The Big Beach Biodiversity Survey

While our sandy beaches may not be the most obvious place to record marine species, taking time to explore the species living on our beaches, and the remains of those cast up by the tide can provide a really useful picture of the biodiversity of the beach and the adjacent seas.

The Big Beach Biodiversity Survey is looking for volunteers to conduct a timed survey, recording bivalve shells and other flotsam cast up on the tide. We are asking you to record both live and dead animals and plants found on the beach. The dead animals will have originated from the adjacent sea area and can provide a really useful indication of the diversity of life living beneath the waves just off the shore.

Getting involved is easy and a The Big Beach Biodiversity Survey can be completed in as little as 30 minutes. All you need is a camera and a smart phone or paper recording sheet.

Pick a beach to survey

Any sandy or cobble beach will do. Do not include any areas of rocky shore as these should be surveyed using the Rocky Shore Safari survey method. Record the date and the location of the start point of your survey.

Record Your Effort

Spend as long as you like conducting your survey, but we ask you to spend at least 30 minutes surveying your site. It is important that you record the start time and end time for your survey and the estimated distance you covered.

Survey Method

Use our online recording form (if you have data access) or our downloadable survey form to record your findings.

We now have a bivalve shells ID swatch available to purchase via our online shop for €6.

Survey initially along the high tide mark, where the seaweed has accumulated. This will often prove the most productive area for seashells, as well as seaweed, shark & ray eggcases, cast up seagrass and other sealife. Take photos of each new species you find – you can either identify them on site or at home later using your photos. You should record any plant or animal species you find whether dead or alive.

After thoroughly surveying the high tide mark it is worth surveying the back of the beach – often here you will find items blown inshore by the wind such as shark and ray egg cases, and larger shells cast up during stormy weather. It is also worth surveying below the high tide mark and down to the water’s edge as you may find different seashells in these areas as well as the burrows of lugworms and the cast up tubes of sandmason worms.

While you are recording your species, please take note of the amount of marine litter on your beach and decide whether the beach is lightly littered, moderately littered or heavily littered.

Uploading Your Results

Using our online recording form, record any seaweeds, seagrass, plants and seashells you find. You can also record stranded fish, seals or marine invertebrates using this form. Be sure to submit a photo for each record as this will help us validate your records. Finally, select whether your beach is lightly, moderately or heavily littered, and submit a photo of the worst area.

If you find shark, skate or ray egg cases (Mermaid’s Purses) then please submit your records with a photo of the eggcase to our colleagues at Purse Search Ireland for identification and recording.

If you find a stranded whale, dolphin or porpoise, please submit your record with a photo of the stranded animal to our colleagues at The Irish Whale and Dolphin Group for identification and recording.


  • Before doing a Big Beach Biodiversity Survey check the weather forecast and the tides.
  • Be aware of the dangers of an incoming tide and becoming trapped or cut off by the tide. Aim to start your survey 1 – 2 hours before low water and be off the beach before the tide changes.
  • Tell somebody where you are going and what time you expect to be back.
  • Dress appropriately for the weather and wear appropriate footwear for the ground you will be walking.
  • Stay clear of the base of cliffs or steep dunes as there is a danger of falling rocks or being buried by sand or cliff material.
  • Bring a fully charged mobile phone with you in case you need to call for help. If you do need to call for help, dial 999 or 112 and ask for the Coastguard.


Photo Credits: Seashells – Dave Wall; Hornwrack – S. Rae/Wikimedia Commons; Mermaid’s Purse – Kyle Hartshorn/Flickr; Seaweed – Gail Hampshire/Flickr


Pollution, Fish Kills, Fly Tipping

If, while out on survey, you notice a water pollution or fish kill incident or fly tipping issue, please use the See It? Say It App to report it to the Environmental Protection Agency. Get the iPhone or Android App by Downloading it from the iTunes APP store or Download it from the Google Play store.