WTT Blog - Tagged with migration

One year on now the weir has gone

Posted on May 31, 2019

One year on now the weir has gone

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 2019 - a note from the committee

Posted on March 20, 2019

NoWPaS 2019 - a note from the committee

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.

Goldilocks weather

Posted on September 03, 2018

Goldilocks weather

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! 

Connectivity at Coniston Cold

Posted on July 09, 2018

Connectivity at Coniston Cold

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.

All about the (sea) trout

Posted on June 14, 2018

All about the (sea) trout

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.

Should I stay or should I go?

Posted on January 05, 2018

Should I stay or should I go?

'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....

Tags under trees tell a tale

Posted on August 07, 2017

Tags under trees tell a tale

In science, new questions are always arising from serendipitous discoveries. Angus Lothian tells us of some interesting data on fish predation that has come to light as a part of his PhD project at Durham University, assessing trout behaviour at fish passes.

Every year, Atlantic salmon (Salmo salar) and sea trout (Salmo trutta) undertake an upstream migration in autumn. People watch these fish ‘heavy-weights’ leap, or at least attempt to, over barriers after having already completed maybe tens of miles on their journey to and from sea. Such a migration allows the fish to use rich marine feeding areas to grow larger than they might achieve by staying in freshwater, thus increasing their fecundity or egg production for when they return to their natal rivers. But there are trade-offs. The migration between freshwater and saltwater is filled with risk, resulting in large annual mortality affecting fish populations. For example, for my MRes, I studied the emigration of salmon smolts from rivers, and their behaviour strongly reflected predator avoidance tactics.