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Where is my nearest salt marsh?

Find your nearest salt marsh using the interactive map here. The map also shows where volunteers are currently active.


Where can I find my local tide times?

There are several websites that provide local tide times. Our favorite is the BBC Tide Tables. Simply select your region to the left of the UK map and find a nearby harbour which has tide time data. Note that you can’t get tidal predictions for every location along the coast – use the nearest harbour to your marsh. Before you visit the marsh, make a note of when high and low tides are, and whether it’s a Neap or Spring tide. Visit the marsh 1 hour after high tide, so you have plenty of time to complete a survey, and leave 2 hours before the next high tide to make sure you can easily leave the marsh.


Where can I download the Saltmarsh App?

The app is downloaded directly on your smartphone, either via the App Store on iOS, or via Google Play on Android. More information about the App can be found here.

Do I need an internet connection to use the Saltmarsh App?

No. You only need an internet connection in order to upload the data after you’ve gathered it. This can be done when you get home, for example.

Do I need permission to work on the marsh?

Yes. Marshes are the property of landowners and are often protected under law. We kindly ask that you contact the landowner to ask for permission to complete a survey on their marsh. We can help you identify the landowner if needed. We have contacted the government bodies responsible for protecting marshes (Natural England, Scottish Natural Heritage, and Natural Resources Wales) asking for consent to work on protected sites on your behalf. For protected marshes in England, we include a consent form in each survey pack and ask that volunteers have the form signed and dated by the landowner before being returned to Natural England.

Will I risk disturbing birds when I visit the marsh?

You may disturb breeding and roosting birds when you visit the marsh. The survey is fairly non-intrusive, since it only takes a couple of hours to complete. You can reduce the risk of disturbing birds by following the same route on and off the marsh, and avoid criss-crossing the marsh as you explore. Keep the number of people visiting the marsh to 2-3 individuals, and don’t bring along a dog. If your marsh is part of a nature reserve, seek advice from the reserve manager on how to minimise disturbance.

When should I do the survey?

Between August and October when it’s still easy to identify plants from the photographs you’ll take


Is it safe to walk on salt marshes?

Yes, if you take proper precaution. Always make sure that:

  1. If applicable, you have been given permission from the land owner to access the marsh

  2. You have appropriate equipment including sturdy waterproof footwear, warm layers, waterproof clothing, sun hat, suncream, water, and a fully-charged mobile phone

  3. You have checked the local weather forecast

  4. You have checked the condition of the tide

  5. If going to the marsh alone, you have told someone else where you’re going and when you’ll be back

  6. You have clear access from the marsh back to the road. Don’t be tempted to cross too many creeks – these can fill with the incoming tide and cut you off if you’re not careful!


For more information about how to safely conduct a survey, visit survey safety and read the risk assessment. 


I can’t reach the seaward end of the salt marsh, what should I do?

Don’t worry if you can’t collect all 5 samples. Even having a few samples at the top of the marsh is still useful.

I know of a marsh that’s not on the interactive map. Can I sample that one instead?

Don’t worry if you can’t collect all 5 samples. Even having a few samples at the top of the marsh is still useful. Yes. Feel free to pick another marsh other than the one we suggest to you, but please let us know you plan to use a different marsh at


Do I have to follow a perfectly straight transect?

No. There might be a creek in the way, or an area that’s fenced off for livestock. Try and find a spot on the marsh where you can sample in as straight a line as possible.  


The syringe is too hard to push into the ground, what should I do?

Sometimes the saltmarsh soil can be difficult to core in if it’s too dry, too compacted, or has too many roots. Try twisting the syringe barrel back-and-forth as you push it into the ground. You can also use the heel of your foot to gently push to corer into the ground.


Does the syringe have to be completely filled?

Ideally yes, but you may find that the top of the core has sunk relative to the surrounding marsh after pushing the syringe chamber all the way into the ground. This is because the soil gets compacted as the syringe chamber goes in. You’re welcome to try and collect another core nearby to see if the compaction is lower – otherwise, leave it as it is and bag the core.


How far apart from each other should the syringe cores be?

Try to collect a cluster of three syringe cores from the top, middle, and bottom of the marsh (9 in total; see step 3). The distance between points in a cluster should be about 10 metres. The distance between clusters will vary depending on the width of the marsh you visit.


Why are the syringes colour-coded?

This helps us to match the soil core to the photograph taken as part of the survey, so that we can identify which marsh plants are nearby and it was collected.

Why are the Ziplock bags numbered?

Each marsh has been assigned a unique ID. The ziplock bag denotes which marsh the cores come from. The coloured syringe helps us separate out which core belongs to which photograph/set of coordinates.

The envelope doesn’t fit in the letterbox, what should I do?

When the envelopes are filled with the cut syringe cores, they do become slightly bulky and may not fit in all letterboxes. If so, we would be very grateful if you could take it to your local post office to post.


Do I have to pay to send the soil cores?

No. Each envelope comes with a stamp and a return address. Simply place your samples back into the padded envelope we sent you, stick the stamp and return address onto the envelope, and post it in a letterbox.


How will the data I collect be used?

Once you post the samples back to us, our team at St Andrews University will measure how compact the soil is (its ‘bulk density’) and measure how much carbon it holds (measured by burning the sediment in a furnace. The change in weight will tell us how much of that soil was organic carbon material). Our team in Bangor will identify the plant species in your photo, and extract the coordinates linked to that image. We’ll combine the data to get an idea of how soil carbon content changes across the UK, and if this can be explained by changes in vegetation type. 


Do I get credited for doing this work?

Yes. Every volunteer will be acknowledged in any output we create (be that in publications, presentations, or outreach activities).

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