Non migratory Freshwater Fish Distribution

Knowledge of, and identification of the distribution of species and communities provides a basis for effective conservation (Leathwick et al. 2008). The concept to recognise sub-populations within species and represent distributions as presented here, and the use of these as a management tool, came about from the identification and development of the spatial distributions of Canterbury mudfish for the Canterbury Regional Council Natural Resources Regional Plan - Water Quantity (Canterbury Regional Council 2011) as described in O’Brien & Dunn (2007). Habitat fragments also allow for effective management, delivery planning, and reporting, and have been used in the Department’s species prioritisation process, the New Zealand Threat Classification System conservation status assessments of freshwater fish (area of occupancy, and number of sub-populations), and assessment of the effects of Conservation Act concession and Resource Management Act consent applications. The report by Dunn (2017) describes the methods used to develop these geospatial files representing known habitat fragments of non-migratory freshwater fish species within the genera Galaxias, Neochanna (both Family Galaxiidae; galaxias and mudfish respectively), and Gobiomorphus (Family Eleotridae; bullies) as they typically have specific geographical distributions, and occur in discrete areas. These species also have conservation status’ of threatened or at risk and hence, there is a requirement to adequately manage their habitats to ensure persistence of the species. Work has also been undertaken to spatially identify known landlocked sub-populations of facultative diadromous species. Identification of catchments containing migratory sub-populations of these species is underway using a different approach and is not reported on further here. Canterbury Regional Council 2011: Canterbury Natural Resources Regional Plan – Chapter 5 Water Quantity. Canterbury Regional Council, Christchurch, New Zealand. 214 p. Dunn, N.R. 2017: Mapping of non-migratory freshwater fish habitat fragment distributions. Unpublished report, Freshwater Team, Science & Policy, Department of Conservation, Wellington, New Zealand. 22 p. Leathwick, J.R.; Julian, K.; Elith, J.; Rowe, D.L. 2008: Predicting the distributions of freshwater fish species for all New Zealand's rivers and streams. NIWA Client Report HAM2008-005 prepared for Department of Conservation. National Institute of Water and Atmospheric Research, Hamilton, New Zealand. 56 p. O'Brien, L.K.; Dunn, N.R. 2007: Preliminary Canterbury mudfish (Neochanna burrowsius) sub-population assessment. Client report to Canterbury Conservancy, Department of Conservation. Ichthyo-niche, Dunedin, New Zealand. 143 p. Six new fields were added when the dataset was last revised (31 March 2021): DOC Region, DOC District, Regional Council, District Council, Status, Spatial order. The full report is available here对物种及群落分布的认知与识别，可为有效保护工作奠定核心基础（Leathwick等，2008）。本文所提出的识别物种种群亚群并呈现物种分布的理念，以及将其作为管理工具的应用思路，源自为坎特伯雷大区议会编制《自然资源区域规划——水量》（Canterbury Regional Council，2011）所开展的坎特伯雷泥鱼（Neochanna burrowsius）空间分布识别与研究工作，相关细节详见O’Brien与Dunn（2007）的研究。生境斑块同样可为高效管理、实施规划与成果报告提供有力支撑，新西兰保护部（Department of Conservation，简称DOC）已将其应用于物种优先级排序流程、新西兰淡水鱼类濒危分类系统（New Zealand Threat Classification System）的保护等级评估（涵盖占用面积与亚群数量），以及《保护法》（Conservation Act）特许申请、《资源管理法》（Resource Management Act）许可申请的影响评估工作中。Dunn（2017）的报告详述了用于生成本数据集地理空间文件的方法：这些文件呈现了新西兰非洄游淡水鱼类的已知生境斑块分布，涉及类群包括南乳鱼科（Galaxiidae）下的Galaxias属（galaxias）、Neochanna属（mudfish，泥鱼），以及塘鳢科（Eleotridae）下的Gobiomorphus属（bullies，塘鳢）——这类物种通常具有专属地理分布，且栖息于离散区域内。上述物种均被列为濒危或受威胁等级，因此需对其生境进行妥善管理，以保障物种的持续存续。相关工作还针对兼性溯河洄游物种的已知内陆封闭亚群开展了空间识别。目前正采用其他方法识别包含这些物种洄游亚群的集水区，相关内容不在本文中进一步展开说明。 坎特伯雷大区议会2011：《坎特伯雷自然资源区域规划——第5章 水量》。坎特伯雷大区议会，新西兰基督城，共214页。 Dunn, N.R. 2017：非洄游淡水鱼类生境斑块分布制图。未出版报告，新西兰保护部科学与政策处淡水团队，新西兰惠灵顿，共22页。 Leathwick, J.R.; Julian, K.; Elith, J.; Rowe, D.L. 2008：新西兰全域河流与溪流的淡水鱼类分布预测。为新西兰保护部编制的NIWA（国家水与大气研究所，National Institute of Water and Atmospheric Research）客户报告HAM2008-005。国家水与大气研究所，新西兰汉密尔顿，共56页。 O'Brien, L.K.; Dunn, N.R. 2007：坎特伯雷泥鱼（Neochanna burrowsius）亚群初步评估。提交给新西兰保护部坎特伯雷管理区的客户报告，Ichthyo-niche，新西兰达尼丁，共143页。 本数据集于2021年3月31日完成最新修订，新增6个字段：DOC大区（DOC Region）、DOC分区（DOC District）、大区议会（Regional Council）、地区议会（District Council）、保护等级（Status）、空间排序（Spatial order）。完整报告可在此处获取