What do fjords, climate change and our microfossil library have in common? | Curator of Micropalaeontology

Earlier this month one of our long term visitors Prof John Murray published a paper with Elisabeth Alve outlining the distribution of Foraminifera in NW European Fjords. The main purpose was to provide a baseline for assessing man’s impact on the environment.

Map Norway, N Sea, Greenland Sea
Map showing the Norwegian Coast, oceanic currents and biogeographic provinces. Murray & Alve Fig. 1. Reproduced with permission by Elsevier License 3958190505543.

Read on to hear how Prof Murray used our microfossil library and collections to support their observations and investigate other factors that could control the distribution of these important environmental indicators.

The term fjord has been widely used in Scandinavian countries to describe coastal inlets. More precisely they are glacial deepened, enclosed marine basins with a sill restricting coastal waters from circulating.

Goes Foraminifera Arctic and Scandinavia
Part of the front cover and some illustrations from Goës (1894) on Arctic and Scandinavian Foraminifera.

Details of the foraminiferal distribution were obtained from 1990s surface sediment samples and published occurrences. The study used the Heron-Allen Micropalaeontology Library to access 19th century publications on NW European benthic foraminifera, especially those of Goës and Sars on Scandinavia and the Arctic.

As well as looking at other publications to gain general background information, he searched our collections for species of Elphidium. It was important to distinguish between the northern species Elphidium clavatum and the southern species Elphidium excavatum as in the past there has been confusion between these two. (See previous blog on the perils of identifying species of Elphidium).

Graph Northern and southern species
Figure 4 from Murray & Alve (2016) showing distribution of northern and southern species of Foraminifera in Fjords. Reproduced with permission by Elsevier License 3958190505543.

Murray and Alve found a clear pattern of distribution with widespread species, northern species, southern species, deep sea species and one recently introduced species recorded. The change from north to south is progressive with the overlap corresponding to a previously recognised boundary between the Barents Sea Province and the Norwegian Coast Province.

Another interesting conclusion is that the source of all fjord faunas is the adjacent shelf and slope.

Murray and Alve commented:

“For those interested in monitoring man’s impact on environments we have shown that the low limit of species diversity measured statistically and used to judge the ‘health’ of an environment is set too low as far as the pristine fjords of Svalbard are concerned because they have naturally low species diversity and no influence from human activity.”

These levels are set in the EU’s Water Framework Directive (WFD; 2000/60/EC).

The Heron-Allen Micropalaeontology Library and the Museum’s collection are ideal for supporting studies like that published by Murray and Alve, and it is part of the Museum’s Library and Archives, one of the most comprehensive collections of natural history material in the world. To learn more please visit the Library and Archives Discovery Layer. The collections and library are available upon request.

This post was written by Giles Miller and John Murray