Effects of copper and butyltin compounds on the growth, photosynthetic activity and toxin production of two HAB dinoflagellates: The planktonic Alexandrium catenella and the benthic Ostreopsis cf. ovata

Abstract

Controlled laboratory experiments were conducted to test the effects of copper (Cu) and butyltins (BuT) on the growth, photosynthetic activity and toxin content of two HABs (Harmful Algal Blooms) dinoflagellates, the planktonic Alexandrium catenella and the benthic Ostreopsis cf. ovata. Microalgae were exposed to increasing concentrations of Cu (10 to 31 nM) or BuT (0.084 to 84 nM) for seven days. When considering the growth, EC values were 0.16 (±0.09) nM and 0.03 (±0.02) nM of Cu for A. catenella and O. cf. ovata, respectively. Regarding BuT, EC was 14.2 (±6) nM for O. cf. ovata, while A. catenella growth inhibition appeared at BuT concentrations ≥27 nM. Photosynthetic activity of the studied dinoflagellates decreased with increasing Cu and BuT concentrations. For O. cf. ovata, the response of this physiological parameter to contamination was less sensitive than the biomass. Cu exposure induced the formation of temporary cysts in both organisms that could resist adverse conditions. The ovatoxin-a and -b concentrations in O. cf. ovata cells increased significantly in the presence of Cu. Altogether, the results suggest a better tolerance of the planktonic A. catenella to Cu and BuT. This could result in a differentiated selection pressure exerted by these metals on phytoplankton species in highly polluted waters. The over-production of toxins in response to Cu stress could pose supplementary health and socio-economic threats in the contaminated marine ecosystems where HABs develop.

Low pH in simulated acid rain promotes the toxicity of copper on the physiological performance in Sargassum horneri

“…Growth: At present, acid rain and copper pollution are widely receiving attentions for their harmful effects to marine ecosystem (Gao et al 2016, Couet et al 2018. S. horneri distributes mainly on rocky shores in the intertidal zone (Fig.…”

ABC Transporters in Prorocentrum lima and Their Expression Under Different Environmental Conditions Including Okadaic Acid Production

“…Heavy metals are usually regarded as a main anthropogenic contaminant in coastal and marine environments all over the world [55], which can also affect the growth and toxin production of dinoflagellate [41,42,43]. However, not all metal elements could promote the production of microalgae toxins.…”

“…As the most important source of organotin compounds in the marine environment, TBT is doomed to be highly persistent due to its reversible adsorption to sediments [50]. Owing to the wide use of Cu in industrial activities and other fields (as an important ingredient in many algaecides and herbicides), Cu accumulation in marine sediments has also been becoming a great concern in marine ecosystems [43]. Here, we found that OA production in P. lima was significantly increased under higher concentrations of Cu 2+ (1575 nM and 5039 nM), but decreased under higher concentrations of TBT (2.7 nM and 8.5 nM).…”

“…Secondly, P. lima was observed to produce OA production in the presence of Artemia salina , a suitable model species to assess the toxicity of marine benthic dinoflagellates [39]. Finally, given that algal toxin production is governed by multiple intricate physiological and ecological factors, such as the imbalance of nutrient ratio, the availability of nutrients, environmental pollutants, and grazing pressure [40,41,42,43,44,45], the relationship between the expression of three ABC genes and OA production under different conditions (nutrient limitations, different sources of nutrients, heavy metal stress, grazing pressure) was investigated.…”

In silicoprediction of the secretome from the invasive neurotoxic marine dinoflagellateAlexandrium catenella

“…ovata (EC 50 = 0.16 nM and 0.03 nM of Cu 2+ for A. catenella and O. cf. ovata respectively) (Couet et al, 2018).…”