WTT Blog - Tagged with migration

A year has already flown by since we (me at WTT, Pete Turner at EA & Kevin Sunderland at Aire RT) worked in partnership to remove the weir at Coniston Cold on the Aire, North Yorks. I’m currently champing at the bit awaiting a bespoke permit from the EA to tackle another. The funding is in place. The owner has granted permission for full removal having seen the transformation at Coniston Cold. The next weir will present its own challenges… but more on that in another blog.

I wanted to focus on developments at the site formerly known as Coniston Cold Weir....

NoWPaS, the International (formerly Nordic) Workshop for PhD and post-doctoral fellows working on anadromous Salmonids, is an annual workshop which consists almost entirely of early career researchers (ECRs) with a focus on PhD students. The workshop, which is organised by a committee of PhD students, allows a small group ECRs to present their research programme and ideas, along with any results that they might have already collected. WTT Research & Conservation Officer, Jonny Grey, was our man in the thick of it at the NoWPaS 2019 meeting, held at the Scottish Centre for Ecology and the Natural Environment (SCENE), the University of Glasgow’s field research station.

What has happened to our young trout during all the recent 'abnormal' weather? It's a question I have heard discussed and been asked directly quite regularly of late, and I intend to post a response with a relatively local flavour, here on the blog, in the not too distant future. However, to pre empt that, I thought I would post some thoughts from my colleague in the south, Andy Thomas. Glaciers were still retreating from Cumbria when Andy first started working on rivers, so he's seen a thing or two....

Please note that this article was originally published in the WTT Summer Newsletter (one of the perks of being a member), and hence was written prior to the extended warm & dry period that subsequently ensued! 

And so it comes to pass….Coniston Cold weir, which in various forms has been a man-made obstruction to fish passage on the R Aire in N Yorkshire for the past 180 years at least, is no more. Instead, there is now 20.4km of uninterrupted free passage along the Aire and a major tributary.... and all for less than £8k!

Coniston Cold Weir: 19m wide and 1.2m headloss, with a 4m horizontal block-stone apron

I will not reinvent the wheel and spend time here discussing how weirs cause environmental issues. The evidence is abundant and simple to find in the scientific literature, and my colleague Paul Gaskell has recently summarised much of that, here. Then there are global-local events like World Fish Migration Day to raise awareness and I would wager that almost every conservation body involved with river restoration has a hit-list of target weirs on their local patch.

Hopefully a few sea trout have found a bit of water (not round here mind) and are starting to return to our rivers at the moment. Fitting then to hand over the blog to Angus Lothian, a PhD student at Durham University (see his first blog here) to reflect on a new network for sea trout research.

Salmo trutta is a truly fascinating ‘species’, with such varying life history strategies and showing large phenotypic plasticity, exemplified by their key characteristic of partial-migration.  It is not yet fully known what drives partial-migration, with a component of a population of trout smolting and emigrating from rivers to sea, and the rest remaining river-resident.  Although the trout has often played second fiddle to Atlantic salmon, recent surges in the interest of trout ecology and biology, and in particular sea trout, has led to a rise in the number of scientists and PhD students researching this field.

World Fish Migration Day is a biennial event and this year falls upon the 21st April. If you have not heard of it, it’s a global-local event to create awareness of the importance of open rivers and migratory fish. Check out some of the events that are going on around the world - there may be something near to you:

'Can I migrate?' is a question that we at WTT often raise on behalf of fish. In most instances, this question is associated with two physical factors. One is whether there is sufficient water in the river for fish to move through; a problem exacerbated in the southern parts of the UK by abstraction pressures. The other is whether there are any barriers or obstacles to free fish passage - and there are usually plenty! But 'Should I migrate or not?'  is an interesting one that does not get asked very often. Luckily I know someone who does ask such questions! With great pleasure, I hand over to Kim Birnie-Gauvin from the National Institute for Aquatic Resources at the Technical University of Denmark who is conducting her PhD research within the AMBER project.

Physiology & partial migration: from the free radical theory of ageing to residancy and migration in brown trout....