Melosira binderana Kutzing, 1844

In Lake Michigan, blooms of S. binderanus have been recorded both in spring and fall. Highest abundance in nearshore areas typically occurs at water temperatures around 8–9°C (Lauer 1976, Round 1972, Stoermer and Ladewski 1976). In Lake Erie, peaks in abundance have been recorded in spring, which is the largest peak, and also around November/December. In Lake Ontario, abundance typically reaches a maximum after the thermal bar spring excursion and declines sharply in summer. In Lakes Erie and Ontario, blooms typically occur in offshore and often central regions (Barbiero and Tuchman 2001, Round 1972, Stoermer and Ladewski 1976). In the Cuyahoga River, S. binderanus has been known to occur at temperatures of 26°C (Williams 1972). It has also been recorded in the north channel of the St. Lawrence estuary at biovolumes over 50% in salinities of 1–5.5 psu (Winkler et al. 2003).

Stephanodiscus binderanus also sometimes occurs at river outlets into lakes. It requires silicon for growth, but populations can persist in low silicon conditions until this resource increases in abundance. Filaments are frequently grazed efficiently by zooplankton in native regions. This species grows best in 12 hours of light and 12 hours of dark (Holopainen and Letanskaya 1999, Knisely and Geller 1986, Sicko-Goad and Andersen 1991, Sommer and Stabel 1983).

In the former USSR, S. binderanus tends to be a eurythermal species that blooms around 15–16°C in the spring and 19–20°C in the summer, and typically occurs in large lakes and reservoirs. It was historically limited to northern regions of the USSR and only a few more southerly locations, but this changed with the building of more reservoirs in southern regions. It is likely that this species requires sediments to overwinter, which often accumulate well in larger lakes and reservoirs (Priymachenko 1973). In Lake Baikal, where it is not endemic, its presence is associated with increasing anthropogenic impacts (Edlund et al. 1995).

Summary of species impacts derived from literature review. Click on an icon to find out more...

Environmental	Socioeconomic	Beneficial

Stephanodiscus binderanus has a moderate environmental impact in the Great Lakes.

Realized:
The introduction and establishment of S. binderanus, along with Actinocyclus normanii f. subsalsa, were accompanied by the reduction of five native diatoms (S. transilvanicus, Cyclotella comta, C. michiganiana, C. ocellanta, and C. stelligera) in Lake Ontario (Edlund et al. 2000, Stoemer et al. 1985). While it is unclear if these local population reductions were due entirely or in part to competition with exotic taxa, the appearance of S. binderanus in Lake Ontario spring diatom collections tends to be associated with the absence or rare occurrence of C. comta, C. michiganiana, C. ocellanta, and C. stelligera (US EPA 2012). These native species reappear at sample sites in summer, when S. binderanus is not longer found (US EPA 2012), suggesting that strong seasonal competition may drive fluctuations in native diatom abundances.
 

Stephanodiscus bineranus thrives in phosphorous rich and silica depleted waters. It reached peak abundance in Lake Michigan and Lake Ontario in the 1950s and 1960s, but since efforts to improve water quality began in the 1970s and grazing from the Dreissena invasion increased in the 1980s, there have been marked declines in S. binderanus populations (Barbiero et al. 2006, Stoermer et al. 1996). In a more recent survey conducted in 2001, S. binderanus was not found Lakes Superior, Michigan, or Huron. However, S. binderanus was present in Lake Ontario and had a few very large populations in Lake Erie reaching biovolumes of 32,028 ug/mL (Barbiero and Tuchman 2001). Current environmental impacts of this species are unknown.

Stephanodiscus binderanus has a moderate socio-economic impact in the Great Lakes.
Realized:
Stephanodiscus binderanus has clogged filters at water filtration plants in both Chicago and Montreal, and has caused water taste and odor problems (Brunel 1956, Stoermer and Yang 1970, Stoermer et al. 1996, Vaughn 1961). Stephanodiscus binderanus also forms surface scums and, at high abundances, reduces water quality, and negatively affects recreational uses of the affected lake (Stoermer et al. 1985).

There is little or no evidence to support that Stephanodiscus binderanus has significant beneficial effects in the Great Lakes.
Potential:
Stephanodiscus binderanus has been used to assess historical pollution and climate conditions both in the Great Lakes and in Lake Baikal, Russia (Edlund et al. 1995, Stoermer et al. 1985).

Regulations (pertaining to the Great Lakes region)
There are no known regulations for this species.

Note: Check federal, state/provincial, and local regulations for the most up-to-date information.

Control
Biological
There are no known biological control methods for this species.

Physical
There are no known physical control methods for this species.

Chemical
Stephanodiscus binderanus thrives in eutrophic waters. The reduction of pollution and nutrient run-off could decrease the viable habitat for S. binderanus.

Note: Check state/provincial and local regulations for the most up-to-date information regarding permits for control methods. Follow all label instructions.

A recent study conducted by Hawrshyn et al. (2012) in Lake Simcoe, Ontario found historical microfossils of S. binderanus dating back the 17th century. This discovery brings the status of S. binderanus as a nonindigenous species in the Great Lakes basin into question. Stephanodiscus binderanus may be better classified as a range expander rather than as a nonidigenous species.