Project Portunus - Discovering Our Local Harbour Marine Life

30/08/2026

Please see update from Langstone Harbour Board's environment officer regarding the removal of oysters and other shellfish (clams, cockles and crabs etc.) from Langstone Harbour. Although not illegal for personal use outside the protected areas (see image below), there are public health and possible criminal activity concerns if significant volumes are being removed without a License.
https://www.southern-ifca.gov.uk/shore-gathering
https://www.gov.uk/government/publications/what-a-gangmasters-licence-is-and-who-needs-one/what-a-gangmasters-licence-is-and-who-needs-one

Removal of oysters in Langstone Harbour
Following resident's concern re whether or not permission is needed for the above activity, Langstone Harbour Board Environment Officer has advised the following:
"...there is a large bed of Pacific Oysters at the northernmost point of the bank (see photo below. Unfortunately, LHB are not authorised to regulate fishing activity, but of course have a close working relationship with the Southern Inshore Fisheries and Conservation Authority.
From [member's] email, I am assuming that what you witnessed was harvesting of Pacific Oysters, as the Native European Oyster populations are so minimal. As the Pacific Oyster is invasive, there are no quotas imposed upon the fishery. What is regulated, is any harvesting activity within seagrass beds in the Solent. I include an infographic detailing where these prohibited areas are for Langstone. [Please see png below downloadable.]
I know that there have been concerns regarding the quantities of
shellfish being harvested, and views that this exceeds what may be expected for personal consumption. In order to report any activity to the fisheries authority and Portsmouth Port Health, if there are concerns about commercial gathering, any intelligence is welcomed - dates, times, locations, and any photographs. If, of course, you do not feel comfortable taking photographs, this is not a problem."
Please pass on this information to others you know & perhaps post on FB. If you have any queries or information please direct them to LHB, specifically Georgios, Environment Officer LHB [email protected]. Tel: 02392 463419.

14/08/2026

Portunus was delighted to be invited by the Environment Officer at HMS Excellent to survey the remarkable Horsea Lake — a unique, man‑made body of water over 1km long, up to 90m wide, and reaching depths of 10m. Home to the MOD’s Defence Diving and Sea Survival Schools, the lake is fed by both freshwater springs and seawater, creating a fascinating brackish environment.

Despite being surrounded by SSSI and RMASAR‑protected areas, very little is known about the life beneath its surface. So our divers, joined by Seasearch Director Lin Baldock, spent two full days exploring the east, middle, and west sections of the lake.

The early findings are genuinely exciting: small patches of flowering seagrass and several unexpected species already recorded. Over the next couple of months, we’ll be analysing the data in detail before submitting a full report to the MOD — providing a much‑needed baseline to support future monitoring and conservation.

A hidden world is beginning to reveal itself, and we’re proud to help bring it into view. 🌊🦀

27/07/2026

Please see the report below by Havant Police.
The area under Hayling Bridge is one of the intertidal survey sites for Portunus, the other being at the Kench. We have seen evidence of large scale gathering of shellfish at both sites.
There are several concerns about this activity;
1) Public health - With several sewage outfall pipes (especially nearby Budd's farm) and frequent storm releases the shellfish are likely to contain harmful bacteria and chemicals. We have noted that the oysters are often shucked at the site so are not fresh/live. once removed. Unregulated harvesting often breaches local fisheries byelaws, risks introducing uncertified, potentially contaminated shellfish into the commercial food chain.
2) Environmental - The removal of crabs and molluscs (oysters, cockles, mussels and clams risks damaging the ecology and food chain for these internationally important and protected wildlife sites. Portunus surveys indicate that the local green crab population may have a parasitic barnacle (Sacculina carcini) which could threaten the crab population - harvesting of crabs could pose an even greater threat.
3) Modern Slavery and Trafficking - The illegal coastal harvesting where vulnerable or trafficked workers are underpaid and forced to work in dangerous conditions. Gangmasters (Licensing) Act 2004, making it a criminal offense to supply or use labour in the shellfish and agricultural sectors without an official government license. Noting that sustainably sourced oysters are sold in supermarkets for £1.25 each there's a potential for easy cash supplying less diligent markets.
Well done Havant Police for raising awareness of this activity.

15/07/2026

🌊 We went looking for one invasive seaweed... but found some real treasures instead.
On a very hot evening, I joined Alison Mayer from Project Portunus - Discovering Our Local Harbour Marine Life to explore Langstone Harbour as part of my Attention All Shipping fieldwork.
We hoped to find wakame, an invasive seaweed from the Pacific. But the water was already too warm. It had gone.
Instead, Alison showed me jagged forests of Pacific oysters, brilliant orange sea squirts, colourful sponges and delicate bryozoans, while green shore crabs scuttled through invasive wireweed (Sargassum muticum). We were also searching for the extraordinary crab hacker—a parasitic barnacle that hijacks a crab's biology and behaviour, taking control of its life to raise its own young.
And yes... we found one.
The real discovery, though, was Alison.
For years she's quietly recorded hundreds of marine observations, helping build one of the best records of Langstone Harbour's changing marine life. Every observation becomes part of a national picture of how our coasts are changing.
That's citizen science at its very best. Before Alison started her observations there were only a few species recorded here on the national database.
As the evening cooled, we reflected on our finds with a lime and soda at The Ferry Inn.
You don't need to travel too far, or even put on scuba gear - to experience extraordinary marine life. Some of Britain's richest wildlife experiences are waiting between the tide marks - we don't nationally know what's there though.
Just download the iNaturalist app
Wait for low tide.
Look closely.
And if you find something interesting, record it. Your observation will help tell the story of Britain's changing coastline.

15/07/2026

🌿 Celebrating Nature Positive Portsmouth — and the amazing work of local community volunteers! 🌿

Portunus is proud to be featured in Hidden but Here, the first of three short films released by Portsmouth City Council as part of their Nature Positive Portsmouth initiative. These films shine a light on the incredible work happening across our region — from shoreline conservation to community‑driven biodiversity and restoration projects.

🎥 Watch Film #1: Hidden but Here
Our volunteer team’s efforts to survey and record marine life in Langstone and Chichester Harbours are showcased beautifully. The film captures the quiet richness of our harbours and the dedication of the people who give their time to understand and protect them.
👉 https://www.youtube.com/watch?v=DHwqdLawK9Y&t=2s

🌊 Why this matters
Healthy harbours depend on engaged communities. Every survey, every observation, every volunteer hour helps build a clearer picture of the marine life that thrives just beneath the surface — often unseen, but always present. These films highlight how local action contributes to a more nature‑positive future for Portsmouth and the wider Solent.

🌱 Explore the full Nature Positive Portsmouth programme
Learn more about the initiative and discover how you can get involved:
👉 https://shapingportsmouth.co.uk/business_programme/nature-positive-portsmouth/

💙 A huge thank you
To our volunteers, partners, and everyone who supports Project Portunus — your passion and commitment make this work possible. These films celebrate you.

If you enjoy the film, please share it and help spread the word about the value of appreciating and protecting our local marine environment.

13/07/2026

Followers will recall the post in May about a seal we saw in Chichester harbour which had a strangulation entanglement.
It was heart breaking and we reported it to the seal monitoring team though there appeared to be little that could be done.
Having shared with BSAC - British Sub-Aqua Club marine champions the Seal Alliance shared more about the problems of entanglement and a petition to ban the sale of flying rings which can cause seals so much suffering.
So sad to see playful seals pay the price for discarded and lost beach toys.
I see ASDA are stocking the flying rings that can so easily harm seals. £2 each.
The Seal Alliance Every signature helps bring us one step closer to protecting the marine life we all care about.
🦭 Please sign the petition today and share it with your club, dive buddies, friends and family.
👉 https://c.org/N7Mv6YTN2f

13/07/2026

BSAC - British Sub-Aqua Club are great advocates for our Portunus project and are keen to encourage others to learn more about their local waters. Thank you BSAC for you encouragement and support.

11/07/2026

More details from the intertidal surveys at the Kench. The Crab Hacker Challenge!

09/07/2026

It was a pleasure to host Helen and Rachel co-founders of Sea-Changers and a team from Sea-Change Wine for an intertidal survey at the Kench, Hayling Island. Their generous grant funding is supporting Portunus surveys to record marine habitats and species in Langstone and Chichester harbours.
Everyone was soon exploring the shallow water looking for crabs (and crab hacker barnacles) and non-native species whilst also learning about the diverse marine life that can be found here.
Highlights included 'Warty Doris', Tufty Chiton, Pacific Oysters sea squirts, sea grass and hundreds of green crabs.
We were also very pleased to welcome Sophie Heptonstall Head of Diving and Training and Vice President Jane Maddocks from BSAC - British Sub-Aqua Club and Georgios Georgiou Environment Officer for Langstone Harbour Board who, on day 3 of his new job was soon joining the fun.
Our sincere thanks to all that took part and for their continued support.

28/06/2026

Our final species for Invasive Species Week is the Japanese Sea Spider. (Ammothea hilgendorfi)
This spider is classified Non-Native rather than Invasive as it does not pose a risk to the environment, economy or health. Only 10-15% of Non-native Species are classified as 'Invasive'.
The spider is a gangly species, translucent yellowish brown to cream in colour, with brown or purplish banding on its long slender legs. It has a prominent proboscis and very small abdomen.
It is native to tropical and temperate waters of the North Pacific. The Japanese Sea Spider was first observed in British waters in 1978 in Southampton Water.
It feeds on hydroids, In all species of sea spiders, males exclusively carry the eggs until they hatch. During mating, the female transfers her eggs to the male who holds them with a specialized pair of legs called ovigers before fertilizing them externally. The male then glues the eggs into clusters and carries them until hatching occurs.
It's a small, easily overlooked species can be just as important to record as larger, more obvious ones.
Project Portunus has recorded Japanese Sea Spider living amongst seaweed and rocks, inhabits intertidal and shallow subtidal waters and may be found among subtidal algae. It's a good illustration to show the value of careful observation.
Thank you to everyone helping to notice, photograph and record marine life in Langstone and Chichester Harbours and beyond. Keep looking closely, keep sharing records, and help stop the spread: Check, Clean, Dry.