Looks like an ornamental bramble (spineless) but growing wild next to the saltmarsh by the River Avon.
No interactions present.
Know it well, I have a steep bank in my garden where I planted this as a ground cover.The fruits are edible(just!).Is mentioned in Stace, and naturalized in parts of the UK. Is quite invasive but an excellent ground cover plant.
David J Trevan
Lat/Lng: 51.4842, -2.6686
OS grid ref: ST536763