TY - JOUR

T1 - Seasonal plankton succession is in accordance with phycotoxin occurrence in Disko Bay, West Greenland

AU - Bruhn, Claudia Sabine

AU - Wohlrab, Sylke

AU - Krock, Bernd

AU - Lundholm, Nina

AU - John, Uwe

PY - 2021

Y1 - 2021

N2 - Harmful algal blooms (HABs) are occurring more frequently in the world's oceans, probably as a consequence of climate change. HABs have not been considered a serious concern in the Arctic, even though the Arctic warms faster than any other region. While phycotoxins and toxin-producing phytoplankton have been found in Arctic waters on several occasions, there is a lack of information on seasonal succession of species and whether the occurrence of harmful species correlates with the presence of their respective phycotoxins. Hence, there is no baseline to assess future changes of HABs in this area. Here, we investigated two periods, from winter to spring and from the spring bloom until summer, in Disko Bay, West Greenland and followed the succession of toxins and their producers using metabarcoding, as well as analyses of particulate and dissolved toxins. We observed a typical seasonal succession with a spring bloom dominated by diatoms, followed by dinoflagellates in summer, with the two most important potentially toxic taxa found being Pseudo-nitzschia spp. and Alexandrium ostenfeldii. The Pseudo-nitzschia spp. peak correlated with a clear increase in particulate domoic acid, reaching 0.05 pg/L. Presence of Alexandrium ostenfeldii could be linked to an increase in spirolides, up to 56.4 pg/L in the particulate phase. Generally, the majority of detected dissolved toxins followed the succession pattern of the particulate toxins with a delay in time. Our results further show that Arctic waters are a suitable habitat for various toxin producers and that the strong seasonality of this environment is reflected by changing abundances of different toxins that pose a potential threat to the ecosystem and its beneficiaries.

AB - Harmful algal blooms (HABs) are occurring more frequently in the world's oceans, probably as a consequence of climate change. HABs have not been considered a serious concern in the Arctic, even though the Arctic warms faster than any other region. While phycotoxins and toxin-producing phytoplankton have been found in Arctic waters on several occasions, there is a lack of information on seasonal succession of species and whether the occurrence of harmful species correlates with the presence of their respective phycotoxins. Hence, there is no baseline to assess future changes of HABs in this area. Here, we investigated two periods, from winter to spring and from the spring bloom until summer, in Disko Bay, West Greenland and followed the succession of toxins and their producers using metabarcoding, as well as analyses of particulate and dissolved toxins. We observed a typical seasonal succession with a spring bloom dominated by diatoms, followed by dinoflagellates in summer, with the two most important potentially toxic taxa found being Pseudo-nitzschia spp. and Alexandrium ostenfeldii. The Pseudo-nitzschia spp. peak correlated with a clear increase in particulate domoic acid, reaching 0.05 pg/L. Presence of Alexandrium ostenfeldii could be linked to an increase in spirolides, up to 56.4 pg/L in the particulate phase. Generally, the majority of detected dissolved toxins followed the succession pattern of the particulate toxins with a delay in time. Our results further show that Arctic waters are a suitable habitat for various toxin producers and that the strong seasonality of this environment is reflected by changing abundances of different toxins that pose a potential threat to the ecosystem and its beneficiaries.

KW - Arctic

KW - Phytoplankton

KW - Protist

KW - Time series

KW - Harmful algal bloom

KW - HARMFUL ALGAL BLOOMS

KW - ALEXANDRIUM-OSTENFELDII DINOPHYCEAE

KW - TOXIN TRACKING SPATT

KW - PSEUDO-NITZSCHIA

KW - CLIMATE-CHANGE

KW - DOMOIC ACID

KW - MARINE DINOFLAGELLATE

KW - CHEMICAL ECOLOGY

KW - DIATOM BLOOM

KW - SPIROLIDE

U2 - 10.1016/j.hal.2021.101978

DO - 10.1016/j.hal.2021.101978

M3 - Journal article

C2 - 33980456

VL - 103

JO - Harmful Algae

JF - Harmful Algae

SN - 1568-9883

M1 - 101978

ER -