Our research interests fall into several interconnected categories that revolve around the basic question of what influences biodiversity and ecosystem function at different spatial scales. To do this, we study anthropogenic stressors in freshwater ecosystems, ranging from populations to communities to food webs. Some of the major research themes in the lab are highlighted below.
The effects of climate change are expected to be most pronounced in high altitude, high latitude, and boreal regions. Using a combination of field survey and experimental techniques, our research has examined the effects of climate on freshwater lake and pond plankton communities in these regions. As a result of their small size and rapid reproduction, organisms like phytoplankton and zooplankton can be the 'canary in the coalmine' and provide invaluable information about the effects of a warmer climate, especially in regions which have already warmed considerably in the past few decades.
Whitney, J.E., J.B. Whittier, C.P. Paukert, J.D. Olden, and A.L. Strecker. 2017. Forecasted range shifts of arid-land fishes in response to climate change: the influence of fish traits. Reviews in Fish Biology and Fisheries doi:10.1007/s11160-017-9479-9 link
Strecker, A.L., T.P. Cobb, and R.D. Vinebrooke. 2004. Effects of experimental greenhouse warming on phytoplankton and zooplankton communities in fishless alpine ponds. Limnology and Oceanography 49: 1182-1190. PDF
Many freshwater ecosystems are threatened by human activities. This is particularly true in the Lower Colorado River basin, where flow modifications, river regulation, non-native species, and land use change have had significant effects on a highly threatened yet highly endemic native fish community. Preserving species diversity in these regions is challenged by the lack of species distribution information and a rigorous quantitative conservation framework. Lab research has used species distribution modeling and optimization algorithms to identify areas that are priorities for conservation for native fishes in the Lower Colorado River basin.
Kuehne, L.M., Olden, J.D., Strecker, A.L., Lawler, J.J. & Theobald, D.M. 2017. Past, present, and future of ecological integrity assessment for fresh waters. Frontiers in Ecology and the Environment 15: 197–205 link
Pool, T.K., Strecker, A.L., and J.D. Olden. 2013. Identifying preservation and restoration priority areas for desert fishes in an increasingly invaded world. Environmental Management 51:631-641 link
Strecker, A.L., J.D. Olden, J. Whittier, and C. Paukert. 2011. Defining conservation priorities for freshwater fishes according to taxonomic, functional, and phylogenetic diversity. Ecological Applications 21: 3002-3013 PDF Supplements
The effects of invasive species on aquatic communities is predicted to be particularly severe, altering native species biodiversity, with largely unknown consequences for the functioning of the ecosystem. Previous lab research has assessed the effect of Bythotrephes longimanus, a predatory planktonic invertebrate on native plankton communities using experiments and landscape surveys. Other lab research has examined the role of the aquarium trade in introducing non-native species, as well as potential consequences of invasion for conservation of endangered native fishes.
Strecker, A.L., and J.D. Olden. 2014. Fish species introductions provide novel insights into the patterns and drivers of phylogenetic structure in freshwaters. Proceedings of the Royal Society - B 281: 20133003. link
Strecker, A.L. and S.E. Arnott. 2010. Complex interactions between regional dispersal of native taxa and an invasive species. Ecology 91: 1035-1047. PDF
Water Quality and Toxins
A critical aspect of having healthy aquatic ecosystems is understanding the prevalence and ecological effects of contaminants. We study water quality issues, such as harmful algal blooms, at the landscape scale to understand the complex factors that influence bloom formation. In addition, lab research seeks to understand mechanisms that influence contaminant exposures and concentrations in aquatic food webs, including harmful toxins like methylmercury and PCBs.
Granek, EF, KE Conn, E Nilsen, L Pillsbury, AL Strecker, B Fish, and S Rumrill. 2016. Spatial and temporal variability of contaminants within estuarine sediments and native Olympia oysters: A contrast between a developed and an undeveloped estuary. Science of the Total Environment 557-558:869-879. link
Habitat Fragmentation and Connectivity
Increasingly, research has demonstrated the importance of spatial processes in ecology. Habitat fragmentation and connectivity are two sides of the same coin, and both have consequences for communities and foodwebs. Lab research focuses on trying to understand the effects of fragmentation, connectivity, and spatial scale in community structure and function.
Strecker, A.L. and J.T. Brittain. 2017. Increased habitat connectivity homogenizes freshwater communities: historical and landscape perspectives. Journal of Applied Ecology DOI: 10.1111/1365-2664.12882 link
Zarnetske, P.L., B. Baiser, A.L. Strecker, S. Record, J. Belmaker, and M.-N. Tuanmu. 2017. The interplay between landscape structure and biotic interactions. Current Landscape Ecology Reports 2: 12–29 link
Most anthropogenic stressors do not occur in isolation, but rather in combination with other stressors. Very little is known about how these stressors may interact to affect aquatic communities and ecosystems. Previous lab research has shown that these multiple stressor interactions are difficult to predict and are often context dependent. Current lab research is focused on elucidating the mechanisms of these interactions, including experiments using stressors that commonly co-occur, such as eutrophication and climate change.
Brittain, J.T. and A.L. Strecker. 2018. The interactive effect of multiple stressors on crustacean zooplankton communities in montane lakes. Water Resources Research, in press. link
Strecker, A.L. and S.E. Arnott. 2005. Impact of Bythotrephes invasion on zooplankton communities in acid-damaged and recovered lakes on the Boreal Shield. Canadian Journal of Fisheries and Aquatic Sciences 62: 2450-2462. PDF