Detection of the phycotoxin pectenotoxin-2 in waters around King George Island, Antarctica

Bernd Krock,Marcelo Hernando,Urban Tillmann,Gastón O Almandoz,Julieta Antoni,Dolores Deregibus,Irene R Schloss,Mona Hoppenrath,Nicole Trefault

doi:10.1007/s00300-020-02628-z

Abstract

In order to set a base line for the observation of planktonic community changes due to global change, protistan plankton sampling in combination with phycotoxin measurements and solid phase adsorption toxin tracking (SPATT) was performed in two bays of King George Island (KGI) in January 2013 and 2014. In addition, SPATT sampling was performed in Potter Cove during a one-year period from January 2014 until January 2015. Known toxigenic taxa were not firmly identified in plankton samples but there was microscopical evidence for background level presence of Dinophysis spp. in the area. This was consistent with environmental conditions during the sampling periods, especially strong mixing of the water column and low water temperatures that do not favor dinoflagellate proliferations. Due to the lack of significant abundance of thecate toxigenic dinoflagellate species in microplankton samples, no phycotoxins were found in net tow samples. In contrast, SPATT sampling revealed the presence of dissolved pectenotoxin-2 (PTX-2) and its hydrolyzed form PTX-2 seco acid in both bays and during the entire one-year sampling period. The presence of dissolved PTX in coastal waters of KGI is strong new evidence for the presence of PTX-producing species, i.e., dinoflagellates of the genus Dinophysis in the area. The presence of phycotoxins and their respective producers, even at the low background concentrations found in this study, may be the seed of possible proliferations of these species under changing environmental conditions. Furthermore, phycotoxins can be used as chemotaxonomic markers for a very specific group of plankton thus allowing to track the presence of this group over time.

Highlights

During the second half of the twentieth century, the Western Antarctic Peninsula was one of the most affected areas by Global Change, some cooling trend was evident after 1998 (Turner et al 2016)
Environmental conditions in the study areas In Fildes Bay, sea surface temperature increased during the studied period (Fig. 2), starting around 16 January, with a peak registered on 23 January (1.25 °C)
Even though solid phase adsorption toxin tracking (SPATT) can only be regarded as semi-quantitative, these results clearly indicate a low abundance of PTX-producing species in coastal water of King George Island (KGI)

Summary

Introduction

During the second half of the twentieth century, the Western Antarctic Peninsula was one of the most affected areas by Global Change, some cooling trend was evident after 1998 (Turner et al 2016). These observations can be better described as a delayed warming shaped by the Southern Ocean’s meridional overturning circulation and reflect the natural variability superimposed to the long-term warming trend (Armour et al 2016). Surface salinity decrease has a significant impact on coastal Antarctic phytoplankton community composition (Hernando et al 2015). As a consequence, warming trends might result in Harmful Algae Bloom (HAB) seed populations appearing in Antarctic surface coastal waters, reflecting the onset of permissive temperatures for germination (Kremp and Anderson 2000) and increased germination rates favored at higher temperatures (Anderson et al 2005)

Objectives

Methods

Results

Discussion

Conclusion