Dispersal of zebra mussels (Dreissena polymorpha) downstream of an invaded reservoir

作者：Olson Jenae; Robertson Josi J; Swannack Todd M; McMahon Robert F; Nowlin Weston H; Schwalb Astrid N^*

来源：Aquatic Invasions, 2018, 13(2): 199-209.

DOI：10.3391/ai.2018.13.2.02

• passive dispersal
• invasive species
• veligers
• dispersal limitation
• source-sink dynamics
• juvenile settlement

Zebra mussels, Dreissena polymorpha, have recently invaded Central Texas. More information is needed to predict their spread in this region and inform management decisions. In this study, we examined riverine zebra mussel dispersal from, and settlement downstream of, a recently invaded reservoir, Lake Belton. Veliger samples and settlement of juveniles on artificial substrata were monitored at sites within Lake Belton and 0.4 to 54.7 river kilometers (rkm) downstream from the lake outlet. Veliger density varied greatly across space and time with peak densities of live veligers found in both early summer (May-June) and fall (October). High juvenile settlement occurred consistently at 2.5 and 6.0 rkm downstream. Juvenile settlement was not observed >= 13 rkm downstream until the spring of 2016 after a period of prolonged increased river discharge. Our findings suggest that mussels were dispersal limited in 2015, and prolonged periods of increased river discharge may have facilitated their dispersal further downstream in 2016.

• 出版日期2018-6