Invasive tunicates

[waterkitty]

Thanks everyone. Hmmm. more details...I got it...http://convoluta.ucdavis.edu/galler...me=West-Coast-Tunicates&id=Didemnum_vexillum2

Scroll through here for Didemnum. Now on this site, it is known as Didemnum vexillum. It's the same thing as Didemnum lahillei.

If you are not sure that's what you see, that'd be fine. I wouldn't mind checking it out anyway. My main goal is to see how widespread they are, already it seems to me they are making quite the appearance.

I will try to provide as much info as I can. Remember, this is a relatively unknown species. I will do my best.

 

[waterkitty]

Kinda looks like this:
http://woodshole.er.usgs.gov/project-pages/stellwagen/didemnum/images/jpg/indexpage/lh_ne_coast.jpg

Thank you, aquageek. That's the pic I should have used.

 

[waterkitty]

While there are many species of tunicates, native to our area, this specific species is the only one that looks like it does in the pics. It's encrusting and yellowish-white. Usually it likes to overgrow mussels and on pilings and other debris. Rarely, but not never, does it encrust over the sea floor.
If you look closely at the tunicate, you can see it's siphons, and being colonial, it just grows in a big mass. If you see a big mass of white stuff growing on anything, it's more than likely Didemnum.
There may or may not be a bright orange mass nearby. This is Botrylloides, another invasive tunicate that has been around a while. They seem to inhabit similar areas. But again this is speculation.

Do we have native species (or is a tunicate a specie) of tunicates? How would we tell the difference? I've seen things that look similar but not so sure and hate to give a false report. Have any Marine Biology Book Pictures of them all cleaned up and pretty for us? Sad part is I forgot my glasses today and can't even see the mussels. I am diving two sites this weekend one South Shore MA and one North Shore MA, if I see anything I'll snap a pic for you and you can decide. Good Luck with your project. Hey maybe Gabe's Friend can grab a handful for a snap shot. (just kidding Gabe).

P

 

[waterkitty]

Thank you. This is valuable information.
I believe fishers have found it before the 'discovery' as well and were using it to scrub their nets. I think the scientists are more or less credited with identifying it as an invasive tunicate. Maybe 'discover' isn't the proper term.

Saw that stuff all over the Plymouth, Massachusetts area dive sites nearly two years ago. Covered pretty much everything at a dive site called Indian Hills. I have not seen it farther north in Gloucester, Massachusetts or Maine.

DSDO

Alan

 

[MSilvia]

Okay Linda, I'll keep a lookout for it.

 

[waterkitty]

Scubastew,
Thank you. I bet you did see this at Sandwich town beach. It has been noted to exist there, as well as serve as food (!) for some local species.
Check out the link I posted and that aquageek posted. These are the best pics close up.

Linda, definitely need a better picture or characteruistics that will distinquish this from other similiar species. I too believe I have seen this at Sandwich town beach and Breant rock beach, but cant be sure without more info from you. thanks. I'm sure we'll all gladly help you out. You'll find most divers are very concerned and environmentally conscience.

 

[waterkitty]

90-100 ft...interesting...
Thanks for the info.

The first place I've noticed them was diving off Isle of shoals. I had never noticed them before until I dove there as they were so many. Mostly 90-100 feet diving Cedar ledge.

I also see them a lot in Portsmouth channel (Shore diving off Pierce Island)

More than happy to show you where.

 

[reefseal]

90-100 ft...interesting...
Thanks for the info.

Where I see it the most is on walls.. Pierce Island is a wall dive. It drops down to 70 feet and I see tons of it on the walls. I don't know if it's because of constant currents in river. (I dive during brief slack period) It's soft and gushy to touch..

Also off Consitution point.

 

[reefseal]

Hey Luis,

how was your dive today? Wasn't it raining?

Great! I was able to squeeze in a 3 fer.. Was close as had a last minute conf. call.. One of those, get out of water, get out of gear, shove in car and go to spot have strong signal on cell to do call.

Did Folly cove first. Always great. Went on left side, beyond point..

Did two at Lanes cove. Vis was better there. Saw some decent keepers but was just looking as don't have license. Some huge mongo bug was able to entice out just to mess with him.. This was a finger loser kind. (can easily cut pinky off!)

Was sunny when I got there. I hit rain on way in but was clear on Cape Ann. Seas were calm as there were NO Winds!

Luis

 

[Cecil]

Well it looks like it's got quite foothold on Back Beach. I also saw it this year between Front and Back Beach. Here's another picture from Back Beach two years ago.

Picture