Kelp for The Living Coast

by Sarah Ryman Marine

Kelp forests cover about 25% of the world's coastlines and are recognised as one of the most productive and dynamic ecosystems on Earth. Kelp flourished across the Sussex coastline, stretching 40km between Shoreham and Selsey but has diminished since the 1980s due to changing fishing practices, the dumping of sediment spoils by dredging boats and storm damage.

Sussex Inshore Fisheries & Conservation Authority have recently announced a proposed new Nearshore Trawling Byelaw to help safeguard and develop sustainable inshore fisheries into the future. Great news for Kelp!

Areas protected by the new bylaw include an area extending 4km seaward between Shoreham-by-Sea and Selsey Bill. Historically, in the late 1980’s this area was associated with large dense kelp beds that supported abundant marine life, including important commercial fish and shellfish species such as bass, sole, spawning black bream, lobsters and cuttlefish.

The Authority’s measures reflect an ecosystem approach toward fisheries management, recognising the importance of healthy marine habitats in supporting long term healthy commercial and recreational fisheries.

In addition to the intended fisheries benefits that should to be gained by enabling the kelp to recover to its former state, the Authority recognises that coastal kelp beds have a high value in respect to both carbon storage; so helping reduce climate change, as well as absorbing wave energy to potentially reduce coastal erosion and help flood management.

The proposed Byelaw will now be submitted to the Marine Management Organisation and Defra for the final steps of its approval and confirmation by the Secretary of State.

Good news for our coast line and hopefully kelp forests across the planet.

Image by Andy Jackson

Quick kelp facts

    • Until the late 1980’s, there used to be a kelp forest off the coast of West Sussex, approximately 177km2.
    • Storm damage, fishing pressure and poor water quality are all believed to be factors which have resulted in its decline.
    • By the late 2010’s, only small patches of kelp remain, estimated to be about 6km2, a reduction of over 95%.
    • 13 species of kelp are found in European waters, three of which were commonly recorded in Sussex: tangle weed (Laminaria hyperborea), oarweed (Laminaria digitata) and sugar kelp (Saccharina latissima).
    • Kelp forests have a density of 5-15 kg per m2.
    • Kelp forest can take up to 20 times more CO2 (per acre) from the atmosphere than land based forest. Kelp also produces oxygen.
    • Kelp supports many species such as lobsters, sole, black seabream, cuttlefish, sharks and seabirds.
    • Over 1000 species have been recorded in kelp habitats around the UK.
    • The kelp provides habitat for feeding, breeding and shelter.
    • Kelp can grow up to 1cm per day with a maximum length of 2.5m.
    • Tangle weed (Laminaria hyperborea) can live for 18 years and takes 2-6 years to become fertile.
    • Kelp have a holdfast which attaches it to rocks and large stones.
    • The blades or fronds of the kelp can break off during storms but a new blade grows from the holdfast.
    • As kelp needs light to photosynthesise, it can only grow in water down to about 10m deep in Sussex.
    • Kelp have a life cycle with two phases; large plants which produce spores and tiny plants which produce eggs or sperm. The large familiar plants produce microscopic spores. These settle on the seabed and develop into tiny plants, either male or female. When there are enough of these tiny plants together, the male will release sperm which fertilises the egg retained by the female. The fertilised egg develops into the large familiar plant phase.
  • Image by Andy Jackson
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