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MEET MASSACHUSETTS' INVASIVE SPECIES

All About Invasive Species

  • ​Invasive species are organisms that are not native to an ecosystem that can potentially cause harm to native species in the area.

  • These species are introduced to new ecosystems, usually through human activities, by means of trade and travel, but can also be dispersed through natural pathways.

  • While some invasive species are able to coexist with native species and cause minimal harm, most times there is a threat to the newly inhabited ecosystem and the organisms living there.

  • When entering a new habitat with different environmental conditions, invasive species may be able to out-compete the native species simply due to novelty. They may have better defenses against predation and/or stressors, or may have the ability to exploit different resources. This includes being bigger than native species, more aggressive towards similar species or predators, having better camouflage, and being poisonous or venomous. Invasive species can outcompete similar species for shelter and nutrients, causing the native species to become both more exposed and weaker. If the invasive species' advantage is too great, they will face little competition. As a result, the population grows rapidly, interrupting the natural ecosystem, which poses threats for native species and can even affect humans as well.

Below are some informational cards on many common invasive species found in the Northeast including:​
​
  • Information about what the species is
  • Why it is classified as invasive
  • Ways that we can help reduce them

  • ● Small clam, averaging less than 1.5 inches and rarely exceeding 3 inches
    ● Their shells can either be light green or light brown with distinctive elevated concentric
    ridges on their shell
    ● They were first reported in the United States in 1930, and have since spread to over 39 states
    ● Prolific and highly competitive species that is capable of fast growth and spread
    ● Can displace native species, reduce biodiversity, alter the food chain, and damage equipment such as boat mortars, intake pipes,
    diving gear, and commercial water systems

  • ● Mechanical methods, such as screens and traps
    ● Chemical control uses chlorine to kill juvenile clams but is limited due to chemical restrictions
    ● Temperature alteration can be used in water intake pipes to reduce clam presence

Asian Clam (Corbicula fluminea)

References:

DCR Massachusetts. (n.d.) Asian clam: An exotic aquatic species. (https://www.mass.gov/doc/asian-clam-0/download)Global Invasive Species Database (2023). Species profile: Corbicula fluminea (http://www.iucngisd.org/gisd/speciesname/Corbicula+fluminea)

Photo: Holger Krisp, License (CC BY-4.0)

  • ● Small shore crab with square greenish black to orangish red carapace and banded walking legs
    ● Extremely competitive with other invasive and native species, removing them from their habitats and taking food from them
    ● Native to Western Pacific shores and likely arrived as a result of trade ships
    ● Eats three common native bivalves in Southern New England and Mid-Atlantic Coasts

    ​

    Click here to view a more in-depth presentation on Invasive Crabs

  • ● Mitigate through removal processes like eating them or using them as bait.
    ● Prevent the spread through ballast and other sea transportation methods.
    ● Spread awareness of the damages
    ● Research is being done to determine best practices for removal or integration of the
    species but is not yet conclusive

Asian Shore Crabs (Hemigrapsus sanguineus)

References:

Global Invasive Species Database (2023). Species profile: Hemigrapsus sanguineus.(http://www.iucngisd.org/gisd/speciesname/Hemigrapsus+sanguineus)

Photo: Jason M Crockwell, License (CC BY-NC-ND)

  • ● Has a pistillate that is usually brown in color and has a fuzzy texture on top and long tapering leaves on the green stalk
    ● Usually around 4-9 feet tall
    ● Considered invasive in all parts of the U.S.
    ● The leaves can create a thick layer on the ground, disrupting growth in many other species and organisms
    ● Cattails have a very dense root system

  • ● Mechanical removal and use of herbicides such as Glyphosate, Imazamox, Imazapyr, and Diquat
    ● Check boating and fishing equipment for the Broadleaf Cattail (and their seeds)

Broadleaf Cattail (Typha latifolia)

References:

Global Invasive Species Database (2023). Species profile: Typha latifolia (http://www.iucngisd.org/gisd/speciesname/Typha+latifolia)
National Geographic Society. (2012, October 9). Invasive Species. National Geographic Society.
(https://www.nationalgeographic.org/encyclopedia/invasive-species/)

Photo: Vyacheslav Makodin

  • ● Fully submerged plant except for leaves and flower
    ● Spreads by stem fragments and can free float for some time without being attached to roots
    ● Native to South America, Southeastern US, and commonly used as an aquarium plant
    ● Spread due to accidental release from Michigan aquarium in 1935
    ● Can clog drainage canals, contaminate drinking water, and outcompete native species by crowding or blocking sunlight

  • ● Consistent washdown of boating and fishing equipment
    ● Herbicides administered by professionals only to avoid harming native species
    ● Water drawdown to dry out the plants, artificial shading as they need light, and hand pulling are all methods of removal

Carolina Fanwort (Cabomba caroliniana)

References:
Carolina fanwort (Cabomba caroliniana) - Species Profile. (n.d.). USGS Nonindigenous Aquatic Species Database. (https://nas.er.usgs.gov/queries/FactSheet.aspx?SpeciesID=231)
Global Invasive Species Database (2023). Species profile: Cabomba caroliniana
(http://www.iucngisd.org/gisd/speciesname/Cabomba+caroliniana)

Photo: Leslie J. Mehrhoff, University of Connecticut, Bugwood.org, License (CC BY-3.0)

  • ● Brown and tan colored, with long club-shaped bodies averaging 8 inches
    ● A good portion of their length is a thin stalk
    ● They are found in shallow waters and tend to stick to docks and fishing gear
    ● When their siphons are open, alternating bands of dark and light colors can be seen on their bodies
    ● Can out-compete native species for space and food, as well as damage boating equipment

  • ● Freezing or desiccation
    ● Lower water levels can expose the club tunicate to the air, which kills them
    ● Various combinations of salinity, temperature, and exposure to air
    ● Dipping in saturated or strong salt solutions

Club Tunicate (Styela clava)

References:
Commonwealth of Massachusetts. (n.d.). Marine Invasive Species identification cards. Mass.gov.
(https://www.mass.gov/service-details/marine-invasive-species-identification-cards)
Global Invasive Species Database (2023). Species profile: Styela clava. (http://www.iucngisd.org/gisd/speciesname/Styela+clava)

Photo: Eric A. Lazo-Wasem, License (CC0 1.0)

  • ● Non-native grass that grows tall and dense along marshes, blocking sunlight from native plant life
    ● Native to North America, Europe, and the Middle East - invasive strains came from Europe in the 1800s, likely introduced by ship
    ballasts
    ● Increases risk of marsh fires
    ● Can damage structure of marshes
    ● Decreases ability to reduce mosquito populations as reeds are too thick to get through effectively

  • ● Landowners can eliminate or reduce fertilizer, herbicide and pesticide use
    ● Do not purposely plant it; instead consider planting only native species in gardens
    ● Avoid transporting Phragmites either via equipment or as compost
     

    Seaside Sustainability is monitoring populations on the North Shore to experiment with organic alternatives to the current eradication methods. This initiative is used as a means of restoring the marsh, organically, safely, and responsibly.

Common Reed or Phragmites (Phragmites australis)

References:
Global Invasive Species Database (2023). Species profile: Phragmites australis. (http://www.iucngisd.org/gisd/species.php?sc=301)
USDA. (n.d.). Common Reed. National Invasive Species Information Center. (https://www.invasivespeciesinfo.gov/aquatic/plants/common-reed)

Photo: PersianDutchNetwork, License (CC BY-SA 3.0)

  • ● Medium sized crab made distinguishable by 5 lateral spines on each side of its pentagon shaped carapace
    ● Native to Europe and spreads quickly and easily, especially through trade ships
    ● Competes with native crabs and responsible for negative impacts to other species such as the soft shell clam
    ● Destabilizes creek banks in salt marshes

    ​

    Click here to view a more in-depth presentation on Invasive Crabs

  • ● Mitigate through removal processes like eating them or using them as bait
    ● Prevent the spread through ballast and other sea transportation methods
    ● Spread awareness of the damages
    ● Biological controls include introducing other non harmful species that outcompete the green crabs

European Green Crabs (Carcinus maenas)

References:
Commonwealth of Massachusetts. (n.d.). Marine Invasive Species identification cards. Mass.gov.
(https://www.mass.gov/service-details/marine-invasive-species-identification-cards)
Global Invasive Species Database (2023). Species profile: Carcinus maenas. (http://www.iucngisd.org/gisd/speciesname/Carcinus+maenas)

Photo: WDFW

  • ● Mostly translucent shrimp, sometimes seen with blue and/or yellow bands on its legs depending on water conditions
    ● Shovel shaped rostrum with 7-9 teeth on top
    ● Can grow up to 2.5 inches long
    ● Native to East Atlantic and Mediterranean coasts, first appeared in New England in 2010
    ● Found along coasts and docks
    ● May increase food base for some birds and fish but can also outcompete other palaemonid shrimp

  • ● No known control mechanisms as this is a recently known issue
    ● Perform checks of ballast water to prevent further spread of invasion

European Rock Shrimp (Palaemon elegans)

References:
Commonwealth of Massachusetts. (n.d.). Marine Invasive Species identification cards. Mass.gov.
(https://www.mass.gov/service-details/marine-invasive-species-identification-cards)
Grabowski, M. (2022). Palaemon elegans (rock shrimp). CABI Compendium, CABI Compendium.
(https://doi.org/10.1079/cabicompendium.70617)

Photo: Cisamarc, License (CC BY-SA 4.0)

  • ● Egg shaped, around 5 inches long
    ● Tend to be thin, a grayish-pink color with a translucent, rough tunic
    ● Common on docks and can be found in shallow waters
    ● They have an inflow at the top of their body, with the outflow jutting out the side
    ● Impacts local fauna by redirecting food chain towards decomposers who feed on their bodies after death due to accumulating large population numbers in their habitats

  • ● Keep fishing gear away from sea squirts to avoid dragging them to unaffected areas.
    ● Dry out any equipment that can host the organism

European Sea Squirt (Ascidiella aspersa)

References:
Commonwealth of Massachusetts. (n.d.). Marine Invasive Species identification cards. Mass.gov.
(https://www.mass.gov/service-details/marine-invasive-species-identification-cards)
Nevata, A.E. (7 April, 2006). Big Trouble from Little Squirts. Woods Hole Oceanographic Institute.
(https://www.whoi.edu/oceanus/feature/big-trouble-from-little-squirts/)
Global Invasive Species Database (2023). Species profile: Ascidiella aspersa. (http://www.iucngisd.org/gisd/speciesname/Ascidiella+aspersa)

Photo: Notafly, License (CC BY-SA 3.0)

  • ● Bright green in color with spongy and rounded branches that turn white when dead
    ● Grows up to 3 feet tall and just under 8 pounds
    ● Native to Northwest Pacific, likely introduced due to shellfish aquaculture and recreational boating
    ● Attaches to hard surfaces in tide pools and shallow coastal waters, including shells of shellfish
    ● Tolerant of various water conditions
    ● Commonly found washed up on beaches, releasing a foul odor unpleasant to beachgoers
    ● Fouling of shellfish beds leads to smothering of many commercially fished species

  • ● No known control mechanisms as this is a recently known issue
    ● Perform checks of ballast water to prevent further spread of invasion

Green Fleece, Dead Man’s Fingers (Codium fragile)

References:
Commonwealth of Massachusetts. (n.d.). Marine Invasive Species identification cards. Mass.gov.
(https://www.mass.gov/service-details/marine-invasive-species-identification-cards)
Global Invasive Species Database (2023). Species profile: Codium fragile.
(http://www.iucngisd.org/gisd/speciesname/Codium+fragile+ssp.+tomentosoides)

Photo: Flyingdream

  • ● Long, thin shrimp with mottled red body and spines along its back
    ● Can be over 2 inches long
    ● Native to Northwest Pacific, first introduced to Northwest Atlantic in 1988, likely from ballast water and/or Pacific oyster imports
    ● Typically found in anthropogenic areas on manmade structures or algaes
    ● Can have very dense populations, leading to competition with native caprellids for food and space, as well as alter feeding practices of other native fish

  • ● There are no known prevention or control methods that definitely work, but some mechanical controls may help
    ● Prevent and remove filamentous algae that the shrimp feed on from submerged structures
    ● Dry structures prior to summer to avoid repopulation
    ● Create new structures near flowing water to reduce salinity

Japanese Skeleton Shrimp (Caprella mutica)

References:
Caprella mutica. (n.d.). Smithsonian Environmental Research Center. (https://invasions.si.edu/nemesis/species_summary/-77)
Commonwealth of Massachusetts. (n.d.). Marine Invasive Species identification cards. Mass.gov.
(https://www.mass.gov/service-details/marine-invasive-species-identification-cards)
Cook, E. (2022). Caprella mutica. CABI Compendium, CABI Compendium. (https://doi.org/10.1079/cabicompendium.107759)

Photo: Hans Hillewaert, License (CC BY-SA 4.0)

  • ● Colony of zooids that form a flat, brick-like pattern on things like kelp, ships, hulls, etc.
    ● White or light grey in color with rounded edges
    ● Unknown native range, but first appeared in New England in 1987
    ● When fouling kelp, photosynthesis become difficult for the algae, allowing for more invasive species to enter the environment

  • ● There are no known controls against this species
    ● If removing manually, it is crucial that ALL parts of the colony are removed as they can reproduce quickly when in danger

Lacy Crust Bryozoan (Membranipora membranacea)

References:
Commonwealth of Massachusetts. (n.d.). Marine Invasive Species identification cards. Mass.gov.
(https://www.mass.gov/service-details/marine-invasive-species-identification-cards)
LACY CRUST BRYOZOAN / KELP SEA MAT. (n.d.). Texas Invasive Species Institute.
(http://www.tsusinvasives.org/home/database/membranipora-membranacea)
Membranipora membranacea. (n.d.). Smithsonian Environmental Research Center. (https://invasions.si.edu/nemesis/species_summary/155824)

Photo: USGS

  • Microscopic organisms that live in colonies, one of two forms:

    ○ Long, dripping ropes or pools that may be described as “pancake batter” that hang from hard substrate
    ○ Low mats with appendages that cover
    rocky seabeds

    ● The tunics have distinctive white dots across them and come in tan, cream, and orange-pink colors
    ● They can overgrow other organisms and choke off bottom-dwellers

  • ● Using a special cutter and vacuum that can be used on ship hulls and the ocean floor
    ● Dump dredging under a barge to suffocate the tunicate
    ● Place plastic wrappings around wharf piles in hopes to suffocate the tunicate
    ● Covering the seabed under the wharf with filter fabric
    ● Inspect your vessel and remove the tunicate when you see one

References:
Commonwealth of Massachusetts. (n.d.). Marine Invasive Species identification cards. Mass.gov. (https://www.mass.gov/service-details/marine-invasive-species-identification-cards)
Global Invasive Species Database (2023). Species profile: Didemnum vexillum. (http://www.iucngisd.org/gisd/speciesname/Didemnum+spp.)

Photo: Dann Blackwood, USGS

“Mystery” Colonial Tunicate (Didemnum vexillum)

  • ● Has a pistillate that is usually brown in color and has a fuzzy texture on top and long tapering leaves on the green stalk
    ● Usually around 4-9 feet tall
    ● Considered invasive in all parts of the U.S.
    ● The leaves can create a thick layer on the ground, disrupting growth in many other species and organisms
    ● Cattails have a very dense root system

  • ● Mechanical removal and use of herbicides such as Glyphosate, Imazamox, Imazapyr, and Diquat
    ● Check boating and fishing equipment for the Broadleaf Cattail (and their seeds)

Broadleaf Cattail (Typha latifolia)

References:

Global Invasive Species Database (2023). Species profile: Typha latifolia (http://www.iucngisd.org/gisd/speciesname/Typha+latifolia)
National Geographic Society. (2012, October 9). Invasive Species. National Geographic Society.
(https://www.nationalgeographic.org/encyclopedia/invasive-species/)

Photo by Vyacheslav Makodin on Unsplash

  • ● Fully submerged plant except for leaves and flower
    ● Spreads by stem fragments and can free float for some time without being attached to roots
    ● Native to South America, Southeastern US, and commonly used as an aquarium plant
    ● Spread due to accidental release from Michigan aquarium in 1935
    ● Can clog drainage canals, contaminate drinking water, and outcompete native species
    by crowding or blocking sunlight

  • ● Consistent washdown of boating and fishing equipment
    ● Herbicides administered by professionals only to avoid harming native species
    ● Water drawdown to dry out the plants, artificial shading as they need light, and hand pulling are all methods of removal

Carolina Fanwort (Cabomba caroliniana)

References:

Carolina fanwort (Cabomba caroliniana) - Species Profile. (n.d.). USGS Nonindigenous Aquatic Species Database. (https://nas.er.usgs.gov/queries/FactSheet.aspx?SpeciesID=231)Global Invasive Species Database (2023). Species profile: Cabomba caroliniana(http://www.iucngisd.org/gisd/speciesname/Cabomba+caroliniana)

Photo: Leslie J. Mehrhoff, University of Connecticut, Bugwood.org, License (CC BY-3.0)

  • ● Small clam, averaging less than 1.5 inches and rarely exceeding 3 inches
    ● Their shells can either be light green or light brown with distinctive elevated concentric ridges on their shell
    ● They were first reported in the United States in 1930, and have since spread to over 39 states
    ● Prolific and highly competitive species that is capable of fast growth and spread
    ● Can displace native species, reduce biodiversity, alter the food chain, and damage equipment such as boat mortars, intake pipes, diving gear, and commercial water systems

  • ● Mechanical methods, such as screens and traps
    ● Chemical control uses chlorine to kill juvenile clams but is limited due to chemical restrictions
    ● Temperature alteration can be used in water intake pipes to reduce clam presence

Asian Clam (Corbicula fluminea)

References:
DCR Massachusetts. (n.d.) Asian clam: An exotic aquatic species. (https://www.mass.gov/doc/asian-clam-0/download)
Global Invasive Species Database (2023). Species profile: Corbicula fluminea (http://www.iucngisd.org/gisd/speciesname/Corbicula+fluminea)

Photo by Holger Krisp on Wikimedia Commons

  • ● Non-native herb that can grow in various levels of saturated soil, allowing it to thrive along coasts
    ● Tall stems, clusters of four-petal white flowers
    ● Native to Europe, and western Asia
    ● Can displace native species by changing soil composition to the point that it must be remediated manually

  • ● Treating with herbicides is most effective during flower bud/flowering stage
    ● If within small patches, repeated pulling of patches is effective
    ● After removal, plant desirable and competitive species


    Every Spring and Summer, Seaside Sustainability partners with a local Audubon office to conduct field surveys to map and mitigate the invasive Pepperweed populations. Through these efforts, we
    strongly believe that the marsh can be restored.


    *Be sure to consult with local conservation commission before taking action as this species typically grows where the Massachusetts Wetlands Protection Act has jurisdiction

Perennial Pepperweed (Lepidium latifolium)

References:
Caprella mutica. (n.d.). Smithsonian Environmental Research Center. (https://invasions.si.edu/nemesis/species_summary/-77)
Commonwealth of Massachusetts. (n.d.). Marine Invasive Species identification cards. Mass.gov.
(https://www.mass.gov/service-details/marine-invasive-species-identification-cards)
Cook, E. (2022). Caprella mutica. CABI Compendium, CABI Compendium. (https://doi.org/10.1079/cabicompendium.107759)

Photo: joergmlpts, License (CC BY 4.0)

  • ● Bushy, purplish-brown, colony forming zooids that grow to about 10cm high
    ● Found on rocky reefs and seagrass leaves
    ● Introduced to new habitats by attaching to oysters being shipped for commercial use
    ● Can survive in polluted waters, making them difficult to remove
    ● Commonly found disrupting boating equipment and docks

  • ● Implement ballast water controls in oyster industry
    ● Copper paint may show some levels of bushy bryozoan attraction and therefore may be used to remove colonies

Purple Bushy Bryozoan (Bugula neritina)

References:
Commonwealth of Massachusetts. (n.d.). Marine Invasive Species identification cards. Mass.gov.
(https://www.mass.gov/service-details/marine-invasive-species-identification-cards)
Global Invasive Species Database (2023). Species profile: Bugula neritina. (http://www.iucngisd.org/gisd/speciesname/Bugula+neritina)

Photo: Dean Janiak, Smithsonian Marine Station, License (CC BY-SA 3.0)

  • ● Woody plant with whorled leaves and five-seven petaled magenta flowers that can grow up to 3m
    ● Woody stems remain intact during winter allowing for regrowth of flowers and leaves during summer
    ● Native to Eurasia, likely introduced in early 1800s through ship ballasts and by use as ornamentation
    ● Although studies have shown that these plants do not provide any more competition than other native plants, they do still outcompete plant species that are necessary for animal survival
    ● Chokes waterways, leading to degradation of wetlands and wetland species

  • ● Mechanical removal, herbicides, and biological controls
    ● Pulling and cutting Purple Loosestrife is very time consuming and labor intensive, but it is effective if done in a timely manner
    ● European beetles can be used to combat Purple Loosestrife
    ● Check boating and fishing equipment for Purple Loosestrife (and their seeds)

Purple Loosestrife (Lythrum salicaria)

References:
Global Invasive Species Database (2023). Species profile: Lythrum salicaria. (http://www.iucngisd.org/gisd/speciesname/Lythrum+salicaria)
USDA. (n.d.). Purple Loosestrife. National Invasive Species Information Center.
(https://www.invasivespeciesinfo.gov/aquatic/plants/purple-loosestrife)

Photo: Ivar Leidus, License (CC BY-SA 3.0)

  • ● Slippery pink, deep red, or reddish brown algae that can grow up to 3 feet long
    ● Seen in clumps or as single organism
    ● Grow in shallow waters on hard surfaces
    ● Native to England and likely introduced by trade with Japan or from European ship hulls
    ● First seen in MA in 2007
    ● Can outcompete native seaweeds and block sunlight from photosynthetic organisms due to its large size
    ● Changes the region’s trophic patterns

  • ● Manual, chemical, and mechanical removal are not viable options as they either do more harm than good or are too expensive to implement
    ● Inspect and clean recreational vessels before and after use to avoid introducing organisms into the environment
    ● Public education is necessary to express the importance of reducing accidental spread

Red Algae (Grateloupia turuturu)

References:
Commonwealth of Massachusetts. (n.d.). Marine Invasive Species identification cards. Mass.gov.
(https://www.mass.gov/service-details/marine-invasive-species-identification-cards)
Mathieson, A., & Dawes, C. (2019). Grateloupia turuturu. CABI Compendium. (https://doi.org/10.1079/cabicompendium.109142)

Photo: cristinacoastal, License (CC BY-NC 4.0)

  • ● A yellow-brownish bubble/cushion shaped algae, sometimes resembling a crumpled paper bag
    ● The skin is thin and tears easily, will deflate when removed from water
    ● Native to the Pacific Ocean, has spread worldwide and made its way to New England as of 2017
    ● Attaches to hard substrates, including shellfish
    ● When filled with air or water, can carry attached shellfish away leading to negative impacts to shellfish beds and the fishing industry

  • ● Manual, chemical, and mechanical removal are not viable options as they either do more harm than good or are too expensive to implement
    ● Inspect and clean recreational vessels before and after use to avoid introducing organisms into the environment
    ● Public education is necessary to express the importance of reducing accidental spread

Sea Potato (Colpomenia peregrina)

References:
Colpomenia peregrina. (n.d.). Smithsonian Environmental Research Center. (https://invasions.si.edu/nemesis/species_summary/11426)
Commonwealth of Massachusetts. (n.d.). Marine Invasive Species identification cards. Mass.gov.
(https://www.mass.gov/service-details/marine-invasive-species-identification-cards)
Massachusetts Office of Coastal Zone Management. (2013). Non-Native Seaweed in Massachusetts.
(https://www.marblehead.org/sites/g/files/vyhlif4661/f/uploads/non-native-seaweed-fact-sheet.pdf)

Photo: Marianne Cornelissen-Kuyt, License (CC BY-SA 4.0)

  • ● Non-native, unrooted, carnivorous plant that grows 3-15 yellow snap-dragon shaped flowers on emerging stalks supported by floating pontoon of 4-10 leaves arranged in the shape of spokes on a wheel
    ● Native to the southern United States
    ● Can grow in a variety of water conditions such as oligotrophic and acidic
    ● Competitive plant that has the potential to displace native species, reduce biodiversity, hamper recreational uses, reduce real estate and aesthetic values, and decrease water quality

  • ● Mechanical removal, being careful not to leave fragments behind that can reproduce
    ● Drawdowns, herbicides, and benthic barriers
    ● No known biological controls exist

Swollen Bladderwort (Utricularia inflata)

References:
DCR Massachusetts. (n.d.) Swollen bladderwort: An exotic aquatic species. (https://www.mass.gov/doc/swollen-bladderwort-0/download)

Photo: Sonnia Hill, License (CC BY 2.0)

  • ● Medium sized crab made distinguishable by 5 lateral spines on each side of its pentagon shaped carapace
    ● Native to Europe and spreads quickly and easily, especially through trade ships
    ● Competes with native crabs and responsible for negative impacts to other species such as the soft shell clam
    ● Destabilizes creek banks in salt marshes

  • ● Mitigate through removal processes like eating them or using them as bait
    ● Prevent the spread through ballast and other sea transportation methods
    ● Spread awareness of the damages
    ● Biological controls include introducing other non harmful species that outcompete the green crabs

Unexpected Bryozoan (Tricellaria inopinata)

References:
Ambrogi, A. O. (2022). Tricellaria inopinata. CABI Compendium, CABI Compendium. (https://doi.org/10.1079/cabicompendium.109093)
Commonwealth of Massachusetts. (n.d.). Marine Invasive Species identification cards. Mass.gov.
(https://www.mass.gov/service-details/marine-invasive-species-identification-cards)
Tricellaria inopinata. (n.d.). Smithsonian Environmental Research Center. (https://invasions.si.edu/nemesis/species_summary/-572)

Photo: WoRMS for SMEBD, License (CC BY-NC-SA 3.0)

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