Karen Boswarva wants to turn the tide of public sympathy for a‘ fabulous but forgotten’ group of marine plants
OCEANSCIENCE
Fanfare for the Fucoids
Karen Boswarva wants to turn the tide of public sympathy for a‘ fabulous but forgotten’ group of marine plants
If it’ s safe to do so, close your eyes just for a moment, take a deep breath and picture a‘ seascape’. What springs to mind? Glacierblue waves crashing onto a sandy shore, a thriving coral reef packed with colourful fish, or perhaps a luscious canopy of kelp fronds swaying back and forth? Can you taste the salt, smell the neoprene?
Close your eyes again and picture a‘ fucoid forest’. Does it invoke the same feeling? Probably not – it’ s not the best known term, after all. Using citation analysis, researchers identified a lacklustre response to this diverse and globally distributed group of seaweeds that separated from other brown seaweeds more than 60 million years ago. Unfortunately, over time, gaps in common knowledge start to creep in, caused by a loss in publicity and overshadowing by trending research fields. So, it’ s no wonder I get funny looks when exclaiming,“ ooft look at those fucoids!”
I ask you to please humour me a while as I attempt to turn the tide on the forgotten fucoids, seaweeds related to the genus, Fucus.
Let’ s start with abundance. The total area of the planet estimated to be covered in fucoids equates to 2.57 million km2. That’ s a whole lot of seaweed [ quite a bit more than the entire surface area of Greenland – Facts Ed ]. In fact, it’ s more than the global cover of seagrass, kelp, coral reef, mangrove, or salt marsh. That’ s because unlike other foundation species that have niche environmental requirements, the fucoids have colonised the world’ s coastlines from the poles to the equator and everywhere in between. They thrive on the cusp of comfort, in the intertidal zone, often consecutively exposed to the roughest seas and the baking heat of the sun, day in day out.
They have diversified greatly in morphology [ shape ] and size into an array of bladed, branched, and bladdered forms, adapted to thrive in the sheltered brackish waters of lagoons and estuaries, or in fully exposed marine waters. In the UK there are five species of fucoids or‘ wracks’ that you will have most likely stepped or slipped on as you entered the sea. They are: serrated wrack, bladder wrack, channelled wrack, egg / knotted wrack and thong weed. There are a further two species that are less common: sea loch egg wrack and horned wrack. All distinctively different and named for their shape, which makes them a pleasure to identify.
Fucoid reproduction is an equally fascinating process. Species have diversified into either dioecious( separate male and female plants) or hermaphroditic( plants containing both male and female gametes). Gametes( eggs and sperm) are stored within conceptacles, small flask shaped cavities within the swollen fertile tips called receptacles. A single plant can then release millions of gametes into the water column for fertilisation and settlement on to the rocks below.
Fucoid forests are ecologically important, long-lived habitats that support productive
“ Fucoid reproduction is an equally fascinating process”
and healthy ecosystems. They perform vital ecosystem services that improve the health and functional quality of the marine environment. From retaining nutrients and storing carbon, to providing nursery habitat for commercially important species and a rich fertiliser for our farming means.
Culturally, fucoids are a valued food and medicinal source, historically harvested by local communities and more recently for biochemical and pharmacological purposes.
Despite their resilience and persistence, these seaweed superstars are not immune to damage and degradation. They are exposed to many stressors that are sadly becoming more common including heatwaves, sediment smothering, eutrophication, bio-invasions, over-grazing, and coastal darkening.
Fortunately, many species are accessible and distinctive enough for citizen scientists to monitor and record. If you fancy taking an interest in fucoid recording, then projects such as Seasearch or the Marine Conservation Society’ s Big Seaweed Search are a great place to start. Or simply take a picture and submit your sighting on to an app such as iNaturalist; every record counts in raising the profile of our“ fabulous but forgotten fucoid forests”.* �
* The above quote is from title of a 2024 scientific paper by Mads Thomsen, Peter Staehr and Paul South, which can be viewed at https:// tinyurl. com / fucoid
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