Ageing Mussels

Simon Hirst – River Esk Project Officer

As mentioned previously, the River Esk in the North York Moors is the only river in Yorkshire with a Freshwater pearl mussel population Margaritifera margaritifera. The population is estimated to be comprised of approximately 1,000 individuals and is in drastic decline, so much so that it is on the verge of extinction. The decline is due to a number of linked causes such as water pollution, choking of the river bed by sediment build-up, deterioration in fish numbers and habitat degradation.

A dense bed of healthy adult mussels in Scotland. Copyright Sue Scott - SNH,

We’re working to improve the riparian habitat and so help secure the local population of Freshwater pearl mussel in the River Esk. We recently sent a sample of mussel shells from the Esk* over to the Swedish Natural History Museum in Stockholm, in order to determine the age of the mussels in the River Esk. The maximum age of Freshwater pearl mussels in the wild has been shown to vary considerably, from a low of 35 years in Spain (warmer, lower latitude rivers) to over 200 years in arctic areas (colder and high latitude rivers). Information from the ageing study would tell us how long we have left to save the Esk population from extinction and help identify the approximate time when the River Esk mussel population went into decline.

Dr Elena Dunca from the Swedish Natural History Museum sectioned (cut though) the shells supplied and then counted the growth lines on the mussel shell using a high powered microscope.

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Growth lines visible on the freshwater pearl mussel shell.

Esk FWPM - Age and length graph - Swedish Natural History Museum

This age/length graph will allow us to age fairly accurately any mussels we find in the wild in the future just by measuring them.

A total of 10 shells were aged by Dr Dunca, and the graph below shows that the mussels sent to Sweden ranged in age from 45 to 88 years of age.  The mussels in the River Esk also showed normal growth rates.

Esk FWPM - Length frequency graph - Swedish Natural History Museum

Length frequency graph of mussels in the River Esk

The smallest live mussel we have found in the Esk up to now was 75mm (approximately 28 years of age). This means the last time the Esk mussels reproduced successfully in the wild was in the late 1980s. The largest mussel we have found in the Esk was 156mm (approximately 100 years of age), which means it was born around the time of the First World War. The vast majority of the mussels are around the 130mm-140mm size range (approximately 80 years of age). We now know for scientific certainty that the Esk has an ageing population in need of help!

The best hope for our mussels is for them to start to successfully reproduce again. We’re working with the Freshwater Biological Association (FBA) who are carrying out captive breeding work in the Lake District. We hope to re-introduce the captive bred young Esk mussels from the FBA Facility back into the Esk once the riparian habitat is restored enough to sustain them, and so ultimately stop this species from becoming extinct in the wild (of Yorkshire).

* Please note – No mussels were harmed in the making of this study! We used empty shells that were found on the banks of the Esk.

Thanks to our funders at Biffa Award, for their support to carry out this vital research work.

Biffa

Biffa Award is a multi-million pound fund that helps to build communities and transform lives through awarding grants to community and environmental projects across the UK, as part of the Landfill Communities Fund.

Another crustacean crisis

Due to the sustained period of dry and hot weather recently an emergency rescue was required last week. We’ve blogged about similar operations in the previous two years, where the River Rye in Duncombe Park, Helmsley tends to dry up during summer months because of numerous natural sink holes. This leaves large numbers of fish and other water-dependent creatures stranded in shrinking pools. This year the crisis was particularly acute with no effective quantities of rain in the short term weather forecast.

The River Rye is one of only a few rivers in the North East of England which supports a population of White-clawed crayfish (Austropotamobius pallipes). The species are “Globally Threatened” according to the IUCN’s Red List of Threatened Species. They are the only native crayfish in the UK, and the majority of populations here are declining due to competition from introduced crayfish species, crayfish plague and water pollution.

So last week, alerted by the local fishing club, staff and apprentices turned up in force under the supervision of Simon our River Esk Officer (because he has a licence to handle the protected crayfish). Using gloves and buckets everyone scooped up what creatures they could and then relayed the buckets upstream to where the collected creatures were released back into the River Rye, safely above the sink holes. Over 500 White-clawed crayfish were rescued along with a variety of fish species – Bullhead (250+), Brown Trout (20+), Stone Loach (20+) and Brook Lamprey (50+).

White-clawed crayfish rescue, River Rye, July 2016. Drought conditions. Copyright NYMNPA.

White-clawed crayfish rescue, River Rye, July 2016. Drought conditions. Copyright NYMNPA.White-clawed crayfish rescue, River Rye, July 2016. Bucket collection. Copyright NYMNPA.White-clawed crayfish rescue, River Rye, July 2016. Cooling buckets to adjust water temperature before releasing. Copyright NYMNPA.White-clawed crayfish rescue, River Rye, July 2016. Releasing White-clawed crayfish (adult). Copyright NYMNPA.White-clawed crayfish rescue, River Rye, July 2016. Releasing White-clawed crayfish (female carrying young). Copyright NYMNPA.The translocated fish and White-clawed crayfish will inevitably recolonise the dried up section once the flows return to normal. The habitat here is ordinarily really good, the only down side being the disastrous disappearing water phenomenon during the summer.

The future for local White-clawed crayfish is somewhat uncertain. Further survey work is needed to establish the location of populations in the Rye, in order to help direct and prioritise effective measures to bolster the populations and make them more resilient to climate change risks like flash flooding and drought crisis. Rescue events may need to become a regularised occurrence.

We have no current evidence that the introduced Signal crayfish, which are such a threat to the White-clawed crayfish, have made it into the River Rye yet. Elsewhere in the country ark sites have been established, away from river networks, where populations of White-clawed crayfish can be introduced and kept in blissful isolation. If feasible here this could be a useful additional safety measure, but the first priority is keeping the Rye White-clawed crayfish populations in the river for as long as possible and conserving this particular element of our local natural heritage.

Mastering the river environment

Rosie Nelson – Masters Student

I’m Rosie and I’m two months in to my research masters at Durham University, kindly sponsored through the North York Moors National Park Authority with funding from Biffa Award. Since my second year of university, I’ve known I wanted to work with (or in) rivers, and this masters should help me get one step closer to achieving that.

I’m investigating the water quality of three hotspot tributaries of the Esk: Danby Beck, Toad Beck and Great Fryup Beck, in the hope to identify point source pollution and its cause/s. Ensuring good water quality is crucial for the health of the river and paramount for the Freshwater pearl mussels that live there. The key contaminants I will be looking at are Phosphate, Nitrogen and Ammonium. The Esk currently exceeds the thresholds for these three elements/compounds which pollute the river environment and damage freshwater systems. I hope that through my data collection and analysis I can identify point source pollution issues and help reduce the contaminants entering the Esk. Hopefully making the Freshwater pearl mussels a little bit happier!

Being based in the Authority’s Conservation Department for at least one day a week is proving to be very helpful. Not only am I extremely productive, but I’m also learning what it’s like to work in a conservation environment – something I definitely hope to be doing in the future.

At the start of May, I got to join in with the Salmon in the Classroom project alongside Simon the River Esk Project Officer and Alex the Catchment Partnership Officer. Simon taught me how to kick sample, something I really wish I’d known how to do before. You get into a safe watercourse with a fishing net, place the net downstream of you and kick the river bed. After several kicks, you empty the net into a bucket of water and hope you’ve found things, like invertebrates and potentially even fish! After several kick samples, we had collected enough living invertebrates for the children and me to identify.

Salmon in the Classroom - this is me and the children identifying what we found - check out my wicked waders! Copyright NYMNPA.

Last week I went out with Alex in Glaisdale in the Esk Catchment, and aside from us both getting stuck in the mud I had a great day (luckily I was holding a spade and could dig us out!). In the morning we visited a farm which is perfect for bank stabilisation work to lessen the amount of sedimentation. In the afternoon at a different site in the dale we planted trees and sowed grass seed to re-vegetate where a new drinking bay had been installed (to provide water for stock which are now fenced off from the river).

Well that’s just a snippet of the things I’ve been getting up to in the past couple of months, not forgetting reading as much as physically possible about anything and everything river related!

Biffa

In Extremis update

From Eloy at the Freshwater Biological Association Facility:

The Esk mussels are settling in. They are buried and stable, not moving that much, as if they had found their space in the cage.

Recently translocated mussels from the Esk now at the FBA Facility - copyright FBA

 

In Extremis

Simon Hirst – River Esk Project Officer

As mentioned before on this Blog, the River Esk in the North York Moors is the only river in Yorkshire with a Freshwater pearl mussel (Margaritifera margaritifera) population. Our population is in drastic decline – currently it is estimated there are approximately 1,000 individuals, all adults.

We’re part of a national project (funded by Biffa Award) to conserve the populations of Freshwater pearl mussel in England. Nine years ago a number of the adult mussels were collected from the Esk and moved to the Freshwater Biological Association’s Facility in the Lake District. A couple of weeks ago, early one morning, Eloy from the Association and I collected another 20 and took them across to join the others at the Facility 130 miles away.

Eloy preparing the FPM transportation unit ie a cool box - copyright Simon Hirst, NYMNPA

River Esk substrate to take to the FBA Facility - home comforts for the Esk mussels - copyright Simon Hirst, NYMNPAThe lid of the cool box had to be left open so oxygen exchange could occur during the 3 hour journey - so the box was thoroughly jammed in - copyright Simon Hirst, NYMNPA

Safely arrived at the FBA Facility - acclimatising the Esk mussels to their new home - copyright Simon Hirst, NYMNPAThe idea is the translocated adults breed and the Facility then rear the captive juvenile mussels with the ultimate idea of reintroducing the young mussels back into their native rivers. In the meantime we’re continuing to tackle the problems that have had and continue to have such a detrimental effect on the mussels. So on the Esk we’re working in partnership to improve the riparian habitat in order to increase water quality and vitally reduce the amount of suffocating sediment so that the river becomes a suitable release site and juvenile mussels have a chance of surviving. Improving the river habitat also benefits the migratory fish which are such a vital part of the mussels’ lifecycle.

We’re trying everything we can to help the Esk population and give it the best chance of survival. Mussels can live to be over 100 but if there are no juveniles, slowly but surely the Freshwater pearl mussel will become locally extinct.

Biffa

Positive messaging from the Midlands

John Beech – Land Management Adviser

I’ve recently returned from the lowlands of Leicestershire and three days training with the Game and Wildlife Conservation Trust (GWCT). The BASIS Conservation Management course was highly informative, well led and thoroughly enjoyed by all who took part.

The Trust’s own Allerton Farm Project at Loddington  was the venue for the course – a 272 hectare mixed farm enterprise that is innovative in its approach to conservation management. One of the first things I noticed when I drove into the village was the amount of farmland birdlife, so I knew somebody was doing something right in terms of conservation land management.

The course covered all of the different elements required when managing farmland for conservation and wildlife, alongside profit. We covered a multitude of subjects including Nitrate Vulnerable Zones, Minimum Tillage systems, Biobeds for pesticide removal, increasing farm energy efficiency, recent pesticide developments, Biodiversity 2020 strategy, Farm Assurance Schemes, Cross Compliance regulations, gamekeeping for wildlife management, maintaining soil sustainability, improving water quality, tackling non-native invasive species, and managing farm woodlands. Starting off in the classroom the lessons were then observed in practice across the farm.

Gamekeeping techniques in practice at Loddington - copyright John Beech, NYMNPA

Settlement ponds seperate out soil particles and reduce run off before water returns to the ditch system at Loddington - copyright John Beech, NYMNPA

The Allerton Farm Project targets management for specific (Red and Amber Status) species such as Grey Partridge, Turtle Dove, Bullfinch, Tree Sparrow and Skylark. Cultivating a mixture of high hedges, managed grass buffer strips, plots for nesting in amongst the cereal crop as well as putting up nest boxes, has added to the aggregate of necessary habitats and increased habitat diversity on the farm.

The farm has benefited from a number of agri-environment grants over the years but is by no means reliant on these. If there is something that an agri-environment scheme promotes but doesn’t fit in with farm practices it isn’t taken up. However this is relatively rare, and the general thinking is that farms should take advantage of these schemes where possible and can do so with a little assistance.

Energy efficiency and recycling are common threads within sustainable farm management and our classroom for the three days was a good example of an energy efficient building: surrounded and insulated by straw bales, heated by a biomass boiler and lit via solar panels on the roof.

The afternoon of Day Three meant sitting a two and a half hour exam – as a middle aged man that’s something that some of us on the course hadn’t done for many a year. I’ll find out how well I’ve done when the results come through in a few weeks!

The Allerton Farm Project is a great example of how mixed farming and wildlife conservation can work in practice, and benefit species recovery and landscape enhancement.

Beetle Bank seeded with a mix of species including Teasel, Yarrow and Knapweed to benefit farmland birds at Loddington - copyright John Beech, NYMNPA

All in all, I learnt a lot and one of the positive messages I’m taking away is that on every farm there is always something that can be done to benefit wildlife without having to lose out on money in the process. I’ll carry these thoughts with me as I start back on my day job in the North York Moors, refreshed and revitalised from my three days at Loddington.

The Allerton Farm Project has its own Research Blog.

Carry on saving the mussels

Simon Hirst – River Esk Project Officer

Our work to safeguard Yorkshire’s last remaining population of Freshwater pearl mussels has received a £300,000 grant from Biffa Award. The River Esk in the north of the National Park is the only river in Yorkshire which still has a Freshwater pearl mussel Margaritifera margaritifera population. The population is estimated to be approximately 1,000 individuals and is in drastic decline. Pollution and sediment build up, decline in fish populations and habitat degradation are all reasons for this.

River Esk Freshwater Pearl Mussel ~40 year old - NYMNPA

The grant received is part of a larger £1.5 million Biffa Award project (2015 – 2018) led by the Freshwater Biological Association that will also see river restoration carried out in river catchments in Cumbria and Devon where freshwater pearl mussels also survive.

One of the key elements of the project will be sharing knowledge and best practice with landowners, the local community and other conservation groups to help give the mussels a more sustainable future. The project will work with farmers to reduce sediment and nutrient input into the Esk, and volunteer groups and angling clubs will be involved in monitoring work such as sampling invertebrate life throughout the river and also restoration work such as planting trees along the river bank and tackling non-native invasive species. The funding will also help sponsor a Master of Research degree at Durham University, which will look at water quality throughout the catchment.

On top of this local effort, the national project will focus on improving the reproductive success of the Freshwater pearl mussel through the Freshwater Biological Association’s captive breeding programme. In 2007, mussels from the Esk were taken to an ‘ark’ facility in the Lake District which houses and breeds populations from threatened Freshwater pearl mussel rivers in England. We’re aiming for sections of the Esk to have been restored enough by 2018 to provide suitable habitat to accommodate the return of the juvenile mussels.

This is a brilliant opportunity for people from different backgrounds to get involved in the conservation of a rare and valuable species. They may not be cute and cuddly but freshwater pearl mussels are an important indicator species; if we get conditions right for them, it will have positive knock on benefits for a range of other wildlife such as otters, Atlantic salmon, dippers and kingfishers.

BiffaBiffa Award is a multi-million pound fund that helps to build communities and transform lives through awarding grants to community and environmental projects across the UK, as part of the Landfill Communities Fund. More information on the award is available at www.biffa-award.org.

Juvenile mussel at captive breeding facility - copyight Louise Lavictoire FBA

River Esk research work - NYMNPA

Encystement project - NYMNPA

This new project which started in March builds on the WREN funded three year Freshwater Pearl Mussel project which finished in February.  This project had similar aims to the new project – to educate and involve people, and to carry out restoration work to limit nutrient and silt input into watercourses which damages spawning gravels and juvenile mussel habitats.

WREN Project Outputs

WREN FWPM Project - river bank fencing - NYMNPAWREN FWPM Project - river bank fencing - NYMNPA WREN FWPM Project - river bank fencing - NYMNPA

 

 

WREN FWPM Project - bank stabilisation - NYMNPAWREN FWPM Project - crossing point - NYMNPAWREN FWPM Project - buffer strip - NYMNPA

 

 

 

 

WREN FWPM Project - tree planting - NYMNPAWREN FWPM Project - trough installation - NYMNPA WREN FWPM Project - tree planting - NYMNPA

 

WREN FWPM Project - river bank fencing - NYMNPAWREN FWPM Project - new cattle watering point - NYMNPA
WREN FWPM Project - gateway improvement - NYMNPA

 

 

WREN FWPM Project - Himalayn balsam control - River Esk Volunteers Task - NYMNPA

As well as nutrient and sediment free water the best habitat for Freshwater pearl mussels is a boulder stabilised substrate with pockets of coarse sand and gravel for burrowing. Water quality monitoring equipment was installed at the key potential re-introduction site on the Esk to measure a variety of water quality parameters such as dissolved oxygen, nitrogen and pH. Redox surveys were carried out to assess juvenile pearl mussel habitat quality – redox surveys measure the water quality within the river gravels (where the young mussels live). One of the Esk sites which was surveyed had redox readings which were potentially suitable for young mussels (which is really positive news), and a few other sites are very close to being suitable.

logoWREN is a not-for-profit business that helps benefit the lives of people who live close to landfill sites by awarding grants for community, biodiversity and heritage projects.

 

Potential FWPM re-introduction site on River Esk - NYMNPAThis is a long term effort. By 2018 all the work and funding over the last 10 years will hopefully come to fruition and the Freshwater pearl mussel will have a sustainable future in the River Esk.

Cosseting coastal streams

John Beech – Land Management Adviser

Over the winter months and tree planting season as part of our on-going quest to promote habitat connectivity in the North York Moors we’ve been working on coastal streams and linking up bankside (riparian) woodlands. There are a number of these coastal streams that run down from the east edges of the moorland plateau and don’t merge with a river but instead each continue east and end up running into the North Sea along the North York Moors coast.

Some of these coastal stream catchments have persistent water quality issues. By judicious land management and habitat stimulus we can combine the two objectives (extend habitat connectivity AND improve water quality) and make best use of available knowledge, skills and resources. Stabilising and fencing off banks to minimise sedimentation and to keep stock out of the water, along with buffering agricultural run-off, can have extensive impacts downstream and on the coast where the streams meets the sea.

Bankside tree planting underway - NYMNPA

This has been a real partnership effort. The National Park Authority’s northern work force – with any luck, skilled environmental workers for the future, the Northern Apprentice Team – strove through the mud and planted a good mix of native trees and shrubs, whilst land managers installed the fencing. Together we managed to fence over 600 metres of land and plant around 1,000 trees in gaps alongside the watercourses.

View of tree planting and fencing work near Mickleby - NYMNPA

Thanks to everyone who contributed to this work, not least the Environment Agency who paid for materials through their Tree Mitigation Programme.

This isn’t a solution in itself, but it’s part of an expanding effort to tackle water quality problems. For information on Defra’s available advice and grants – see Catchment Sensitive Farming.

Pink peril

Kirsty Brown – Conservation Project Assistant

Himalayan balsam (Impatiens glandulifera) - NYMNPA

Himalayan Balsam (Impatiens glandulifera) in the UK can be a contentious plant – some people like it and some people loathe it. From a water quality point of view, it’s bad news.

Now in the winter months the detrimental effects of the species are obvious on bare unvegetated river banks where the invasive plant has died back and where it suppressed other vegetation during the summer which could have stabalised the bank, and so the soil from the banks crumbles and slips into the water and chokes the river habitat.

Because of this, the National Park has been tackling Himalayan balsam in Bilsdale, in the west of the North York Moors, since 2008. It’s a long term task.

A targeted top-down approach is being taken which started with the River Seph in the north, with the objective of eliminating Himalayan balsam from the uppermost reaches of the catchment by repeat control over and over again, and expanding slowly downstream and onto the River Rye. It’s this targeted concerted effort that can make a difference as it is the abundant seed released each year and carried downstream that means the balsam is so prolific and recalcitrant.

Over the last seven years contractors, land managers, volunteers and apprentice teams have been tackling the plant. Hand-pulling and strimming have been the only methods of control used, due to the proximity to the watercourse. Permission from the land owners and land managers along the banks has been vital, and the local Bilsdale Beacon newsletter has been used regularly to keep the wider local community informed.

The work is proving effective – in 2014 only a few Himalayan balsam plants were found along the River Seph and were easily hand pulled by our apprentices, at the same time the banks are becoming revegetated with native meadowsweet and willowherb. This is very encouraging and makes the aim of the project to eradicate Himalayan balsam from the Seph catchment and the stretch of the Rye catchment that lies within the National Park, seem actually possible. The efforts over the past seven years have made great inroads into achieving this aim, but there is still work to do.

River Rye in Duncombe Park - where Himalayan balsam is being tackled through a Higher Level Stewardship agri-environment agreement

 

Last year’s top 5 posts

Iron oxide running down walls inside abandoned mine - NYMNPA

1. Hangover from the past

Update posted by Emily just last week with a suggested Hangover cure

 

 

 

Philip Wilkinson, Westerdale - Ami Walker2. A week in the life of a Land Manager Adviser        

 

 

 

3. Peculiarity of Character: part 1 and part 2

11c 11a11b

In addition to the characterful structures mentioned previously – here are three photos of the faces of a stone near to Worm Sike Rigg – it’s inscribed to “G. BAKER AGED 68 YEARS WHO WAS LOST ON THE 5 OF DECEM 1878 AND WAS FOUND HERE ON THE 26 OF JANUARY 1879”. The supposition is G Baker died of exposure out on the moors and the stone was erected as a memorial to the man and the tragic event.

Heptageniid - Emily Collins

4. River Monsters

Emily is carrying on Sam’s good work – this is a photograph she’s taken of a Heptageniid down the end of a microscope.

 

Hovingham Market - Chris J Parker

 

5. 129 Projects in 129 Pictures

Following on from the previous North York Moors, Coast and Hills LEADER Programme which finished in 2013, we submitted a bid to Defra in September 2014 for a new LEADER Programme which would run from 2015 to 2021.

We’re just waiting to hear whether we have been successful, and we’ll share any news as soon as possible!

If we are successful, the new LEADER Programme will be looking for projects that generate jobs and support the local economy under the following six priority areas:

  • Increasing Farm Productivity
  • Micro and Small Enterprise and Farm Diversification
  • Rural Tourism
  • Rural Services
  • Cultural and Heritage Activity
  • Increasing Forestry Productivity

In the meantime we are working out how to approach these priorities and what we would like to fund over the next six years so we’ll be ready to go as soon as we find out if this area’s LEADER Programme is approved.  Keep in touch through our website, follow us on Twitter  and keep an eye on this Blog.    

Winter landscape - Lower Bilsdale - NYMNPAAnd if you’re wondering whether last year’s blatant attempt to get someone from Iceland to view our Blog succeeded – unfortunately not. But we won’t give up – við hlökkum til annars árs varðveislu í North York Moors þjóðgarðurinn og við munum tryggja að láta þig vita hvað við erum að gera í gegnum bloggið okkar.