WTT Blog

Malcolm Greenhalgh's September Blog

Posted on October 11, 2017

SEPTEMBER 2017

I am writing this blog on the 28th, and in the 28 days thus far we here in northwest England have had rain on 25 of them, thus ensuring that the year’s trout season has been the worst I have known over the past 45 years.

How do chalk stream fish respond to flow and habitat restoration?

Posted on October 04, 2017

How do chalk stream fish respond to flow and habitat restoration?

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.

World Rivers Day 2017 (Grantham)

Posted on September 28, 2017

I had the great pleasure of participating in a fantastic event in the lovely setting of Wyndham Park in Grantham on the River Witham for World Rivers Day 2017.

As well as drawing attention (and deserved accolades) to the habitat improvement works carried out in partnerships between Lincolnshire Rivers Trust, Environment Agency and the good ol' Wild Trout Trust, it was a great chance for enjoyment and learning.

Tons of stalls, tours of the habitat works, invertebrate samples in tanks, Model Rivers, Fly casting with Peter Arfield and Tenkara casting with myself - even an epic pooh sticks race off the bridge in the park. The weather was kind too.



Throughout the day there was a steady stream of visitors either strolling through the park and becoming engaged in the activities or folks who had seen the social media advertising and come along especially.



And, in the course of taking a walk along the river with some particularly interested (and interesting folks)...

First Survey Record of Wild Trout Returning to Lyme Brook Habitat Works Site!

Posted on September 11, 2017

You may have seen the first three phases of works on the middle reaches of the Lyme Brook (shown in previous blogs Here and Here) from project works that began in 2015...

Well although the first surveys after that work found some nice coarse fish populations - there was no cold hard evidence that any trout had found the newly-improved habitat...Until now!
EA Midlands Survey Teams reportedly found "More than one...but less than five" wild trout like this one on Sept. 7th 2017I received a phone call today from Matt Lawrence who is the EA's Catchment Host for the Trent Valley Catchment Partnership (with key partners Groundwork West Midlands and the Wild Trout Trust who conceived and delivered the habitat works). Matt told me that he'd had some exciting preliminary reports from a EA Midlands fisheries surveys team. Their survey on 7th September had caught several wild trout as part of their sample on the habitat works site.
These are the first modern records of trout in the brook and is also the exciting news that we have been waiting for on these first phases of work to create...

Re-Meandering The Upper Lyme Brook

Posted on August 30, 2017

Take a bow Groundwork West Midlands (particularly Richard, Francesca & Chris) - myself and Tim Jacklin from team Wild Trout Trust really enjoyed working with you and the great volunteers from the National Citizens Service.

Together we turned what was one of possibly the straightest of any straightened sections of brook into a section with quite a lot more variety. This is what the section looked like in winter:

Though, in high summer, almost none of the water was actually visible when the 360 digger arrived on site ahead of the volunteers (I wanted a day to sculpt the basic shape of the brook before Tim, Francesca, Chris and the volunteers came on site for days 2 and 3).
So, once we found the wet bit of the river, operator David and me could start to collaborate in remodelling the stream. I'm always in awe of how much control these folks have with a machine and bucket - and we soon got into a great working and communication routine. It is fantastic to see the physical changes to the river taking shape before your eyes -...

Genetics to underpin effective management

Posted on August 30, 2017

Genetics to underpin effective management

As WTT Conservation Officers, we are asked to make assessments on what is good and bad habitat for trout populations based upon visual observation and expert judgement; this is the basis of a typical Advisory Visit Report. If we had the time and resource, we'd look to the fish themselves to tell us! In this latest blog from current researchers, Jess Fordyce from the University of Glasgow Scottish Centre for Ecology and the Natural Environment outlines how an understanding of the genetic diversity within a catchment can inform more efficient management strategies for safe-gaurding trout populations.

The brown trout, Salmo trutta, is an extremely diverse species in terms of behaviour, physiology, genetics and morphology. Brown trout can adopt a range of life-history strategies which include freshwater residency in rivers and/or lakes, or anadromy – the movement from fresh to saltwater and back again (ie sea trout). The diversity of brown trout in terms of genetics and morphology was the focus of my PhD which was funded by an EU project called IBIS (Integrated Aquatic Resource Management Between Ireland, Northern Ireland and Scotland) and the Atlantic Salmon Trust. My study site was the Foyle catchment which is a large dendritic (branching) system with an area of around 4500km2 located in both Ireland and Northern Ireland. This catchment is managed by the Loughs Agency. Like other catchments across Britain and Ireland, sea trout numbers have been sharply declining over the last few decades. Therefore, it is important to understand the genetic population structuring of brown trout (the pattern of genetic variation) and which environmental factors shape such structuring. From this information, it is possible to detect exactly which populations contribute significantly to the production of sea trout and hence provide focused management.

Reducing Flooding & Creating Urban Oasis (and a Home for Wild Trout)

Posted on August 18, 2017

You probably know the basic story now (e.g. This Yorkshire Post article), but whether you do or you don't, it is worth reflecting that this whole project was given the go-ahead because it tackled a number of critical problems.

A big one was the flood risk posed by blockages in the original culvert - but Sheffield CC went beyond that and created an "amphitheatre" shaped park that actually created even more flood-water storage than an open channel would. They didn't stop there though, and with the help of multiple partners (including us at the Wild Trout Trust, the Environment Agency and also community volunteers from SPRITE as well as local offices such as the prestigious Jaywing advertising agency), a valuable urban green-space was created. This video explains all that (and also has a lush clip of a rising trout that made my day when I filmed it):

Here's the really exciting thing for me though, as well as the aesthetic amenity value of the formal planting in the park's landscape, there was also a genuine will to have meaningful ecological benefits too. This is possibly one of the Pocket Park's greatest successes - the blending of formal/aesthetic planting...

Stocked fish or native invader?

Posted on August 17, 2017

Anyone with an interest in rivers or lakes and the life within them, be it from a conservation, management, or angling perspective (and of course those three are not mutually exclusive) will be aware of invasive non-native species (INNS), the impacts they may cause in certain situations, and the importance of biosecurity. Ecologists with a particular interest in invaders differentiate between non-native (i.e. those species introduced beyond their original distribution range, a pertinent example being pink salmon) and native invaders (referring to species that add to existing or establish new populations within their native range). The artificial stocking of salmonids into waterbodies is one such example of the deliberate introduction of native invaders, to allegedly enhance commercial and recreational fisheries, as well as for conservation purposes in some instances. The evidence accruing as to the benefits of this approach makes interesting reading.

In 2016, Buoro and colleagues used the global-scale introductions of salmon and trout as a robust biological model (i.e. lots of studies with plenty of data to analyse) to investigate the ecological effects of changing intraspecific (within species; e.g. stocking farmed brown trout in to rivers containing wild brown trout populations) and interspecific (between species; e.g. stocking rainbow trout into lakes with Arctic char) diversity. The enormity of the dataset collated from the literature allowed them to look at various levels of organisation which introduces a lot of complexity. However, the take home message was that, overall, introduction of native invaders resulted in stronger ecological effects than those associated with changes in interspecific diversity caused by non-native species.

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.

Habitat to Help Trout and Native Crayfish in a Midlands Brook

Posted on July 26, 2017

I was recently able to use the Trout in the Town project to provide two days of training in habitat work for the Friends of Bilbrook (find them on Facebook here: https://www.facebook.com/Bilbrookfriends/ ).


We used some very simple techniques of woody material introduction and stabilisation to help create submerged "cover" habitat for fish (and hopefully the native crayfish that have been recorded in the brook). Some simple tweaks to those techniques also helped to promote more diverse depth over the cross-section of the brook at selected points.

At the same time as creating localised bedscour - the installed material also encourage patches of sediment deposition. The combination of those actions produce a pattern of separation between areas of fine silt and coarser bed material in a patchwork fashion. In this way, a greater variety of micro-habitats are created and this creates many more opportunities for aquatic species. At the same time, it also creates the variety needed for different critical life-cycle stages within individual species such as trout.

Because the materials for the woody material introduction and stabilisation were...

Low flows and salmonid rivers: an update

Posted on July 14, 2017

Low flows and salmonid rivers: an update

Jess Picken was the first to contribute to our new series of guest blogs in which she outlined plans for her PhD. And clearly, she has been busy! She is back with an update already...

To recap on my previous post, numerous studies have reported that low flow reduces the density of salmonids within streams. What is not so well-known is what, or how, other parts of the salmonids’ ecosystem are also affected by low flow. Riverflies and other aquatic macroinvertebrates make up a large proportion of juvenile salmonid diet, which is subsequently reflected in salmonid growth rate, condition and survival. Understanding how the availability of these macroinvertebrates changes with reduced summer flow is important to help conserve fish species of high UK and European importance.

My life at the moment... macroinvertebrates down the microscope!

Malcolm Greenhalgh's June Blog

Posted on July 11, 2017

In this blog post, WTT Vice President Malcolm Greenhalgh reflects on climate, weather, pollution and sea trout fishing prospects for July. Malcolm lives in the north west of England, not dry dustbowl that is the south east !

I am now not only a believer in global climate change, but I am 90% sure that Homo sapiens is probably responsible for the change that has occurred since at least the middle of the 20th century.

Here’s one I made earlier….The Hoffer Brook

Posted on June 26, 2017

Here’s one I made earlier….The Hoffer Brook

By Rob Mungovan, WTT Conservation Officer for East Anglia and Central Region

As a new starter my colleagues have been interested to know what projects I’ve already delivered whilst working as a local authority ecologist. I’m able to explain all the usual techniques of channel narrowing and bed raising but one novel approach keeps getting more questions. So the clearest way to explain it is to write it down, and include some pictures. The one below hows the restored brook. 

The restored (or re-built?) brook. The new bed is suspended over soft silt through the use of grass mesh.

What makes an apex predator: the ferox trout

Posted on June 05, 2017

What makes an apex predator: the ferox trout

I have to admit, the topic of this research really floats my boat (as you may have noticed from the latest Salmo Science Spot)…. I spent several years trying to convince people that perched at the top of the Loch Ness food web was not an elusive plesiosaur but something much, much more sexy. Ferox! So I’m really pleased that the newly doctored Martin Hughes has taken time out to precis his completed PhD, but it does mean I’ll have to review the WTT ferox pages with his new findings.

The brown trout, Salmo trutta, is an incredibly diverse species. Individuals from the same population can adopt completely different life history strategies, which are often given vernacular names. For example, some S. trutta remain in small freshwater streams their entire lives; these are referred to as resident trout. Others migrate into large rivers or lakes to complete their life cycle and retain the name brown trout, but some that migrate into estuarine waters are referred to as slob trout and others that fully migrate into marine waters before returning to natal streams to spawn are called sea trout. One relatively understudied life history is that of ferox trout. ‘Ferox’ which is Latin for ‘Fierce’ is aptly used for these large piscivorous trout which can grow to large size (14kg UK record) and are exceptionally long lived (23 years oldest UK record- reports of 39 years old in Norway). Their impressive growth potential and life span combined with their rarity and near mythical status only adds to the allure to both anglers and scientists alike.