Sussex Kelp Forest Restoration: Enhancing Essential Fish Habitats and Biodiversity
A Sussex marine environment enhancement and monitoring program
Our natural environment is our most precious inheritance. It is this Government’s ambition to leave our environment in a better state than we found it. In the inshore marine environment, protecting and enhancing essential fish habitats will ensure improved and sustainable fisheries. By fishing appropriately we will help to protect the wider marine ecosystems that underpin the fish species we rely on. In Sussex, we are working together to enhance the sites of historic dense kelp forest from Bognor Regis to Brighton. These historic kelp forests have disappeared since the 1980s. The reasons implicated in their loss include changes in fisheries practices, water quality and storm damage.
See a short film, narrated by Sir David Attenborough, talking about the value of Sussex kelp forests here.
Check out this video on our You Tube channel showing kelp a few miles south east of Selsey.
Kelp provides a range of benefits including: the capture of carbon dioxide and the production of oxygen, the support of biodiversity, the support of commercial and non-commercial marine species, cultural heritage and as a harvestable resource. Research indicates that macroalgae are an ecosystem component critical to the delivery of a broad range of ecosystem services, meaning this habitat should be given special attention when considering management.
To monitor impact and associated fisheries benefits from the Nearshore Trawling Byelaw, Sussex IFCA has established 8 north to south research lines to be the focus of research efforts. These lines are placed 4-8km apart between Shoreham and Selsey, covering a variety of habitats and conditions. These have been surveyed using a towed video array in 2019 and 2020 to establish conditions before any change in management and will continue to be surveyed to monitor change following the introduction of the byelaw in March 2021.
A factsheet for these transects can be found here.
A report comparing our 2019 and 2020 towed seabed video survey data, written by experts at the Zoological Society of London can be found here.
See our report on the value of ecosytem services of kelp, authored by the NEF Consulting.
In the coastal waters off West Sussex, within living memory, there used to be a large area of kelp forest but this is no longer the case. Fishers from Worthing tell of how when they had launched their small open boats off the beach, they had to row out nearly two nautical miles before they could start their outboard motor without the propeller becoming tangled in the kelp. In winter storms, some of the kelp washed up on the beaches from Lancing to Bognor and local farmers would come down in their tractors to collect it to use as fertiliser on their fields. Divers in the 1980’s recorded the presence of kelp as abundant or common from Selsey to Eastbourne, in over 50% of their dive sites. Three species were recorded: Laminaria hyperborea, Laminaria digitata and Saccharina latissima.
The fishers say that during the famous autumn storm of 1987, large amounts of kelp were washed ashore, including some with the holdfasts still attached to cobbles. This severely decreased the density of the main kelp bed which, alongside the development of new fishing technology, allowed trawlers to tow their nets through the area. This is suspected to have inhibited the recovery of the kelp forest, alongside eutrophication and poor water quality. Divers in the 1990’s recorded the presence of kelp as occasional or rare at less than 5% of their dive sites and fishers have commented on the reduction in commercial species. By the late 2010’s, only small patches of kelp remain. The decline of this important habitat is likely to have caused a concomitant decline in associated species and ecosystem function.
Looking at the extent and condition of the historic kelp forest and taking evidence from peer reviewed articles which document the benefits that kelp can provide, it is considered that the restoration of the Sussex kelp would be beneficial for commercial fisheries specifically and for the marine environment more broadly. It is also considered that the restoration of kelp could provide socio-economic benefits, such as increased tourism, increased catches for recreational and fishers and improved water quality.
Sussex IFCA is working with a variety of partners to deliver research which focusses on kelp restoration and habitat enhancement. Contact us if you would like to be involved.
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.
For more information about kelp, click here to go to the UKMPA centre page on kelp on reefs and click here to go to the Macroalgal Research Group.