Penny Johnes

@pennyjohnes.bsky.social

Professor of Biogeochemistry, UBris. Researches freshwater nutrient pollution and biodiversity loss in lakes, rivers and wetlands, and mitigation strategies. Nitrogen, phosphorus, carbon, isotopes, dissolved organic matter. ORCiD: 0000-0003-1605-6896

Challenging but fun @erc.europa.eu and @ukri.org science now underway! We next add snails to the jars at 96 h, and return to collect them with remaining biofilms and bryophytes at 192 h. Looking forward to @mgenner.bsky.social joining us at 192 h to sample for our omics work. Roles advertised soon!

programme.here

ERC REFRESH programme@ercrefresh.bsky.social · last yr.

Four time points out of 6 completed in our first experiment (chalk stream) and it's all going well. Next stop is deployment of the biofilm frames in our clay stream to develop biofilms for experiment 2 in 3 weeks time. Great help from @sydneyenns.bsky.social from our @ukri.org QUANTUM team. 🧪

PI setting up for 48 h sampling at our chalk stream site.

Our team of 3 PDRAs, 3 research techs and 3 PhD students (5 still tba) will work with me, @mgenner.bsky.social & Mark Beaumont of @bristoluni.bsky.social Biological Sciences, and OGU (Ian Bull), @ukceh.bsky.social Dan Read, Ellie Mackay, Daren Gooddy, @bangoruniversity.bsky.social (Davey Jones).

ERC REFRESH programme@ercrefresh.bsky.social · last yr.

Follow the team @ercrefresh.bsky.social as we investigate controls on rates & pathways of DOM uptake into stream foodwebs. This week we ran the first of 3 experiments exploring if environmental character, warming or velocity affect uptake this week. Chalk stream first, then clay stream, then peat! 🧪

Meet the team! Drs Charlotte Briddon and @jameslmcdonald.bsky.social, working on setting up the motors to drive the paddles in our warming (bubble wrap jackets, elevated higher in the water column) and warming plus high (double the rpm) flow velocity experiment. Further along, Dr @acastrocastellon.bsky.social from our @ukri.org NERC QUANTUM programme is setting up the jars for our ambient temperature with stirring experiment in this classic chalk stream. The catchment comprises calcium carbonate rich chalk, flows to the river are dominated by groundwater and deeper throughflow, and the stream ecosystem supports Ranunculus spp. (water crowfoot), Callitriche spp. (starwort) and Rorippa nasturtium-aquaticum (watercress) along with a native brown trout population. How will biotic response rates to isotope dosing of 13C15N labelled compounds in this alkaline, and gin-clear stream contrast with those in a more turbid clay stream (experiment 2) and dystrophic peatland stream (experiment 3). We look forward to finding out!

We've now completed our QUANTUM sampling at 33/60 sites, in SW of England, W England and Wales. Next stop N England and Scotland! By focusing on streams draining sheep, beef and dairy farmland, we are building a national picture of their impacts on UK river water quality to better inform policy.🧪

Lowland sheep impacts on streams sampled in SW England in our @ukri.org QUANTUM programme, with help from @a.castrocastellon.bsky.socialBeef cattle typically (like sheep) have direct access to watercourses where there is defecation in the channel and poaching of stream bank sediments, contributing to a high risk of contaminant transfer to streams. We are testing samples to determine their ecotoxin, pathogen, nutrient and organic matter composition.In around 50% of dairy farmed catchments, outdoor-grazed livestock are able to directly access streams. This leads to the same impacts as in beef cattle systems. In the other 50%, where animals are housed, water is abstracted to provide the cows with the capacity to produce milk. The average production rate is 22 litres per cow per day, with some high yielding cows producting much more.  If a farmer has a herd of 500 cows, this can amount to over 11000 litres of water per farm, exported from the catchment every day in the form of milk or milk products.  As a result where there are large commercial herds kept indoors streams often run bone dry or at very low flows in the summer months, reducing their dilution capacity for contaminants, increasing environmental exposure rates for stream biota, and making the stream ecosystem much more susceptible to climate warming effects.

As we finish our NERC QUANTUM field experiments and move on to upscaling and modelling work at national scale, we'd like to thank the residents of Rickford and our hugely helpful farmers, Paul and Roger Keel for their support. We'll return in the autumn to tell you what we've found!

Roger Keel, ready to repair the fencing in our enclosure prior to letting the extensive beef cattle back in to graze off the lush grass on our slurry amended plots. @acastrocastellon.bsky.social, @jameslmcdonald.bsky.social, @bristoluni.bsky.socialPaul and Roger Keel in conversation with Catchment Sensitive Farming officers at our autumn stakeholder event.Paul in conversation with Ed Fredenham of Bristol Water, during our autumn stakeholder event.

Last day in the field, returning our NERC QUANTUM field kit to the @bristoluni.bsky.social Fenswood field store where we bumped into our Aviation Engineering colleagues flying drones. They kindly agreed to fly over our field site producing aerial images for our future presentations. Great teamwork!🧪

Aviation Engineering PhD students from University of Bristol, flying a drone over our field site to capture aerial images of the impacts of slurry amendments on vegetation growth.  Very grateful to them, as we interrupted them at their summer BBQ and drone festival. Good spot by our new research team member, @jameslmcdonald.bsky.social‬Drone at the field site, set up to capture aerial and multi-spectral data.  Drone flying over our field site at Rickford, N Somerset. @acastrocastellon.bsky.social, @jameslmcdonald.bsky.social‬ Kilian Meier, 2nd year PhD student in the @bristoluni.sky.social Aviation Engineering group, flying a drone over our field site at Rickford, N Somerset.