Assessment of larval fish assemblages and nursery habitat in the St. Clair River delta

Ichthyoplankton metabarcoding: An efficient tool for early detection of invasive species establishment

“…By contrast, most ichthyoplankton samples contain DNA from fewer individuals and of higher quality and concentration, providing a better template for amplification (Harrison et al, 2019). In our study and studies of similar systems, ichthyoplankton samples often average between 1-4 species per sample (McReynolds et al, 2021;Tucker et al, 2019). While it remains critical to consider costs associated with sample collection, processing and the local diversity of ichthyoplankton communities, our results suggest that it may be most efficient to sequence fewer representative individuals from more samples for the detection of newly established invasive species.…”

“…While each gear type was shown to work better for particular groups of fishes, in general, we found that light traps detected a larger number of species than bongo nets (Figure 3). Other studies conducted in rivers draining into the Great Lakes have reported a similar advantage of light traps compared with passive net-based methods (Niles & Hartman, 2007;Tucker et al, 2019). By contrast, net-based methods often work better in marine habitats (Brogan, 1994;Hubert et al, 2015).…”

“…The optimal criteria for collecting ichthyoplankton samples for metabarcoding may be more difficult to standardize than eDNA, which has been more extensively studied (Doble et al, 2020; Hunter et al, 2019; Tillotson et al, 2018). For ichthyoplankton, sample design must account for variation in spawning times, emergence and larval recruitment, which can differ interannually and vary over small geographic scales (McReynolds et al, 2021; Tucker et al, 2019). However, in contrast to eDNA, ichthyoplankton metabarcoding can differentiate newly established populations from transient individuals (Gold, Curd, et al, 2021) or DNA from upstream or non‐natural sources (Balasingham et al, 2017; Fukaya et al, 2021), making it a valuable tool for those managing the containment and eradication of invasive species.…”

“…Light‐trap samples are often dominated by older larvae, which are better able to move towards an attractant light (Doherty, 1987). Other ichthyoplankton surveys have also noted an advantage of light traps for detecting invasive gobies, which lack a planktonic stage (Tucker et al, 2019). By contrast, invasive carp, primarily passive dispersers at early life stages, are more effectively captured using net‐based methods (Roth et al, 2021).…”

“…The optimal criteria for collecting ichthyoplankton samples for metabarcoding may be more difficult to standardize than eDNA, which has been more extensively studied (Doble et al, 2020;Hunter et al, 2019;Tillotson et al, 2018). For ichthyoplankton, sample design must account for variation in spawning times, emergence and larval recruitment, which can differ interannually and vary over small geographic scales (McReynolds et al, 2021;Tucker et al, 2019).…”