Aquaculture Journal

Antimicrobial use (AMU) in finfish aquaculture production raises concerns about the link between AMU and the development of antimicrobial resistance (AMR) in bacteria found in aquatic organisms and potential transmission to humans and the environment. The objective of this study was to describe the antimicrobial susceptibilities of a historical collection of bacterial isolates from diagnostic submissions from farmed finfish in British Columbia (BC), Canada. Antimicrobial susceptibility data were obtained from the BC Ministry of Agriculture via submissions to the Animal Health Centre for 2007 to 2018 for florfenicol (FLOR), oxytetracycline (OXY), trimethoprim-sulfadiazine (SXT), and triple-sulfa compound (TRI). There were 1237 unique isolates from all finfish species (68 unique bacterial species), of which 1042 were from Atlantic salmon. For all fish species, the most common bacterial species isolated were Aeromonas salmonicida (n = 174), Aliivibrio wodanis (n = 84), and Yersinia ruckeri (n = 79). Resistance was detected to most antimicrobials tested, but levels were generally low. Resistance to FLOR was only detected in A. salmonicida. Low annual isolate numbers precluded genera-specific annual comparisons for all pathogens. Multi-drug resistance was detected, but at low levels. These results provide an important baseline for antimicrobial susceptibility data from bacterial isolates that may cause disease in finfish aquaculture in BC, Canada that will support future Canadian AMR surveillance in farmed aquaculture.

Aquatic animal products are vital to global food security and nutrition, necessitating accurate, scalable, and non-destructive methods for quality assessment in aquaculture. Conventional techniques such as dissection and biochemical analysis are invasive, labor-intensive, and unsuitable for real-time or high-throughput decision-making. This review synthesizes six major categories of non-destructive technologies—electrical, spectroscopic, natural sensory, acoustic, radiographic, and infrared and microwave—classified by their underlying sensing mechanisms and therefore differing measurement capabilities and deployment feasibilities. To support objective technology selection, an Analytic Hierarchy Process (AHP) framework was developed using general performance criteria (cost, accuracy, speed, usability) and one decision-critical application-specific criterion (non-invasiveness), and was demonstrated for ovarian maturation staging in mud crabs by ranking 19 candidate techniques. Accuracy had the highest weight (0.416), but non-invasiveness (0.224) and usability (0.197) substantially influenced the final ranking, illustrating how operational and welfare constraints could shift preferred solutions despite differences in analytical accuracy. Based on the global priority weights (GA), computer vision (CV) was identified as the most suitable option (GA = 0.076), balancing affordability, throughput, ease of deployment, and animal welfare compatibility, whereas high-end modalities such as nuclear magnetic resonance (NMR; GA = 0.073) and computed tomography (CT; GA = 0.070) were constrained by cost and operational complexity. Overall, this review–AHP–case study pipeline provides a transparent and reproducible decision-support basis for selecting non-destructive technologies across aquaculture species and quality targets.

Fish is highly prone to spoilage due to a combination of intrinsic biochemical processes and microbial proliferation, which together drive rapid quality deterioration during post-harvest handling and storage. These processes are further accelerated by factors such as elevated temperatures, mechanical damage, and suboptimal handling. In Mediterranean aquaculture, ice slurry is the standard harvesting method. This study aimed to characterize the initial post-harvest enzymatic activity of key proteolytic enzymes, calpain, collagenase, cathepsin B (CTSB), and cathepsin L (CTSL), in the white muscle of three commercially important species (Sparus aurata, Dicentrarchus labrax, and Pagrus major) harvested under standard practices across three seawater harvest temperatures (low, medium, and high). Muscle samples were collected over a 13-day chilled storage period post-harvest, and enzymatic activity was assessed using standardized fluorometric assays. Our findings establish the basal post-mortem proteolytic profiles for each species and reveal marked species-specific differences in enzyme activity patterns. Calpain and collagenase exhibited early and parallel activation, while CTSB and CTSL showed a coordinated increase during storage. Harvest temperature emerged as a critical factor, with the highest enzymatic activities consistently observed during the moderate temperature period. These results underscore the importance of species-specific physiology and seasonal conditions in shaping post-harvest filet degradation, offering a basis for refining harvest strategies to enhance quality management in Mediterranean aquaculture.