Question: what makes the squirt dangerous, as to me it appears to be an innoxious specemin

Leathery Sea Squirt answered on 10 Nov 2017:

Good question! When we say a species is dangerous, we don’t always mean in the ‘likely to bite your face off’ sense. Sea squirts are ‘dangerous’ because they are very hardy, and good at rapidly breeding in new areas. Because some ecosystems are very delicate, an invasive species like the sea squirt coming in and taking up valuable space and resources can be really bad for some of the species which lived in that area already.
It is already known that sea squirts can have a negative impact on muscle and oyster farms, but they may have other negative effects in other ecosystems we don’t know about yet. If we can control their spreading to new places, that would probably be a good thing…