Bangia fuscopurpurea var. atropurpurea, Bangia fusco-purpurea, Bangiadulcis atropurpurea, Bangiella atropurpurea, Conferva autropurpurea

Size varies greatly depending on the population. In the Great Lakes, spores are around 15.5 µm in diameter and asexual filaments are around 75 µm in diameter (Sheath and Cole 1984). For information on other regions, see (Sheath and Cole 1984; Sheath et al. 1985).

The genetics and life cycle of B. atropurpurea are complicated. In marine environments, this species produces both asexual and sexual plants. Plants from freshwater environments in North America are all monosporic and asexual with three chromosomes. When marine plants also exhibit three chromosomes, the third chromosome is larger than that found in freshwater plants. This indicates that marine and freshwater plants may not actually be conspecific. Populations along the North American coast have complex genetic composition with different numbers of chromosomes and comprise sexual or monosporic plants (Müller et al. 2003). In one known case from Sicily, a freshwater population exhibited both sexual and asexual forms (Gargiulo et al. 2001). Finally, there are genetic differences between northern hemispheric and Australian isolates of B. atropurpurea, indicating that the taxonomy may not be synonymous (Gargiulo et al. 1998; Woolcott and King 1998; Notoya and Iijima 2003).

Marine asexual plants, which tolerate osmotic stress well, are likely the source of the asexual, monospore-producing populations that lack alternation of generations in the Great Lakes. Bangia atropurpurea is often recorded from regions of the Great Lakes that are disturbed by higher salt concentrations than normal (Sheath and Cole 1980). Moreover, Great Lakes freshwater parent plants can produce offspring that adapt to 2.6% salt water in just three generations (Graham and Graham 1987). Bangia atropurpurea occurs in the Great Lakes in the littoral splash zone from just at or below the waterline to a maximum +1m on exposed permanent rocky substrates; there, such native species as Cladophora and Ulothrix are unable to survive due to extremes in temperature, irradiance, and desiccation. Bangia atropurpurea grows best in the Great Lakes at 15–20°C and produces the most monospores at around 15°C and 16 hour day length. It produces the highest biomass in spring and fall and persists through the summer at low biomass. In Lake Simcoe, B. atropurpurea occurs at maximum “vitality” in early June (Damann 1979; Jackson 1985, 1988).

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

Environmental	Socioeconomic

Realized:

Bangia atropurpurea can adapt to a broad range of salinities over time and can tolerate desiccation and osmotic stress. These traits allow B. atropurpurea to occupy the high littoral zone where other filamentous algae do not typically grow (Lin and Blum 1976; Sheath and Cole 1984; Graham and Graham 1987; Jackson 1988; Stewart and Lowe 2008). There are conflicting reports about whether these characteristics allow B. atropurpurea to out-compete native species (Edlund et al. 2000; Stewart and Lowe 2008).

The mucilaginous cell wall of B. atropurpurea is advantageous when living in the upper littoral zone; however it supports approximately 1000 fewer epiphyte cells/mm2 compared to native organisms like Cladophora (Lowe et al. 1982). This lack of quantity and diversity of algal epiphytes could negatively impact the littoral food web. Furthermore, B. atropurpurea can only support larval chironomids, while native Cladophora supports a larger diversity of macroinvertebrates (Chilton et al. 1986). Whether this will have an impact on invertebrate composition hinges upon the ability of B. atropurpurea to outcompete Cladophora.

Bangia atropurpurea can be a biofouling organism and has contributed to hypoxic conditions in Lake Erie (Edlund et al. 2000; Stewart and Lowe 2008). The populations of B. atropurpurea in the Great Lakes are limited to asexual reproduction and therefore will not affect native species genetically (Sheath and Cole 1984; Chilton et al 1986).

There is little or no evidence to support that Bangia atropurpurea has significant socio-economic impacts in the Great Lakes.

Realized:

Bangia atropurpurea typically grows in association with Uthorixa and Cladophora. All three of these species are considered biofouling organisms (Lin and Blum 1977). There is considerable research on the negative impacts of these three macrophytes in Lake Erie, however, it is difficult to identify what impacts can be specifically attributed to B. atropurpurea (Lowe et al. 1982; Chilton et al. 1986; Jackson 1988; Edlund et al. 2000; Stewart and Lowe 2008).

There is little or no evidence to support that Bangia atropurpurea has significant beneficial effects in the Great Lakes.

Potential:

Bangia atropurpurea contains a variety of compounds that may be beneficial in the pharmaceutical, cosmetic, and water treatment industry (Cardozo et al. 2007). Bangia atropurpurea contains high concentrations of Porphyra-334, a mycosporine-like amino acid that is a UV protector and is a potential component in sunscreen production (Hoyer et al. 2001; Torres et al. 2006; Figueroa 2021). This species also has high antioxidant activity and may be a new source for preventative agents against oxidative stress related diseases and act as a non-toxic food colouring agent (Punampalam et al. 2018). Bangia atropurpurea that was modified with a nitrilotriacetate (NTA) ligand had high potential for the removal of uranium(VI) ions and could be implemented in wastewater treatment (Bayramoglu et al. 2018).

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
The distribution of B. atropurpurea in the Great Lakes is associated with elevated salinity and eutrophic conditions (Lin and Blum 1976; Sheath and Cole 1984; Graham and Graham 1987; Jackson 1988; Stewart and Lowe 2008). The reduction of pollution and nutrient run-off could decrease the viable habitat for B. atropurpurea.

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