Scientists have pinpointed Karenia cristata as the source of the most powerful brevetoxins. These toxins are what’s behind the recent algal bloom plaguing South Australia’s waters. This invasive species is a growing international threat, with unanticipated impacts in today’s rapidly evolving ocean environment. UAA Marine Biology Professor Shauna Murray (center) and her lab team conducted extraordinary, far-reaching research to confirm the bloom. Like us, they started their investigation when it showed up off the Victor Harbor beaches back in March.
In early May, the South Australia Shellfish Quality Program announced a major find. When they finally detected brevetoxins in local waters, it was confirmation of a major breakthrough. This particular bloom has made waves due to its extreme toxicity. It is largely composed of different Karenia species, with K. cristata prevailing for the majority of its duration. This unexpected finding serves as a reminder of the many layers of complexities and challenges involved with studying often fragile marine ecosystems.
Emergence of Karenia cristata
It is known to be found in the waters off of South Africa and once near Newfoundland, Canada. This species had not been recorded in Australian waters until now. It is one of five Karenia species detected in the ongoing South Australian algal bloom. Preliminary taxonomic research indicates that K. cristata was the species that dominated this bloom. Other Karenia species such as K. mikimotoi, K. brevisulcata, K. longicanalis, and K. papilionacea contributed to its formation as well.
Usually, blooms of Karenia species are a mix, rather than a single species, Professor Murray pointed out. She thinks that K. cristata may have been in Aussie waters all along. This misconception comes from not just its respective geographic locations of past detections. This proves challenging both in terms of understanding the historical abundance and the ecological dynamics of marine environments.
“It’s part of what we would call the hidden flora — the species that are present but not very abundant that we never really investigated.” – Professor Shauna Murray
K. cristata is a summer grower, making its most vigorous growth from May onward. The role of this growth pattern in the factors underlying the recent increase in harmful algal blooms has not yet been studied.
Research Methodology and Findings
The research team conducted an intensive sampling effort, gathering data from affected waterways for more than six months. To examine population dynamics and species associations of K. cristata with other species, they sampled 39 sites on a regular basis. Such a massive data grab fast-tracked the identification process at a shocking speed.
Professor Murray remarked on the efficiency of their research methods, stating, “Typically, this type of research might take a few years to establish, and we did it in just months rather than years.” This incredible progress was only possible through partnership between a dynamic, committed, and creative team that went above and beyond on this project.
“That was because we set up a really, really big team and we all worked extremely hard on this.” – Professor Shauna Murray
In these results, K. cristata was found to be a significant contributor to the bloom, along with other established Karenia species. The chair of the state government communication approved, and I had fledged ongoing collaboration. They worked quickly to collect samples and analyze them.
“Research teams from multiple state government agencies have been collecting samples from impacted waters for more than six months, which has generated the data integral to this research.” – State government spokesperson
Implications for Future Research
The ramifications of this finding reach far past alarm over the short-term dangers posed by algal blooms. Learning more about the role of K. cristata will help us learn how shifting ocean conditions may impact life beneath the waves. Due to climate change and nutrient pollution, ocean temperatures are rising and nutrient levels are changing. As K. cristata has shown, it’s important to keep watch for up and coming species.
Professor Murray emphasized the importance of this research for future studies: “Generally, across the period, Karenia cristata was the dominant one, but some of the other species were dominant at different times, in different locations.” This kind of variability underscores the need for ongoing monitoring. We need to continue supporting proactive research on algal blooms’ effects on marine life and human health.
Even with these concerns, public health officials have stated that current public health guidance for algal blooms has not changed.
“This finding does not alter existing health recommendations regarding algal bloom.” – Source not explicitly mentioned
