Life history, distribution, and production of Diporeia near the Keweenaw Peninsula Lake Superior

Convergence of trophic state and the lower food web in Lakes Huron, Michigan and Superior

“…For example, Diporeia densities have tended to peak at depths just below the thermocline (Nalepa et al, 2000). This species has all but disappeared from these depths in Lake Huron and Lake Michigan in recent years (Barbiero et al, 2011b), while intermediate depths still support the highest Diporeia populations in Lake Superior (Auer et al, 2009, Barbiero et al, 2011b. So while profundal abundances of this species have been converging recently in the three lakes, abundances at shallower sites have in fact diverged.…”

Trends in Diporeia populations across the Laurentian Great Lakes, 1997–2009

“…The similarities in population densities and rates of decline in the two lakes in the face of such different dreissenid densities suggest that either Diporeia populations in Lake Huron are much more sensitive to any deleterious remote effects of Dreissena than those in Lake Michigan or that declines during this period in the two lakes were not directly or entirely related to dreissenids. Perhaps some support for the former possibility is provided by the observation of Auer et al (2009) that pre-decline Diporeia from Lake Huron had notably less weight per unit length than individuals from lakes Michigan or Ontario.…”

Measuring the effects of food availability on Lake Superior Diporeia consumption rates using radiolabeled algae

“…The dampening phenomenon could be a result of differences in carbon lability or increased predation pressure at high amphipod densities. The position of Lake Erie as an outlier may reflect the small size and shallow depth of the lake's profundal zone (Dermott and Kerec, 1997), the relative importance of macrobenthos other than Diporeia in this lake (compare Dermott and Kerec (1997) for Lake Erie and Auer et al (2009) for Lake Superior) and the high degree of sediment resuspension and processing occurring there (Bloesch, 1982). Perhaps most interesting is the position of Lake Superior where a non-zero J POC intercept suggests that Diporeia would not be sustained below flux values on the order of 25 mg C/g DW/d.…”

“…Auer et al (2009) in Lake Superior, Nalepa et al (2007) in Lake Huron, Nalepa et al (2000) in Lake Michigan, Dermott and Kerec (1997) in Lake Erie and Nalepa (1991) in Lake Ontario). Auer et al (2013) focused on depth distribution in characterizing a "ring of fire" where amphipod populations reach peaks in density at depths along nearshore-offshore transects in Lake Superior.…”

“…They are also a favored prey for Lake Whitefish and other benthivorous species (Ihssen et al, 1981). Lake Superior Diporeia are nutrient-rich organisms, having an overall average lipid content of 32% (Auer et al, 2009) throughout most of the year, and almost 50% following spring phytoplankton blooms (Cavaletto et al, 1996). This high lipid content makes them capable of efficiently recycling nutrients and energy to predators.…”