In recent years, blooms of the neurotoxic dinoflagellate
- PAR ID:
- 10020191
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- Geophysical Research Letters
- Volume:
- 43
- Issue:
- 19
- ISSN:
- 0094-8276
- Page Range / eLocation ID:
- 10,366 to 10,376
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
More Like this
-
more » « less
Abstract Alexandrium catenella have been documented in Pacific Arctic waters, and the paralytic shellfish toxins (PSTs) that this species produces have been detected throughout the food web. These observations have raised significant concerns about the role that harmful algal blooms (HABs) will play in a rapidly changing Arctic. During a research cruise in summer 2022, a massive bloom ofA. catenella was detected in real time as it was advected through the Bering Strait region. The bloom was exceptional in both spatial scale and density, extending > 600 km latitudinally, reaching concentrations > 174,000 cells L−1, and producing high‐potency PST congeners. Throughout the event, coastal stakeholders in the region were engaged and a multi‐faceted community response was mobilized. This unprecedented bloom highlighted the urgent need for response capabilities to ensure safe utilization of critical marine resources in a region that has little experience with HABs. -
Toxic Algal Bloom Recurrence in the Era of Global Change: Lessons from the Chilean Patagonian Fjordsmore » « less
Toxic and harmful algal blooms (HABs) are a global problem affecting human health, marine ecosystems, and coastal economies, the latter through their impact on aquaculture, fisheries, and tourism. As our knowledge and the techniques to study HABs advance, so do international monitoring efforts, which have led to a large increase in the total number of reported cases. However, in addition to increased detections, environmental factors associated with global change, mainly high nutrient levels and warming temperatures, are responsible for the increased occurrence, persistence, and geographical expansion of HABs. The Chilean Patagonian fjords provide an “open-air laboratory” for the study of climate change, including its impact on the blooms of several toxic microalgal species, which, in recent years, have undergone increases in their geographical range as well as their virulence and recurrence (the species Alexandrium catenella, Pseudochattonella verruculosa, and Heterosigma akashiwo, and others of the genera Dinophysis and Pseudo-nitzschia). Here, we review the evolution of HABs in the Chilean Patagonian fjords, with a focus on the established connections between key features of HABs (expansion, recurrence, and persistence) and their interaction with current and predicted global climate-change-related factors. We conclude that large-scale climatic anomalies such as the lack of rain and heat waves, events intensified by climate change, promote the massive proliferation of these species by creating ideal conditions for their growth and persistence, as they affect water-column stratification, nutrient inputs, and reproductive rates.
-
more » « less
Abstract Early detection of predators is critical to the survival of all living organisms. For phytoplankton, recognition and response to chemical cues from predators, as evidence of predation risk, are particularly crucial. The phytoplankton
Alexandrium minutum upregulates its toxicity when exposed to copepodamides, a suite of compounds released by copepod predators. However, howA. minutum perceives these predatory cues and what metabolic pathways are involved in initiating toxin induction remains unknown. In this study, liquid chromatography‐mass spectrometry and NMR‐based metabolomics uncovered subtle physiological responses ofA. minutum to copepodamides, including altered regulation of branched‐chain amino acid biosynthesis and potential enhancement of butanoate metabolism and arginine biosynthesis. While we have yet to identify a chemoreceptor directly activated by copepod cues, based on the results of inhibition experiments, detection of copepodamides appears to disrupt the activity of serine/threonine phosphatases leading to increased jasmonic acid biosynthesis and signaling, which leads to amplified gonyautoxin biosynthesis inA. minutum . This study is an important step toward a better understanding of chemosensory ecology of predator–prey interactions in phytoplankton.
