛西侧的受保护海湾，部署了5个实验浮筏（experimental rafts），坐标为66.16°S，110.30°E。每个浮筏包含8个实验单元，每个单元均设有一块水平放置、浸没于水下4~6厘米的定居基板（colonization panel，陶瓷砖，ceramic tile）。通过紫外截止滤膜（UV cut-off filters），将辐射处理随机分配至各实验单元。处理组设置如下：无UVR组（仅透过光合有效辐射，photosynthetically active radiation, PAR，400~700nm）、无UVB组（透过PAR+UVA，320~700nm）、有机玻璃组（全光谱280~700nm，程序对照）、无滤膜组（全光谱，处理对照）。此外还设置了三类消费者处理水平：允许取食（容器侧壁完全移除）、限制取食（容器侧壁钻有4mm孔径的孔）、对照组（3个侧壁钻孔，1个侧壁移除）。

7周后，所有基板被带回实验室进行检测。结果显示所有基板均以硅藻（diatoms）为优势类群，未发现固着无脊椎动物（sessile invertebrates）。首轮试验已完成，但其余若干基板仍在原位。参与实验的各国将于2002年初召开会议，讨论实验结果与发现。

2001/2002夏季实验季分为三个独立项目，旨在为前几季的观测数据提供补充佐证。项目1为回收并重新部署位于杰弗里湾（Geoffrey's Bay）和霍林岛海峡（Hollin Island Channel）的定居深度阵列（settlement depth arrays）。受天气条件限制，航行与潜水作业时长有限，仅回收了1组阵列。经检测该阵列后，研究人员决定增设更多重复组，以更清晰地解析群落的时间动态。

项目2与项目3采用相似的实验设计，但均针对较浅的附着深度（海平面下1m和2m）开展为期1个月的监测。项目2在奥布莱恩湾（O'Brien Bay）和雪莉海峡（Shirley Channel）的冰盖（ice sheet）下方设置阵列，包含2个深度梯度，每个深度设置2块基板，设置3组重复，基板附着基质深度为20m，硅藻样本将在澳大利亚境内进行分析。项目3与项目2设计相似，但监测的是浅开阔水域的幼体补充（recruitment）情况，实验位点为努南湾（Noonan Cove）和杰弗里湾，基质深度为5m，这些基板同样将在返回澳大利亚后进行分析。

本研究共使用5个实验浮筏，编号为R1至R5。实验设计包含两个因子：(i) 捕食者可及性：笼养组（C）、半笼养组（H）与开放组（O）；(ii) UV暴露水平：有机玻璃组（P）、Macrolon组（M）、无滤膜组（N）与膜+有机玻璃组（F）。

定居基板上发现的硅藻物种名录可通过以下URL获取。

本数据集包含以下字段：物种（"Species"）、样本（"Sample"）