WTT Blog - Tagged with research

Just over a year ago, we posted news of a project, Love for Lothersdale Beck, which was shaping up in the home village of our Research & Conservation Officer, Jonny Grey. With most works complete, read about the progress of this holistic project

Freshwater scientists have been studying the phenomenon of “hydropeaking”, the artificial variation in flow below hydropower plants, for around 25 years. One particular aspect has been the harmful effects of flows, fluctuating in some cases on an hourly basis, upon salmonid fish species. In response to the growing awareness of the need to reduce the impacts of hydropeaking, a team of freshwater ecologists and engineers recently published a timely review article. One of the authors, Daniel Hayes (a PhD candidate at the University of Natural Resources and Life Sciences, Vienna) tells us a little more about the issue.

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.

Climate change and intensification of land-use are causing fundamental shifts in the ecology of northern lakes with potentially dire consequences for the species they contain and the human populations which depend on them

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.

I’ve just had the pleasure of hosting two MSc students from Queen Mary University of London (co-supervised with Dr Chris Eizaguirre), partly for the WTT Annual Get Together, and partly to undertake some fieldwork specifically for Charlotte Pike’s project. I alluded to their research projects in a former post and now I have the pleasure of handing over to them to update you.

Charlotte’s project focuses on the use of stable isotopes to determine the success of river restoration. I will be analysing samples from pre and post intervention works against an unimpacted control site on the same river to see how the restoration has affected the ‘architecture’ of the food web. Hopefully it should be more like the control! The intervention works have been carried out by the Ribble Rivers Trust at two locations; Bashall Brook and Towneley Hall. At Bashall Brook, a riparian zone has been created where banks of the river were previously bare; essentially livestock exclusion fencing now removes the impacts of grazing and poaching. This strip of vegetation acts as a buffer to reduce nutrient run-off from farmland, keeps the ground more stable and resilient to flood damage to reduce soil erosion, and provides necessary refuge for wildlife. At Towneley Hall, a partial weir removal and a rock pass re-instates the connectivity of the River Calder allowing fish to move between formerly fragmented habitats. These interventions have been conducted to improve the quality of the habitat at these two sites, and it’s my job to find out what changes have occurred as a result! 

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:

Quite a few of our guest bloggers recently have been at the same conference. Unfortunately, I could only follow the key scientific revelations via Twitter from afar but I have been alerted to some work of which I was previously unaware, so I am hoping to establish contact with those people and perhaps they will contribute a blog or two in the near future. Here, Jess Marsh (she of the water crowfoot and salmonid community research) has kindly offered to tell us briefly about NoWPas.

A week after the 14th annual NoWPaS workshop was wrapped up in spectacular style with a traditional Finnish nuotio, or campfire, we are reflecting on an inspiring week of exciting salmonid research, new experiences and friendships.

NoWPaS 2018 participants at Oulanka Research Station, Finland. Photo taken by Angus Lothian

Gather some fine fishy folk into a room and get them talking (as if you could stop ‘em) about brown trout. How long do you reckon it would be before the topic of colour or more likely spotting pattern would creep in? Let’s face it, we love our spotties! It’s just such an integral part of their beauty and wonderful diversity.

So, for no other reason than the sheer beauty of ‘em, I’m going to ask you good supporters of WTT to snap a few images of wild brown trout spots when you’re out this season but specifically trying to focus on one area – square on and below the dorsal fin. In fact, just like the images scattered around this page, trying to avoid any large patches of glare / reflection / contrast. These images were lifted from 'whole' fish shots, and hence aren't the best quality. I'm hoping you can provide some close ups of the fish flank.

There are few more captivating sights than a river reach swathed in water crowfoot flowers, for what delights might be hidden beneath?  William Barnes (1801–1886) was certainly inspired:

O small-feac’d flow’r that now dost bloom,To stud wi’ white the shallow Frome,An’ leäve the clote to spread his flow’rOn darksome pools o’ stwoneless Stour,When sof’ly-rizèn airs do coolThe water in the sheenèn pool,Thy beds o’ snow white buds do gleamSo feäir upon the sky-blue stream,As whitest clouds, a-hangèn highAvore the blueness of the sky

This humble member of the buttercup family is considered by ecologists as an autogenic engineer: it can change the surrounding environment via its own physical structure. While many people have tried to study where and why water crowfoot grows, especially in relation to nutrients, few have considered how the plant influences the assemblages of organisms around it. Cue Jessica Marsh’s PhD study….

With my ‘Research’ & Conservation Officer cap on, I can straddle the often hefty divide between academia and NGO/grass roots conservation groups and do a little bit to pull them together. Queen Mary University of London buy out some of my time and expertise from WTT to give their aquatic ecology MSc students practical training and experience in the field. As a part of a week-long fieldcourse based in the Lake District, I have forged a link between them and Wyre Rivers Trust but I’ll let some of the excellent members of this year’s cohort tell you about it, below. Thanks to Dr Christophe Eizaguirre and the rest of the students who worked efficiently on the day to provide the data, and of course, to Tom Myerscough from Wyre RT for sorting out the relevant permissions.

The Wyre is one of the key rivers of Lancashire, with its catchment covering much of the North of the county. It has historically been known as one of the best sea-trout fisheries in England. However, in the post-war 20th Century, like most rivers it suffered from intensified agriculture, urbanisation and new engineering methods, and these changes have cumulatively affected fish communities.

As anglers, we often struggle to find fish in a stream, river or lake / loch, and we're generally seeking the bigger fish! Keeping track of the vulnerable juvenile life-stages is even more tricky, and then imagine translocating that problem to the sea.... OK, so with advances in acoustic telemetry, the boffins have a few tricks up their sleeves and are making some headway but the logistics of tracking in such a potentially vast environment are nonetheless challenging. Isabel Moore from the Scottish Centre for Ecology & The Natural Enviornment has risen to that challenge during her PhD and outlines one aspect below.

The brown trout is a remarkably diverse species; it can utilise multiple life-history strategies, ranging from freshwater residency through to migration into marine environments for a period of time before returning to freshwater to reproduce (i.e. anadromous sea trout). Unfortunately, this iconic species has been faced with significant population declines in recent decades across the UK and other parts of the world. A significant portion of the anadromous population decline is thought to occur in marine environments. However, the sheer areal extent of habitats utilised by sea trout makes the monitoring of their movements very difficult, leaving many unanswered questions about the types of challenges that sea trout face and how those challenges might affect the their survival rates. Both environmental (i.e. predation, climate change, etc.) and anthropogenic influences (i.e. overfishing, aquaculture, etc.) have been identified as potential sources of increased mortality, but further research is required to determine the effect of each on wild sea trout.

Resident brown trout (left) and anadromous sea trout with acoustic tag on the rule below (right)