A rapid assessment approach to prioritizing streams for control of Great Lakes sea lampreys (Petromyzon marinus): a case study in adaptive management

Abstract

We developed and evaluated an alternative method (rapid assessment or RA) for assessment of larval sea lampreys, Petromyzon marinus . We determined that using RA would result in at least as many, if not more, sea lampreys being killed than would using the current assessment method (quantitative assessment sampling or QAS) to select streams for lampricide treatment. Both assessment methods were carried out simultaneously throughout the entire Great Lakes basin from 2005 to 2007. RA required fewer resources than the current method and thus allowed for the chemical treatment of additional streams with lampricides, given a fixed overall budget for control. Population estimates generated from the QAS surveys showed that using RA would result in approximately equal numbers of metamorphosing lamprey and greater numbers of larval lamprey killed than by using QAS. Mark–recapture results indicated that prioritizing streams for treatment using RA may result in higher numbers of metamorphosing and larval lampreys killed than by using QAS. RA is currently being adopted throughout the Great Lakes as the method for assessing larval sea lamprey populations. Other fishery management programs may benefit from examining the value of their assessment programs relative to other uses of resources.