Disease and parasitism cause major welfare, environmental and economic concerns for global aquaculture. In this review, we examine the status and potential of technologies that exploit genetic variation in host resistance to tackle this problem. We argue that there is an urgent need to improve understanding of the genetic mechanisms involved, leading to the development of tools that can be applied to boost host resistance and reduce the disease burden. We draw on two pressing global disease problems as case studies—sea lice infestations in salmonids and white spot syndrome in shrimp. We review how the latest genetic technologies can be capitalised upon to determine the mechanisms underlying inter‐ and intra‐species variation in pathogen/parasite resistance, and how the derived knowledge could be applied to boost disease resistance using selective breeding, gene editing and/or with targeted feed treatments and vaccines. Gene editing brings novel opportunities, but also implementation and dissemination challenges, and necessitates new protocols to integrate the technology into aquaculture breeding programmes. There is also an ongoing need to minimise risks of disease agents evolving to overcome genetic improvements to host resistance, and insights from epidemiological and evolutionary models of pathogen infestation in wild and cultured host populations are explored. Ethical issues around the different approaches for achieving genetic resistance are discussed. Application of genetic technologies and approaches has potential to improve fundamental knowledge of mechanisms affecting genetic resistance and provide effective pathways for implementation that could lead to more resistant aquaculture stocks, transforming global aquaculture.

Aquaculture creates ‘aquatic foods’ such as fish, shellfish, and seaweeds that are critical for food security. Gene editing using CRISPR‐Cas9 has the potential to transform aquaculture by improving animal welfare, nutritional attributes, and farming efficiency, with benefits for environmental sustainability. However, gene editing also poses risks of harm via side effects on other important traits or genetic introgression into wild populations. Public acceptance of gene edited aquatic species will rapidly erode if risk mitigation is ineffective or not applied. Here, we review the benefits and risks for gene editing in aquaculture. A general framework for risk–benefit analysis of gene editing in aquaculture is proposed, incorporating nine key considerations: genetic impacts, ecological impacts, disease risk mitigation, nature of edit, supply chain environmental footprint, animal welfare, human nutrition, ethical business implications and impacts on local communities. When applied on a case‐by‐case basis, the framework will help identify how gene editing of a farmed species can most enhance production and nutritional benefits while minimising harms to animal welfare, the environment, and society.

Atlantic cod is a historically abundant species in the North Atlantic region and has contributed to the prosperity of many nations. But a decline in stocks in the last century has prompted to initiate commercial farming of cod in captive conditions. Several approaches have been employed ranging from stock enhancement, capture‐based aquaculture and intensive cod farming. However, except for the enhancement efforts which were carried out for almost a century, efforts on other methods were intermittent coinciding with lower quotas. Intensive farming was attempted in Norway, Scotland, Ireland, Canada, Iceland and Faroe Islands in the 2000s. But it was carried out hastily to cash in the demand for cod in the market even though there were many biological knowledge gaps that are required for a successful aquaculture venture. The reasons for the failure of commercial farming in Norway during the 2000s were not only because of limited knowledge of the biology of cod but also the economic meltdown in Europe in 2008. Cod farming came to a halt; however, the Norwegian National Cod Breeding Program (NCBP) initiated in 2003 continued to operate and produced a fifth generation of a domesticated cod in 2019. Efforts to fill the gaps and the selective breeding for better growth and disease resistance within NCBP have improved the quality of the juveniles produced. We will discuss the past efforts and reasons for failure in farming of cod, how the current situation looks and the future direction in terms of cod biology, political atmosphere and market.

The Norwegian Lundehund is a highly endangered native dog breed. Low fertility and high frequency predisposition to intestinal disorder imply inbreeding depression. We assessed the genetic diversity of the Lundehund population from pedigree data and evaluated the potential of optimal contribution selection and cross-breeding in the long-term management of the Lundehund population. The current Norwegian Lundehund population is highly inbred and has lost 38.8% of the genetic diversity in the base population. Effective population size estimates varied between 13 and 82 depending on the method used. Optimal contribution selection alone facilitates no improvement in the current situation in the Lundehund due to the extremely high relatedness of the whole population. Addition of (replacement with) 10 breeding candidates of foreign breed to 30 Lundehund breeders reduced the parental additive genetic relationship by 40–42% (48–53%). Immediate actions are needed to increase the genetic diversity in the current Lundehund population. The only option to secure the conservation of this rare breed is to introduce individuals from foreign breeds as breeding candidates.

Purpose: To evaluate the management of prolonged indwelling ureteral stents and the newly developed KUB (kidney, ureter, and bladder) grading system for the classification of encrusted stents in urolithiasis. Method: This study involved 69 patients that had indwelling and forgotten ureteral stents for more than 6 months after urolithiasis treatment. They were categorized into 4 groups based on indwelling time and were reviewed retrospectively. Patients whose ureteral stent could not be removed with simple cystoscopy were graded according to stone surface area and the KUB system. Results: The mean stent indwelling time was 23.1 months. Stone burden in KUB and, in proportion to that, total KUB (T) score showed increased association that was directly proportional to indwelling time (p < 0.001, p = 0.008). Surgical intervention was required in 73.9% of patients. Among patients requiring surgery, 78.4% were treated in a single session and multi-modal interventions were performed in 70.5%. K score >= 3 was found to be associated with multiple surgery requirements (odds ratio [OR];11.25, %95 confidence interval [CI]:2.132-59.375), multi-modal procedure requirements (OR;16.50, %95 CI:3.434-79.826), and lower stone-free rates (p = 0.04). B score >= 3 was associated with multi-modal procedure requirements (OR;8.90, %95 CI:1.052-75.462). U score >= 3 and T score >= 9 were associated with an operating time >180 minutes (p < 0.001, p = 0.008). Conclusion: Prolonged indwelling time of the ureteral stent in urolithiasis is associated with increased encrustation and stone burden. Since the KUB system specifies stone burden and its particular localization, it can be used as a simple, convenient method for the planning treatment of encrusted ureteral stents.

Introduction Kidney stones occur more frequently in patients with a horseshoe kidney (HSK) anomaly. Abnormal anatomy may make the stone removal procedures more difficult. Therefore we aimed to evaluate and compare retrograde intrarenal surgery (RIRS) and percutaneous nephrolithotomy (PCNL) for the treatment of renal stones in the HSK anomaly. Material and methods In this descriptive study, patients with HSK anomaly who underwent RIRS and PCNL procedures were retrospectively evaluated. Demographic and renal stone characteristics, success and complications associated with the surgical methods were compared across patients. Results A total of 49 patients were evaluated, 28 underwent RIRS and 21 underwent PCNL. No differences were determined between the groups concerning the demographics of patients and stone characteristics. A single session and final stone-free rate was 71.4% and 85.7% in RIRS, 81% and 90.5% in PCNL (both p = 0.05). However, RIRS had more re-treatment rate, while its mean length of hospital stay was shorter than PCNL (p = 0.035, p = 0.001). While no differences were detected between the associated complication rates, more of the complications encountered in the PCNL group were of a serious nature. Conclusions In the HSK anomaly, renal stones can be treated with RIRS and PCNL procedures with high success. With its minimal morbidity, low complication rates and the minor character of the associated complications, the RIRS procedure can sometimes be preferred to avoid complications related to PCNL in HSK anomaly with big sized kidney stones.