Seaweed: Safe, Responsible and Legal Harvesting
Due to the volume of interest and enquiries I receive about seaweed and its application in skincare, I felt the need to write something more comprehensive on the subject than my usual short posts on social media. And so I created The Sea Section, which I hope becomes a helpful resource for anyone interested in seaweed for personal use.
Disclosure: I am not a specialist or expert in this area. I write from experience and years of personal research and seaweed skincare formulation. There are far more comprehensive resources on seaweed available online than anything I can write here, and where appropriate I have included references and links to some of these resources. Natural Resources Wales have some excellent guidance which you can find here.
I hope it's helpful if I highlight here some of the key points that should be considered before harvesting seaweed by hand from your local beach, although variations in guidance may occur across different regions and different local authorities.
Working with seaweed
Rather than say that I use seaweed in my skincare formulations, I prefer to say that I work with it. It is the star ingredient of my new Sea to Skin workshops, launching in March 2023, and if that helps inspire wider interest in seaweed-based skincare and home therapies, that's wonderful. But of the utmost importance to me is that this is done in a way that advocates safe, responsible, sustainable and legal harvesting of seaweed for personal use.
The wonder of seaweed
Seaweed is a critical component of the marine environment, and it plays a vital role in maintaining the health and balance of the ocean and coastal ecosystems. It provides a habitat for a variety of marine organisms, supporting a vast amount of ocean biodiversity.
Above: Oarweed (Laminaria Digitata), Brandy Cove, Gower
It is able to absorb and store large amounts of carbon dioxide from the atmosphere through photosynthesis, helping to mitigate the effects of climate change by reducing the amount of carbon dioxide in the atmosphere, and mitigating ocean acidification.
Seaweed can also help protect shorelines from erosion by providing a physical barrier and absorbing the energy of waves. It can be used to restore damaged marine habitats, such as coral reefs and oyster beds. By providing a structure for other marine organisms to grow on, seaweed can help rebuild damaged ecosystems.
To sum it up, seaweed is a plant (although not always technically a plant) of epic proportions, but its abundance and ubiquity can bely its fragility and environmental significance. Anyone considering foraging/harvesting seaweed, whether to eat, for use in skincare, or otherwise, first needs to consider how to do so in a way that is safe, responsible, sustainable, and legal.
Legalities and consent
The following relates to harvesting seaweed by hand. Mechanised harvesting, or using a vehicle on the foreshores or in the sea, is a whole different matter requiring special consent and licensing, and I don't cover that here.
Harvesting seaweed, whether alive and attached to rocks, or dead and washed up on the beach, may require permission from the land owner.
Where permission for harvesting is not needed
You do not need permission to collect seaweed by hand if it is unattached and floating in the sea. For example, if you are out on your SUP board or snorkelling and you spot some seaweed floating in the water, and it is not attached to anything, you can take it without permission. But please do ensure that there are no living organisms attached to the seaweed (bycatch).
Creatures such as the Blue-rayed Limpet attaches itself to deepwater kelp, and these stunning little creatures do not like to be out of the water for long, so if you spot one attached to the seaweed, it is likely to be deeply embedded and it's best to leave the seaweed where you found it.
Above: Blue-rayed Limpet, Brandy Cove, Gower. White substance on kelp is sea mat, a colony of individual animals called zooids
Where permission is needed
If you want to harvest seaweed that is attached, whether that is on the seabed or exposed in rock pools at low tide, you will need permission from the land owner. Sometimes the land owner may be the Crown Estate, sometimes it may be your Local Authority. Sometimes it may be owned by the Crown Estate but managed by the Local Authority on behalf of the Crown. You will need to make your own enquiries. You can read more about the Crown Estate and seaweed harvesting here.
Equally, if you want to collect seaweed that has made its way to the foreshore, for example unattached and washed ashore by the tide (drift seaweed), you will also need to consider permission as set out above.
Special consideration should also be given when collecting seaweed on the strandline. Firstly, it may be old and decomposed beyond any beneficial use. Secondly, it will likely have become a habitat for tiny creatures such as sand hoppers. Thirdly, it may be contaminated, e.g., from dog fouling. Use your descretion and assess each find accordingly, but ensure that you avoid disturbing or harming any ecosystems in the seaweed.
Some coastal areas are protected, for example as an Important Plant Area (IPA) or Site of Special Scientific Interest (SSSI). Harvesting seaweed in these areas may require special application and consent, or it may be prohibited completely. IPAs can be searched via Plantlife, here. Natural Resources Wales also have a very useful interactive map to check for protected areas.
Many seaweed species grow in intertidal zones that are either always under water (such as kelp), or revealed on a receding tide (such as laver and bladderwrack). Harvesting fresh seaweed is best done at low tide. Different species grow at different depths on the seabed.
Spring tides, which are bigger tides that occur around a full or new moon, will recede the furthest and reveal more of the seabed and a greater variety of species. Always check tide times to ensure that you don't get caught by an incoming tide. For Swansea and Gower, check GowerLive for tide data, including dates for the biggest tides.
Harvesting seaweed invariably involves stepping over slippery rocks, and carries the risk of disturbing fragile ecosystems, so do tread very carefully. Wear waterproof footwear with good grip. Flip-flops are not recommended.
Above: rock pools contain intricate and fragile ecosystems; tread carefully...
Seaweed is cleverly designed to retain moisture when it is exposed at low tide, to prevent it from dehydration. So even on a hot summer's day it may remain wet and slippery. Try sticking to 'sand channels' - areas of sandy beach in between rock pools - both for safety and also to minimise disrupting ecosystems.
When to harvest
It is best practice to avoid harvesting during a seaweed's reproductive phase. This will be species-specific, so please do your research beforehand.
Being respectful and responsible
When harvesting seaweed (with the appropriate permission) that is attached to rocks or the seabed, snip only a small section from the top third of the seaweed, using a sharp scissors. Take only a small amount from any one plant and any one area.
Never tug at seaweed. Seaweed attaches itself to a substrate, usually a rock, by what's called a Holdfast. Never tear the holdfast from the rock, as you will kill the entire seaweed plant, and also disrupt its surrounding habitat. If you remove any loose rocks while harvesting, do so slowly and carefully, and gently place them back as you found them.
Above: The 'Holdfast' (photobombed by Maui the Collie)
Once you have collected your seaweed, ensure you remove any bycatch and debris by thoroughly swishing it around in sea water. Always give a final check over to look out for any creatures clinging to the seaweed.
I hope you find this information useful. I would reiterate the importance of doing more thorough research before embarking on any seaweed harvesting/foraging, and I can't recommend enough the resources by Natural Resources Wales for more comprehensive information. Similar resources will be available online for other areas of the UK.