Invasive Tunicates at Shellfish Restoration and Aquaculture Sites
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70.8°W 41.3°N 41.4°N 41.5°N 70.7°W 70.6°W 70.5°W Martha’s Vineyard Massachusetts, USA Lake Tashmoo Lagoon Pond Menemsha Pond Tisbury Great Pond Edgartown Great Pond Oak Bluffs Harbor Katama Bay Pocha Pond Sengekontacket Pond N B. violaceus B. schlosseri D. vexillum D. listerianum S. clava M. manhattensis A. aspersa C. intestinalis D. albidum A. constellatum A. irradians irradians C. virginica M. mercenaria M. arenaria S Q C C C S S S S O S O O C O Q S O Q S Q N A T I O N A L O C E A N I C A N D A T M O S P H E R I C A D M I N I S T R A T I O N U . S . D E P A R T M E N T O F C O M M E R C E NOAA Acknowledgements We extend gratitude to our field assistants Hannah Allen and Mimi Carman, shellfish constables and deputy consta- bles Paul Bagnall, Warren Gaines, Andrew Jacobs, Derek Cimeno, Fred Benson, Alex Bailleres, Peter Estrella, Danielle Ewart, shellfisherman Jeff Clements, scuba divers from the EPA Atlantic Division, Narragansett, Rhode Island, and pho- tographers Dann Blackwood and Amy Nevala. This project received support from Woods Hole Oceanographic Institu- tion, NOAA Aquatic Invasive Species Program, Martha’s Vineyard Shellfish Group, Inc., Sailors’ Snug Harbor of Boston, and the Link Foundation. Abstract Shellfish restoration efforts on the island of Martha’s Vineyard, Massachusetts are impacted by invasive tunicate species. Several species of non-endemic tunicates invaded New England marine coastal and offshore habitats in the 1980s and 1990s. While the presence of invasive tunicates is well documented at harbors and marinas in New England, there are few published reports on tunicates at shellfish restoration areas and aquaculture farms. Species such as bay scallops Argopecten irradians irradians, Eastern oysters Crassostrea virginica, quahogs Mercenaria mer- cenaria and soft shelled clams Mya arenaria are being cultured and stocked on Martha’s Vineyard in Lagoon Pond, Lake Tashmoo, Menemsha Pond, Sengekontacket Pond, Katama Bay, Poacha Pond, Edgartown Great Pond and Tis- bury Great Pond. Our surveys of shellfish restoration areas indicate that the invasive colonial tunicates Botrylloides violaceus, Botryllus schlosseri, Didemnum vexillum, Diplosoma listerianum, and solitary tunicates Ascidiella aspersa, Ciona intestinalis, Styela clava were common. The native tunicates Aplidium constellatum, Didemnum albidum, Molgula manhattensis were found to be less common among the fouling organisms on cultured shellfish and shell- fish equipment. Untreated aquaculture equipment and cultured shellfish were infested with tunicates in areas with salinities of 28.0 to 33.5. Shellfish in bottom sediments were not fouled with tunicates. Treatment methods such as the spraying of aquaculture gear and shellfish with freshwater, shellfish dipping in salt brine and air-drying were found to be effective biofouling control practices. Native and invasive species designation of Martha’s Vineyard tunicate fauna (dates of introduction to New England given in parentheses) Native species: Invasive species: Aplidium constellatum Ascidiella aspersa (introduced 1980s) Didemnum albidum Botrylloides violaceus (introduced 1970s) Molgula manhattensis Botryllus schlosseri (introduced early 1800s) Didemnum vexillum (introduced 1980s) Cryptogenic species: Diplosoma listerianum (introduced 1980s) Ciona intestinalis Styela clava (introduced 1970s) Geographic distribution of tunicate species and shellfish (cultured and wild) species on Martha’s Vineyard in 2008 Notice that more than one species of tu- nicate occurred per location, Botrylloides violaceus was the most common tunicate species, Didemnum albidum and Aplidium constellatum (native species) were the least common, both colonial and solitary tuni- cates were present at each location where tunicates occurred, no tunicates were found in lower salinity waters (Edgartown Great Pond and Tisbury Great Pond). David Grunden, Peter Estrella (in back), Jeff Clements, Mary Car- man, Mimi Carman in an Oak Bluffs Shellfish Department boat. We were preparing to mark the infestation of tunicates on the remain- ing eelgrass meadow in Sengekontacket Pond, at Major’s Cove, us- ing a GPS unit, viewer buckets, temporary buoys, and a volunteer crew of scuba and snorkel divers. Sengekontacket Pond is a bay scallop restoration site for the towns of Oak Bluffs and Edgartown. The invasive sponge Halichondria panicea (next to the scallop) has a commensal, mutualistic relationship with scallops and does not cause harm to the scallops. The invasive tunicate Botrylloides violaceus (top photo and 4 colonies on the shell of the scallop in bottom photo) will grow, merge and eventually smother the scallop to such an extent that it can no longer open to feed. Treatments currently practiced for prevention and control of tunicate fouling on shellfish and shellfish aquaculture gear during spring, summer and fall Aquacultured Shellfish Argopecten irradians irradians Scallops removed from fouled bags and placed in clean bags (replaced every 2-3 months) Mercenaria mercenaria Place quahogs in floating, chemically (peroxide) treated boxes or benthic cages that allow quahogs to burrow into sand Mya arenaria Soft shell clams (steamers) kept in cages or silos that are sprayed with freshwater for a few minutes weekly Crassostrea virginica Place oysters in lower salinity waters or in floating bags that are turned over every other week; tumble oysters or dip oysters in salt brine for 10 minutes and air dry for 1.5 hours Note: Wild bay scallops, quahogs, soft shell clams, or oysters placed in a natural habitat tend to not have tunicate fouling Shellfish Aquaculture Gear On land: Air drying for a minimum of 3 days, air drying for 3+ days then spray with freshwater, or just freshwater spray for a few minutes On water: Flip floating bags on routine (every 2 weeks) basis On scow (in water): Air dry bags for 3+ days We tested our hypothesis that wild bay scallops im- mediately adjacent to ma- jor infestations of tunicates (Martha’s Vineyard Shellfish Group, Inc., dock and aqua- culture bags at Sandy Point) would be tunicate free. Four experimental trawls (lasting on average 45 sec- onds) collected 78 live scal- lops at both sites. None of these wild living scallops had attached tunicates. Ascidiella aspersa (1), Botryllus schlosseri (2), Diplosoma listerianum (3), and Styela clava (4) were attached to the shells of bay scallops Argopecten irradians irradians in Lake Tashmoo aquaculture cages. Bay scallop spat bags with tunicate fouling that was dominated by the solitary species Ascidiella aspersa and included Aplidium constellatum, Botrylloides violaceus, Botryllus schlosseri, Didemnum vexillum in Lagoon Pond, near Sandy Point. Sailors’ Snug Harbor of Boston 1 Martha’s Vineyard Shellfish Group, Inc., P.O. Box 1552, Oak Bluffs, Massachusetts 02557 USA; phone 508-693-0391; e-mail [email protected] 2 Town of Oak Bluffs Shellfish Department, P.O. Box 1327, Oak Bluffs, Massachusetts 02557 USA; phone 508-693-0072; fax 508-696-6472; e-mail [email protected] 3 Woods Hole Oceanographic Institution, Geology and Geophysics, Woods Hole, Massachusetts 02543 USA; phone 508-289-2987; fax 508-457-2183; e-mail [email protected] 4 NOAA, National Ocean Service, National Centers for Coastal Ocean Science, 101 Pivers Island Road, Beaufort, North Carolina 28516 USA; phone 252-728-8782; fax 252-728-8784; e-mail [email protected] 5 Woods Hole Oceanographic Institution, Marine Policy Center, Woods Hole, Massachusetts 02543 USA; phone 508-289-2867; e-mail [email protected] Richard Karney 1 , David Grunden 2 , Mary Carman 3 , James Morris 4 , Porter Hoagland 5 Invasive Tunicates at Shellfish Restoration and Aquaculture Sites on Martha’s Vineyard, Massa chusetts Mya arenaria and silos were kept free of tunicates by spraying with freshwater weekly. An abundance of tuni- cates were close by, attached to the wooden sides of the upweller system (see inset above). Right: David Grunden displays a floating, puffy aquaculture bag for oysters. The upper surface of the bag protrudes out of the water and is exposed to air to control fouling. In the background are floating bags of oysters in Menem- sha Pond. Left: Shellfisherman Art MacIn- tosh in Lake Tashmoo raked for wild (restored) quahogs. Wild quahogs that live free in the ben- thos were tunicate free. Martha’s Vineyard Shellfish Group, Inc. dock on Lagoon Pond had: Ascidiella aspersa, Botrylloides violaceus, Botryllus schlosseri, Didemnum vexillum, Diplosoma listerianum, and Styela clava fouling ropes, shellfish cages, and bay scallops. 1 1 1 2 3 3 3 4 4 4 4 4
Transcript of Invasive Tunicates at Shellfish Restoration and Aquaculture Sites
70.8°W
41.3°N
41.4°N
41.5°N
70.7°W 70.6°W 70.5°W
Martha’s VineyardMassachusetts, USA
LakeTashmoo
LagoonPond
MenemshaPond
TisburyGreat Pond
EdgartownGreat Pond
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KatamaBay
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B. violaceusB. schlosseriD. vexillumD. listerianumS. clavaM. manhattensisA. aspersaC. intestinalisD. albidumA. constellatum
A. irradians irradiansC. virginicaM. mercenariaM. arenaria
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Acknowledgements We extend gratitude to our field assistants Hannah Allen and Mimi Carman, shellfish constables and deputy consta-
bles Paul Bagnall, Warren Gaines, Andrew Jacobs, Derek Cimeno, Fred Benson, Alex Bailleres, Peter Estrella, Danielle Ewart, shellfisherman Jeff Clements, scuba divers from the EPA Atlantic Division, Narragansett, Rhode Island, and pho-tographers Dann Blackwood and Amy Nevala. This project received support from Woods Hole Oceanographic Institu-tion, NOAA Aquatic Invasive Species Program, Martha’s Vineyard Shellfish Group, Inc., Sailors’ Snug Harbor of Boston, and the Link Foundation.
AbstractShellfish restoration efforts on the island of Martha’s Vineyard, Massachusetts are impacted by invasive tunicate
species. Several species of non-endemic tunicates invaded New England marine coastal and offshore habitats in the 1980s and 1990s. While the presence of invasive tunicates is well documented at harbors and marinas in New England, there are few published reports on tunicates at shellfish restoration areas and aquaculture farms. Species such as bay scallops Argopecten irradians irradians, Eastern oysters Crassostrea virginica, quahogs Mercenaria mer-cenaria and soft shelled clams Mya arenaria are being cultured and stocked on Martha’s Vineyard in Lagoon Pond, Lake Tashmoo, Menemsha Pond, Sengekontacket Pond, Katama Bay, Poacha Pond, Edgartown Great Pond and Tis-bury Great Pond. Our surveys of shellfish restoration areas indicate that the invasive colonial tunicates Botrylloides violaceus, Botryllus schlosseri, Didemnum vexillum, Diplosoma listerianum, and solitary tunicates Ascidiella aspersa, Ciona intestinalis, Styela clava were common. The native tunicates Aplidium constellatum, Didemnum albidum, Molgula manhattensis were found to be less common among the fouling organisms on cultured shellfish and shell-fish equipment. Untreated aquaculture equipment and cultured shellfish were infested with tunicates in areas with salinities of 28.0 to 33.5. Shellfish in bottom sediments were not fouled with tunicates. Treatment methods such as the spraying of aquaculture gear and shellfish with freshwater, shellfish dipping in salt brine and air-drying were found to be effective biofouling control practices.
Native and invasive species designation of Martha’s Vineyard tunicate fauna (dates of introduction to New England given in parentheses)
Native species: Invasive species:
Aplidium constellatum Ascidiella aspersa (introduced 1980s)
Didemnum albidum Botrylloides violaceus (introduced 1970s)
Molgula manhattensis Botryllus schlosseri (introduced early 1800s)
Didemnum vexillum (introduced 1980s)
Cryptogenic species: Diplosoma listerianum (introduced 1980s)
Ciona intestinalis Styela clava (introduced 1970s)
Geographic distribution of tunicate species and shellfish (cultured and wild) species on Martha’s Vineyard in 2008
Notice that more than one species of tu-nicate occurred per location, Botrylloides violaceus was the most common tunicate species, Didemnum albidum and Aplidium constellatum (native species) were the least common, both colonial and solitary tuni-cates were present at each location where tunicates occurred, no tunicates were found in lower salinity waters (Edgartown Great Pond and Tisbury Great Pond).
David Grunden, Peter Estrella (in back), Jeff Clements, Mary Car-man, Mimi Carman in an Oak Bluffs Shellfish Department boat. We were preparing to mark the infestation of tunicates on the remain-ing eelgrass meadow in Sengekontacket Pond, at Major’s Cove, us-ing a GPS unit, viewer buckets, temporary buoys, and a volunteer crew of scuba and snorkel divers. Sengekontacket Pond is a bay scallop restoration site for the towns of Oak Bluffs and Edgartown.
The invasive sponge Halichondria panicea (next to the scallop) has a commensal, mutualistic relationship with scallops and does not cause harm to the scallops. The invasive tunicate Botrylloides violaceus (top photo and 4 colonies on the shell of the scallop in bottom photo) will grow, merge and eventually smother the scallop to such an extent that it can no longer open to feed.
Treatments currently practiced for prevention and control of tunicate fouling on shellfish and shellfish aquaculture gear during spring, summer and fall
Aquacultured Shellfish
Argopecten irradians irradians Scallops removed from fouled bags and placed in clean bags (replaced every 2-3 months)
Mercenaria mercenaria Place quahogs in floating, chemically (peroxide) treated boxes or benthic cages that allow quahogs to burrow into sand
Mya arenaria Soft shell clams (steamers) kept in cages or silos that are sprayed with freshwater for a few minutes weekly
Crassostrea virginica Place oysters in lower salinity waters or in floating bags that are turned over every other week; tumble oysters or dip oysters in salt brine for 10 minutes and air dry for 1.5 hours
Note: Wild bay scallops, quahogs, soft shell clams, or oysters placed in a natural habitat tend to not have tunicate fouling
Shellfish Aquaculture Gear
On land: Air drying for a minimum of 3 days, air drying for 3+ days then spray with freshwater, or just freshwater spray for a few minutes
On water: Flip floating bags on routine (every 2 weeks) basis
On scow (in water): Air dry bags for 3+ days
We tested our hypothesis that wild bay scallops im-mediately adjacent to ma-jor infestations of tunicates (Martha’s Vineyard Shellfish Group, Inc., dock and aqua-culture bags at Sandy Point) would be tunicate free. Four experimental trawls (lasting on average 45 sec-onds) collected 78 live scal-lops at both sites. None of
these wild living scallops had attached tunicates.
Ascidiella aspersa (1), Botryllus schlosseri (2), Diplosoma listerianum (3), and Styela clava (4) were attached to the shells of bay scallops Argopecten irradians irradians in Lake Tashmoo aquaculture cages.
Bay scallop spat bags with tunicate fouling that was dominated by the solitary species Ascidiella aspersa and included Aplidium constellatum, Botrylloides violaceus, Botryllus schlosseri, Didemnum vexillum in Lagoon Pond, near Sandy Point. Sailors’ Snug Harbor
of Boston
1Martha’s Vineyard Shellfish Group, Inc., P.O. Box 1552, Oak Bluffs, Massachusetts 02557 USA; phone 508-693-0391; e-mail [email protected] of Oak Bluffs Shellfish Department, P.O. Box 1327, Oak Bluffs, Massachusetts 02557 USA; phone 508-693-0072; fax 508-696-6472; e-mail [email protected]
3Woods Hole Oceanographic Institution, Geology and Geophysics, Woods Hole, Massachusetts 02543 USA; phone 508-289-2987; fax 508-457-2183; e-mail [email protected], National Ocean Service, National Centers for Coastal Ocean Science, 101 Pivers Island Road, Beaufort, North Carolina 28516 USA; phone 252-728-8782; fax 252-728-8784; e-mail [email protected]
5Woods Hole Oceanographic Institution, Marine Policy Center, Woods Hole, Massachusetts 02543 USA; phone 508-289-2867; e-mail [email protected]
Richard Karney1, David Grunden2, Mary Carman3, James Morris4, Porter Hoagland5
Invasive Tunicates at Shellfish Restoration and Aquaculture Sites on Martha’s Vineyard, Massachusetts
Mya arenaria and silos were kept free of tunicates by spraying with freshwater weekly. An abundance of tuni-cates were close by, attached to the wooden sides of the upweller system (see inset above).
Right: David Grunden displays a floating, puffy aquaculture bag for oysters. The upper surface of the bag protrudes out of the water and is exposed to air to control fouling. In the background are floating bags of oysters in Menem-sha Pond. Left: Shellfisherman Art MacIn-tosh in Lake Tashmoo raked for wild (restored) quahogs. Wild quahogs that live free in the ben-thos were tunicate free.
Martha’s Vineyard Shellfish Group, Inc. dock on Lagoon Pond had: Ascidiella aspersa, Botrylloides violaceus, Botryllus schlosseri, Didemnum vexillum, Diplosoma listerianum, and Styela clava fouling ropes, shellfish cages, and bay scallops.
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