Ecosystem responses to sportfish stocking and aeration in boreal foothills lakes

生态系统对北方山麓湖泊中运动鱼放养和通气的反应

• 批准号: 356984-2007
• 负责人: Tonn, William
• 金额: $ 4.4万
• 依托单位: University of Alberta
• 依托单位国家: 加拿大
• 项目类别: Strategic Projects Supplemental Competition
• 财政年份: 2007
• 资助国家: 加拿大
• 起止时间: 2007-01-01 至 2008-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=366261
• 关键词: Ecosystem; responses; sportfish; stocking; aeration

Throughout western North America, the stocking of inland waters that naturally lack sportfishes with non-native trout is a well-established management activity that creates new recreational fisheries. Alberta Sustainable Resource Development (ASRD) and the Alberta Conservation Association (ACA) currently stock lakes throughout the province, including small Boreal Foothills lakes. However, adding a top-predator into a fresh water ecosystem can have significant ecological impacts on potential trout competitors, and for aquatic invertebrates and amphibians that are the prey of the trout. These direct impacts can, in turn, affect other components of the food web. Unlike settings of most previous studies, however, the Boreal Foothills lakes of our study are more productive, and contain native populations of invertebrates and hardy forage fishes. Thelakes are often small and shallow and are therefore prone to winterkill for large, fast-growing fish such as trout.  In their fisheries management plan, the ACA has therefore implemented an aeration program for some of the stocked lakes. In its first phase (2005-2007) our project applied a "Control vs. Impact" study design, comparing nearby stocked and aerated, stocked and not aerated, and unstocked lakes. As ASRD stocks lakes we are studying that were previously unstocked, we can implement a "Before-After-Control-Impact" (BACI) design that is recognized as very powerful for studying ecological impact. We will monitor community consequences of stocking and aeration in this context by continuing to assess forage-fish population sizes, performing invertebrate and amphibian population surveys, as well as studying water quality and the food-web of the lake types through stable-isotope analysis. The research is important for managing sustainable recreational fishery in ways that minimizes its impact on native biodiversity. Our study provides us a unique opportunity to monitorthis stocking management program and develop strategies for the benefit of the ecological communities here (and elsewhere fish-stocking is implemented) and for the recreational interests of the region's residents and visitors.

在整个北美西部，在自然缺乏运动鱼类的内陆水域放养非本地鳟鱼是一项行之有效的管理活动，创造了新的休闲渔业。阿尔伯塔可持续资源开发（ASRD）和阿尔伯塔保护协会（ACA）目前在全省范围内储存湖泊，包括小型北麓湖泊。然而，在淡水生态系统中增加一种顶级捕食者会对潜在的鳟鱼竞争对手以及作为鳟鱼猎物的水生无脊椎动物和两栖动物产生重大的生态影响。这些直接影响反过来又会影响食物网的其他组成部分。然而，与大多数先前研究的设置不同，我们研究的北麓湖泊更富有生产力，并且包含无脊椎动物和耐寒饲料鱼类的本地种群。湖泊通常又小又浅，因此容易被大型、快速生长的鱼类（如鳟鱼）冬杀。因此，在他们的渔业管理计划中，ACA对一些有库存的湖泊实施了曝气计划。在第一阶段（2005-2007年），我们的项目采用了“控制与影响”的研究设计，比较了附近放养湖泊和曝气湖泊、放养湖泊和不曝气湖泊以及未放养湖泊。由于我们正在研究的ASRD储存了以前未储存的湖泊，我们可以实施“控制-影响前-后”（BACI）设计，该设计被认为对研究生态影响非常有效。在这种情况下，我们将通过继续评估饲料鱼类种群规模、进行无脊椎动物和两栖动物种群调查，以及通过稳定同位素分析研究水质和湖泊类型的食物网，来监测放养和通风对群落的影响。这项研究对于管理可持续休闲渔业，最大限度地减少其对本地生物多样性的影响具有重要意义。我们的研究为我们提供了一个独特的机会来监测这种放养管理计划，并为这里的生态社区（以及其他地方实施的鱼类放养）和该地区居民和游客的娱乐利益制定策略。