To ensure the comparability of monitoring data 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 taken at standard depths in standard spatial areas (sections).

In order to evaluate the state of the physical environment several sources of information are used. Area surveys of temperature and salinity are conducted in January-February during the joint winter survey, and in August-October during the joint ecosystem survey. The standard sections also form an important base to evaluate temperature and salinity. In particular, seasonal changes are monitored at the Kola and Fugløya-Bear Island sections, and at the fixed station in Ingøy.

Data from standard transects constitute a long marine time series dating back more than 100 years. At the beginning of the 20th century  monitoring — of temperature, salinity, nutrients, and chlorophyll a — was initiated in the Kola Section of the Barents Sea (Knipovich 1906), and by the 1930s, a network of such transects had been developed in this section (Figure 3.2.1). During the last decades, zooplankton has also been sampled.