Effect of temperature and salinity on the growth and cell size of the first cultures of Gymnodinium aureolum from the Black Sea

Abstract

Algal blooms are natural phenomena that may cause human health problems, millions of dollars in losses and ecological disasters worldwide. Anthropogenic pressures like eutrophication may increase the frequency and intensity of these phenomena. The Black Sea is characterized by rapid changes in salinity and temperature in surface waters. In addition, it has suffered increasing environmental pressure from human activities. This work presents the first cultures of Gymnodinium aureolum to be isolated from the Black Sea. Morphological and phylogenetic analyses confirmed our strain as G. aureolum. The effects of temperature and salinity on growth were tested in experiments combining two temperatures and five salinities in 10 experimental treatments. This provides baseline data on the physiological adaption and acclimatization potential of the species to bloom under present and future climatic scenarios in the Black Sea. Gymnodinium aureolum grew exponentially in all experimental treatments, except for cultures at salinity 5. Growth rate increased significantly with increasing temperature reaching the maximum at 20 °C and salinity 15 (0.38 ± 0.02 d−1). This suggests an adaptation to the salinity and temperature of Black Sea waters and, together with previous records of G. aureolum in both water and sediments, supports the idea that this may be a bloom-forming population of G. aureolum.

Comparative effects of temperature and salinity on growth of four harmful Chattonella spp. (Raphidophyceae) from tropical Asian waters

“…It is difficult to ascertain the origin and the geographical introduction of these Chattonella, but the ability to adapt to a new environment has been suggested as an important driver for the widespread distribution of some phytoplankton especially the bloom-forming raphidophytes and dinoflagellates (Richlen et al, 2010;Zerebecki and Sorte, 2011;Sala-Peŕez et al, 2021). They can adapt to warmer temperatures, less saline water, lower nutrient availability, and/or high CO 2 concentration (Cubillos et al, 2007;Hallegraeff, 2010;Thomas et al, 2012;Sala-Peŕez et al, 2021). As a case in point, the harmful raphidophyte H. akashiwo is widely distributed globally, likely owing to its adaptability to a wide growth temperature and salinity range, where it has high growth in warmer temperatures (Zhang et al, 2006;Fu et al, 2008).…”

“…Its widespread global distribution has been well-known, and many newly detected locations have been reported since its first discovery (Richlen et al, 2010;Kudela and Gobler, 2012;Thoha et al, 2019). Similarly, the adaptation of Gymnodinium aureolum (Hulburt) Hansen in the Black Sea since its first report in the USA has also been pointed to its euryhaline traits (Sala-Peŕez et al, 2021).…”

The impacts of anthropogenic activity and climate change on the formation of harmful algal blooms (HABs) and its ecological consequence

“…It is difficult to ascertain the origin and the geographical introduction of these Chattonella, but the ability to adapt to a new environment has been suggested as an important driver for the widespread distribution of some phytoplankton especially the bloom-forming raphidophytes and dinoflagellates Zerebecki and Sorte, 2011;Sala-Peŕez et al, 2021). They can adapt to warmer temperatures, less saline water, lower nutrient availability, and/or high CO 2 concentration (Cubillos et al, 2007;Hallegraeff, 2010;Thomas et al, 2012;Sala-Peŕez et al, 2021). As a case in point, the harmful raphidophyte H. akashiwo is widely distributed globally, likely owing to its adaptability to a wide growth temperature and salinity range, where it has high growth in warmer temperatures (Zhang et al, 2006;Fu et al, 2008).…”

“…Its widespread global distribution has been well-known, and many newly detected locations have been reported since its first discovery Thoha et al, 2019). Similarly, the adaptation of Gymnodinium aureolum (Hulburt) Hansen in the Black Sea since its first report in the USA has also been pointed to its euryhaline traits (Sala-Peŕez et al, 2021).…”