Help our Kelp
The kelp forest off England’s southern Sussex coastline was once so abundant that fishermen had to pass through it using nothing more than muscle and oar, the density of fronds and their propensity to entangle making the use of propellers foolhardy. Today, no fisher need worry about having to sweat their way out to waters beyond the forest’s outer edge, for no such forest remains.
The loss of Sussex’s extensive kelp forest, which once stretched along a roughly 40km length of coastline from Shoreham-by-Sea to Pagham, has happened as a result of both nature and a lack of nurture. Swathes of the forest’s standing stock were destroyed during the Great Storm of 1987. Then, in the ensuing years, opportunistic trawlermen made the most of being able to fish a previously inaccessible area of the English Channel. It is believed that regular fishing activity has kept the ecosystem from bouncing back by removing or damaging juvenile kelp and dispersing the larger rocks kelp requires to anchor. The forest declined, then largely disappeared.
The impact of the forest’s disappearance has not, over the years, been of huge bother for many onshore. One local council had, at one point during the forest’s healthier years, been so concerned with the amount of kelp washing up on Sussex beaches after storms that they commissioned a report entitled The problem of kelp, where a variety of kelp eradication measures were considered, including the use of explosives. Mercifully, attitudes have changed in recent years. The problem of kelp has turned into Help Our Kelp (HOK). The HOK initiative – a campaign group made up of a number of organisations including the Sussex Wildlife Trust, Blue Marine Foundation, Marine Conservation Society, Big Wave TV, Brighton University, Portsmouth University and ZSL London Zoo – has a singular objective: to return Sussex’s kelp forest back to its former bountiful glory.
The loss of Sussex’s extensive kelp forest… has happened as a result of both nature and a lack of nurture.
In the summer of 2019, I joined the Sussex Inshore Fisheries & Conservation Authority (IFCA) aboard their patrol vessel Watchful for a day at sea. Using a towed camera to survey the seabed, we examined the full length of the forest’s historical habitat. Our propeller remained untangled throughout; we saw no kelp at all. The survey laid bare the extent of kelp loss in the area – practically an entire ecosystem lost in just a few decades.
Despite seeing no kelp throughout the day, I harboured a lingering doubt. Our towed camera was limited to areas of flat seabed and I couldn’t help but wonder if kelp might be present in the more inaccessible areas that our camera couldn’t reach. Dr Raymond Ward of Brighton University has been leading groups of volunteer divers for the last few years, to identify the location and extent of kelp along the Sussex coast. He says that in good years, sugar kelp, oarweed and tangle weed has been found to sprout on exposed reefs and artificial structures along the Sussex coastline but these haven’t developed into stable formations, most likely as a result of constant anthropogenic disturbance. It was more than a year before I was able to return to see for myself.
During that time HOK’s onshore work has continued, and with encouraging success. If kelp is to return to Sussex’s waters in any meaningful way, it will need the time and space to do so. Stopping trawling in the area would be a massive boost to potential recovery. To that end Sussex IFCA has proposed a new byelaw to prohibit trawling up to 4km from the coastline, covering the area of the former kelp habitat. It is hoped that this trawling ban will remove one of the main impacts on the seabed and permit kelp habitat restoration. Jen Lewis, Senior Research O’cer of Sussex IFCA, says: “Our proposed ecosystem-based management measures would prevent damage to essential fish habitats, hopefully creating the necessary environment for kelp to re-establish itself in the area and to support local fish populations.”
After a consultation period with interest groups the byelaw has been approved at local level. It now requires approval from central government before trawlers will be legally obliged to refrain from fishing in the area. Despite the obvious Brexit and Covid-19 resource-sapping hurdles in getting the byelaw ratified, members of HOK are hopeful it can be signed off and implemented in 2021. Peter Jones, board member of Sussex IFCA and an expert researcher in marine governance at University College London, has been following the progress of the byelaw closely. He says: “Consultations around big changes to fishing practices can be long and difficult processes. I was delighted when the proposed trawling prohibition finally made it through local committee approval. We still have to wait for the government’s decision, including addressing further objections and challenges, but I am hopeful we will get final approval next year.”
We deployed the ROV and, encouragingly, soon encountered plenty of long, stringy brown seaweed.
While the passing of the byelaw and the associated cessation of trawling in the area are pivotal to the prospective return of Sussex’s kelp forest, there is no guarantee that a ban would instigate the forest’s return. We can nurture the habitat, but nature still has to do the rest. With that in mind, I remained keen to get back out to sea to see if kelp was anchoring in the rocky areas we had yet to assess. Was nature doing its bit where it could? On a warm morning in early September, I arrived at Itchenor Harbour, a small marina in the Chichester Channel. Now a tranquil area pockmarked with small harbours popular with leisure sailors, Chichester Channel once thronged with commercial activity as one of the most important anchorages in early Roman Britain – a time when kelp forests doubtless thrived off Provincia Britannia’s southern coastline, and when the power of muscle and oar to navigate such forests sufficed just fine. I was met at the harbour by ZSL colleague Steve Long, who had with him the Trident ROV that would allow us to investigate the rockier areas of seabed to which we had previously been blind. With Arksen Foundation providing a RIB for the day – and Foundation director Olly Hicks at the helm – we set off for Selsey Bill.
In 2016, a survey at Selsey Bill had found kelp. We deployed the ROV and, encouragingly, soon encountered plenty of long, stringy, brown seaweed known as dead man’s rope. This was seen regularly, often entangling the ROV’s propeller. We also found a few pieces of sugar kelp, identifiable by its wavy edges and long, broad frond. Sugar kelp derives its name from the sweet white residue that appears when it is dried – sugars that make it a valuable crop and therefore popular choice in seaweed farms. “The sightings were encouraging, but worked more as supporting evidence to 2016’s survey than fresh data.
Moving on to one of the day’s primary target sites, the concrete remains of the World War II Mulberry Harbour platform, we redeployed the undersea drone. This site is made up of large slabs of broken concrete and rock – potentially excellent attachment points for kelp. Not only this, but the hazardous nature of the area should have kept trawlers at bay. Observing good kelp growth here would be a strong indicator that natural restoration could be achieved in the area at large. We saw plenty of dead man’s rope but no sugar kelp, though our disappointment was allayed by the amount of fish we saw, evidently benefitting from the protection of the concrete reef.
As dark clouds began to roll and waves began to swell, we moved on to Bognor Rocks. The conditions became challenging, quickly. Topside we were buffeted by strong winds and driving rain, while below the waterline the sea began to churn and the visibility deteriorate. Unable to clearly see the ROV screen, we were largely flying blind. We continued to record though, content to watch the video back in the office, even if we couldn’t watch it live. Despite having further test sites on our plan, we headed back to harbour as the conditions worsened around us.
From the evidence collected to date, we remain unsure whether a ban on trawling will be enough to ensure a kelp forest recovery, but we do know it is a necessary first step. There are several factors that we need to consider to better understand recovery potential, such as whether there are sufficient source populations nearby to seed a recovery, and whether there are sufficient large and stable rocks for kelp to anchor.
The HOK partnership is investigating methods for speeding up restoration. One intervention could be ‘seeding’ bare rocks in the area, giving new kelp better places to take hold, though our survey suggests this may not be enough. Another, novel and innovative solution would be the use of ‘green gravel’, the growing of kelp on small rocks in culture facilities, which are then planted at sea. Using the green gravel technique could potentially solve both the source population and rock problems, though care would need to be taken to not introduce new organisms into the area. Special permissions would also have to be sought, as would funding.
Regardless of the restoration road down which we choose to travel, it will doubtless be a long one – this is a conservation project very much in its infancy. I for one am in it for the long haul, as are all the HOK partners. I hope to watch as the kelp forest grows, to witness fish stocks boom and snorkel tourism thrive, and to hear of fishermen enjoying bolstered catches as stock spills from an ocean forest brought back to life.
Original Article by Chris Yesson for Oceanographic Magazine.