The Toxicity of Copper to Crocosphaera watsonii and Other Marine Phytoplankton: A Systematic Review

Abstract

The cupric ion (Cu 2+) plays a dual role as both nutrient and toxicant to freshwater and marine phytoplankton, functioning in multiple photochemical processes, as well as reactive oxygen species (ROS) production. This duality has been investigated through a variety of methods to determine the consequences of natural and anthropogenic copper introduction to algal ecosystem composition. Studies conducted over the past few decades have described the growth responses of many unique organisms to copper availability. Such observations are critical for describing the global distributions of major phytoplankton species in terms of global trace metal abundance; however, highly variable experimental practices impede direct inter-study comparison. The aim of this systematic review is to summarize the available data regarding the effects of copper concentration on diverse marine phytoplankton growth rates. Through extensive literary comparison, 143 studies were systematically reviewed, and data on copper concentrations and growth rates reported were extracted. From the data available, we conclude that trends in phytoplankton sensitivity to copper are mainly driven by a single study. We discuss the obstacles to inter-study comparison and detail both the concurring and conflicting results to date, with an emphasis on taxonomic trends and methodologies employed. Finally, we present the first copper sensitivity measurements for marine unicellular diazotrophs using three representative strains of the unicellular nitrogen-fixing cyanobacterium, Crocosphaera watsonii.

Life and death of Crocosphaera sp. in the Pacific Ocean: Fine scale predator–prey dynamics

“…These grazers include numerous prymnesiophytes, nanoflagellates like Metromonas , ciliates like Uronema or Strobilidium , and dinoflagellates like Gymnodinium . The negative interaction identified between Crocosphaera and Pseudo‐nitzschia in the network could have been mediated by copper rather than predation, which specifically increases the former productivity (Lopez et al 2019) but inhibit the growth of Pseudo‐nitzschia and promotes the production of the domoic acid toxin (Maldonado et al 2002) at the concentrations measured during MESO‐SCOPE (N. Hawco pers. comm.).…”

“…Predator : prey C 0.13*/0.07** 0.12/0.05 0.14/0.06 m (d −1 ) 6 ×10 −4 AE7×10 −4 0.52AE0.38 0.14AE0.17 Gymnodinium. The negative interaction identified between Crocosphaera and Pseudo-nitzschia in the network could been mediated by copper rather than predation, specifically increases the former productivity (Lopez et al 2019) but inhibit the growth of Pseudo-nitzschia and promotes the production of the domoic acid toxin (Maldonado et al 2002) at the concentrations measured during MESO-SCOPE (N. Hawco pers. comm.).…”

New insights into the distributions of nitrogen fixation and diazotrophs revealed by high-resolution sensing and sampling methods

“…Although high concentration of copper may be toxic to diazotrophs and phytoplankton [71], a positive correlation was found between N 2 fixation rates and DCu. DCu concentrations along the transect ranged from 0.68 to 4.2 nM near the coast, typical of this region [72,73].…”

Impacts of Aerosol Copper on Marine Phytoplankton: A Review

“…The inversion of diadinoxanthin to diatoxanthin could be hindered by high Cu levels, resulting in a rise of the DT index (DT index refers to [34]. Copper could also catalyze the production of reactive oxygen species [38,41]. Chlorophyll molecules could be destroyed when Cu 2+ replaces Mg 2+ in the porphyrin ring [34].…”