Mytilus galloprovincialis's role in Integrated Multi-Trophic Aquaculture (IMTA): A comprehensive review

Batır, E., Aydın, _I., Theodorou, J. A., & Rakaj, A.

Integrated Multi-Trophic Aquaculture (IMTA) represents a promising approach for continued development of sustainable aquaculture practices. In this review, the authors summarized innovative aquaculture techniques focusing on the synergistic relationships between Mytilus galloprovincialis, the Mediterranean mussel, and other aquatic species. Mussels are a key extractive species that feed on phytoplankton and contribute to environmental health and nutrient cycling. They proposed three models to optimize their extractive potential and utilize the hydrodynamic conditions of aquaculture sites. These models include:

1. Placing mussels close to each other to enhance feeding efficiency in an aquaculture setting that has lower water movement.
2. Arranging mussels downstream in areas with stronger currents so filtering time is increased.
3. Spreading mussels out so they can slow currents in a way that improves feeding opportunities when high-hydrodynamic conditions exist.

The authors note that it is critical to understand the scalability of IMTA systems in the context of environmental and economic sustainability. Based on the current information and practical applications for finfish, they recommend an IMTA approach of incorporating mussels alone or mussels in combination with sea cucumbers or algae.

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The National Regulatory Cost Burden on US aquaculture farms.

Engle, C. R., van Senten, J., Hegde, S., Kumar, G., Clark, C., Boldt, N., Fornshell, G., Hudson, B., Cassiano, E. J., & DiMaggio, M. A.

This study assessed US aquaculture and how various regulations impact this industry. While many U.S. regulations have improved environmental and social well-being, others have created costly burdens that impact aquaculture and other industries. This study estimated that in 2023, regulatory compliance was among the top five operational expenses for U.S. aquaculture and totaled $196 million. This represented total farm costs of 9% to 30%, with smaller farms bearing disproportionate shares of these fixed costs. Additionally, regulatory restrictions led to $807 million in lost annual revenue, or 36% of total sales value. Considering broader economic impacts and multiplier effects, the industry forfeited $1.4 billion annually and lost over 8,000 jobs due to these constraints. The U.S. regulatory environment is complex and challenging, as it often involves overlapping federal, state, and local rules. A 2012 executive order highlighted the growing compliance burden for aquaculture, which was valued at $4 billion in 2022 and considered a vital industry for rural economies. The U.S. is now the world's largest seafood importer, with a $20.3 billion trade deficit in 2023. This is driven by domestic production barriers that often involve regulatory issues. By importing seafood, regulatory inefficiencies in the U.S. have essentially shifted environmental harms abroad, compromised food security, and blocked the development of key sectors like marine finfish farming. This study can be considered a first of its kind in that it assesses nationwide regulatory costs for aquaculture and argues for more balanced, evidence-based regulation for the industry. This may include sunsetting outdated rules, incentivizing compliance, harmonizing fish health standards, improving non-lethal testing, and streamlining permits. The authors suggest that by implementing smarter regulations, built on science, stakeholder input, and flexible frameworks, the cost of compliance could be reduced without compromising oversight.

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Quantification of endogenous marker acid-insoluble ash in commercial aquaculture ingredients and feeds..

Camperio, J., Suarez, J. A., Glencross, B., & Benetti, D. D.

This study evaluates acid-insoluble ash (AIA) as a low-cost, naturally occurring alternative to traditional external markers like chromic oxide and yttrium oxide for aquaculture feed digestibility studies. External markers, though effective, are often impractical for small-scale feed production due to cost and logistical issues. This research is the first to quantify AIA levels in 18 commercial aquaculture feeds and 27 ingredients from various global sources, and assess the recovery rate of pure AIA. Analyses revealed wide variation in AIA content across ingredient types, with the highest being found in marine and animal meals (up to 25.8% and 5.0%, respectively), and the lowest in plant-based meals (as low as 0.2%). Shrimp and crab meals showed especially high AIA due to mineral-rich exoskeletons, and they found that processing to enhance meal quality typically lowered the AIA levels. A limit of quantification (LOQ) was also established for the method’s reliability. The study demonstrates that many commercial feeds contain measurable AIA levels, making this a viable, cost-effective marker for in vivo digestibility trials. Therefore, AIA offers a practical alternative to external markers, enabling more efficient and affordable nutritional evaluations. These findings support feed manufacturers and farmers by providing a means of quickly assessing feed quality and optimizing performance, particularly under least-cost formulation strategies.

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