A behavioural framework for trapping success and its application to invasive sea lamprey

Abstract

Scientific advances are needed to contend with invasive species. Trapping is often used for control or assessment, and understanding the invasive species’ behaviour is important for trapping success. A framework linking behaviour to trapping success and management responses was used to test hypotheses for the low trapping success of invasive sea lamprey (Petromyzon marinus) in the St. Marys River connecting Lakes Superior and Huron. Behaviour of sea lamprey approaching and at traps was quantified using external and internal tags and video. Multistate Markov models identified phenotypic and environmental factors influencing trapping success. Low trapping success for invasive sea lamprey in the St. Marys River is due to individuals not encountering traps, not entering upon encounter, not remaining at the trap, and not returning upon departure. All trapped lamprey were retained. Encounter with, and entrance into, traps varied with sea lamprey class, release date, and time of day, but not body length or river discharge. The conceptual and analytical methods applied here could be used to understand and improve trapping success for other invasive animals.