Stand on the shoreline and take in the vast views across the waters of Chichester Harbour… The surface shimmers, changing from blue to green to grey. But have you ever wondered, what lies beneath?
Environmental DNA analysis
Recent “Environmental DNA” water sampling offers us some answers. As fish swim through the water, they leave a DNA signature behind. With careful sampling and analysis, scientists can use this Environmental DNA to know just what fish have been in that water in the minutes and hours before sampling.
Since 2023 staff from Chichester Harbour Conservancy and Portsmouth University have been collecting samples as part of the Solent Seascape Project. Focussed on restoring coastal habitats including saltmarsh, seagrass, native oyster and coastal bird habitats, quality scientific evidence is a vital part of the project. Environmental DNA is one of many scientific techniques used to assess how restoring coastal ecosystems is impacting marine life.
58 species of fish
So, what have they found so far? The samples analysed to date have detected 58 different species of fish. The most-commonly found were Sea Bass, Common Goby, Grey Mullet, Black Seabream and Sand Smelt. There were some rarities too, including the critically endangered European Eel.
Sharks!
There were also sharks and rays! The Small-spotted Catshark, Starry Smoothhound, Spotted Skate and Thornback Ray were all detected.
Seahorses
But perhaps most astonishingly, was the presence of seahorses! Not just the inhabitants of tropical reefs, two species of seahorse make their home right here in Chichester Harbour. Both the Long-snouted and Short-snouted Seahorse have been detected through their environmental DNA. It is likely that they make use of our intertidal seagrass meadows. They’re notoriously poor swimmers and rely on their tails to hold on to seagrass and seaweed to avoid being swept away!
Visit www.solentseascape.com to find out more about the Solent Seascape Project.
Read more about “What Lies Beneath” and the finds from Project Portunus, a citizen science dive project in the 2026 edition of Harbour Life magazine. Pick up a copy at the harbour office and many locations around the harbour, or read online here.
Image: Spiny Seahorse, Robert Watkins, Project Portunus.
Cover image: Small-spotted Catshark, Martin Davies, In Depth Photography