Did sturgeon once breed in British rivers? New research says yes

For decades, sturgeon have been treated as little more than rare, wandering visitors to British waters — large, startling fish that occasionally turned up in a net and made the local paper, but never confirmed to have bred here. A new study published in Royal Society Open Science overturns that assumption, and IFM’s own Steve Colclough is one of the authors behind it.

The paper, Did sturgeon ever breed in Britain? Evaluating historical evidence and conservation implications, was led by Samuel Turvey of the Zoological Society of London (ZSL) and involved researchers from the Natural History Museum, National Museums Scotland, the University of Cambridge, Ipswich Museums and the Institute of Fisheries Management. Two species once lived in northwest European waters: the European sturgeon (Acipenser sturio) and the Atlantic sturgeon (A. oxyrinchus). Both have effectively vanished from the wild in Europe, and until now it was officially unclear whether either species had ever actually spawned in Britain, as opposed to simply straying into our rivers from spawning populations on the continent. That uncertainty has held back plans to consider sturgeon for reintroduction here.

To settle the question, the team turned to an extraordinary body of historical evidence: a database of more than 2,300 British sturgeon records built up since 2006, drawn mainly from nineteenth- and twentieth-century newspaper archives, alongside museum specimens and even Roman-era archaeological remains from Canterbury. The database — compiled by Steve Colclough and published as the UK Sturgeon Sightings map (uksturgeonsightings.org) — forms the backbone of the study, documenting 1,273 individual sturgeon recorded in British rivers between 1593 and 2015, with the Severn alone yielding 196 records.

The patterns in that data turn out to be striking. Sturgeon reports in British rivers show a strong spring–summer peak, with 92% of records falling between April and August and a sharp spike in June — matching the known spawning migration season of sturgeon elsewhere in Europe and North America almost exactly. Multiple fish were often reported from the same river within days of each other, a pattern consistent with fish moving upriver together to spawn. Twelve historical records describe fish caught “heavy with roe” in ten different rivers, including a female taken from the Wye in 1877 carrying an estimated 27 lb of eggs. And critically, several records and surviving museum specimens document very small juvenile sturgeon — some under 30cm — of a size that modern research shows would still be resident in a natal river or estuary, rather than fish that had wandered in from abroad.

Taken together, the authors argue this is strong evidence that sturgeon were genuinely breeding in British rivers as recently as the early twentieth century, and should be reclassified as a native species on the UK’s freshwater fish Red List rather than treated merely as occasional foreign vagrants.

For IFM, the paper is a welcome piece of recognition of the value of long-term data collection and record-keeping in fisheries science. Steve Colclough’s contribution — built from years of painstaking archival research — has helped provide the evidence base that conservation bodies need to properly evaluate whether British rivers could one day support sturgeon again, as part of wider European efforts to restore the species through stocking and reintroduction programmes. It’s also a reminder of how much can still be learned from historical records, newspaper archives and museum collections about species we assume we already understand.

The full paper is open access and can be read at doi.org/10.1098/rsos.260521