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ARS Home » Northeast Area » Orono, Maine » National Cold Water Marine Aquaculture Center » Research » Research Project #443806

Research Project: Utilizing Hormone Implants to Develop Improved Spawning Strategies for Lumpfish

Location: National Cold Water Marine Aquaculture Center

Project Number: 8030-31000-005-046-R
Project Type: Reimbursable Cooperative Agreement

Start Date: Jan 1, 2023
End Date: Dec 31, 2024

The objective of this project is to develop improved spawning strategies for lumpfish. Currently, the spawning season for lumpfish in captivity in Maine can run from early April through early June. This poses a challenge given the log egg stage and then a prolonged season for caring for larval fish. Production would be improved if females could be induced to spawn synchronously, thereby synchronizing the egg development and larval stages. Likewise, male lumpfish typically produce low amounts of milt in captivity, which requires the use of lethal spawning techniques. Use of hormone implants is a proven technology in other fish species used to address both of these issues. The domestic salmon aquaculture industry is moving forward with the development of lumpfish for use as a cleaner fish to manage sea lice on salmon production in marine net-pens. Industry trials have shown that use of lumpfish to control sea lice can reduce costs by 10% compared to the use of the existing mechanical treatments currently in place. As such the development of lumpfish in Maine is a key strategy currently being pursued by industry to manage sea lice. Recent collaborative work between the USDA and the University of New Hampshire (UNH) has developed a set of guidelines for hatchery culture of lumpfish. The largest hurdle to the development of a lumpfish industry in Maine is a source of captive reared local eggs. This project aims to utilize hormone implants to improve spawning techniques with locally sourced potential broodstock.

The National Cold Water Marine Aquaculture Center (NCWMAC) and University of New Hampshire (UNH) both have experience spawning locally sourced lumpfish. The Zohar lab at the University of Maryland Baltimore County are world experts in using hormone implants to address spawning issues in fish. Based on their experience the Zohar lab will make a range of doses in an implantable form and will train the staff at UNH and NCWMAC on how to implant them. The training will be captured in a set of written and video standard operating procedures (SOPs) to be developed as part of the grant. Implants will be tested in both male and female animals. Spawning records including date of spawning, percentage of eyed eggs at 100 degree days (dd), and percent hatch success for females with either hormone implants or control implants will be recorded. Non-lethal strip spawning will be attempted on males implanted with either hormones or control implants. The volume of milt recovered will be recorded as well as the gonadal-somatic index calculated for a sub-sample of lethally spawned males at 7 and 14 days post implantation. The results from the first set of spawnings will then be used by the Zohar lab to refine the implant doses in a second year of spawning. The project will transfer the technology gained through inclusion of the written and video SOPs in a revised version of the Lumpfish Hatchery Guidelines developed collaboratively by NCWMAC and UNH. The video SOP will be filmed and edited by staff from New Hampshire Sea Grant that specialize in video development. A workshop will also be hosted at the NCWMAC to present lumpfish hatchery techniques including the use of spawning aid implants.