Atlantic Ocean
Biological Parameters
The Biological data includes Phytoplankton, Zooplankton, and Fish. Data were collected during the period of 16 years from 1963 to 1989.
Methods of sampling and sample processing used in the Atlantic Ocean by the Institute of Biology of the Southern Seas ( Sevastopol, Ukraine).
Fish
Instruments and methods: The fish catches were carried out by the scientific mid-water non-closed trawl.
There was a small-mesh section with minimum mesh size of 0.14- 0.09 mm in the trawl bag. Vertical opening of the trawl made up to 6 m. The trawling duration under catches in the sound-scattering layers made 1 hour. Speed of trawling made 3.0 knots.
Total number and weight of each species in a catch, and average dry weight of one specimen of a species were determined. The standard fish body length (SL) was measured in mm (from the tip of snout to the basement of the middle rays of the caudal fin).
The samples were fixed in 10% buffered formaldehyde for further processing in the IBSS laboratories.
Phytoplankton
Instruments and methods
Sampling was carried out at depths of 0, 10, 25, 50, 75, 100, 150, 200, 300, and 500 m. The depths were chosen in accordance with the goals of the expeditions and the regions sampled. In the upwelling zone of the South Atlantic Ocean, samples were taken to 300 m. In regions of seamounts or shallower depths sampling was restricted to 100-250 m. There were a number of open ocean regions where sampling was carried out to depths of 4000m. In the case of the drift stations, the sampling interval in the time series was 4-6 hours.
The 1.5 L Nansen bottles and 30 L bottles were used for water sampling. Samples were preserved in buffered 4% filtered formaldehyde.
On return to the Laboratory, the samples were stored for 2 weeks to allow the cells to settle.
Excess water was decanted from the samples leaving sample volumes between 220 and 250 cm3. A second decanting was carried out 7 days later leaving a sample volume of 10-15 cm3. This volume varied according to the initial sample volume.
Cell Counts. Sample aliquots of 0.1 cm3 were taken using a 1 cm3 pipette and placed into a glass counting chamber with engraved parallel lines with 1 mm resolution. The sample aliquot was covered with a thin glass micro sheet and cells counted under a binocular microscope (MBI-1, MBI-3, with 45-70-280-630X magnification). Two replicates were taken.
To count the Dinoflagellata fraction (usually damaged by formalin preservation), a 0.1cm3 fresh aliquot was processed on board, (i.e. without formalin). Final assessment of cell abundance was completed later, when data obtained from both the fresh sample and the
preserved sample were merged (Rouhiyainen, 1975).
From middle 1970¡¯s, the method of inverse filtration replaced the above method of sample processing (Sorokin, 1983; Suhanova, Ratkova, 1977; Suhanova, 1983). This later method gave better preservation of the taxonomic groups. According to this method, 1 to 4 L samples were sub-sampled from the 25-40 L bottles. These bottles were Plexiglas, with open and closing mechanisms.
Water samples (50-100 cm3) were filtered, through nucleopore filters (1-1.5 ¦Ìm pore diameter) using the inverse filtration cone.
The samples were preserved with Lugol¡¯s solution (2 cm3 per sample) and 1 ml of formalin was added to the sample one week later. For processing, a sample was condensed to 3 cm3 and cells counted. Sorokin (1983), Suhanova and Ratkova (1977), and Suhanova (1983) gave detailed technical descriptions of the inverse filtration cone.
Zooplankton
Instruments and methods:
Samples were taken by open-closing JUDAY nets with a 36 cm ring diameter and mesh sizes of 112 to 120 mkm. The JOM net (the JUDAY oceanic model), with a mesh size 300 mkm was also used occasionally. All tows were taken in either a vertical or oblique manner and were hauled at a speed of approximately 0.5 m s-1.
The open-closing mechanism used was the Nansen mechanical lock system allowing nets to be vertically towed through standard depths (0-10, 10-25, 25-50, 50-100, 100-200, 200-300, 300-500 m) and closed at the upper depth level. Integrated hauls (0-100, 0-200 m) were also taken.
The 10-20 ml samples were preserved in 3-4% buffered formaldehyde and processed on return to the laboratory. Before processing, the sample was stirred and aliquots of 1 to 5 ml were taken out of the sample using pipettes. Organisms were identified and enumerated to the species level under a binocular microscope (MBS-1 or MBS-3) in Bogorov chambers.
Abundance of males, females, and copepodites for each species and the total abundance of nauplii were determined. Two replicates from each sample were processed as a rule and these replicates were averaged. The large size organisms were counted in the whole sample.
Individual weight of organisms was calculated from measurements of body length using the so-called Tables of Standard Weights (Kanaeva, 1962; Shmeleva, 1963; Kryilov, 1968; Gruzov, Alexeeva, 1970) or nomograms relating the length and a typical body shape with the weight of animals (Chislenko 1968).
Hydraological
The standard hydrological methods were used to produce the hydrological data:
Nansen Bottles with deep-sea reversing thermometers;
CTD-sounding systems.
For salinity determination before 1969 the argenometric titration from the chlorine was used with salinity calculated from Knudsen's formula.
From 1969 year salinity was determined by means of laboratory electrical salinity-meter GM-65
Temperature observation during batometric casts was provided by means of Deep-sea reversing thermometers - DSRT.
CTD-sounding systems were used for temperature, salinity and depth observations from 0 to 2000 meters depth. Device types are ISTOK-3, ISTOK-4, and ISTOK-5.
Chemical Parameters
Different methods were used to determine the same hydrochemical parameter in different cruises and it should be recognized to analyze and compare information of this general data set correctly.
The next methods were used:
1. Dissolved oxygen was determined by Winkler's method
2. The method of Denige and Atkins (with SnCl2 as a reducer of phosphomolibdate complex) was used since 1966 to 1975 to determine inorganic phosphates. Since 1979 the method of Murphy and Riley (with ascorbic acid as reducer) has been using.
3. The method of Griess-Ilosvay was used to determine nitrites.
4. pH-meters "pH-262" and "pH-340" were used to determine pH value.
5. Total alkalinity was determined by volumetric method of Bruevich (titration of sample of water with hydrochloric acid and flushing it with CO2-free air).