WTT Blog

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….

'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....

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)

Here at WTT, we're (no pun intended!) all for reconnecting fragmented systems: see recent news items from Tim Jacklin's work on letting the Dove flow, applications of Mike Blackmore's patented #weirbegone, or some of my recent work with Aire Rivers Trust as just a few examples. Europe wide, indeed globally, there is growing recognition of such issues but do we know even the true extent of the problem? Hence, it's great to hear from Siobhán Atkinson regarding her current PhD research.

River connectivity is vital for sustaining healthy freshwater ecosystems. It is important for maintaining resident as well as migratory fish populations, natural sediment movement, and habitat for macroinvertebrate communities and other aquatic organisms. Despite this, few rivers remain uninterrupted across Europe.

At the WTT Annual Get Together earlier this year, I had the pleasure of bumping into a former MSc student of mine, Simon Whitton, who now works at Affinity Water and is collaborating with colleagues at Cranfield University, supervising PhD students of his own; a perfect opportunity for another guest blog or four! Since abstraction and chalk streams have hit the headlines repeatedly and this year especially, we should follow Mickaël's progress with interest (and that of Jess Picken too)....

Chalk streams are highly important ecosystems and are a fundamental component of the landscape in the south and east of England. They are hotspots of ecological diversity and support important fisheries for trout and dace amongst others. However, the water that feeds chalk streams originates from groundwater, which is under increasing pressure from abstraction to supply our expanding urban populations. This conflict puts chalk streams squarely in the sights of environmental regulators and water companies as they try to find the best ways to preserve the ecology and the water supply. Hence, my project is sponsored by Affinity Water, and the Environment Agency, and is a part of Cranfield University’s Industrial Partnership PhD studentship programme.