Acoustic Telemetry Monitors Movements of Wild Adult Catfishes in the Mekong River, Thailand and Laos

George P. Naughton,Peter J. Graf,Teresa Campbell,Charles Farwell,Naruepon Sukumasavin,Zeb S. Hogan

doi:10.3390/w13050641

Abstract

Research on fish movement and habitat use in large tropical rivers is urgently needed to protect fisheries that are a primary source of protein for millions of people. In this pilot study, acoustic telemetry was used to monitor movements of wild catfishes in a 94.6 rkm reach of Mekong River, where it functions as the border between Thailand and Lao People’s Democratic Republic (PDR). Twenty fish were tagged and released in May 2006 and monitored through May 2007 with 17 fixed-site acoustic receivers. Ten receivers had detection probabilities ranging from 0.67 to 1.00, and five receivers had detection probabilities of 0.50 or less. Detection probability was not correlated with river width. Eighteen (90%) of the tagged fish were detected by at least one receiver. Monitoring durations of individual fish ranged from 0.1 to 354.4 days. The longest total movement was 88.3 rkm, while the longest upstream movement was 52.1 rkm. Movement rates ranged from 0.1 to 156.7 rkm/d. This work provided preliminary data on movement patterns of wild Mekong catfishes. The methods and lessons learned from this study can be used for future positional telemetry research to address management-relevant uncertainties about migration corridors, habitat use, efficacy of fish reserves, and river development planning.

Highlights

The Mekong River Basin supports one of the most diverse fish faunas in the world [1], harboring more species than any other river basin in Asia
Data on fish migrations are urgently needed in the Lower Mekong Basin, where people depend on migratory fishes for their livelihoods and these same fishes are heavily threatened by human development such as hydropower
The study results demonstrated that acoustic telemetry is a viable tool to address knowledge gaps about migratory fishes in the Mekong and provided preliminary information about wild catfish migrations

Summary

Introduction

The Mekong River Basin supports one of the most diverse fish faunas in the world [1], harboring more species than any other river basin in Asia. An estimated 60–70% of Mekong fishes are migratory, making seasonal movements up or downstream or from the main channel to floodplain habitat [6]. These migrations are usually for breeding or dispersal, which are related to the annual hydrograph [1,7,8]. Most of the information on fish migrations and habitat use in the Mekong River is inferred from catch statistics and local knowledge [7,9] Beyond this general understanding, empirical data on localized movement, seasonal migration patterns, and life history are limited. Research to understand these important life history attributes is urgently needed to create effective management plans, inform environmental impact assessments, and develop species conservation strategies

Methods

Results

Discussion

Conclusion