Associations between cyanobacteria and indices of secondary production in the western basin of Lake Erie

Abstract

Large lakes provide a variety of ecological services to surrounding cities and communities. Many of these services are supported by ecological processes that are threatened by the increasing prevalence of cyanobacterial blooms which occur as aquatic ecosystems experience cultural eutrophication. Over the past 10 yr, Lake Erie experienced cyanobacterial blooms of increasing severity and frequency, which have resulted in impaired drinking water for the surrounding communities. Cyanobacterial blooms may impact ecological processes that support other services, but many of these impacts have not been documented. Secondary production (production of primary consumers) is an important process that supports economically important higher trophic levels. Cyanobacterial blooms may influence secondary production because cyanobacteria are a poor‐quality food resource and cyanotoxins may be harmful to consumers. Over 3 yr at 34 sites across the western basin of Lake Erie, we measured three indices of secondary production that focus on the dominant bivalve taxa: (1) growth of a native unionid mussel, (2) the size of young‐of‐year dreissenid mussels, and (3) the mass of colonizing animals on a Hester‐Dendy sampler. Associations between these indices and cyanobacterial data were estimated to assess whether cyanobacteria are associated with variation in secondary production in the western basin of Lake Erie. The results suggest cyanobacterial abundance alone is only weakly associated with secondary production, but that cyanotoxins have a larger effect on secondary production. Given recurring late‐summer cyanobacterial blooms, this impact on secondary production has the potential to undermine Lake Erie's ability to sustain important ecosystem services.

Preliminary analysis to estimate the spatial distribution of benefits of P load reduction: Identifying the spatial influence of phosphorus loading from the Maumee River (USA) in western Lake Erie

“…In contrast, Maumee Bay and the Maumee River mouth are areas that appear to have very high rates of secondary production (thus supporting fisheries and other higher trophic levels; Larson et al, 2016). Secondary production in Maumee Bay is likely affected by cyanobacteria and cyanotoxins (Larson et al, 2018), and cyanobacterial abundance in Maumee Bay seems unlikely to be influenced by proposed reductions in TBP loads.…”

“…Many of these benefits are concentrated in nearshore areas and the areas surrounding tributary inputs (Braden, Taylor, et al, 2008; Braden, Won, et al, 2008; Elliott & Whitfield, 2011; Larson et al, 2013). Some of these services appear to be directly threatened by the continued presence of cyanobacterial blooms, including water use, commercial fishing, and recreational fishing (Bullerjahn et al, 2016; Larson et al, 2018). Due to the threats to these and other ecosystem services, an international team was assembled to identify a strategy to reduce four “eutrophication response indicators,” which included the maximum cyanobacterial biomass in the western basin of Lake Erie (Annex 4 Task Team, 2015).…”

“…Many of these benefits are concentrated in nearshore areas and the areas surrounding tributary inputs (Braden, Taylor, et al, 2008;Braden, Won, et al, 2008;Elliott & Whitfield, 2011;Larson et al, 2013). Some of these services appear to be directly threatened by the continued presence of cyanobacterial blooms, including water use, commercial fishing, and recreational fishing (Bullerjahn et al, 2016;Larson et al, 2018).…”

Spatiotemporal Variability in Phytoplankton Bloom Phenology in Eastern Canadian Lakes Related to Physiographic, Morphologic, and Climatic Drivers

“…However, annual or seasonal water temperatures (Table 3 and Appendix C) do not show any clear relationships with the phenological variables. Although several temperature descriptors have often been related to phytoplankton growth, including atmospheric temperature [19,38], water temperature [85], hours of sunlight [38], and degree-days [86,87], it is the latter descriptor that most directly impact the growth of ectotherm organisms [88]. For instance, Ralston et al [87] used degree-days to assess inter-annual variability in the onset date of algal blooms, their development and date of decline in the Nauset estuary, and proposed this metric as an efficient warning indicator.…”

Ecosystem change as a driver of fish recruitment dynamics: A case study of two Lake Erie yellow perch populations

“…This lack of understanding is often attributed to difficulties associated with disentangling the influences of multiple, interacting stressors such as climate change, invasive species, and eutrophication (Folt, Chen, Moore, & Burnaford, 1999; Harley et al., 2006; Jackson et al., 2016; Reid et al., 2019). Although delineating the mechanisms driving population responses to environmental change is challenging, doing so is critical for forecasting the effects of continued ecosystem change on aquatic organisms (Sterner et al., 2017), setting management and conservation targets at appropriate levels (Cooke et al., 2016; Szuwalski et al., 2015), and sustaining ecosystem services by avoiding ecological surprises (Cheung et al., 2009; Jackson et al., 2016; Larson et al., 2018; Paine et al., 1998).…”