Invader mussels encroach on British beaches
They might look harmless, but these Asian Date mussels are actually foreign invaders - and they could have an effect on Britain's native sealife, including its own oysters and mussels.
The species is native to the west Pacific, but now, the Asian Date Mussel has been spotted in the UK - and a marine biologist has warned that it's not likely to be a good thing.
Scientists don't know exactly how this new arrival will affect habitats of British wildlife - but invasive species tend to have dramatic impacts on ecosystems and global economies, and can drive others that share their environment into extinction.
Find out more in the video above.