Submerged cage aquaculture of marine fish: A review of the biological challenges and opportunities

Abstract

Surface‐based cages are the dominant production technology for the marine finfish aquaculture industry. However, issues such as extreme weather events, poor environmental conditions, interactions with parasites, and conflicts with other coastal users are problematic for surface‐based aquaculture. Submerged cages may reduce many of these problems and commercial interest in their use has increased. However, a broad synthesis of research into the effects of submerged culture on fish is lacking. Here, we review the current status of submerged fish farming worldwide, outline the biological challenges that fish with fundamentally different buoyancy control physiologies face in submerged culture, and discuss production benefits and problems that might arise from submerged fish farming. Our findings suggest that fish with closed swim bladders, and fish without swim bladders, may be well‐suited to submerged culture. However, for fish with open swim bladders, such as salmonids, submergence is more complex as they require access to surface air to refill their swim bladders and maintain buoyancy. Growth and welfare of open swim bladder fish can be compromised by submergence for long periods due to complications with buoyancy regulation, but the recent addition of underwater air domes to submerged cages can alleviate this issue. Despite this advance, a greater understanding of how to couple advantageous environmental conditions with submerged culture to improve fish growth and welfare over the commercial production cycle is required if submerged cages are to become a viable alternative to surface‐based cage aquaculture.

Evaluation of the green development efficiency of marine fish culture in China

“…Although offshore cage aquaculture was most productive, ordinary pond aquaculture and ordinary cage aquaculture were still the dominant aquaculture modes in marine fish culture in China, which influenced the GDE of marine fish culture in China. Since offshore cage aquaculture, industrial recirculating aquaculture, and engineering pond aquaculture can guarantee aquaculture economic activities, optimize environmental conditions, and reduce interactions with harmful organisms (Gui et al, 2018;Sievers et al, 2021), it is necessary to increase the production of these green modes (with higher GDE) to promote the green development of marine fish culture in China.…”

Numerical study on the lifting operation of a gravity-type fish cage

“…Fish cages are the most used equipment in aquaculture [1][2][3]. As technology advances, the number of different types of fish cages used in aquaculture are becoming less [4].…”

Monitoring Farmed Fish Welfare by Measurement of Cortisol as a Stress Marker in Fish Feces by Liquid Chromatography Coupled with Tandem Mass Spectrometry

“…Despite of its success, the industry is still facing issues around fish health and welfare that need to be resolved [3]. With the typical production in surface-based cages, fish health can be challenged by a range of events, including weather, parasites, algae, jellyfish, diseases, reduced oxygen, and crowding by net deformation [4]. Following a jellyfish bloom occurrence for example, both direct and indirect effects on fish health can be observed.…”