Antarctic alert for invading mussels

Mussels may look rather mild-mannered, but they are prominent in a new list of non-native species most likely to invade the Antarctic Peninsula over the next decade. 

They fill three of the 13 spots, in fact, with the Chilean mussel and the Common blue mussel at one and two respectively. Also included are other marine or terrestrial invertebrates, a marine algae and two species of buttonweed.

The list was compiled by the British Antarctic Survey (BAS), working with researchers from Argentina, Austria, Belgium, Cyprus, Ireland, Italy, Spain, the UK and the US. 

They studied hundreds of academic papers, reports and databases to identify species most likely to invade, then selected the most threatening 13 from 103 examined in detail. The aim, they say, was to provide a baseline for operators in the region to look at mitigation measures.

“The Antarctica Peninsula region is by far the busiest and most visited part of Antarctica due to growing tourism and scientific research activities,” says BAS’s Kevin Hughes, lead author of a paper in the journal Global Change Biology.

“Non-native species can be transported to Antarctica by many different means. Visitors can carry seeds and non-sterile soil attached to their clothing and footwear. Imported cargo, vehicles and fresh food supplies can hide species, including insects, plants and even rats and mice.

“Marine species present a particular problem as they can be transported to Antarctica attached to ship hulls. They can be very difficult to remove once established.”

BAS marine biologist David Barnes says marine invertebrates such as mussels and crabs are top of the list because they can survive in polar waters and spread easily. 

“When they establish, they can dominate life by smothering the native marine animals that live on the seabed,” he says.

The good news is that while rats, mice or other vertebrates have already invaded sub-Antarctic islands such as Marion Island and South Georgia, this is not expected to happen on the Antarctic Peninsula, at least in the near future anytime soon.

“We think the conditions in the Antarctic Peninsula region will remain too extreme to allow rodents to colonise outside,” says Helen Roy, an ecologist at the UK Centre for Ecology & Hydrology, who oversaw the study.

“However, rats and mice could survive by hiding within research station buildings, so everyone needs to remain vigilant for droppings and gnaw marks”.

Some non-native species have already established themselves near research stations and visitor sites. 

The new list of possible invaders is:

1. Chilean mussel (Mytilus chilensis) – marine invertebrate

2. Common blue mussel (Mytilus edulis) – marine invertebrate

3. Springtail (Protaphorura fimata) – terrestrial invertebrate

4. Mite (Nanorchestes antarcticus) – terrestrial invertebrate

5. Flattened crab (Halicarcinus planatus) – marine invertebrate

6. Sea vase (Ciona intestinalis) – marine invertebrate

7. Buttonweed (Leptinella scariosa) – terrestrial plant

8. Colonial Ascidian (Botryllus schlosseri) – marine invertebrate

9. European shore crab (Carcinus maenas) – marine invertebrate

10. Asian kelp (Undaria pinnatifida) – marine algae

11. Buttonweed (Leptinella plumose) – terrestrial plant

12. Parchment worm (Chaetopterus variopedatus) – marine invertebrate

13. Mediterranean mussel (Mytilus galloprovincialis) – marine invertebrate