Is Good Fish Culture Management Harming Recovery Efforts in Aquaculture‐Assisted Fisheries?

Abstract

To make conservation aquaculture successful, a paradigm shift is needed in what is considered good hatchery management as defined by production aquaculture as well as in the metrics that are used to evaluate hatchery success. In production aquaculture, managers strive to maintain exceptional environmental conditions to maximize yield, the number of fish produced, and survival. However, this type of aquaculture management could decrease the likelihood of success of imperiled species recovery programs due to domestication and epigenetics. Consequently, good management practices in conservation aquaculture should produce conditions that resemble the environment where the fish will be stocked in order to minimize domestication and epigenetic problems that will lower the fitness of wild stocks following augmentation. Changes in what are considered good culture conditions require a new set of hatchery evaluation metrics. The key metric that needs to be altered is the survival rate. Survival is the keystone metric because it determines other metrics such as the number produced, yield, and profits. High survival rates influence domestication, which adversely affects post‐augmentation survival and the fitness of the wild stock. Consequently, lower hatchery survival rates produced by selective pressures in conservation aquaculture are needed to improve success in imperiled species recovery programs. We propose that survival be 10–25% to improve success. Our proposed evaluation metrics for conservation aquaculture are to produce “wild” fish and not lower the fitness of the wild population. We recognize that these recommendations are controversial, but a major goal of this paper is to start a discussion about the most appropriate way to evaluate this type of aquaculture so that recovery efforts for imperiled species can be improved.

Microbial ecology of Atlantic salmon, Salmo salar, hatcheries: impacts of the built environment on fish mucosal microbiota

“…While freshwater systems currently outproduce marine systems (51.4 MT vs. 28.7 MT; 2016), marine aquaculture has a tremendous potential to expand with estimates of theoretical production of 15 billion tonnes (522 × increase) (2, 3). One of the primary challenges to scaling aquaculture production is improving seed quality by increasing survival rates and strengthening immune development of larvae and juveniles in the hatchery environment (4). This becomes challenging particularly when there are an estimated 369 different species of fish currently grown for commercial aquaculture with additional species in experimental production (3).…”

Effect of Temperature on Survival of Lost River Suckers with a Natural Infection of Ichthyobodo spp.

“…Furthermore, domestication can lead to the survival of limited genotypes that are more suited to captivity than the wild (Lorenzen et al 2012; Thompson and Blouin 2015). To limit domestication, conservation hatcheries often attempt to grow fish in more natural environments, avoid supplementation with artificial feeds, and limit the use of therapeutics (Coutant 1998; Tave and Hutson 2019; Tave et al 2019). Thermal manipulation may be a highly beneficial tool to optimize growth and survival while decreasing the domestication of endangered fish in rearing programs (Kindschi et al 2008; Kappenman et al 2012).…”

Raising Fish in a Purpose‐Built Conservation Aquaculture Facility Using Conservation Aquaculture Management

“…Because the goal of conservation aquaculture is to raise fish in an environment that resembles that of the target environment, survival rates will be lower than those that can be achieved at traditional production hatcheries. High hatchery survival rates in aquaculture‐assisted fisheries are counterproductive for two reasons: (1) they can lead to higher poststocking mortality (Wales ; Suboski and Templeton ) and (2) they can increase domestication selection, whereas a major goal of conservation aquaculture is to produce fish that are “wild,” not farmed (Tave and Hutson , this special section).…”