Sponge fauna of Lake Baikal in the monitoring system for six years of observations
O. O. Maikova, N. A. Bukshuk, L. S. Kravtsova, N. A. Onishchuk, M. V. Sakirko, I. A. Nebesnykh, I. A. Lipko, I. V. Khanaev
Limnological Institute, Siberian Branch, Russian Academy of Sciences, Irkutsk, Russia
Keywords: sponge damage types, projective cover, monitoring
Abstract
In the last decade, mass death of endemic sponges has been observed in the coastal zone of Lake Baikal. This paper presents observations of the Baikal sponge fauna within the transects established throughout Baikal in 2015. Based on visual descriptions, the types of damage to Baikal sponges are characterized. A downward trend was revealed from 2015 to 2020 in the projective cover of the bottom with healthy sponges of various body shapes: encrusting - 3.6 times, branched - 2 times and globulous - 4 times. The reduction in the total area occupied by healthy and damaged sponges of various forms occurred more than 2 times, from 238 m2 to 110 m2.
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