Oral Presentation Australian Society for Fish Biology Conference 2024

Movin’ on up: Understanding pouched lamprey climbing behaviour to improve habitat connectivity at instream structures.   (111078)

Cindy Baker 1 , Shad Mahlum 1 , Paul Franklin 1 , Peter Williams 1 , Emily White 1 , Gordon Tieman 1
  1. National Institue of Water and Atmospheric Research, Hamilton, WAIKATO, New Zealand

The pouched lamprey (Geotria australis) is considered an obligate anadromous species and represents New Zealand’s (NZ) sole lamprey species. Migratory adult lamprey constitutes an important cultural fishery, and are considered a taonga (treasured) species by NZ Māori. During their freshwater spawning migration, manmade barriers (e.g. dams and other high-head barriers) prevent lamprey reaching critical breeding habitats, and declining populations are presently classified as Threatened – Nationally Vulnerable. The pouched lamprey is one of only three lamprey species that can climb vertical surfaces using their oral disc with their body completely out of water. This climbing ability has led to the development of specialised passage structures enabling the Pacific lamprey (Entosphenus tridentatus) to migrate past high head barriers. Understanding how the morphological characteristics of lamprey influence climbing success can help improve the design of passage structures that facilitate the upstream migration of adult lamprey. This presentation summarises the results of laboratory trials that examine the kinematics of pouched lamprey climbing behaviour and determine effective design criteria for promoting pouched lamprey passage at instream structures.