Today, at the Academic Council of FEFU, a report was presented with the results of a comprehensive expedition to the site of an environmental incident in Kamchatka. The authors conclude that the immediate cause of the events was the rapid multiplication of unicellular algae, known as the "red tide". How the researchers came to this conclusion - in the column of one of the expedition members, associate professor of the Department of Ecology of the School of Natural Sciences of the Far Eastern Federal University Vladimir Mordukhovich.
The investigation of what happened off the coast of Kamchatka has actually been completed. On October 23, the results of the work of the Russian Academy of Sciences were announced. I have no doubts about these results, but I am sure they will be discussed and, for sure, criticized. It seems to me that it would be correct to tell in a little more detail why exactly algae became one of the main suspects in what happened. Almost immediately after the first reports in the media appeared, the version of "red tides" was voiced by many marine biologists - for example, here, here and here - and was actively discussed among my colleagues in Vladivostok as one of the possible and highly probable. How did it occur to these crazy scientists to shift the responsibility to such fragile, such graceful single-celled organisms?
Firstly, marine biologists are well aware that microalgae blooms, including large-scale ones, covering tens and hundreds of kilometers, are a characteristic phenomenon off the coast of Kamchatka, often recorded. True, on October 6, on Khalaktyrsky beach, my colleagues from FEFU and I voiced this version under the heavy and bewildered glances of surfers, bloggers, and activists. For a part of the audience, including those who had lived in Kamchatka for many years, the information about the frequent blooms of sea waters here and the death of people in the past as a result of phytotoxin poisoning was absolutely new.
By now, many have already read or briefly familiarized themselves with the 1995 publication of Galina Konovalova "Red tides off Eastern Kamchatka." I would especially like to note the scale of the blooms identified in the past and the water area where they were recorded. So, Galina Vladimirovna cites the message of the long-distance sailing captain SP Lebedev: “The fishing area  between Cape Navarin and Cape Olyutorsky turned out to be, unlike previous years, at this time of the year completely empty. No life was observed on the surface of the sea. The entire visible surface was covered with brownish-red stripes, located at equal intervals from north to south."
If you look at the map, we are talking about the vast open water area of the Bering Sea. And here is a quote from a 1992 work: “Since the second half of the 1980s, the" bloom "of water in the vast region of the Russian Far Eastern seas has acquired not only a new quantitative, but also a qualitative character. It becomes more intense and stable, CPs appear, caused by species not only rare, but also new for the Far Eastern seas (Konovalova, 1988, 1992).  According to observations from a helicopter in September 1990, spots and stripes of various shades of red were noted along the entire eastern coast of Kamchatka from the bay. Corfa to the southern tip of the peninsula (N. G. Klochkova, pers. Comm.). They were especially intense near the village. Tilichiki (Korf Bay), in Kronotsky and Avachinsky bays (Avachinsky bay) and near Cape Lopatka. In May 1991, after a strong storm, I observed an intense "tide" of mustard-yellow color along the entire coastal strip of Avacha Bay, caused by the "bloom" of diatoms in April-May near the shores, concentrated by surge winds."
I draw your attention to the geography of the noted "tides", in particular, their intensive development in Avacha Bay, as well as the seasons: flowering can occur in spring, summer, and autumn, moreover, they can occur in winter.
So, once again, it is well known that off the coast of Kamchatka (including in Avacha Bay) in the past, microalgae blooms were observed many times, some of which caused the death of people. Interestingly, in August 2020, the flowering of dinoflagellates of the genus Alexandrium, which can produce saxitoxin, was confirmed off the coast of Chukotka.
The second important point is the symptoms of poisoning in humans: eye and skin damage, sore throat, nausea, gastrointestinal upset, fever. All these symptoms are known for poisoning with marine microalgae toxins. Exposure can occur through direct contact with water containing toxins, or through generated aerosols, or through ingestion. You can get acquainted with the toxins themselves, the main symptoms of poisoning, the peculiarities of identifying toxins in the reviews in Russian and in English.
For those who find scientific publications boring and long, I will give here two links with short explanations of what red hot flashes are, and listing some of the symptoms: one and two.
Third, microalgae blooms can lead to the death of various aquatic organisms, moreover, with the development of both toxic and non-toxic species (for example, due to a change in the transparency of water, accumulation in the gills, and a decrease in the content of dissolved oxygen). Research demonstrates the possibility of negative effects of toxins on both vertebrates and invertebrates, including sea urchins (for example, this work, this and this one). There are many described, well-documented examples of changes in marine ecosystems as a result of algal blooms, often leading to mass death of aquatic organisms. For example, in New Zealand, the decrease in the number of sea urchins in 2004 in a number of coastal communities is associated with the blooming of dinoflagellates of the genus Ostreopsis. Representatives of this genus have long been observed only in the waters of tropical regions, but in recent decades they have been increasingly recorded in temperate zones. The water temperature near eastern Kamchatka for the mass development of the known species of Ostreopsis is probably still rather cold, but this does not mean that other microalgae could not actively develop. An extremely illustrative example is associated with the events off the coast of California at the end of August 2011. Over a distance of about 100 km in coastal communities, the previously numerous sea urchins Strongylocentrotus purpuratus and the starfish Leptasterias sp. Almost completely disappeared; increased mortality was noted for Cryptochiton stelleri, the sea star Pisaster ochraceus, and sublittoral sea urchins. All of these species were found en masse in emissions from the shore. A picture so reminiscent of what happened in Kamchatka, with a shift to slightly shallower communities! The wave impact during the period of the described events was typical for the region, the water and air temperatures were also within the normal range (fluctuated in the range of 10-14 degrees Celsius). The death of benthic aquatic organisms was preceded by active “blooming” of dinoflagellates of the genus Gonyaulax, whose representatives produce yessotoxins.
Thus, after studying the first data about what happened in Kamchatka, the researchers had every reason to consider the "red tides" as one of the possible reasons. And then the usual work of hypothesis testing began. It should be noted right away that in this work, scientists did not just reject the rest of the reasons and the flowering is called according to the residual principle, as the least contradicting the facts.No, facts were revealed that directly confirm this hypothesis: data on the content of chlorophyll in water during September - October 2020, the discovery of extensive "spots" in the sea, information on the presence of toxins in water and aquatic organisms, the species composition of phytoplankton, the nature of changes in marine communities.
What happened, in my opinion, is a lesson for everyone involved: bloggers, media, users of social networks, executive authorities, supervisory authorities, residents of Kamchatka, scientists. And, of course, I really want to draw conclusions from this lesson.
Author: Vladimir Mordukhovich
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