Sea spiders and Asian crabs: new invasive species threatening Jersey marine life

Phil Wellbrook went to find some of the new species that could be threatening Jersey's marine life...

A marine researcher who monitors invasive wildlife around Jersey's coastline has found an increasing number of species typically found in warmer waters.

Chris Isaacs has spotted new species of sea slugs, sea spiders and Asian shore crabs which would not have been seen last year.

He suspects the invasive species are migrating north as the water gets warmer.

Scientists do not know the long-term effect this will have on the local marine ecosystem and Chris fears that the new creatures will displace local species.

Some of the sea spiders found at La Rocque in Jersey. Credit: ITV Channel

Pacific Brown Banded sea spiders are feeding on local species, whilst - Xantho hydrophilus - or Montagu's crabs are displacing them from their habitats.

Chris says: "About ten years ago it was quite difficult to find them, now they're under pretty much most rocks in most rock pools.

"They are having an impact because they're displacing other local species and it is related to warming sea temperatures.

"So effectively it's a native species behaving like an invasive."

A sea spider in one of the tanks. Credit: ITV Channel

As well as studying the creatures in their ocean habitats, Chris also brings some of the species back home to his tanks.

He says: "There's only so much you can learn from studying creatures in their natural environment.

"So I've got study tanks at home where I keep a lot of these invasive species just to see how they behave.

"It's quite an effective way of learning a bit more about them and what impacts they could potentially have."