Historical reconstruction of sturgeon (Acipenser spp.) spatiotemporal distribution and causes for their decline in North-Western Europe

Abstract

This study aims to reconstruct the historical spatiotemporal distribution of the anadromous sturgeons, Acipenser sturio and A. oxyrinchus, in NW-Europe (especially in the Rhine, Meuse, Scheldt, and Ems rivers, and in the North Sea), in light of evaluating the possibilities for their reintroduction. It is based on fisheries data from the 14th–twentieth century, consisting of > 5000 records of sturgeon landings and sales (c. 40,000 specimens) from the Netherlands, Belgium, Germany, Luxemburg, France and Switzerland. Most data originate from fisheries in the Rhine-Meuse delta (c. 28,000 specimens, 98% of the Rhine catches). Further upstream, far fewer sturgeons (c. 600 specimens) were reported from the Rhine’s mainstem and its principal tributaries, Mosel, Neckar and Main. Smaller tributaries and the Ems, Meuse, and Scheldt rivers seldom yielded sturgeons. This spatial pattern can be related to the species’ preference for large-river habitat, combined with fisheries activities that were most intensive in the delta areas. Sturgeon catches began to dwindle in the late nineteenth century, at a time when river engineering first strongly affected the sturgeon’s reproductive habitats in the Lower Rhine and delta areas. Also from then onwards, North Sea fishery pressure increased, as trawlers switched from sail to steam-powered propulsion. These sea fisheries harvested all age-classes of sturgeons year-round, including populations from other European rivers. The outcomes strongly suggest that NW-European sturgeon populations were initially impacted by intensive river fisheries, but especially by destruction of reproductive habitat, due to river regulation, and an intensified North Sea fishery, ultimately resulting in total population collapse.

Faunal Remains from Archaeological Sites Document Human Impact on the Terrestrial and Aquatic Environment: examples from the last thousand years in Belgium

“…However, archaeozoological work has shown that an additional species (A. oxyrinchus) occurred in Western Europe and that it was even more abundant in the North Sea (Thieren et al 2016). It is only now that this archaeozoological information, combined with genetic studies on sturgeons from natural history museum collections, is being used in the discussion of reintroductions (Brevé et al 2022a). There is some concern that hybridisation would jeopardise the introduction of A. sturio, but besides interbreeding, which likely also occurred naturally in the past, there is also a risk of hybridisation with acipenserids that are not native at all (Brevé et al 2022b).…”

Updates on putative bull shark (Carcharhinus leucas) occurrences in the upper Mississippi River Basin of North America

“…Additionally, the widespread digitization of historical records such as newspapers or archival image and manuscript collections have provided a powerful new tool in understanding the past geographic distributions and relative abundance of fishes (Cochran 2007;McClenachan 2009;Cochran and Elliott 2012;Cochran 2015;Palsson and Astthorsson 2017;Disspain et al 2018;Keevin and Lopinot 2019;Bom et al 2020;Brevé et al 2022). However, it is crucial to acknowledge that unusual cases such as these must be approached with greater scrutiny and a higher standard of evidence.…”

Factors influencing migration of short‐finned eels (Anguilla australis) over 3 years from a wetland system, Lake Condah, south‐east Australia, downstream to the sea

“…Migratory fish are particularly vulnerable to human disturbance because they are exposed to multiple threats along their migration pathways (Deinet et al, 2020). Well-known examples include losses or declines of migratory giant catfish in Asia (Hogan et al, 2004), sturgeon across Europe and North America (Brevé et al, 2022), and anguillid eels in the Northern Hemisphere (Jellyman, 2021). This vulnerability presents significant challenges for conservation and sustainable fishery management of migratory fishes (Jacoby et al, 2015).…”