Reference | Sypitkowski, E., W. G. Ambrose, C. Bohlen, and J. Warren. 2008. Harvest efficiency of bloodworms on Maine mudflats. North American Journal of Fisheries Management 28:1506-1514. |
Abstract | Efficiency of diggers of varying experience levels in harvesting bloodworms Glycera dibranchiata was documented during multiple tides on several intertidal flats in midcoast Maine. Individually coded-wire-tagged bloodworms were seeded in 20-m2 plots and harvested by professional diggers after allowing ample time for bloodworms to burrow. To ensure that bloodworms reached depths similar to those of naturally occurring individuals, we measured the depths at which tagged and naturally occurring bloodworms were found in preliminary experiments. Using the same methods but without measuring bloodworm depths, we performed efficiency experiments. The rate of tag loss was also determined. Measured efficiency of diggers ranged from 26% to 75% and averaged about 45%. Retrieved bloodworms were marginally larger than seeded bloodworms. Diggers generally dug deeper than bloodworms burrowed, and all seeded bloodworms reached depths similar to those of naturally occurring bloodworms within 1 h. The relatively low observed harvest efficiency and the bias towards larger individuals may contribute to the long-term sustainability of the bloodworm fishery. |
Tag | Coded Wire Tags (CWT) |
Objective | Harvest management |