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Long and important time series

Access to time series is essential when scientists are painting scenarios for the future. Time series can be divided into two types: physical or biological.

The Kola Section

Our longest hydrographic time series (measurements of salt content and temperature) are the “Kola Section” in the Barents Sea and the “Scripps Pier Time Series” from La Jolla, California. These started up in 1900 and 1916, respectively. The former provides monthly information on the top 200 m of the water column in a “section” (transect) from Kola and straight northwards into open waters (from 70°30’N, 33°30’ E to 72°30’N, 33°30’ E). The value of the Kola Section is doubled by the fact that it reflects not only temperature and salt content over time, but also the strength of the incoming North Atlantic Drift (the tail end of the Gulf Stream). The data from Scripps Pier, on the other hand, are extremely detailed and

include several measurements each week. Both the Kola Section and the Scripps Pier series have led to a basic understanding of oceanographic processes, documented in innumerable journals.

When it comes to biological time series, Norway is uniquely placed in having three of the longest marine fisheries–biological data series in the world: one for northeast arctic cod (“skrei”), one for Norwegian spring-spawning herring, and one based on beach seine catches on the south coast of Norway. The first two started up in 1900, the last one in 1919 and they have provided a basis for ground-breaking research.

Ecosystem surveys

One recent result, for instance, shows that the current (record large) size of the skrei population, can be attributed to a combination of good fisheries management based on 50-60 years of close collaboration between Norway and Russia, and favourable climate over the past decade. The warmer climate has allowed the cod to expand its feeding area significantly; the population can now be found both at the far east and the far north of the Barents Sea. In the North Sea, the Norwegian Sea and the Barents Sea, research institutes now conduct regular “ecosystem cruises” which focus on ecosystem function and structure, in addition to calculating the size of individual populations.

The ecosystem cruise in the Barents Sea in the late summer/early autumn is especially important for studying changes at the more northerly latitudes. This cruise has had an interdisciplinary profile since 2004. Among other things, it has shown that arctic species are under pressure from more thermophilic species migrating in from areas further south.

Other ambitious cruise programmes have been set up for specific purposes; an example is the Mareano programme, which is mapping benthic habitats. Among other things, this has contributed to 18 coral reef complexes along the Norwegian coast being defined as marine protection areas where trawling is prohibited. Passive fishing gear may be used, but the authorities are now in the process of implementing total protection in some areas. These are intended to serve as “reference areas” for studies of the effects of climate change.