Spatio-temporal spawning and larval dynamics of a zebra mussel (Dreissena polymorpha) population in a North Texas Reservoir: implications for invasions in the southern United States

Abstract

Invasive species alter ecosystems and harm economies. Improved understanding of past invasions can inform and improve current and future management efforts. We investigated the global and North American distribution of nonindigenous species (NIS) prior to their establishment in the Laurentian Great Lakes (GL). For the subset of NIS first recorded in North America in the GL, we also investigated the likelihood of these species to spread beyond the basin. With respect to biological invasions, we assessed if the GL basin is a beachhead (i.e., most NIS in the basin originating from outside North America) or a gathering place (i.e., most NIS arriving in GL already in North America). We found that the GL are both a beachhead and a gathering place, depending on the vector of introduction to the basin. Ballast water release introduces most beachhead NIS (43 of 65, 66%), whereas canals, authorized release, and unauthorized release primarly introduce gathering place NIS (67 of 101, 66%). Overall, gathering place NIS currently outnumber beachhead NIS in the GL (101 vs. 65). Regarding spread of beachhead NIS beyond the GL, we found that time elapsed since discovery in the GL predicts secondary spread with 87% accuracy. Our classification model suggests that beachhead NIS established populations outside the GL basin within 77 years of discovery there, suggesting that numerous NIS may be poised to spread beyond the GL basin in the near future. Given the established policy goal of both Canada and the United States to reduce harm from invasions, several recommendations arise from our analysis: (1) maintain, strengthen, and monitor the efficacy of ballast water regulations to prevent the introduction of additional beachhead NIS, (2) conduct risk assessments of NIS that are already in North America but not yet in the GL to prioritize management actions, and (3) seek regional coordination of regulations of vectors of gathering place NIS to shore up weak policy links.

Dynamics ofDreissenaspp. veliger larvae in some Bulgarian reservoirs

“…The spawning of D. polymorpha in the Ovcharitsa Reservoir happens earlier than other investigated reservoirs, which reflects on the larval dynamics of the veliger larvae. Similar high settlement rate was observed by Churchill [19] for the larval dynamics of the zebra mussel population in a North Texas Reservoir.…”

Mass Mortality Events of Invasive Freshwater Bivalves: Current Understanding and Potential Directions for Future Research

“…In estuarine areas, drought can lead to increases in salinity, which may be a contributing factor to Corbicula mass mortality events within the Minho River in Portugal (Ilarri et al, 2011). Within lakes, drought can lead to water level fluctuations, leaving individuals stranded, as was observed in a zebra mussel mortality event in Lake Balaton, Hungary (Balogh et al, 2008) and in Lake Texoma on the border between Texas and Oklahoma, USA (Churchill, 2013;Churchill et al, 2017). Mortality events may occur regularly during heat waves and with a large enough magnitude to control population sizes, as Ilarri et al (2011) noted that the lowest observed population densities of C. fluminea corresponded to years with summer heat waves.…”

Explosive demographic expansion by dreissenid bivalves as a possible result of astronomical forcing

“…C. blanci Westerlund, 1890) -originally endemic to the Balkan lakes Ohrid/Prespa and Trichonis -started to invade artificial water bodies. Size and density of recent dreissenid populations follow different trajectories (Churchill, 2013). Many populations display stable cycles of population size on sub-decadal scales (Burla and Ribi, 1998;Strayer and Malcolm, 2006;Strayer et al, 2011).…”

“…Others are characterised by boom-and-bust patterns (Stanczykowska, 1977;Casagrandi et al, 2007) and some studies revealed irregular population behavior (Nalepa et al, 2006). The trigger mechanisms are complex and result from an interplay of recruitment, survivorship of post-recruits and changing environmental conditions (Strayer and Malcolm, 2006;Churchill, 2013).…”