Investigating occupancy, habitat use, and migrations of Arctic Grayling (Thymallus arcticus) in northern barrenland streams

Gahcho Kué项目是一个钻石矿开发项目，位于新界耶洛奈夫东北约280公里处，靠近一个小型源头湖肯纳迪湖。肯纳迪湖的一大部分将被脱水，以进入湖下含钻石的金伯利岩管道。肯纳迪湖养育了几种北方鱼类，包括北极灰鱼(Thymallus Arcticus)--一种对土著渔民具有文化和生存意义的物种，以及一种受欢迎的运动鱼。 肯纳迪湖下游的溪流栖息地被北极灰熊用来产卵和繁殖，很可能会受到肯纳迪湖降水后流量减少的影响。为了减轻该项目对Grayling使用的溪流栖息地的影响，戴比尔斯制定了一项水流增强计划。这项计划是否有效还存在相当大的不确定性，因为我们对北极灰熊的迁徙和分水岭中的栖息地利用了解很少，而且收集基线数据的根深蒂固的方法往往无法在未来几年进行强有力的评估。 我们的研究包括两个互补的组成部分。声学遥测研究的结果将提供对北极灰熊迁徙的时间和方向性的洞察，解决拟议缓解流动的适宜性，并为用于评估灰熊栖息地使用的模型(栖息地占用模型)的设计提供信息。栖息地占用模型的开发将使受影响和未受影响的流域在脱水前后对灰熊栖息地的使用进行量化和比较。 这项研究计划的结果将有助于对北极灰熊栖息地利用如何随着开发和缓解行动的变化进行强有力的评估和预测。结果将使戴比尔斯能够实施适应性管理计划，最大限度地提高其缓解行动的有效性，并设计和采用高效、有效和有科学依据的监测计划。成果还将包括一个可转移到其他采矿作业的方法模板。

The Gahcho Kué Project is a diamond mine development located approximately 280 km northeast of Yellowknife, NT, near a small headwater lake, Kennady Lake. A large portion of Kennady Lake will be dewatered to access diamond-bearing kimberlite pipes under the lake. Kennady Lake supports several northern fish species, including Arctic Grayling (Thymallus arcticus) - a species of cultural and subsistence significance to Aboriginal fishers, and a popular sport fish. Stream habitats downstream of Kennady Lake are used by Arctic Grayling for spawning and rearing, and will likely be affected by reductions in flows after the dewatering of Kennady Lake. To mitigate effects of the Project on stream habitats used by Grayling, De Beers developed a flow augmentation plan. There is considerable uncertainty as to whether this plan will be effective because we have a poor understanding of Arctic Grayling migrations and habitat use in the watershed, and because entrenched methods of collecting baseline data often do not allow for robust assessments in future years. Our research includes two complementary components. Results from an acoustic telemetry study will provide insight into the timing and directionality of Arctic Grayling migrations, address the suitability of proposed mitigation flows, and inform the design of models used to assess Grayling habitat use (habitat occupancy models). Development of habitat occupancy models will allow quantification and comparison of Grayling habitat use in affected and unaffected watersheds, before and after dewatering. Results from this research program will facilitate robust assessments and predictions of how habitat use by Arctic Grayling changes in response to development and mitigation actions. Results will enable De Beers to implement an adaptive management plan that maximizes the effectiveness of their mitigative actions, and to design and employ an efficient, effective, and scientifically defensible monitoring plan. Outcomes will also include a methodological template that can be transferred to other mining operations.