Status of colonies and factors determining the development of Common (Uria aalge) and Brünnuch's (U. lomvia) guillemot's populations on Murman coast southwestern part of the Barents Sea

• Main Authors: 3rd World Seabird Conference 2021, Nikolaeva, Natalia
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: Underline Science Inc. 2021
• Subjects: Ornithology; Environmental Engineering; FOS Environmental engineering; Barents Sea; Kola Peninsula; Murmansk; kola peninsula; Uria aalge; uria
• Online Access: https://dx.doi.org/10.48448/sxw2-4045; https://underline.io/lecture/34829-status-of-colonies-and-factors-determining-the-development-of-common-(uria-aalge)-and-brunnuch's-(u.-lomvia)-guillemot's-populations-on-murman-coast-southwestern-part-of-the-barents-sea

Abstract: Against a general pattern of guillemot's reduction in colonies along Murman coast (Russia, southwestern part of the Barents Sea) large-scale fluctuations in their number were observed. In 2000-2018 in four colonies the number of Common and Brunnich's guillemots has decreased by 66% and 81% respectively with maximum drop in numbers of both species was recorded in one of them, by 71 and 90%respectively. It was established that the number of Common and Brunnich's guillemots in Murman colonies largely depends on availability and size of capelin spawning stocks in winter and spring. Capelin spawning and feeding areas do not remain constant and vary from year to year depending on the Barents Sea water masses temperature. Positive anomalies in water temperature contribute to more powerful capelin accumulations occur and rapidly increase in its abundance in the southern regions of the Barents Sea and off the Kola Peninsula coast. In these years favorable feeding conditions for seabirds may exist in pre-breeding period in Eastern Murman area. Spawning stocks of capelin move eastward in warm years resulted in trophic conditions in the western regions, and possibly along the Murman coast may deteriorate. In such years comparing to years with normal temperature conditions, a restricted capelin stock can be distributed over a wider water area. Evaluating trophic conditions for the guillemots, the impact of the fishing fleet which regularly reduces capelin stocks must be considered. Their restoring occurs with the advent of high-yielding generations, caused a subsequent fishing recovery. Combination of restricted recruitment and intensive fishing can significantly destroy guillemots' food supply in the southwestern part of the Barents Sea. The degradation of guillemot's colonies is due to impact of a complex of factors, including abundance and availability of capelin stocks, capture level and temperature regime of water masses determining distribution of capelin in coastal waters. Authors: Alexey Ezhov¹, Yuri Krasnov¹, Natalia Nikolaeva² ¹Murmansk Marine Biological Institute KSC RAS, ²Lomonosov Moscow State University