Phycotoxin poisoned mussels of Avacha bay
The entire surface of the water area of the Avacha Bay was stained purple-crimson by the flowering bands of Mesodinium rubrum infusoria (Lohmann, 1908), Kamchatka.Today reports with reference to KamchatNIRO.
They noted that phycotoxin domoic acid (Stonik et al., 2023), which was produced by representatives of this genus of diatom microalgae in the Kamchatka waters, had previously been detected in cultures of pseudonitzschia spp., as well as in mussels from the Avacha Bay.
Domoic acid (also known as “zombie acid”) is a neurotoxin that causes amnesia in shellfish poisoning; an analog of kainic acid and proline. Structurally, it is a heterocyclic non-proteinogenic amino acid. It can reach significant concentrations in the environment when the water blooms in the seas.
At the end of April, scientists collected samples of phytoplankton and zooplankton to characterize the biogenic background and pollutants.
According to Ekaterina Lepskaya, the head of the fisheries ecology laboratory, water was taken from the “red spot” in Rakovaya Bay with a bathometer to identify the causes of discoloration. Examination of the sample under a microscope showed the presence of many ciliates – Mesodinium rubrum (Lohmann, 1908). The concentration of mesodynium was 2.8 million cells/L. The scientist also noted that another name for this organism, Myrionecta rubra, is currently an invalid synonym.
“Now the band of “blooming” mesodynium stretches from Rakovaya Bay to Cape Signalny. Diatom microalgae Skeletonema spp., Thalassiosira spp. were also found in the water. Mainly Thalassiosira nordenskioldii and singly Rhizosolenia setigera and Bacterosira fragilis. Colonies of diatoms of the harmful “blooming” complex Psedo-nitzschia seriata & pungens with a population of 170 thousand cells/l have been detected in the surface water layer,” the Kamchatka Territory reported.
As reported, scientists noticed the first streaks of the so-called red tide in Avacha Bay back in mid-April.