Increasing stocking success in alkaline lakes in British Columbia: characterizing the factors that affect high pH tolerance in rainbow trout

在加拿大，休渔是一项受欢迎的经济重要活动，直接和间接经济活动的收入超过80亿美元，约为加拿大商业渔业经济影响的五倍。仅在不列颠哥伦比亚省，每年就有约40万淡水垂钓者被吸引到不列颠哥伦比亚省的湖泊，为该省的经济带来了5.46亿美元的直接利益，并产生了4.11亿美元的间接和诱发经济影响。卑诗省淡水渔业协会（FFSBC）支持这一重要活动，每年在卑诗省湖泊放养500多万条鳟鱼。但是放养后的死亡率对FFSBC来说可能是一个巨大的经济成本。将鳟鱼放养到碱性（高pH值）湖泊中会导致特别高的死亡率。目前，FFSBC储存的湖泊中约有四分之一具有高pH值，这些高pH值湖泊的数量及其pH值在过去几十年中一直在增加。 这项研究合作的主要目标是帮助FFSBC提高高pH值湖泊中放养鱼类的生存率。这项研究将帮助FFSBC决定是否尝试选择性地培育一种耐pH的鳟鱼品系，或者是否投资基础设施以改变孵化场的饲养条件，从而提高现有鳟鱼品系的高pH耐受性。作为这项工作的一部分，我们还将探索高pH耐受性变异的遗传基础以及环境因素对高pH耐受性的影响，有助于更好地了解鱼类pH耐受性的机制。提高高pH值湖泊中放养鱼类的生存率每年可以为FFSBC节省180多万美元，为BC垂钓者提供更多的机会，并支持不列颠哥伦比亚省的重要经济活动。

Recreational fishing is a popular and economically important activity in Canada, generating more than $8 billion in both direct and indirect economic activity, which amounts to about five times the economic impact of the commercial fishery in Canada. In British Columbia alone, ~400,000 freshwater anglers are drawn to BC lakes annually contributing $546 million in direct benefits to the province's economy and $411 million in indirect and induced economic impacts. The Freshwater Fisheries Society of BC (FFSBC) supports this important activity by stocking BC lakes with over five million trout each year. But mortality following stocking can represent a substantial economic cost to the FFSBC. Stocking trout into alkaline (high pH) lakes results in particularly high mortality. At present, about one quarter of the lakes stocked by the FFSBC have high pH, and the number of these high pH lakes, and their pH levels, have been increasing over the last few decades. The primary goal of this research partnership is to help the FFSBC improve the survival of stocked fish in high pH lakes. This research will help the FFSBC decide whether to attempt to selectively breed a pH tolerant strain of trout, or whether to invest in infrastructure to alter the rearing conditions in the hatchery in ways that could increase the high pH tolerance of existing strains of trout. As a component of this work, we will also explore the genetic basis of variation in tolerance of high pH and the effects of environmental factors on high pH tolerance, contributing to an improved understanding of the mechanisms involved in pH tolerance in fish. Improving survival of stocked fish in high pH lakes could save the FFSBC more that $1.8 million each year, provide additional opportunities for BC anglers, and support an important economic activity in British Columbia.