The Olsen Piscatorial atlas: what species were fished in the North Sea more than 100 years ago? Check it in this marvellous atlas from 1883. [read more]

We proudly present an exceptional acquisition for the VLIZ library collection: the Piscatorial Atlas (1883) from Ole Theodore Olsen. This physical oceanographer started his career as an assistant to the American Matthew Maury, one of the pioneers in marine meteorology from the 19th century. For Maury, he collected the local oceanographic data around the British Isles, using the extensive British fishery fleet as his sampling platform. Gradually, Olsen became interested in the fishery and biology aspect of data collecting. Therefore he designed simple forms to collect fishery data and distributed these to all vessel captains on their campaigns. The result of some ten years of systematic fishery data collecting, were compiled in this beautiful atlas.

This publication is not only interesting for fishery history. Due to the combination of fishery statistics and oceanographic data, the book gives us a good snapshot of the condition of the North Sea, and the adjacent areas. The atlas shows us that the 19th century North Sea bottom was quite different from today. In front of the Dutch coast for instance, Olsen draws a so-called ‘moorlog’ area. Here, the bottom consisted of a thick layer of coarse peat, and boats were warned not to anchor or trawl here because they would get stuck with their nets. The peat formed a hard substrate, very favourable to a unique fauna on the North Sea continental shelf. Through erosion and covering by sandbanks, the ‘moorlog’ has since disappeared, and so has the unique fauna.

Olsen’s bottom chart of the North Sea also shows a remarkable large red spot in the Dutch and German area of the southern North Sea Bight. This was an oyster bank (Ostrea edulis) estimated at a huge 20.000 km²! Olsen writes on this: "The oyster culture around the British Isles does not equal the demand; but Mother Sea has yet in store a bed or beds of 200 miles in length, and varying even to 70 miles in width, situated between Heligoland and the Doggerbank. Oyster vessels are now being added to the great Grimsby fishing fleet". Fifty years later, in 1936, the last oysters were commercially harvested. Since 1970, not one oyster is left there…

Other species, depicted in this book, like sturgeon and halibut have also declined since, sometimes dramatically to even complete disappearance. Luckily enough, the marvellously edited Olsen Atlas is not all ‘bad news’! One can see for instance that species as plaice, whiting, the North Sea crab, and the brown shrimp seem to be as happy in our regions as they were in 1883. All 50 maps, beautifully coloured and illustrated with 19th century vessels and typical fishermen, can be consulted during opening hours in the VLIZ-library.

Olsen, O.T. (1883). The piscatorial atlas of the North Sea, English and St. George's Channels, illustrating the fishing ports, boats, gear, species of fish (how, where, and when caught), and other information concerning fish and fisheries. Taylor and Francis: London, UK. 50 maps pp. details