Iain D. Phillips

Ecosystem consequences of potential range expansions of Orconectes virilis and Orconectes rusticus crayfish in Canada — a review

Canadian water bodies are presently experiencing fluctuations in orconectid crayfish ranges largely as a result of human activities. The range of Orconectes virilis, Canada’s most widespread crayfish, is expanding westward into previously uninhabited water bodies of Alberta. This species is also set to re-colonize watersheds in the eastern extent of its range as post-acidification recovery of aquatic ecosystems continues. In addition, the non-native Orconectes rusticus has invaded Central Canada. This species has the potential to rapidly invade boreal water bodies and out-compete native congeners, including O. virilis. Both these crayfish species are known to affect benthic ecosystems and their invasions may have adverse consequences for Canadian water bodies if left unchecked. Here we review the current documented distribution of O. virilis and O. rusticus in Canada, and identify the potential impacts that their invasion may have on boreal aquatic ecosystems. Finally, we consider options that resource ma...

Salvage Logging and Edge Effects on Pill Beetle Abundance (Coleoptera: Byrrhidae)

Abstract Pitfall traps were employed to investigate the effects of post-fire salvage logging on abundance of pill beetles (Coleoptera: Byrrhidae) across an ecotone from unsalvaged habitat into the interior of a salvaged stand in the Canadian boreal forest. Byrrhids (mainly Byrrhus geminatus LeConte) were dramatically more abundant at the edge of salvaged habitat and more common in the salvage habitat relative to the unsalvaged stand. This holarctic beetle, herein reported for the first time from Alberta, is characteristic of disturbance, and its abundance appears to reflect a relative degree of disturbance over natural post-fire conditions.

Effects of Pitfall Trap Lid Transparency and Habitat Structure on the Catches of Carabid Beetles (Coleoptera: Carabidae) in Tame Pasture

ABSTRACT Captures of insects in pitfall traps are affected by features of trap design that may confound the interpretation of data. One such feature is a lid suspended over the opening of the trap to exclude debris and rainwater. In this study, we tested whether use of these lids affected captures of carabid beetles by altering the light conditions at the opening to the trap. In one experiment, we examined the effects of lid transparency (opaque, semitransparent, or transparent) on catch rates. In a second experiment, we manipulated the heights (high, medium, or low) of vegetation adjacent to the traps to test for lid transparency and vegetation height interactions. We found that significantly more carabids were captured with use of transparent lids compared with other lid transparencies. Fewest Agonum cupreum Dejean, 1831, were captured with use of opaque lids. No other effects were detected. Given these results, we advocate the use of transparent lids, which provide the benefits of traditional opaque lids while minimizing the effects of lid use on light conditions at the opening to the trap.

Biological Notes and Range Expansion of the Non-Biting Midge Odontomesa fulva (Kieffer) (Diptera: Chironomidae)

ABSTRACT During research on brook trout (Salvelinus fontinalis [Mitchill]), we collected larval and pupal specimens of the midge Odontomesa fulva (Kieffer) (Diptera: Chironomidae) from Pine Cree Creek, in the Cypress Hills area of the Northern Great Plains of Saskatchewan, Canada. This record is the first observation of O. fulva from the province. The larvae of the population of O. fulva in this study prefer shallow pools in this first-order, cold water stream. The species displays a univoltine emergence phenology. This range extension of O. fulva highlights and reinforces the importance of the Cypress Hills to the unique aquatic faunal biodiversity and ecology of Saskatchewan and the Northern Great Plains.

Species traits modify the species-area relationship in ground-beetle (Coleoptera: Carabidae) assemblages on islands in a boreal lake

Life-history traits influence colonization, persistence, and extinction of species on islands and are important aspects of theories predicting the geographical distribution and evolution of species. We used data collected from a large freshwater lake (1,413 km2) in central Canada to test the effects of island area and isolation on species richness and abundance of carabid beetles as a function of body size, wing length, and breeding season. A total of 10,018 individual beetles from 37 species were collected during the frost-free period of 2013 using transects of pitfall traps on 30 forested islands ranging in area from 0.2 to 980.7 ha. Life-history traits improved the predictive ability and significantly modified the shape of species-area and abundance-area curves. Abundance and richness of small-bodied (< 13.9 mm), macropterous (winged), and spring-breeding species decreased with island area and increased with isolation. In contrast, richness and abundance of larger-bodied (> 14.0 mm) and flightless species increased with area, but not isolation. Body size of female Carabus taedatus Fabricius, the largest-bodied species, was positively related to island area, while body size on the adjacent mainland was most similar to that on smaller islands. Overall, species with large body size and low dispersal ability, as indicated by flightlessness, were most sensitive to reductions in area. We suggest that large-bodied, flightless species are rare on small islands because habitat is less suitable for them and immigration rates are lower because they depend on freshwater drift for dispersal to islands.

Turnover of hydrogen isotopes in lake sturgeon blood: implications for tracking movements of wild populations

ABSTRACT Naturally occurring deuterium (2H) in biota can be used to trace movement, migration and geographic origin of a range of organisms. However, to evaluate movements of animals using δ2H measurements of tissues, it is necessary to establish the turnover time of 2H in the tissues and the extent of isotopic discrimination from different environmental 2H sources to those tissues. We investigated the turnover of 2H in lake sturgeon (Acipenser fulvescens) blood by manipulating both environmental water δ2H and diet δ2H over a four-month period. The half-life of deuterium in lake sturgeon blood was 37.9 days after an increase in the environmental water δ2H of +714 ‰. However, no clear turnover in blood 2H occurred over the same period in a separate trial following a change of −63.8 ‰ or +94.2 ‰ in diet. These findings suggest that environmental water 2H exchanges much faster with blood than diets and that blood δ2H values can be used to trace movements of sturgeon and other fish moving among isotopically distinct waters.

Range Extension of the Giant Water Bug Belostoma flumineum Say 1832 (Hemiptera: Belostomatidae) to Saskatchewan, Canada

Abstract. We collected a single specimen of the giant water bug Belostoma flumineum Say 1832 (Hemiptera: Belostomatidae) during routine macroinvertebrate biomonitoring in the Souris River, Saskatchewan. This is the first record of B. flumineum in the province of Saskatchewan and represents a more northern record than the previously documented locations in Montana, North Dakota, and southeastern Manitoba.

Evidence for Substrate Influence on Artificial Substrate Invertebrate Communities

Abstract Cobble baskets are frequently used as a tool to measure differences in benthic macroinvertebrate communities between waterbodies; however, underlying differences in substrate type may influence the resultant colonization of baskets, misrepresenting communities. This study tests the hypothesis that cobble basket placement influences the resulting benthic macroinvertebrate community. Cobble basket arrays (n = 4) were deployed in Dog Lake, Saskatchewan, in 2011 (97 d) and 2012 (95 d) on cobble habitats and soft or sandy substrates ~100 m apart. Baskets placed on cobble substrate had significantly higher Shannon–Weaver diversity relative to those placed on soft substrate in both years, and higher % EPT (Ephemeroptera Plecoptera Trichoptera) in 2011, but total density was not significantly different. Nonmetric multidimensional scaling revealed that the community was different between both treatments, characterized by higher densities of Gammarus lacustris Sars in baskets placed on soft sediment in both years, higher densities of Aeshna sp. and Mystacides sp. on cobble substrate in 2011, and higher densities of Helobdella stagnalis (L.) and Glossophinia complanata (L.) on cobble substrate in 2012. The results were consistent with the hypothesis that baskets placed on cobble substrate versus soft substrate will result in differing community colonization. The resulting recommendation for monitoring and assessment using cobble baskets in lakes is that baskets be placed on comparable substrate type when comparing between lakes, and that cobble beds be chosen as a more appropriate substrate for deployment, as the added habitat complexity of baskets on soft sediment may act as an attractant and not reflect the true community composition of that habitat.

Macroinvertebrate communities in a Northern Great Plains river are strongly shaped by naturally occurring suspended sediments: implications for ecosystem health assessment

Rivers are typified by considerable seasonal flow variability. In rivers that flow through alluvial deposits, fine sediment (<63 μm) is readily suspended, especially during periods of high discharge. Therefore, assessment of the effects on biota of anthropogenic stressors must occur within the context of dynamic turbidity and background flow conditions. We used the Qu’Appelle River in southern Saskatchewan as a study system for which we developed a model in which discharge is a principal determinant of in-stream suspended sediment. We explored this relationship with a case study showing that macroinvertebrate community structure was strongly correlated with suspended sediment gradients and, ultimately, predicted by discharge. Factors affecting sediment loads and ecosystem responses in managed systems should be considered so that in-stream water quantity and quality needs are met. This new understanding should enable development of improved ecosystem-based flow-management objectives.

Hidden in Plain View: The Range Expansion of Carabus granulatus L. (Coleoptera: Carabidae) and New Provincial Record for Saskatchewan, Canada

IAIN D. PHILLIPS TRoutreach Saskatchewan, Saskatchewan Wildlife Federation #9 Lancaster Road, Moose Jaw, Saskatchewan, CANADA, S7J 1M8 Department of Biology, University of Saskatchewan #112 Science Place, Saskatoon, Saskatchewan, CANADA, S7N 5E2 Water Quality Services, Integrated Water Services, Water Security Agency of Saskatchewan #101-108 Research Drive, Saskatoon, Saskatchewan, CANADA, S7N 3R3