Maine’s salmonid industry is eager to deploy lumpfish Cyclopterus lumpus into salmon net pens for biological control of sea lice. However, health certification requirements make it challenging and costly to source lumpfish from outside Maine territorial waters. Recent research activity has focused on establishing a lumpfish breeding colony in Maine and identifying factors that optimize captive breeding.
In 2018 the University of Maine Center for Cooperative Aquaculture Research (CCAR)
initiated a broodstock development program whereby wild, young-of-the-year (YOY) juveniles are captured from the Gulf of Maine to be acclimated and reared to reproductive maturity in CCAR recirculating aquaculture systems (RAS) .
Juvenile lumpfish associate with free-floating mats of seaweed (Ascophyllum nodosum and Fucus spp. ), which can be netted onto a skiff and sorted to capture the YOY. Fishing occurs from July – September when surface sea water temperatures range from 12-18°C. Captured fish are typically 5-15mm length and <1g, but specimens as large as 15cm have been captured in this fashion . In 2018 158 YOY fish were captured; in 2019 429 YOY fish; and in 2020 716 YOY fish. Post-capture survival was poor the first year (≈20%), but in following years was improved to about 50% by co-feeding the smallest of the captured juveniles live prey (Artemia) along with specialty formulated post-larval diets (Otohime). It’s also important to size grade the fish, as larger fish are aggressive and will cannibalize smaller individuals. Once acclimated to captivity the fish grow rapidly, reaching reproductive maturity in their 2nd year. This approach has proven to be successful but ultimately needs to be transitioned to a self-sustaining captive breeding program to avoid further impacting the wild resource.