Portage connectivity does not predict establishment success of canoe-mediated dispersal for crustacean zooplankton

Abstract

Although community structure may be largely determined by local abiotic and biotic conditions under moderate levels of dispersal, anthropogenic activities can enhance dispersal rates far beyond what would otherwise occur in natural systems. We investigated the potential impact of recreational canoeing on crustacean zooplankton community structure in Killarney Provincial Park, Canada, where canoes that are transported between lakes via portage routes may enhance zooplankton community connectivity by providing a dispersal ''short-cut.'' We conducted a study to (1) quantify zooplankton attachment to canoe hulls after paddling through a lake and assess the importance of canoes to overall seasonal dispersal within a lake relative to other means of dispersal, (2) test the prediction that zooplankton survivorship is negatively correlated with portage duration using a mesocosm experiment, and (3) test whether variation in lake community composition was better explained by models based on reduced portagecorrected distances or true edge-to-edge distances between lakes along popular canoe routes. Here, we report the findings that canoes have the potential to act as frequent dispersal vectors, but appear to have little impact on community structure in portage-connected lakes. Substantial numbers of adult zooplankton became attached to canoe hulls and were able to establish viable populations even after exposure to portage conditions for 30 min. However, canoe-mediated dispersal only accounted for a very small proportion (\1% in this case) of overall seasonal dispersal. Moreover, environmental variables explained the greatest amount of variation in community composition among park lakes. Nevertheless, this study indicates that canoe dispersal could be more effective for specific species such as Sida crystallina than is evident by analysis of entire communities and could facilitate the spread of invasive species amenable to attaching to boat hulls. Thus, the debate about whether community composition is more strongly influenced by local environmental conditions or Handling Editor: Piet Spaak.Electronic supplementary material The online version of this article (regional dispersal may vary depending on the scale of consideration (i.e., individual species vs. whole community).

Biosecurity and Vector Behaviour: Evaluating the Potential Threat Posed by Anglers and Canoeists as Pathways for the Spread of Invasive Non-Native Species and Pathogens

“…This coupled with the low frequency with which anglers and canoeists clean and dry their equipment suggests that these groups may have the potential to act as vectors for their spread. The results are in accord with studies in North America which showed that anglers and boaters were travelling hundreds of kilometres between sites [31] , [32] and were frequently transporting muddy waders [31] , and the remnants of invasive aquatic plants on their boats [33] , [34] . Within this research, we investigated the movement patterns of anglers and canoeists to evaluate the biosecurity risk that they would pose should they become contaminated with INNS or pathogens.…”

Increased habitat connectivity homogenizes freshwater communities: historical and landscape perspectives

“…For instance, we assumed that canals were the major zooplankton dispersal pathway; however, other dispersal vectors, such as waterfowl or boaters, may be important in moving organisms between waterbodies (Havel & Shurin ; Stasko et al . ). We found no significant influence of boat ramps on communities inside the CBP; additionally, Gray & Arnott () demonstrated that the egg bank and stream connections were the largest contributors of individuals to a lake, which suggests that canals likely outweigh other pathways of dispersal.…”

A bobber’s perspective on angler-driven vectors of invasive species transmission

“…First, as younger anglers' participation in fishing increases, mobile platforms offer management agencies an opportunity to outreach and learn more about these demographics, as these are also less likely to engage with mail-in or inperson surveys (Fisher 1996;Recreational Boating and Fishing Foundation Outdoor Foundation 2018;Gundeland et al 2020). Second, mobile-based data provide information about the movement of a largely unknown group of anglers accessing waterbodies using non-motorised recreational boats, such as canoes and kayaks and who are similarly dispersal vectors for aquatic invasive species (Stasko et al 2012;Anderson et al 2014), but are not subject to conventional creel surveys conducted at boat launches. In summary, while prior work has demonstrated that actively collected mobile data (i.e.…”