Catch statistics in the bloodworm fishery in Maine

Though they are of critical importance as tools for fisheries managers, catch statistics of small-scale artisanal fisheries are rare. The bloodworm (Glycera dibranchiata) fishery in Maine has lacked catch data since the 1970s, and the extent of the disturbance to the mudflats from which they are dug has never been examined. We tested the hypothesis that worm catch rates have declined since the 1970s. Using both interviews with diggers and observational data, we gathered catch per unit effort data on the time diggers spend digging per tide, worms dug per digger-tide, area dug per digger-tide, and the size of harvested individuals. We found that an average digger digs about 90 m2/h for roughly 2 h each tide. Diggers, however, averaged longer tides and dug larger areas in 2007 than in 2004–2005. Also, diggers harvested an average of 702 (±36S.E.) worms per tide in 2007, more than twice the average for 2004–2005 (328 ± 24). This is most likely due to higher worm density (5.6 worms/m2 in 2007 vs. 0.3 worms/m2 in 2004–2005 at the Worm Conservation Area, Wiscasset, ME). Harvested worms in the past few years have been on the order of 10% larger than worms dug during the 1970s. While managers should consider the extent of disturbance caused by bloodworm digging, from the standpoint of the removal of the target species, the industry at present appears to be sustainable.