Bringing back the sturgeon

May 20

Bringing back the sturgeon

Pádraic Fogarty 21st May 2023

Dublin’s wonderful Natural History Museum has a lot to say about our sea fish. The Victorian cabinets that line the walls of the hall on the ground floor speak to not only the great diversity of marine life that once abounded around our coasts but also the great size of fish in the past. The mackerel are a metre in length, plaice are the size of a dinner plate, turbot the size of a dinner table, common skate (no longer common) bigger than a car bonnet.

But one in particular has always caught my eye: the sturgeon. It’s a whopper, around two metres in length. The museum card says it’s an Atlantic sturgeon Acipenser oxyrinchus and was “taken from the Poolbeg Salmon Fishery, River Liffey, Poolbeg, Dublin in June 1890”.

Dublin’s salmon fishery is long gone, indeed virtually all the fisheries of the Irish Sea are gone but more gone than most is the sturgeon. Research from Declan Quigley, who has analysed records since the 1600s, has found that while sturgeon were never very common they were regularly found around our coast. More than that, he has found evidence that they may have been spawning in our rivers, including the Rivers Lee and Suir.

The Atlantic sturgeon from Dublin’s Natural History Museum

Sturgeon are ‘anadromous’, meaning that, like the Atlantic salmon, they spawn in freshwaters but then migrate to the sea where they spend most of their lives snuffling about on the sea floor, feeding on crabs and small fish.

The sturgeon can grow to three meters but there are likely very few left of this size in Western Europe. At around the same time that the last sturgeon of the 20th century was recorded in Ireland (from the coast of Dublin in 1987), they were disappearing from across their former range. Today, all 27 species of sturgeon are threatened with extinction; over-fished, over-exploited, their sea habitats dredged and trawled, their spawning habitats polluted and/or inaccessible due to dams and weirs.

The last river in Western Europe with spawning sturgeon was the Garonne in France, these are European sturgeon A. sturio, which was believed to be the same species as the one in the Dublin museum, until DNA tests in 2016 which showed that is was in fact the Atlantic species. On the Garonne, as well as the Elbe and the Rhine, reintroduction efforts have been under way, prompted by a Europe-wide action plan published in 2007 under the Bern Convention on migratory species.

This plan urged all signatory nations to join the effort in restoring sturgeons to their former habitats was bolstered in 2018 with the publication of a Pan-European Action Plan for Sturgeons. Ireland, a signatory to the Bern Convention, has not indicated whether it intends to participate in these initiatives. This is perhaps, because the sturgeon has not been officially recognised as extinct from our waters, a ‘red list’ assessment from 2011 excluded it from its analysis, saying it was a “rarely recorded vagrant”, although this doesn’t tally with what is known about the fish.

In 2021, Melissa Vanderheyden from what was then the Galway-Mayo Institute of Technology (now the Atlantic Technology University) studied a number of big rivers in Ireland (the Shannon, Boyne, Suir, Barrow and Munster Blackwater) to see if suitable spawning habitat is available for sturgeon today.

She found that “in all of the analysed rivers, medium to highly suitable spawning and rearing habitat is found, which according to a subsequent population viability analysis would be sufficient to sustain a viable population of European sturgeon”. She also found that were barriers to migration removed along the lower stretches of these rivers, even more suitable habitat would become available.

As it happens, the removal of barriers on rivers is a requirement under a number of policy stipulations including the Water Framework Directive, the EU Biodiversity Strategy and the (hopefully soon to be enacted) Nature Restoration Law. The latter will also require restoration measures for a number of marine species, including the sturgeon. The creation of Marine Protected Areas around the Irish coast, something which will be provided for under legislation which is due to be enacted later this year, will also help the sturgeon by creating zones free of bottom trawling.

The Irish Wildlife Trust and the Blue Marine Foundation in the UK have just released a report which looks at sturgeon reintroduction to Ireland. We asked marine lawyer, Dr Sarah Ryan Enright, for an analysis of the legal status of the sturgeon and she confirmed that Ireland is obliged under the Habitats Directive, to examine the feasibility of reintroducing a range of species, including the sturgeon, as it is listed by the EU as in need of special protection. Her report noted that Ireland has no legally enforceable obligation to undertake such a reintroduction but has signed up to a range of international conventions to that effect.

We have seen that reintroducing species can be successful but there is no commitment to examine all the species that we’ve lost over the centuries or coordinated approach to reintroducing them.

This is badly needed. The sturgeon could, feasibly, swim into our waters following reintroductions in France, Holland and Germany. The UK Sturgeon Alliance last month released a report urging their government to act. But this could take decades. Sturgeon need all the help they can get right now. They would serve as an ‘umbrella species’ that would spearhead the restoration of our seas and waterways as part of a wider European effort.

Currently, the only place to see an Irish sturgeon is in a museum. There’s no reason that needs to remain the case.

You can read the full report ‘Restoring the Sturgeon to Irish Waters’, as well as the legal review, on our website.

If you want to learn more, I’ll be talking at the Patagonia store on Wicklow St. in Dublin on Thursday evening (May 25th) at 7:30pm, it’s free and there’s no need to book.