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(A) Map showing location of the Belcher Islands in southeastern Hudson Bay, Nunavut, Canada. (B) Air photograph showing the hamlet of Sanikiluaq and the locations of Annak and Imitavik lakes. Air photograph reproduced under license from Her Majesty the Queen in Right of Canada, with permission of Natural Resources Canada.
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Many Arctic communities use lakes as a cost effective method for facultative treatment and disposal of sewage and other liquid
wastes. These sites represent ideal locations to study eutrophication processes in Arctic regions, where very little is known
about accelerated nutrient fertilization, despite increasing threats from growing populations and...
Contexts in source publication
Context 1
... Hermanson (1991,1998) and Herman- son and Brozowski (2005) studied the geochemical and pollution history of Annak Lake (Fig. 1), a culturally eutrophied lake located on the Belcher Islands (Nunavut, Arctic Canada). This lake is an ideal location to study Arctic eutrophication processes because the nearby hamlet of Sanikiluaq has used it for open water season facultative treatment of domes- tic waste since about 1968. Predictably, the lake is currently ...
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... Lake is located near the hamlet of Sanikiluaq (568 53N, 798 27W) on northern Flaherty Island, the largest of the Belcher Islands, in southeastern Hudson Bay, Nunavut (Figs. 1A, B). The lake is small (surface area = 2 ha) and moderately shallow (Z mean = 1.9 m, Z max = 4.5 m) with a single basin. It has no appreciable input streams other than runoff from its 44.3 ha drainage basin. Based on precipitation data (0.477 m yr -1 ; average measured at Kuujjuaraapik, Quebec, 1981-1990), we estimate the flushing rate of ...
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... recording thermometer, and an eight-inch diameter Secchi disc. Dissolved oxygen concentra- tions were performed using the Winkler titration method. For comparison purposes, the same variables were also recorded from nearby Imitavik Lake (August data only), a relatively pristine lake that is used as the source for the municipal water supply (Fig. ...
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... is unlikely that forcing mechanisms other than the sewage inputs could be responsible for the observed changes in Annak Lake. For example, although no long-term climate data exists for Saniki- luaq, temperature records from nearby Kuujjuaraapik (Fig. 1A) show no warming trend over the timeframe of interest (http://www.climate.weatheroffice.ec.gc.- ca/). Catchment disturbances have been minimal, with the only activity being the development of a road that Aquat. Sci. Vol. 69, 2007 Research Article allows the sewage truck direct access to the lake (Fig. 6B). The diatoms were also not ...
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Meretta Lake (Resolute Bay, Cornwallis Island, Nunavut, Canada) is a high arctic lake that received raw sewage for almost 50 years from the Canadian Department of Transport Base. The lake was sampled from 1968–72 during the International Biological Programme, as part of the Char Lake Project. As the number of users at the Transport Base declined th...
Nutrients from the waste products of large seabird colonies can enter freshwater ecosystems, markedly altering water quality and biotic assemblages, especially in nutrient-poor regions like the Canadian High Arctic. Here, we investigate the influence of nutrient-rich seabird wastes on freshwater larval chironomid assemblages from two distinct seabi...
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Anthropogenic stressors to freshwater environments have perpetuated water quality and quantity challenges for communities across Arctic Canada, making drinking water resources a primary concern for northern peoples. To understand the ecological trajectory of lakes used as freshwater supply, we conducted a paleolimnological assessment on two supplem...
Citations
... There are notable, albeit rare taxa with high nutrient optima, which are consistent with biotic nutrient introductions, such as Fistulifera saprophila in D012, A135, and A085 ( Figure 4). This taxon was found in Resolute sewage ponds (Stewart et al., 2014) and Annak Lake on Belcher Islands, also with high nutrient concentrations from sewage inputs (Michelutti et al., 2007). ...
Algal bioindicators, such as diatoms, often show subdued responses to eutrophication in Arctic lakes because climate‐related changes (e.g., ice cover) tend to be the overriding factors influencing assemblage composition. Here, we examined how sub‐Arctic ponds historically receiving high nutrient inputs from nesting seabirds have responded to recent climate change. We present diatom data obtained from 12 sediment cores in seaduck‐affected ponds located on islands through Hudson Strait, Canada. All study cores show consistently elevated values of sedimentary ẟ¹⁵N, an established proxy for tracking marine‐derived nutrients, indicating seabirds have been present on these islands for at least the duration of the sediment records (~100 to 400 years). We document diverse epiphytic diatom assemblages to the base of all sediment cores, which is in marked contrast to seabird‐free Arctic ponds—these oligotrophic sites typically record epilithic diatom flora prior to recent warming. Diatoms are likely responding indirectly to seabird nutrients via habitat as nutrients promote the growth of mosses supporting epiphytic diatom communities. This masks the typical diatom response to increased warming in the Arctic, which also results in habitat changes and the growth of mosses around the pond edges. Changes in sedimentary chlorophyll a were not consistently synchronous with large changes in ẟ¹⁵N values, suggesting that primary production in ponds is not responding linearly to changes in seabird‐derived nitrogen. Across all ponds, we recorded shifts in diatom epiphytic assemblages (e.g., increases in % relative abundance of many Nitzschia species) that often align with increases in chlorophyll-a . The changes in diatoms and chlorophyll-a, although variable, are most likely driven by climate change as they are generally consistent with longer ice‐free conditions and growing seasons. Together, our results show that to effectively use diatoms in animal population reconstructions across the sub‐Arctic and Arctic, a strong understanding of eutrophication and climate change, based on supplementary proxies, is also required.
... Another example is Annak Lake [13][14][15][16][17], a lake also used for sewage discharge since the 1960s by the community at Sanikiluaq situated on the Belcher Islands (Nunavut). It has a well dated 210 Pb profile, that is further constrained by stable geochemical metals and other proxies linked to human sewage in the core profile, anchoring and corroborating the 210 Pb dates (as described in the cited papers). ...
Gajewski offers a formal comment on Griffiths et al. (2017), a paper that explored how microclimates and their varying ice cover regimes on lakes and ponds in Arctic regions modified the diatom assemblage responses to recent warming. One of Gajewski's main criticisms is that the microclimate classification scheme used in Griffiths et al. (2017) is merely anecdotal; a claim which ignores the value of observational evidence and misunderstands the frequency that each site was visited or surveyed. We clarify that the study sites were visited multiple times via recurrent aerial surveys and ground observations dating back to the 1970s, which supports our microclimate classification scheme. Many of Gajewski's claims regarding climate, catchment characteristics, and ice melting properties from field locations he has not visited were refuted by veteran Arctic scientists with long-term field experience in these regions. In addition, Gajewski makes several criticisms concerning radioisotopic dating , core chronology, sediment mixing, diagenesis, and preservation of bioindicators that relate more to general paleolimnological assumptions than to conclusions reached by Grif-fiths et al. (2017). Research from the 1980s and 1990s, when scientific consensus on these issues was first reached, readily show that the methodologies and data interpretation of Grif-fiths et al. (2017) are sound. We appreciate the opportunity to expound on the finer details of the Griffiths et al. (2017) paper, work based on field research by the study's co-authors spanning almost three decades, with additional observations from colleagues dating back to the 1970s. We address Gajewski's criticisms with relevant literature, expert statements, and a few clarifying comments.
... Another example is Annak Lake [13][14][15][16][17], a lake also used for sewage discharge since the 1960s by the community at Sanikiluaq situated on the Belcher Islands (Nunavut). It has a well dated 210 Pb profile, that is further constrained by stable geochemical metals and other proxies linked to human sewage in the core profile, anchoring and corroborating the 210 Pb dates (as described in the cited papers). ...
Gajewski offers a formal comment on Griffiths et al . (2017), a paper that explored how microclimates and their varying ice cover regimes on lakes and ponds in Arctic regions modified the diatom assemblage responses to recent warming. One of Gajewski’s main criticisms is that the microclimate classification scheme used in Griffiths et al . (2017) is merely anecdotal; a claim which ignores the value of observational evidence and misunderstands the frequency that each site was visited or surveyed. We clarify that the study sites were visited multiple times via recurrent aerial surveys and ground observations dating back to the 1970s, which supports our microclimate classification scheme. Many of Gajewski’s claims regarding climate, catchment characteristics, and ice melting properties from field locations he has not visited were refuted by veteran Arctic scientists with long-term field experience in these regions. In addition, Gajewski makes several criticisms concerning radioisotopic dating, core chronology, sediment mixing, diagenesis, and preservation of bioindicators that relate more to general paleolimnological assumptions than to conclusions reached by Griffiths et al . (2017). Research from the 1980s and 1990s, when scientific consensus on these issues was first reached, readily show that the methodologies and data interpretation of Griffiths et al . (2017) are sound. We appreciate the opportunity to expound on the finer details of the Griffiths et al . (2017) paper, work based on field research by the study’s co-authors spanning almost three decades, with additional observations from colleagues dating back to the 1970s. We address Gajewski’s criticisms with relevant literature, expert statements, and a few clarifying comments.
... Bottom-up increases in chl a and decreases in hypolimnetic oxygen were more rapid than the response of higher trophic levels, as expected, but there was some resistance to change even in DO and chl a, which had time lags of one to several years. Resistance to disturbance from anthropogenic or experimental nutrient inputs to arctic lakes can be very low (i.e., an immediate response; Schindler 1974;Lienesch et al. 2005;O'Brien et al. 2005) or moderate, with response lags of two to many years (Welch et al. 1989;Michelutti et al. 2007;Stewart et al. 2018). The cause of such muted responses is thought to be related to the extreme environment and long ice cover in arctic lakes (Douglas and Smol 2000;Stewart et al. 2018), although we note here that the strength of nutrient addition is also likely important. ...
... The cause of such muted responses is thought to be related to the extreme environment and long ice cover in arctic lakes (Douglas and Smol 2000;Stewart et al. 2018), although we note here that the strength of nutrient addition is also likely important. For example, low resistance occurs with strong, experimental, or anthropogenic additions (Schindler 1974;O'Brien et al. 2005;Lienesch et al. 2005), while moderate resistance is observed with lower-level fertilization (this study; Welch et al. 1989;Michelutti et al. 2007;Stewart et al. 2018). ...
Effects of climate change-driven disturbance on lake ecosystems can be subtle; indirect effects include increased nutrient loading that could impact ecosystem function. We designed a low-level fertilization experiment to mimic persistent, climate change-driven disturbances (deeper thaw, greater weathering, or thermokarst failure) delivering nutrients to arctic lakes. We measured responses of pelagic trophic levels over 12 yr in a fertilized deep lake with fish and a shallow fishless lake, compared to paired reference lakes, and monitored recovery for 6 yr. Relative to prefertilization in the deep lake, we observed a maximum pelagic response in chl a (+201%), dissolved oxygen (DO, -43%), and zooplankton biomass (+88%) during the fertilization period (2001-2012). Other responses to fertilization, such as water transparency and fish relative abundance, were delayed , but both ultimately declined. Phyto- and zooplankton biomass and community composition shifted with fertilization. The effects of fertilization were less pronounced in the paired shallow lakes, because of a natural thermokarst failure likely impacting the reference lake. In the deep lake there was (a) moderate resistance to change in ecosystem functions at all trophic levels, (b) eventual responses were often nonlinear, and (c) postfertilization recovery (return) times were most rapid at the base of the food web (2-4 yr) while higher trophic levels failed to recover after 6 yr. The timing and magnitude of responses to fertilization in these arctic lakes were similar to responses in other lakes, suggesting indirect effects of climate change that modify nutrient inputs may affect many lakes in the future.
... Eutrophication of Arctic lakes is not a novel problem: in fact, there are several examples of nutrient enrichment as a result of sewage inputs and municipal wastes (Schindler et al., 1974;Michelutti et al., 2007;Stewart et al., 2014), including Niven Lake from Yellowknife (Stewart et al., 2018). In the past, however, biological responses to eutrophication were somewhat mitigated by the cold climatic conditions (Douglas and Smol, 2000;Michelutti et al., 2007;Antonaides et al., 2011) and nuisance cyanobacterial blooms, a common repercussion of nutrient enrichment in temperate and tropical regions, were not previously reported (Schindler et al., 1974). ...
... Eutrophication of Arctic lakes is not a novel problem: in fact, there are several examples of nutrient enrichment as a result of sewage inputs and municipal wastes (Schindler et al., 1974;Michelutti et al., 2007;Stewart et al., 2014), including Niven Lake from Yellowknife (Stewart et al., 2018). In the past, however, biological responses to eutrophication were somewhat mitigated by the cold climatic conditions (Douglas and Smol, 2000;Michelutti et al., 2007;Antonaides et al., 2011) and nuisance cyanobacterial blooms, a common repercussion of nutrient enrichment in temperate and tropical regions, were not previously reported (Schindler et al., 1974). Hence, the recent blooms of Planktothrix spp. at Jackfish Lake can be considered a novel response to the combined effects of eutrophication and climatic changes within the context of northern lakes. ...
Cyanobacterial blooms have been increasing in frequency and intensity but are often considered an issue restricted to temperate and tropical lakes. Here we report on one of the first occurrences of recurring cyanobacterial (Planktothrix spp.) blooms in a sub-Arctic lake from Yellowknife (Northwest Territories, Canada) and provide a long-term environmental context for the recent blooms using local meteorological data and multi-proxy paleolimnological analyses. Multiple co-occurring regional (gold mining emissions and climatic change) and local (land clearance and urbanization) stressors have impacted Jackfish Lake during the 20th and early-21st centuries, which have led to biological responses across multiple trophic levels. The unprecedented post-2013 cyanobacterial blooms were likely a cumulative response to nutrient enrichment and complex climate-mediated changes to lake thermal properties. A regional analysis of eight lakes around Yellowknife revealed that reduced ice cover duration and longer growing seasons have led to an increase in whole-lake primary production, whilst urban lakes were also fertilized by nutrients from local land-use changes in their catchments. Our findings suggest that anthropogenically nutrient-enriched sub-Arctic lakes, akin to their lower-latitude counterparts, may be vulnerable to cyanobacterial blooms in a warming world.
... Most Fistulifera species have lightly silicified frustules with inconspicuous margins and few features discernible using light microscopy (LM). Though small, their global range is broad and includes the Arctic (Michelutti et al. 2007), temperate (Gevrey et al. 2004, Vouilloud et al. 2005, and subtropical (this study, Hustedt 1962) regions. Within these regions, Fistulifera has wide ecological occurrence, inhabiting fresh (Lewin 1955, Stancheva et al. 2007), brackish (Bella et al. 2007), saline and marine (Hustedt 1962, Matsumoto et al. 2014) waters, and terrestrial environments (see Navicula JB12 Genbank #KF791556; Qiao & Liu, unpub.). ...
... Within these regions, Fistulifera has wide ecological occurrence, inhabiting fresh (Lewin 1955, Stancheva et al. 2007), brackish (Bella et al. 2007), saline and marine (Hustedt 1962, Matsumoto et al. 2014) waters, and terrestrial environments (see Navicula JB12 Genbank #KF791556; Qiao & Liu, unpub.). Furthermore, the genus is found in a spectrum of trophic states including oligotrophic, eutrophic, and even hypereutrophic (Krammer & Lange-Bertalot 1986, Michelutti et al. 2007). ...
... Pennate diatoms are abundant in Lake Okeechobee drainages associated with disturbed or eutrophic waters . Fistulifera alcalina is another example of a Fistulifera species that takes advantage of eutrophic or saprobic waters, like F. saprophila (Szabo et al. 2005, Michelutti et al. 2007). Unlike F. saprophila, F. pelliculosa may be found in oligotrophic waters (Krammer & Lange-Bertalot 1986), while F. iranensis and F. solaris are saline and marine species, respectively (Hustedt 1962, Matsumoto et al. 2014). ...
In this work, we propose and describe a novel diatom species, Fistulifera alcalina sp. nov., isolated from Port Mayaca on Lake Okeechobee, Florida (USA). This new diatom species represents a distinct lineage within the genus Fistulifera, which includes F. iranensis (Hustedt) Lange-Bertalot, F. saprophila (Lange-Bertalot & Bonik) Lange-Bertalot, F. pelliculosa (Kützing) Lange-Bertalot, and F. solaris S. Mayama, M. Matsumoto, K. Nemoto & T. Tanaka. Morphometric and molecular phylogenetic analyses of the 18S rRNA and rbcL genes strongly support Fistulifera alcalina as a new species. Fistulifera alcalina sp. nov. is cultured in media with moderate salinity and high bicarbonate concentrations in contrast to the other species of Fistulifera which show ecological preferences for high salinity and eutrophic or oligotrophic waters. This is also the first record of Fistulifera in the southeastern United States (Florida, USA).
... values between~15 cm and the top of the sediment core may indicate dilution of 210 Pb unsupp. by increased sedimentation of organic material caused by eutrophication and increased production (e.g., Michelutti et al., 2007). This is supported by enhanced sedimentary contents of TN and TC, respectively, and enriched δ 15 N signals in these sediment layers. ...
... Overall, environmental stressors played a limited role in structuring the diatom community of Lake Yuxian, possibly due to that the dominance of generalist diatoms exhibited a high degree of tolerance and resilience capacity in this nutrient-poor lake (cf. Michelutti et al., 2007). ...
... Rather than nutrients in the water, organic C-rich compounds on the sediment surfaces were probably important for the development of Navicula and Nitzschia species (McGowan et al., 2018) since these compounds allowed for heterotrophic nutrition under unfavourable light conditions (Lewin, 1953;Tuchman et al., 2006). This is in line with modern studies that found high abundances of Navicula and Nitzschia species in organic-rich and saprobic environments (e.g., Van Dam et al., 1994;Hofmann et al., 2013;McGowan et al., 2018), as well as with paleo studies from Arctic lakes that reported increased abundances of Navicula and Nitzschia species (amongst others Nitzschia palea) as response to pollution with sewage (Douglas and Smol, 2000;Michelutti et al., 2002Michelutti et al., , 2007. ...
In the context of global warming, extreme drought events have occurred more frequently and this is projected to continue in the future in many parts of the world. However, their ecological consequences on shallow lakes are not well studied. Here we compare the succession of diatom assemblages of two medium-sized shallow lakes in southwest China during the past ~70 years, comprising an extreme drought event between ~2009 and ~2013. The diatom community of Lake Chahei showed a clear response to eutrophication from ~1980. The pioneer species Achnanthes minutissima increased strongly with elevated sedimentary total nitrogen content and at the expense of Epithemia sorex. In contrast, the diatom community of Lake Yuxian was stable and constantly dominated by the Fragilaria construens/pinnata complex. For both lakes, the most striking change occurred with the extreme drought event when environmental conditions and diatom compositions were homogenised. With strongly shrinking lake areas, peaks in the proportion of silt were observed in the sediments, suggesting increased particle burial rates and decreased light availability. These conditions selected for motile and presumably heterotrophic species mainly of the genera Navicula and Nitzschia which exhibited abrupt increases in their relative abundances at both lakes. Meanwhile, the degree of community homogeneity (inferred by Jaccard's similarity index) of the formerly distinct diatom assemblages increased strongly between both lakes. Hence, the extreme drought event has overridden and homogenised previous abiotic conditions and led to a decrease in beta diversity between the two study sites. Navicula and Nitzschia species may be reliable (paleo)indicators for extreme drought events in comparable shallow lake systems.
... Also the increase in A. minutissimum has been related to climate warming in several Arctic records (Antoniades et al. 2004;Keatley et al. 2006;Lim et al. 2008;Paul et al. 2010), but it is also found in mossy habitats (Griffiths et al. 2017) suggesting that the lake-catchment area has become more productive. The recent increase in Nitzschia spp. is also likely related to increase in nutrients, as previously recorded from the Canadian Arctic (Michelutti et al. 2007). In all, the recent changes in diatom assemblages are likely related directly (e.g. ...
Lakes are a dominant feature of the Arctic landscape and a focal point of regional and global biogeochemical cycling. We collected a sediment core from a High Arctic Lake in southwestern Svalbard for multiproxy paleolimnological analysis. The aim was to find linkages between the terrestrial and aquatic environments in the context of climate change to understand centennial-long Arctic biogeochemical cycling and environmental dynamics. Two significant thresholds in elemental cycling were found based on sediment physical and biogeochemical proxies that were associated with the end of the cold Little Ice Age and the recent warming. We found major shifts in diatom, chironomid and cladoceran communities and their functionality that coincided with increased summer temperatures since the 1950s. We also discovered paleoecological evidence that point toward expanded bird (Little Auk) colonies in the catchment alongside climate warming. Apparently, climate-driven increase in glacier melt water delivery as well as a prolonged snow- and ice-free period have increased the transport of mineral matter from the catchment, causing significant water turbidity and disappearance of several planktonic diatoms and clear-water chironomids. We also found sedimentary accumulation of microplastic particles following the increase in Little Auk populations suggesting that seabirds potentially act as biovectors for plastic contamination. Our study demonstrates the diverse nature of climate-driven changes in the Arctic lacustrine environment with increased inorganic input from the more exposed catchment, larger nutrient delivery from the increased bird colonies at the surrounding mountain summits and subsequent alterations in aquatic communities.
... However, diatoms belonging to the genus Fistulifera show a broad ecological tolerance due to their significant ability to adapt to various environmental conditions, including heavy-metal-polluted waters. 47 This adaptability might contribute to the high titanium-resistance demonstrated in this study. Subsequently, further cultivation experiments with F. solaris were performed in the presence of 2 mM TiBALDH. ...
... It is likely that they compete very effectively in highly organic biofilms and in lakes with abundant organic C because exopolymers are also important for diatom motility (Smith and Underwood 1998). In line with this observation, contamination of an Arctic lake with organic sewage was shown to increase the relative abundance of Navicula and Nitzschia taxa (Michelutti et al. 2007b). It is noteworthy that the replacement of Fragilaria/fragilarioid taxa with Nitzschia has been observed in several Arctic lakes in recent decades (Antoniades et al. 2005b;Keatley et al. 2006), raising the question that such shifts may indicate organic enrichment of lakes, which could be associated with important Arctic processes such as permafrost melt (Pokrovsky et al. 2011) and'Arctic greening' (McGowan et al. 2016). ...
Benthic diatoms are commonly used for palaeoenvironmental reconstruction in Arctic regions, but interpretation of their ecology remains challenging. We studied epilithic diatom assemblages from the shallow margins of 19 lakes from three areas (coast-inland-ice sheet margin) along a climate gradient in Kangerlussuaq, West Greenland during two periods; shortly after ice-off (spring) and in the middle of the growth season (summer). We aimed to understand the distribution of Arctic epilithic diatoms in relation to water chemistry gradients during the two seasons, to investigate their incorporation into lake sediments and to assess their applicability as palaeoenvironmental indicators. Diatoms were correlated with nutrients in the spring and alkalinity/major ions in the summer, when nutrients were depleted; approximately half of the variance explained was independent of spatial factors. When categorised by functional attributes, diatom seasonal succession differed among regions with the most obvious changes in inland lakes where summer temperatures are warmer, organic nutrient processing is prevalent and silicate is limiting. These conditions led to small, motile and adnate diatoms being abundant in inland lakes during the summer (Nitzschia spp., Encyonopsis microcephala), as these functional attributes are suited to living within complex mats of non-siliceous microbial biofilms. Seasonal succession in silica-rich lakes at the coast was less pronounced and assemblages included Tabellaria flocculosa (indicating more acidic conditions) and Hannaea arcus (indicating input from inflowing rivers). The nitrogen-fixing diatom Epithemia sorex increased from the coast to the ice sheet, negatively correlating with a gradient of reactive nitrogen. The presence of this diatom in Holocene sediment records alongside cyanobacterial carotenoids during arid periods of low nitrogen delivery, suggests that it is a useful indicator of nitrogen limitation. Nitzschia species appear to be associated with high concentrations of organic carbon and heterotrophy, but their poor representation in West Greenland lake sediments due to taphonomic processes limits their palaeoenvironmental application in this region. Proportions of epilithic taxa in lake sediment records of coastal lakes increased during some wetter periods of the Holocene, suggesting that snowpack-derived nutrient delivery may offer diatom taxa living at lake margins a competitive advantage over planktonic diatoms during the “moating” ice melt period. Thus, further research investigating linkages between epilithic diatoms, snowpack and nutrient delivery in seasonally frozen lakes is recommended as these taxa live on the ‘front-line’ during the spring and may be especially sensitive to changes in snowmelt conditions.
