Genetic evidence for canal-mediated dispersal of Mapleleaf,Quadrula quadrula(Bivalvia:Unionidae) on the Niagara Peninsula, Canada

Abstract

Alterations to watercourses affect connectivity in aquatic systems and can influence dispersal of aquatic biota. Dams fragment populations and act as isolating barriers, but canals create connections between waterbodies that can be used as corridors for dispersal by opportunistic invaders. The Niagara Peninsula of Ontario, Canada, has a 200-y history of canal operation, resulting in major modification of the watercourses in the region. This modification allowed numerous invasive species to enter the upper Great Lakes (e.g., sea lamprey) and probably has facilitated dispersal in native species. The purpose of our study was to explore the effects of canal and dam construction on the genetic structure of Mapleleaf (Quadrula quadrula), a widespread and relatively common species in the central Great Lakes that has been found only recently in several western Lake Ontario harbors. Establishment of Q. quadrula in Lake Ontario may have been a recent event, facilitated by the Niagara Peninsula's history of canal operation. We used analyses of microsatellite DNA genotypes to examine the effect of canals on the genetic structure of mussel populations. Structure analysis revealed a pattern of gene flow between lakes that cannot be explained by watercourse connections prior to the creation of the Welland Canal. Evidence suggestive of historical bottlenecks at some Lake Ontario sites may indicate that these populations became established after canal creation. After considering genetic structure, hydrogeography and isolation-by-distance (IBD) analysis, the first iteration of the canal (1829-1833) is most supported as the configuration that facilitated colonization. However, weak IBD signals across canal models may signify continued gene flow across configurations. Our study demonstrates the connective effect of canals on freshwater mussel populations and has the potential to improve conservation strategies for this and other unionid species at risk.

Modeling habitat of freshwater mussels (Bivalvia:Unionidae) in the lower Great Lakes 25 years after the Dreissena invasion

“…The relative abundance of another species in the nearshore mussel assemblages of Lake Erie, Quadrula quadrula, has increased, and its distribution in Lake Erie may have expanded in the last few decades (Zanatta et al 2015). We did not find Q. quadrula in our surveys of southern Lake Ontario, but recently it was discovered in abundance in a few coastal embayments and drowned river mouths in western Lake Ontario in Canada (Hoffman et al 2018). This discovery brings total diversity in the lake to 12 species.…”

Isolation and characterization of 21 polymorphic microsatellite loci for the rockpool shrimp Palaemon elegans using Illumina MiSeq sequencing

“…In fact, there are ongoing projects that aim to analyze Atlantic and Mediterranean localities along the European coastlines using these markers to address the genetic differentiation between these basins. This microsatellite set will be also greatly useful for inferring the introduction routes and the genetic profiles of the introduced populations of this species in European and North America waters 41 – 43 .…”

Population structure, genetic diversity, and colonization history of the eastern pondmussel, Sagittunio nasutus, in the Great Lakes drainage

“…Within the Great Lakes region and surrounding area, natural as well as anthropogenically influenced host fish dispersal, like fish stocking, canal construction, and accidental bait fish introductions, are hypothesized to have facilitated the movement of S. nasutus . Canals can provide new avenues of movement for host fish carrying glochidia larvae (Dean, ; Hoffman, Morris, & Zanatta, ; Rahel, ). Also, fish stocking is a potential colonization route for unionids while glochidia are encysted on host fish (Popa, Baratáková, Bryja, Reichard, & Popa, ; Sárkány‐Kiss, ).…”