Temperature effects explain continental scale distribution of cyanobacterial toxins
Journal
Toxins
Date Issued
April 2018
Author(s)
DOI
10.3390/toxins10040156
Abstract
Insight into how environmental change determines the production and distribution of
cyanobacterial toxins is necessary for risk assessment. Management guidelines currently focus on
hepatotoxins (microcystins). Increasing attention is given to other classes, such as neurotoxins (e.g.,
anatoxin-a) and cytotoxins (e.g., cylindrospermopsin) due to their potency. Most studies examine
the relationship between individual toxin variants and environmental factors, such as nutrients,
temperature and light. In summer 2015, we collected samples across Europe to investigate the effect
of nutrient and temperature gradients on the variability of toxin production at a continental scale.
Direct and indirect effects of temperature were the main drivers of the spatial distribution in the toxins
produced by the cyanobacterial community, the toxin concentrations and toxin quota. Generalized
linear models showed that a Toxin Diversity Index (TDI) increased with latitude, while it decreased
with water stability. Increases in TDI were explained through a significant increase in toxin variants
such as MC-YR, anatoxin and cylindrospermopsin, accompanied by a decreasing presence of MC-LR.
While global warming continues, the direct and indirect effects of increased lake temperatures will
drive changes in the distribution of cyanobacterial toxins in Europe, potentially promoting selection
of a few highly toxic species or strains.
cyanobacterial toxins is necessary for risk assessment. Management guidelines currently focus on
hepatotoxins (microcystins). Increasing attention is given to other classes, such as neurotoxins (e.g.,
anatoxin-a) and cytotoxins (e.g., cylindrospermopsin) due to their potency. Most studies examine
the relationship between individual toxin variants and environmental factors, such as nutrients,
temperature and light. In summer 2015, we collected samples across Europe to investigate the effect
of nutrient and temperature gradients on the variability of toxin production at a continental scale.
Direct and indirect effects of temperature were the main drivers of the spatial distribution in the toxins
produced by the cyanobacterial community, the toxin concentrations and toxin quota. Generalized
linear models showed that a Toxin Diversity Index (TDI) increased with latitude, while it decreased
with water stability. Increases in TDI were explained through a significant increase in toxin variants
such as MC-YR, anatoxin and cylindrospermopsin, accompanied by a decreasing presence of MC-LR.
While global warming continues, the direct and indirect effects of increased lake temperatures will
drive changes in the distribution of cyanobacterial toxins in Europe, potentially promoting selection
of a few highly toxic species or strains.
File(s)![Thumbnail Image]()
Name
toxins-10-00156-v4.pdf
Size
16.02 MB
Format
Adobe PDF
Checksum (MD5)
32b5a214e6f0ee4afa735d16dd2ee81c