Specialists of the Scientific Center for Marine Biology named after. A.V. Zhirmunsky Far Eastern Branch of the Russian Academy of Sciences analyzed samples and found that tens of thousands of crustaceans – representatives of zooplankton of the genera Neocalanus, Pseudocalanus, Metridia and Microcalanus – were frozen into the ice. It turned out that due to the presence of carotenoid pigments in the bodies of the crustaceans, the water turned red. The phenomenon was recorded during monitoring in the area of the Vostok Marine Biological Station in the bay of the same name. The discovered species of copepods form the basis of the zooplankton population in the bay in winter and are typical inhabitants of its open deep-sea areas, said specialists from the National Scientific Center for Marine Biology, Far Eastern Branch of the Russian Academy of Sciences.
During the melting period, colored ice is discovered annually on the coast in the Primorsky Territory. However, its color usually changes to green or brown, which is explained by the presence of a large number of microalgae in it. This time, there is virtually no vegetation on a number of ice areas, unlike zooplankton.
Most groups of copepods are ectoparasites of invertebrates and vertebrates. Free-living representatives of the orders Calanoida (calanoids) and Cyclopoida (cyclopoids) are the most important component of the zooplankton of the seas and continental reservoirs. Species of the order Harpacticoida (harpacticids) are common representatives of benthos and interstitial fauna, less common in plankton. There is a World Association of Copepodologists that publishes the Monoculus copepod newsletter.
Neocalanus
– Raman spectroscopy confirmed that the carotenoids found in the bodies of crustaceans extracted from the ice of Vostok Bay contain the pigment astaxanthin. The spectrum was obtained both for pigmented granules in ice and for water, and compared with the spectra previously obtained for the astaxanthin standard, the press service added, noting that scientists continue to study ice blooms.
Neocalanus is a genus of marine copepods. They are the dominant component of open water ecosystems in the North Pacific Ocean. Neocalanus are large copepods, with the body length (i.e. prosoma length) reaching over 8 mm (0.31 in) in Neocalanus plachrus. For pollock, herring, flounder, mackerel, and saury of the North Pacific Ocean, a number of researchers have established that the composition of the food of the larvae of these fish depends on the composition of the plankton, and the manifestation of selectivity as the larvae grow is determined by the size, number and mobility of food organisms.
Metridia
For example, the basis of the diet in the Olyutorsky and Karaginsky bays of fingerlings (young fish of the current year) in the summer consists of copepods, and in the autumn-winter period – euphausiids. The size of fingerlings in Olyutorsky Bay is 2–3 cm larger than in Karaginsky Bay, which is explained by different feeding conditions. In the northern part of the Sea of Okhotsk in June–October, the diet of fingerlings is dominated by Pseudocalanus minutus, P. newmani and juvenile euphausiids, and the value of their daily food ration (DAR) ranges from 5–9% of body weight.
In November-December, the main food of the underyearlings consists of juvenile euphausiids and larger copepods – Calanus glacialis, Neocalanus plumchrus, Metridia okhotensis, and the value of SPR sharply decreases, amounting to 2.5–3% of body weight. Yearling herring in the Sea of Japan feed intensively from April to December, then there is a decline that continues until March inclusive.
Typically, red snow is a phenomenon observed high in the mountains and in the polar regions of the Earth. The unusual reddish or pink color of the snow is due to the massive proliferation of one of the species of chlamydomonas algae (Chlamydomonas nivalis). Along with heat-loving algae, there are also those that prefer low temperatures. Living in seemingly unfavorable conditions, these algae reproduce so intensively that their mass stains the surface of the snow. In addition to the green pigment chlorophyll, the cells of this algae contain the red carotenoid astaxanthin.
This single-celled green algae is one of the most commonly found species of cryophilic (cold-loving) algae. In addition to the green pigment chlorophyll, the cells of this algae contain the red pigment astaxanthin. In order for Chlamydomonas snowy to develop successfully, you need a lot of sunlight and fairly cold weather. It was precisely these conditions that persisted for a long time in the area of the Shaman snowfield, which allowed the algae to multiply and color the snow red. If the temperature on the snowfield rises to + 4°C, it will go into a dormant stage or die.
Snow and ice algae are a very interesting group of organisms, since they actively develop at temperatures around 0°C and are able to tolerate frost. Among cryophilic algae, green algae, cyanoprokaryotes, and diatoms predominate. They can cause green, yellow, blue, red, brown, brown or black “blooming” of snow and ice. Red snow is usually found high in the mountains and in the polar regions of the Earth. It is widespread in the Caucasus, Northern Urals, in the eternal snow zone of Kamchatka, it was also found in Siberia (on the Aldan Range) and in the Arctic at the foot of the snow mountains in the southwestern part of Novaya Zemlya, in many places on Franz Josef Land, in Kara sea and so on.
Chlamydomonas nivalis
Snow algae can survive in adverse conditions as resting cells or spores. There are several factors that cause sleeping cells to “wake up”: a certain amount and quality of light, dissolved gases, nutrients or water. It is believed that light may be a decisive factor in promoting the rapid proliferation of algae. “Blooming” is observed exclusively when the upper layers of snow cover thaw. Under the influence of sunlight, Chlamydomonas snowy, whose cells contain red pigment, begins to actively multiply, forming a color spot.
The size of such a color spot formed by chlamydomonas can reach several square kilometers. And the color of the snow varies depending on the amount of algae: from pale pink to dark burgundy. However, red is far from the only color that snow in the mountains and Antarctica is “capable” of coloring. You can find such snow even in the mountains of California. Besides being pink (red), it tastes and smells like watermelon! You can taste red snow, but it is dangerous to abuse it, as it can cause stomach upset (however, this is the case with many algae).
The first information about watermelon snow is contained in the works of Aristotle. It has puzzled climbers, explorers and naturalists for thousands of years. Some have speculated that the snow’s color is caused by mineral deposits or oxidation products that have been leached from the rocks. The species of single-celled green algae Chlamydomonas nivalis, which gives snow its red color, dies already at a temperature of +4 C, literally “from the heat.” There are most likely no organisms with a stronger heat phobia than Chlamydomonas.
The color of the snow depends on the species that predominates among the snow algae. If you believe the monograph “Applied aspects of the use of microalgae in agrocenosis” by Vyacheslav Lukyanov and Anatoly Stifeev, the red pigment is contained only in the cells of the above-mentioned Chlamydomonas nivalis. However, Chlamydomonas flavor-virens turns the snow yellow-green during its reproduction process. But Chlamydomonas pascher, which also lives in the snow layer, belongs to blue-green algae. That is why snow in cool latitudes can be not only red, but also green, blue, brown, yellow, and even black.