Developing biomonitoring protocols for shallow Arctic lakes using diatoms and artificial substrate samplers

Abstract

Growing concerns over effects of climate warming and other stressors on shallow Arctic lakes and ponds stimulate the need to develop and implement effective protocols to track changes in ecological integrity. This study assesses seasonal and spatial variability of periphytic diatom communities in a shallow Arctic lake in northern Yukon Territory to establish biomonitoring protocols. Artificial substrate samplers, which mimic macrophytes, allow direct measurement of biotic responses to shifting environmental conditions and control for possible confounding factors (e.g., accrual time and microhabitat type). Artificial substrate samplers were deployed at three locations and retrieved at three times (early, mid, and late) during the ice-free season. Analyses identified that diatom abundance increased exponentially and community composition changed significantly over the ice-free season, despite little variability in water chemistry, but did not differ among the three sampling locations within the lake. Patterns of seasonal succession in diatom community composition were characterized by first arrival of well-dispersed taxa, which included several planktonic taxa, followed by a transitional phase composed of planktonic and periphytic taxa, and culminated with dominance by periphytic species, mainly Achnanthes minutissima (Kützing). Results highlight the role of seasonal succession on artificial substrate colonization and the need to deploy artificial substrate samplers for the duration of the ice-free season to capture peak periphytic algal abundance. Low spatial variability of shallow Arctic lakes allows for samplers to be deployed at one single location to characterize diatom community composition.

Ice-cover is the principal driver of ecological change in High Arctic lakes and ponds

“…It has been suggested that vegetation substrates may release carbohydrates and nutrients into the water to be taken up by epiphytic diatoms [ 88 , 89 ], potentially promoting growth and may partially explain the coincident timing of inferred production and epiphytes. The variability of the vegetative substrate, the additional competitive advantage it affords, and the lengthened growing season, which allows for greater complexity [ 90 ], may contribute to the increased diversity in epiphytic diatom communities in contrast to their epilithic and epipelic counterparts.…”

Settlement preferences of leeches (Clitellata: Hirudinida) for different artificial substrates

“…Much has been written about their use as a tool in the assessment of aquatic environment quality (De Pauw et al, 1994;Czerniawska-Kusza, 2004;MacDonald et al, 2012;Loke et al, 2014) or biomass production of phyto and zoobenthos (Moura et al, 2007;Plá & Alveal, 2012). In relation to inland waters, research has mainly focused on their habitat-creation role and concerns entire groups of benthic fauna (De Pauw et al, 1986, De Pauw et al, 1994Czerniawska-Kusza, 2004;Poznańska et al, 2009;Czarnecka et al, 2009).…”

Using Water Isotope Tracers to Develop the Hydrological Component of a Long-Term Aquatic Ecosystem Monitoring Program for a Northern Lake-Rich Landscape

“…In recognition of the value and need for coordinated hydrological and ecological monitoring to systematically observe the status and trends of aquatic ecosystems, we are working towards integrating the hydrological monitoring program with an ecological monitoring program, protocols of which were described by MacDonald et al (2012b). Northern ecosystem monitoring remains challenging.…”