Biodiversity, biogeography, and conservation of freshwater fishes

淡水鱼是世界上最濒危的物种之一。北美超过30%的淡水鱼和加拿大超过25%的淡水鱼都需要保护。与危害相关的主要电流压力源是生境的改变和破坏，以及水生入侵物种。在本土物种减少的同时，水生入侵物种（AIS）正在北美蔓延。预计这些趋势在未来会因气候变化和人口增长等压力因素而加剧。生物同质化——整个景观和全球范围内群落的相似性日益增加——是这些趋势的结果，也是生物多样性丧失的一个指标。我的研究项目的目的是更好地了解加拿大淡水鱼在多种分类和地理尺度上的模式、过程和压力源。这些知识对于加拿大淡水鱼生物多样性的养护、保护和恢复是必不可少的。将在加拿大和劳伦森大湖及其流域和支流范围内审查淡水鱼生物多样性的模式。将使用即将出版的国家鱼类地图集、在线五大湖鱼类地图集以及安大略省南部支流未出版和新收集的鱼类分布数据来检查总体丰富度和群落模式。构建这些模式的历史（冰期后历史、系统发育）和环境过程（非生物、生物）将使用各种统计技术加以确定。此外，还将对目前影响生物多样性格局的人为压力因素进行研究。为了确定加拿大现有的保护区网络实际保护淡水鱼生物多样性的程度，将进行一项覆盖生物多样性和保护区层的差距分析。这种差距分析将确定需要额外保护的鱼类种类和群落。为了阐明本地淡水鱼和鱼类AIS之间相互作用的潜在机制，我们将研究它们在五大湖共现的历史。根据最近出版的书籍章节，每个五大湖的物种列表将从1870年前到2010年每十年重建一次，并用于研究本地物种损失和AIS入侵的历史。这将有助于检验与AIS的建立和影响有关的许多假设（例如，生物耐药性、生态位重叠）。这些假设将通过对生态和生活史性状的多变量分析来检验性状空间随时间的变化。提出的研究包括几个新的组成部分。研究历史、环境、系统发育和压力源对淡水鱼的影响的分析还没有对加拿大或五大湖进行全面的研究。评估保护区对淡水鱼的保护程度的差距分析尚未在加拿大或五大湖发表。五大湖年代际数据库提供了一个独特的机会来测试入侵理论假设和物种同质化在很长一段时间内。

Freshwater fishes are among the most imperiled taxa in the world. Over 30% of freshwater fishes in North America, and over 25% in Canada, are of conservation concern. The primary current stressors related to imperilment are habitat alteration and destruction, and aquatic invasive species. While native species are declining, aquatic invasive species (AIS) are spreading in North America. These trends are expected to be exacerbated in the future by stressors such as climate change and human population growth. Biotic homogenization - the increasing similarity of communities across the landscape and the globe - is a result of these trends and is an indicator of biodiversity loss. The objective of my research program is to better understand the patterns, processes, and stressors of Canadian freshwater fishes at multiple taxonomic and geographic scales. Such knowledge is essential for the conservation, protection, and recovery of freshwater fish biodiversity in Canada. Patterns of freshwater fish biodiversity will be examined at the scales of Canada and the Laurentian Great Lakes and their watersheds and tributaries. Overall richness and community patterns will be examined using data from a soon-to-be published national fish atlas, an online Great Lakes fish atlas, and unpublished and newly collected fish distribution data for southern Ontario tributaries. The historical (postglacial history, phylogeny) and environmental processes (abiotic, biotic) that structured those patterns will be identified using a variety of statistical techniques. In addition, the human stressors that currently influence the biodiversity patterns will also be examined. To determine how well Canada’s existing network of protected areas actually protect freshwater fish biodiversity, a gap analysis will be undertaken that overlays biodiversity and protected areas layers. This gap analysis will identify fish species and communities in need of additional protection. To elucidate the underlying mechanisms of interactions between native freshwater fishes and fish AIS, their history of co-occurrence in the Great Lakes will be examined. Based on recently published book chapters, species lists for each Great Lake will be reconstructed by decade from pre-1870 to 2010 and used to examine the history of native species loss and AIS invasion. This will facilitate testing of many of the hypotheses related to the establishment and impact of AIS (e.g. biotic resistance, niche overlap). These hypotheses will be tested through multivariate analyses of ecological and life-history traits to examine trait space changes over time. The proposed research includes several novel components. Analyses that examine the influence of history, environment, phylogeny, and stressors on freshwater fishes have not been conducted comprehensively for Canada or the Great Lakes. Gap analyses to evaluate how well freshwater fishes are protected by protected areas have not been published for Canada or the Great Lakes. The decadal Great Lakes database provides a unique opportunity to test invasion theory hypotheses and species homogenization over an extended time periods.