The 2011 Coastwatch season has started and is well under way. In my first year participating in the CZM Marine Invasive Species Program, I am joining the monitoring teams at Salem Sound Coastwatch, coordinated by Barbara Warren, and Provincetown Center for Coastal Studies, coordinated by Beth Larson. In June, Adrienne Pappal of the CZM hosted a launching workshop in Barnstable for the Cape Cod Group and Barbara organized a workshop on Winter Island for the Salem Sound group.
Earlier in the season, I made a pre-summer visit to Provincetown and Wellfleet Harbors (late May) to gather information about dock configurations and to assess overwintered and cleaned surfaces. The July surveys have just passed and August monitoring dates are scheduled. For the 2011 summer season, the CZM designated the following 16 species as Marine Invasive:
Invertebrates (includes Ascidians, Bryozoans, Anthozoans, Molluscs, and Crustaceans):
- Didemnum vexillum (mystery beige colonial tunicate)
- Diplosoma listerianum (green/brown colonial tunicate)
- Ascidiella aspersa (bumpy translucent tunicate) (solitary)
- Styela clava (club tunicate) (solitary)
- Botryllus schlosseri (star colonial tunicate)
- Botrylloides violaceus (orange colonial tunicate)
- Membranipora membranacea (lacy crust bryozoan) (single layer of zooids)
- Bugula neritina (purple bushy bryozoan) (branching upright growth)
- Diadumene lineata (orange striped anemone)
- Ostrae edulis (European oyster)
- Carcinus maenus (green crab)
- Hemigrapsus sanguineus (asian shore crab)
- Palaemon elegans (European rock shrimp)
- Caprella mutica (Caprellid amphipod, skeleton shrimp)
- Codium fragile (green fleece)
- Grateloupia turuturu (leafy red algae)
Each location and substrate has a unique distribution of species. The ascidians Styela clava, Botryllus schlosseri, and Botrylloides violaceus are common invertebrates found in marinas on flotation devices. Mooring ropes which stay suspended in the water during the summer are prime settlement substrates for algae, ascidians, bryozoans, anemones, and bivalves.
Styela clava, Botryllus schlosseri, and Botrylloides violaceus
on a rope at MacMillan Wharf, Provincetown, MA
on a rope at MacMillan Wharf, Provincetown, MA
The large, solitary Styela clava and the bright orange colonial Botrylloides violaceus on the rope are instantly recognized, but the colonial Botryllus schlosseri to the left takes closer examination to evaluate the number and size of colonies.
Botryllus schlosseri - Close-Up View
Underwater photograph of Botryllus schlosseri by Rokus Groeneveld - http://www.diverosa.com/
Botryllus schlosseri - Microscopic View
Botryllus schlosseri - Close-Up View
Botryllus schlosseri - Microscopic View
Botryllus schlosseri zooids are arranged in small, star-shaped groups.
Light and dark-pigmented cells give the colony its dual star-patterned coloration.
Stereomicroscopic image recorded with QImaging 5.0 MicroPublisher Camera
and QCapture software.
Other common invasive ascidians include Didemnum vexillum, Diplosoma listerianum, and Ascidiella aspersa, but these species are not equally present throughout the area (data available at MORIS webpage link). In addition, Ciona intestinalis (classified by the CZM as cryptogenic, but in some studies included as invasive or non-indigenous) and the native ascidians Aplidium sp. (sea pork) and Molgula sp. (sea grape) have been seen at the monitoring sites, too. On the other hand, the native stolidobranch solitary species, Boltenia ovifera (sea potato, stalked tunicate) and Halocynthia pyriformis (sea peach) are subtidal in Massachusetts Bays, prefering colder water, and are not usually encoutered in these shoreline studies.
In future posts, I'll take a closer look at some of these species in more detail, and in the process, hopefully we'll learn more about the fauna and flora of our coastline. Additional histologic and stereoscopic images will also be appearing at http://www.seapeachbio.com/ and http://www.tunicarium.com/.
(Photocredits: Photographs and micrographs by Tom Ermak unless specified here or in the caption.
Photograph of Tom surveying docks by Carl Johnson)
Photograph of Tom surveying docks by Carl Johnson)
