IMIS - Marine Research Groups

Southern Ocean Investigation, RV Ob SOVIET ANTARCTIC EXPEDITION. Cruise I-II- March-May 1956, cruise II -January-March 1957.The stations of cruise III presented in these protocols are sampled in March 1958. The aim of zooplankton studies of Ob cruises was the investigation of its composition, abundance and quantitative distribution in Antarctic. The material was sampled by closing vertical hauls of Juday net ( mouth opening 0,1m2,and 176 µm mesh gause) within the upper 0-500m layer. The sampled layers were usually the next: 0-10, 10-25 (or 0-25), 25-50, 50-100, 100-200 and 200-500 m. The length of lowered wire and the closing depth depended on the angle. Unfortunately a lot of samples are broken during the storms, so the obtained results are not full. The samples processing included identification and counting of plankters. All largerer organisms (>3-5 mm) were enumerated in a total sample. Small organisms were counted in a subsample of ½ -1/10 of the total sample volume, according of the standard methods used at the Plankton Laboratory of the Institute of Oceanology. The sampling was fulfilled in the I cruise by Dr. M.E.Vinogradov and Dr. K.A. Brodski, in the II cruise by Dr. K V. Beklemishev and V.S. Korotkevich and in the III cruise by Dr. K.A. Brodski and A.G. Naumov. The processing of all samples was carried by N.M. Voronina. In total from the I cruise 134 samples from 34 stations are sampled and analyzed, from the II cruise 371 sample from 83 stations and from the III cruise 23 samples from 10 stations . R.V.ACADEMIC KURCHATOV, cruise 11, October 1971-January 1972. The task of this cruise was to obtain a general characteristic of mesoplankton species composition and abundance and its changes in space and time. The samples were usually collected by vertical hauls of closing Juday type nets with mouth opening 0,1 m2 and 180 µm mesh gause. But at station 909 an oceanic modification of this net was used (JOM mouth opening 0,5 m2). The following layers were usually sampled: 0-50, 50-100, 100-200,200-300, 300-400,400-500 and 500-1000 m. In the second part of the cruise the layer 1000-1500 was additionally sampled. The length of lowered wire and the closing depth depended on the angle. The samples processing included identification and counting of Copepoda Calanioida species. . In addition within the upper 100 m all other mesoplankton groups or species and copepods nauplia were counted. All larger organisms (>3-5 mm) were enumerated in a total sample. Smaller organisms were counted totally or in a subsample of ½ -1/10 of the sample volume, according of the standard methods used at the Plankton Laboratory of the Institute of Oceanology. The sampling was fulfilled by Dr. N.M. Voronina, Dr. Y.A. Rudyakov, Dr. B. Vilenkin and an assistant. The treatment of samples was carried out by N.M. Voronina. In total 225 samples from 31 stations are collected and analyzed. Among them 63 samples are collected at station 909 during diurnal investigations, where 9 series in the depths between 0-600 m are sampled. ( NB. It seems that the absence of Neocalanus tonsus on the St. 932 is a mistake). RV DMITRY MENDELEEV, cruise 43, 1989 The tasks of plankton studies in this cruise were: 1) to observe the time changes in the age composition and vertical distribution of main copepod species and 2) to obtain a general comparative characteristic of importance of different taxonomic groups in mesoplankton. The samples were collected mainly with Juday net, mouth opening diameter 0,1 m2 or with JOM net, 0,5 m2 mouth opening at several stations. In both cases the gause was 180 µm. The series of vertical hauls were done in daytime from depths from 0 to 1500 m. The catched layers were usually the next: 1500-1000, 1000-1500,500-200 and 25-0 m; between the last they depended on the hydrographic structure of the water. Sampling was conducted using an electronic closing system (Flint at all, 1978). It was fulfilled by Dr. A.S.Fedotov and engineer A.S. Malishev. The laboratory analyses were carried by Dr. N.M. Voronina during the cruise. They included counting and identification of organisms. Depended of plankton quantity the samples were counted totally or a subsample ½ -1/5 of it was taken. In total 65 samples from 8 stations were collected and treated. R.V.ACADEMIC IOFFE, cruise 6, 1992. The tasks of plankton studies in this cruise were: 1) the comparison of species composition in different modifications of Antarctic surface waters, 2) the observation of the dependence of vertical distribution of plankton organisms on the hydrophysical structure of the water and 3) the consideration the influence of salps on the copepod populations. The samples were collected with vertical hauls of Juday net, mouth opening diameter 0,1 m2 , mesh size 180µm. The series of hauls were done in daytime from depths from 0 to 1500 m. The catched layers were usually the next: 1500-1000, 1000-1500, 500-200 and 25-0 m; between the last they depended on the hydrophysic structure of the water. Sampling was conducted using an electronic closing system (Flint at all, 1978). It was fulfilled by Dr. A.F.Sazhin and engineer S.N.Sedelnicov. The laboratory analyses were carried by Dr. N.M. Voronina during the cruise. They included counting and identification of organisms. Only selected species were considered. They were the most abundant Antarctic copepods, euphausiids and salps. After this all findings of subantarctic copepods were registred. Depended of plankton quantity the samples were counted totally or a subsample ½ -1/5 of it was taken. In total 65 samples from 8 stations were collected and treated.