This study compares the catch composition and amount from 2007–2013 of two fishery gear types, the bagnets of the largest commercial fishery, the Dai fishery, and gillnets, which are deployed ubiquitously by independent fishers. The authors used resource selection ratios to quantify selection pressure by the gillnet fishery, relative to the Dai fishery, on fish from different genera and trait groups. The gillnet selected for fish that migrate laterally from the floodplain to the main river and for higher trophic level fish. Gillnets may target groups of fish that are less impacted by the long-standing Dai fishery. For both fisheries, a need for monitoring fish lengths in order to understand the effects of selection on population dynamics and species-specific trait changes is noted.
Kelson, S.J., Z. Hogan, C.L. Jerde, S. Chandra, P.B. Ngor, and A. Koning
9 July 2021
selection; body size; trophic level; migration; flood pulse; tropical; Mekong; Tonle Sap; resource selection ratios; river flows