Much of the sea around and to the south of Portland is protected as part of the Studland to Portland Marine Protected Area (MPA). These protected waters range from the shallow, rocky shores and plunge to depths of over 80 metres south of Portland Bill. Even on a calm day, the tidal race off Portland Bill swirls in a maelstrom of white water as currents from east, west and south of the Bill collide, creating a high-energy area of sea.

The site has been made an MPA to protect reef habitats in the waters around Portland which are regarded as being of excellent quality and supporting a high number of plant and animal species.

The MPA is hugely popular with many different sea users including divers, anglers, commercial fishermen, sailors, and those on land who walk, run or cycle the coastline to enjoy dramatic sea views and watch the local wildlife. Whilst they all enjoy and use the sea in different ways, all these groups enjoy the benefits of clean and healthy seas.

The Portland coastline is filled with iconic views enjoyed by all those using the coast whether on land or at sea. The lighthouse at Portland Bill has warned mariners for centuries of the perilous rocks upon which many a vessel has floundered. 


Image: © Raimond Spekking / CC BY-SA 4.0 (Wikimedia Commons) 









Protected Features

The MPA around Portland is designated to protect the different variety of reef features over all depths and seabed types. They are are monitored to ensure they remain in good, healthy condition and are not adversely affected by human activities. The different reef types are described below.

Seabed Features

Extending its reach southward into the English Channel, Portland forms a distinctive feature in the centre of the Jurassic Coast World Heritage Site. Appearing to rise from the depths, the steep limestone cliffs are somewhat deceptive – beneath the waves much of Portland’s east side is flanked by shallow ledges. To the west however the seabed does drop away more quickly and reaches depths of over 30 metres within a few hundred metres from shore. South of Portland Bill the waters are deeper still, reaching over 100 metres in Portland Deep.

Currents from Lyme Bay, Weymouth Bay and the Channel move along undersea cliffs and ledges and over sandbanks before clashing together in the tidal race between Portland Bill and the Shambles sand bank. This creates a maelstrom of white water, visible even on a calm day, of which all mariners must be wary.

Most of the reefs around Portland are formed of limestone and support several protected habitats and species. Huge boulders fallen from the cliffs above litter the seabed close to shore creating a range of different homes for many different species to thrive. The MPA’s protected features are monitored to ensure they remain in good, healthy condition and are not adversely affected by human activities.

The Dorset Integrated Seabed survey (DorIS) mapped the Dorset seabed using sonar technology. DorIS provided accurate maps of the local seabed features within the MPA.

On the map you can explore the seabed features inside the MPA boundary along with the other incredible undersea formations around the Dorset coast. If using a touch screen, use two fingers to zoom and scroll.

The varied seabed geology around Portland creates wide-ranging reef features including canyons, cliffs, ledges, overhangs and boulder fields. These reefs are found throughout more than 70% of the MPA (as visible on the seabed map here) all providing home to a wide diversity of life.

Seabed maps showing the different rocks and sediments around Portland and based on available survey data can be viewed via the European Marine Observation and Data Network.

The reefs surrounding Portland are full of life supporting commercial fisheries, recreational angling, drawing divers to the area and providing feeding, breeding and nursery areas for many different animals.

Habitats and species

Strong tides racing down each side of Portland toward the Bill coupled with the south-westerly swell up the English Channel create a high energy environment across Portland’s reefs. This results in high food availability and often clearer waters compared with calmer areas within Portland Harbour and Weymouth Bay where more fine sediments settle on the seabed.

The strong currents being forced south of Portland and the imposing presence of Portland itself, create a biogeographical barrier to the migration of species. Whilst not making it impossible for plants and animals to spread east and west of Portland, these conditions can make movement around Portland Bill more difficult. One possible example of this is the far higher numbers of pink seafans encountered in Lyme Bay compared with the seas east of Portland.

Portland’s productive reefs are popular with commercial fishermen, recreational anglers, spear fishers and divers. Important commercial species include scallops, crabs, lobster, bass, pollack, mackerel, plaice, black bream and cod. With the exception of Chesil Cove, divers must use a boat to access most of the dive sites around Portland and those that do can be rewarded by wonderful and colourful reefs to explore.

The galleries below provide a glimpse into life on the seabed around Portland whilst the word cloud provides links to some of the more commonly recorded species inside the MPA.

Underwater Portland

Portland’s reefs are a ‘hotspot’ for marine life. They contain significant populations of important species like crabs, lobsters, wrasses and pink seafan corals. Mussel beds occur east of Portland Bill amongst the kelp and help create reefs full of life and colour.

ROLL over each image to find out more. CLICK on each image to see a larger version. ESC to return to the main screen.

TAP each image ONCE to find out more, TWICE to see a larger version. Tap off the image to return to the main screen.

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Residents of the reefs

ROLL over each image to find out more. CLICK on each image to see a larger version. ESC to return to the main screen.

TAP each image ONCE to find out more, TWICE to see a larger version. Tap off the image to return to the main screen.

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Special encounters

Sometimes whilst at sea the unexpected can happen and we might meet some astounding marine creatures. This video shows just one of those moments when local diver Colin Garrett came face to face with a bottlenose dolphin just off Portland.

Image: Peter Tinsley

People and Portland’s seas 

Surrounded by the sea almost completely, Portland has a long-standing maritime history which continues to change and develop in modern times.

In the past, Portland’s rugged coastline and many coves were exploited by smugglers bringing their contraband ashore. Once home to the Royal Navy and to the Coastguard helicopter, Portland Harbour now plays host to the Weymouth and Portland National Sailing Academy and Portland Port amongst others.

Fishing has always happened around Portland, with the methods and vessels changing with the times. Portland’s MPA overlaps with the Chesil Beach and Stennis Ledges MPA and the Chesil and the Fleet MPA. Those pages give additional insight into the historical and present-day fishing activities from Chesil Beach.

Portland’s rugged and often inaccessible coastline means that both historically and today access to fishing grounds is usually via boat from Portland and Weymouth harbours, across Chesil Beach or further west from within Lyme Bay.

However, one ingenious method remains in place which allowing direct access to and egress from the sea at Portland Bill…

Red Crane – located on an old stone loading quay (now a historical monument) is a fishermen’s crane at Portland Bill. Used to lower fishermen’s boats to the sea it remains in use today, albeit when sea conditions allow.

Image © Raimond Spekking / CC BY-SA 4.0 (via Wikimedia Commons)

This archive footage from 1949 shows one incredibly strong and agile local fisherman, Jack Comben launching his potting boat from the Red Crane, setting his pots and retrieving and landing his catch. Launching and fishing this way was only possible in calm seas as the image of the crane during stormier times demonstrates!

© Sue Hogben / CC BY-SA 2.0 (via Wikimedia Commons)
© Sue Hogben / CC BY-SA 2.0 (via Wikimedia Commons)

Fishing today

The Portland MPA supports a number of commercial fisheries for fish and shellfish species including crab, lobster, cuttlefish and wrasse species using baited pots and traps. A small number of recreational pot fishers also use the site.

Other fish targeted by both recreational sea anglers, charter boat anglers and commercial fishing vessels are caught using rod and line, longlines or nets. These fish include bass, sole, plaice, rays, brill, turbot, grey mullet, wrasse and mackerel.

Scallops are hand caught by commercial and recreational fishers whilst diving. No trawling or dredging has been permitted in the Portland MPA since 2016.

Until recently, dredging for young blue mussels (Mytilus edulis), known as seed mussel occurred in the MPA. They were then re-layed in Poole Harbour to be grown on for human consumption. The dredging ended in 2014 after the extreme winter storms destroyed many of the mussel beds and they needed to recover. Since 2019 dredging for seed mussel is licensed outside of the MPA and the mussel population is closely monitored.

Edible crab
Ballan wrasse
Shore diving in Chesil Cove
Walkers at Church Ope Cove © Jim Champion (via Wikimedia Commons)

Other sea users

Church Ope Cove on the east side of Portland is popular with swimmers, anglers and spear fishers. Even some divers are hardy enough to occasionally haul their heavy kit up and down the steep concrete steps to the shore. In the summertime, clear waters and abundant marine life reward those willing to make the effort.

Hallelujah Bay on the west side of Portland, just along from Chesil Cove is similarly popular with swimmers and snorkelers when conditions are calm.

Divers are most often seen on the shore in Chesil Cove. Videos and photos of the marine life in Chesil Cove can be seen HERE. Diving elsewhere around Portland requires boat access with vessels launched in Portland Harbour, Weymouth or within Lyme Bay.

Other visitors to Portland come to watch wildlife around its shores, walk the coastal paths and enjoy the dramatic sea views and fresh sea breezes. No specific value has been put on these activities but tourists bring money to the local communities and the value of MPAs for physical and mental well-being is increasingly recognised as described in THIS REPORT from the United Nations Environment Program.

Further information on the value of the Portland MPA to the Dorset communities is described alongside that of the Purbecks MPA as both areas, although separated geographically, come under the same joint designation as a Marine Protected Area.

Management in a nutshell – DRAFT plans

The Portland reefs of the Studland to Portland MPA are considered to be of national importance and support an abundance of marine life. The MPA was established in September 2017 under the EU Habitats Directive which aims to protect animals, plants and habitats that are rare, special or threatened within Europe.

The MPA is used by a range of recreational and commercial fishers who target shellfish and finfish using nets, pots, rod and line, hand-gathering and spear fishing. Charter boat skippers make a living taking divers and anglers to the area, drawn there by the abundant sealife.

Management of fisheries in the MPA is mostly carried out by Southern IFCA although the Environment Agency is responsible for the management of migratory fish around England. To achieve effective fishery management, collaborative working is required between Southern IFCA, the Environment Agency and Natural England.

With the entire MPA around Portland closed to bottom towed gear, only low impact fishing methods are widely used – these require only a small number of management measures. European and Southern IFCA minimum take sizes (MTS) for landed fish and shellfish apply to all fishers, recreational and commercial.

Net fishing

Net fishing around Portland targets bass, sole, plaice, rays, grey mullet and mackerel.

Net fishers must adhere to the MTS for these fish, outlined in European legislation and Southern IFCA byelaws. These include a larger local minimum size for grey mullet species.

Pot fishing

The MPA’s reefs support strong populations of crabs, lobster, cuttlefish and whelks which are caught with baited pots or creels by commercial and recreational potters. All potters must follow minimum conservation reference sizes and the national restriction on the prohibition of removing berried (egg bearing) lobsters and crawfish.

More recently, fishers have begun to target wrasse species, particularly ballan and goldsinny wrasse for transport to Scotland to use as cleaner fish on Scottish fish farms to control lice numbers. Given the vital role of wrasse in coastal ecosystems and the lack of knowledge on their population status the area’s wrasse fishers follow ‘Southern IFCA’s Wrasse fishery Guidance’ – a voluntary code of conduct to ensure sustainable wrasse fishing. This includes a number of no take zones, minimum and maximum conservation reference sizes, a pot limit and seasonal closure. The IFCA’s response to the wrasse fishery is a good example of its ability to respond to changes in fishery practice that were previously unregulated.

Sea angling

Recreational anglers fish from shore for fish like mackerel, cod, pollack, bass, rays and plaice. Charter vessels target similar species as well as black sea bream. The MPA is very popular with anglers and it is important that angling remains sustainable – the pastime has important social and economic value for the local communities and for those to travel to Dorset’s shores.

Commercial angling occurs mainly for bass in the Portland tidal race although commercial anglers are now also targeting wrasse for the purposes cited above.

All anglers must obey the minimum species sizes set out under Southern IFCA byelaws.

Dredge and trawl fishing

Fishing with towed gear is prohibited throughout the Portland MPA by Southern IFCA to protect the delicate reefs. Towed gears include otter and beam trawls and dredges used for scallops or mussels.


For more detailed information on the fishing management within the MPA, see the full management plan on the IFCA website.

Nicola L dredging seed mussel
Nicola L dredging seed mussel
Potting boats in Weymouth Harbour
Potting boats in Weymouth Harbour
Fishing pots, Weymouth Harbour
Fishing pots, Weymouth Harbour

Looking to the future

Natural England is responsible for monitoring the MPA and its protected reefs which are presently considered to be in ‘favourable’ condition. Any evidence arising about potential impacts to the reefs from commercial or recreational fishing are assessed by Southern IFCA who then consider any necessary management responses.

Southern IFCA works to improve awareness and understanding of regulations among fishers via active engagement with all fishery sectors. Compliance is monitored during patrols and inspections of fishermen, anglers and divers by Inshore Fisheries and Conservation Officers (IFCOs). Non-compliance can result in warnings, financial penalties or prosecutions.

During patrols and inspections IFCOs can update fishers on any regulatory changes. Patrols also provide opportunities for fishers to discuss the status of local fisheries with IFCOs and to make their own management suggestions.

Meetings through groups such as the Dorset Coast Forum, Dorset and East Devon Fisheries Local Action Group (FLAG), Dorset Wildlife Trust and Southern IFCA continue to ensure that stakeholders and regulators engage with one another on a regular basis. The MPA Community Planning project funded by the Dorset and East Devon FLAG held initial workshops in 2018 to engage with the various groups using MPAs and help shape future management plans.

The prohibition of trawling and dredging throughout the Portland MPA can only lead to positive changes in the future for the seabed communities. Leaving them relatively undisturbed will allow them to flourish and become even more productive areas for marine wildlife and successful fisheries.

The on-going monitoring, enforcement, informing and discussion aims to ensure healthy and productive local seas are secured and improved for future generations.