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* By Nick Gosling
Salmon farms have been an important part of the northeast U.S. aquaculture industry for over 50 years, but sea lice, a pesky parasitic crustacean that feed on and injure of the salmon. Integrating lumpfish—a cleaner fish that naturally feeds on sea lice off salmon—into aquaculture farms can provide a sustainable mitigation strategy.
Research at the University of New Hampshire and the New Hampshire Agricultural Experiment Station found that lumpfish hatcheries can reduce such behavior by altering light conditions and fish densities inside tanks.
“Lumpfish are crucial in addressing the high demand for cleaner fish in salmonid farming, but their aggressive behavior, including cannibalism, poses a challenge,” said Station scientist Elizabeth Fairchild, a research associate professor with UNH’s College of Life Sciences and Agriculture (COLSA). “Understanding the factors that exacerbate lumpfish aggression, and providing guidelines for mitigating this behavior to aquaculturists, are essential for increasing hatchery production and rearing efficiency.”
Fairchild and her co-authors, including Brittany Jellison, an assistant professor in UNH’s biological sciences department, and Shelby Perry, a Master of Science student in COLSA’s marine biology program, recently published their research in the North American Journal of Aquaculture. Conducting their research at the UNH’s Coastal Marine Lab, the scientists found that, especially for smaller lumpfish, instances of tail fin nipping as a sign of aggression lessened when the fish had 12 hours of light followed by 12 hours of dark (versus constant light) and when the density of fish was reduced.
These management conditions become less influential as lumpfish grow larger, allowing for more flexibility in rearing practices, said Fairchild. However, further research is needed to explore the long-term impacts of these conditions and to develop comprehensive guidelines for lumpfish rearing.
As more becomes known about sustainable lumpfish management in edge and practices could help further to sea lice.
The species that is particularly impactful, Lepeophtheirus salmonis, feeds on the mucus, skin and blood of salmon, causing lesions, stress and sometimes mass mortality of salmon and can cost an estimated $1.3 million per farm over a two-year production cycle in sea lice infestation management.
Current mitigation methods for sea lice, including waterjets, hot water showers and other mechanical and thermal treatments, aren’t fully effective and can harm the fish, resulting in lower growth and survival rates for the salmon.
Which is why finding optimal environmental conditions for lumpfish development, thus enhancing their effectiveness as a cleaner fish in aquaculture settings, is so critical, said Perry.
“By adopting these recommendations, fish farmers can improve lumpfish hatchery production, reduce juvenile mortality and enhance the sustainability of salmonid farming through effective sea lice management,” she added. “And increasing aquaculture sustainability and efficiency is vital to meeting the future demand for animal protein, as well as protecting the planet we live on.”
Funding
This material is based on work supported by the NH Agricultural Experiment Station through joint funding from the USDA National Institute of Food and Agriculture (under Hatch award number 1026188) and the state of New Hampshire.
About the NHAES
Founded in 1887, the NH Agricultural Experiment Station at the UNH College of Life Sciences and Agriculture is UNH’s first research center and an elemental component of New Hampshire’s landrant university heritage and mission. We steward federal and state funding, including support from the USDA National Institute of Food and Agriculture, to provide unbiased and objective research concerning diverse aspects of sustainable agriculture and foods, aquaculture, forest management, and related wildlife, natural resources, and rural community topics.
We maintain the Woodman and Kingman agronomy and horticultural research farms, the Macfarlane Research Greenhouses, the Fairchild Dairy Teaching and Research Center, and the Organic Dairy Research Farm. Additional properties also provide forage, forests, and woodlands in direct support to research, teaching, and outreach.
* Nick Gosling
UNH College of Life Sciences and Agriculture
Contact the Researcher: Elizabeth Fairchild
Research Associate Professor
UNH College of Life Sciences and Agriculture
Elizabeth.Fairchild@unh.edu
For further details, you can read the full research article “THE EFFECTS OF LIGHT, REARING DENSITY, AND FISH SIZE IN CULTURING JUVENILE LUMPFISH” developed by: PERRY, S., FAIRCHAILD, E.-University of New Hampshire, and JELLISON, B. The original article was published on JULY, 2024, through NORTH AMERICAN JOURNAL OF AQUACULTURE.
The full version can be accessed online through this DOI: 10.1002/naaq.10347.
