To ensure the comparability of observation results and to estimate seasonal and year-to year variations in oceanographic variables, it was suggested in Stockholm as early as 1899 that measurements should be made at standard depths and on standard sections. At the beginning of the 20th century observations started on the Kola Section in the Barents Sea (Knipovich 1906), and by the 1930s, a network of such sections had been developed in the area (Figure 3.2.1).
In the last 50 years regular observations of ecosystem components in the Barents Sea have been conducted both at sections and by area covering surveys from ship and airplanes. In addition, there are conducted many long and short time special investigations, designed to study specific processes or knowledge gaps. Also, the quality of large hydrodynamical numeric models is now at a level where they are useful for filling observation gaps in time and space for some parameters. Satellite data and hindcast global reanalysed datasets are also useful information sources.
Old “G.O. Sars” and “Vilnius” under an intercalibration run of acoustic equipment.
The observation system of the ecosystem and human activities in the Barents Sea are based on existing time-series of data collected by a number of Norwegian and Russian institutes. The contribution of different institutes to this monitoring is reflected in Tables 3.1.1-3.1.2.
Table 3.1.1 - Table 3.1.2. Click to enlarge
Monitoring methods are often developed for one or several target species or ecosystem variables (e.g. temperature and salinity). Utilisation of a measurement platform is essential for building up a broad knowledge of the ecosystem structure and variability, and therefore observations are conducted as broadly as possible. However, it is an impossible task to monitor all species in the ecosystem (e.g. ~3000 species of benthos, ~200 species of fish, ~25 species of marine mammals, etc). Therefore, historically, the main effort on biological monitoring is on the key species, but in the last years there have been more focus on species diversity and trophic interactions.
During a year an ecosystem component (e.g. zooplankton) is often monitored by multiple measuring platforms (e.g. sections, surveys, fixed stations, etc). Therefore this chapter is basically divided on two parts. The first part describes the monitoring “platforms”, in a broad understanding of the word (chapter Monitoring of the ecosystem - Monitoring platforms). The second part describes the monitoring from the ecosystem component perspective (chapter Monitoring of the ecosystem - Monitoring divided by ecosystem components).
It should be emphasised, that even though the institutions participating in the preparation of this report are responsible for the vast majority of ecosystem monitoring in the Barents Sea, others are also conducting monitoring in this ocean. This report basically focuses on the monitoring conducted by the institutions that have contributed to the report.