California Department of Fish and Wildlife

Hagfish Studies

The Northern and Central California Finfish Research and Management Project has implemented a fishery-dependant sampling program to monitor the hagfish fishery. Project biologists gather data on the average size of hagfish landed at their local ports of landing. Because it is difficult to measure the length of a live hagfish, biologists record the average number of hagfish per pound from the sampled catch to document changes in the average size of harvested fish. Monthly port landing totals and changes within the fishery are also documented.

The first-ever collaborative hagfish survey was completed by the Project in Monterey Bay on March 25-28, 2013. Using 96 standard bucket traps, of which there were 24 buckets for each hole diameter (0.375, 0.50, 0.5625, 0.625 inches), Project staff counted 7,595 hagfish for a total weight of 1,811 lb over the course of 3 full survey days. An additional 1,441 hagfish were counted on the first “prospecting” day. During the prospecting day, soak times were only 2-4 hr, while on full survey days soak times were approximately 24 hr. Based on field observations and average counts per pound per bucket hole diameter, the hypothesis that hole diameter influences average size of hagfish caught was proven correct.

Staff at work during a hagfish research cruise. CDFW file photo.      Biologist sampling commercial hagfish using the average number of hagfish per pound method. CDFW photo by Kim Penttila.