Location
Chandelier Room
Start Date
12-12-2018 11:00 AM
End Date
12-12-2018 12:40 PM
Description
We have implemented a multiple lines of evidence approach to assessing the efficacy of fishways in the Houay (small stream) Peung and Houay Souy, Lao PDR. The methods include socio-economic surveys of households, direct observation of fisherman catch, trapping within the fishways, and surveys of fish assemblages in each fishway wetland, along with comparison wetlands that do not have a fishway installed. The in-wetland surveys are designed to be a long-term program and in this presentation I report on the design, monitoring and preliminary results. Whilst there are several differences in the types of fish present in each of the wetlands, there was no statistically significant difference in the CPUE, species richness or the composition of fish assemblages between fishway wetlands and comparison wetlands, regardless of season, during the first two years of our study. This is consistent with previous studies, that found only one or two species are likely to respond in the first few years and it may take 4 or more seasons of operations for major compositional changes in assemblages to be recognised. Our results are consistent with expectations from pre-fishway operations and the monitoring program is well placed to detect changes as the fishways enter full operational mode. We also discuss the implications of high fishing pressure in these wetlands and how this may affect the rate of change and detection of those changes.
Wetland fish communities above stream regulators with and without fish passage in Lao PDR
Chandelier Room
We have implemented a multiple lines of evidence approach to assessing the efficacy of fishways in the Houay (small stream) Peung and Houay Souy, Lao PDR. The methods include socio-economic surveys of households, direct observation of fisherman catch, trapping within the fishways, and surveys of fish assemblages in each fishway wetland, along with comparison wetlands that do not have a fishway installed. The in-wetland surveys are designed to be a long-term program and in this presentation I report on the design, monitoring and preliminary results. Whilst there are several differences in the types of fish present in each of the wetlands, there was no statistically significant difference in the CPUE, species richness or the composition of fish assemblages between fishway wetlands and comparison wetlands, regardless of season, during the first two years of our study. This is consistent with previous studies, that found only one or two species are likely to respond in the first few years and it may take 4 or more seasons of operations for major compositional changes in assemblages to be recognised. Our results are consistent with expectations from pre-fishway operations and the monitoring program is well placed to detect changes as the fishways enter full operational mode. We also discuss the implications of high fishing pressure in these wetlands and how this may affect the rate of change and detection of those changes.