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MEET MASSACHUSETTS' INVASIVE SPECIES

All About Invasive Species

  • The USDA defines invasive species as non-native species that cause or are likely to cause harm to native species.

  • 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

  • ● Asian Clams are small, 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.
    ● These clams are a prolific and highly competitive species, capable of growing fast and spreading.
    ● Their existence 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 can be used.
    ● Chemical control uses chlorine to kill juvenile clams but can be limited due to chemical restrictions.
    ● Temperature alteration can also 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)

Asian Shore Crabs (Hemigrapsus sanguineus)

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

    ​

    A more in-depth presentation on Asian Crabs can be found in our The Invasion of the Crabs Slideshow.

  • ● Mitigate their presence through removal processes like eating them or using them as bait.
    ● The spread can also be prevented through ballast and other sea transportation methods.
    ● Spreading awareness of the damages is vital.
    ● Research is being done to determine best practices for removal or integration of the species but is not yet conclusive.

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

References:

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

Broadleaf Cattail (Typha latifolia)

  • ● Cattails have pistillate that is usually brown in color and has a fuzzy texture on top and long tapering leaves on the green stalk.
    ● The plant usually stands around 4-9 feet tall and is 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.
    ● They have a very dense root system.

  • ● Mechanical removal and use of herbicides such as Glyphosate, Imazamox, Imazapyr, and Diquat to remove.
    ● Individuals should also check boating and fishing equipment for the Broadleaf Cattail (and their seeds).

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

  • ● Fanworts are a fully submerged plant except for their leaves and flower.
    ● They spread by stem fragments and can free float for some time without being attached to roots.
    ● These plants are native to South America, Southeastern US, and are commonly used as an aquarium plant.
    ● Fanworts initially spread due to accidental release from Michigan aquarium in 1935.
    ● They clog drainage canals, contaminate drinking water, and outcompete native species by crowding or blocking sunlight.

  • ● People should washdown boating and fishing equipment.
    ● People should also try using 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)

Club Tunicate (Styela clava)

  • ● Tunicates are 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.
    ● They can also out-compete native species for space and food, as well as damage boating equipment.

  • ● Freezing or desiccation these creatures can remove them.
    ● Using lower water levels can expose the club tunicate to the air, which kills them.
    ● Various combinations of salinity, temperature, and exposure to air is also effective.
    ● They can be dipped in saturated or strong salt solutions.

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)

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

Common Reed or Phragmites (Phragmites australis)

  • ● Common Reed is a non-native grass that grows tall and dense along marshes, blocking sunlight from native plant life.
    ● They are native to North America, Europe, and the Middle East - invasive strains came from Europe in the 1800s, likely introduced by ship ballasts.
    ● These plants Increase the risk of marsh fires.
    ● Common Reed can damage structure of marshes.
    ● They also decrease the ability to reduce mosquito populations as reeds are too thick to get through effectively.

  • ● Landowners can eliminate or reduce fertilizer, herbicide and pesticide use to reduce the abundance of Common Reeds.
    ● 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.

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)

European Green Crabs (Carcinus maenas)

  • ● It is a medium-sized crab made distinguishable by 5 lateral spines on each side of its pentagon shaped carapace.
    ● These crabs are native to Europe and spread quickly and easily, especially through trade ships.
    ● They compete with native crabs and are responsible for negative impacts to other species such as the soft shell clam.
    ● They also destabilize creek banks in salt marshes

    ​

    A more in-depth presentation on European Green Crabs can be found in our The Invasion of the Crabs Slideshow.

  • ● Mitigation 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 controlling methods include introducing other non-harmful species that outcompete the green crabs.

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

European Rock Shrimp (Palaemon elegans)

  • ● It's a mostly translucent shrimp, sometimes seen with blue and/or yellow bands on its legs depending on water conditions.
    ● They have a shovel shaped rostrum with 7-9 teeth on top and can grow up to 2.5 inches long.
    ● These shrimps are 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 while outcompeting other palaemonid shrimp.

  • ● No known control mechanisms for these shrimps as this is a recently known issue.
    ● Performing checks of ballast water may prevent further spread of invasion.

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)

  • ● Sea squirts are egg shaped creatures, around 5 inches long.
    ● They tend to be thin, a grayish-pink color with a translucent with 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.
    ● Impact 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.
    ● Killing by drying 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)

  • ● Green Fleece is bright green in color with spongy and rounded branches that turn white when dead.
    ● They grow up to 3 feet tall and just under 8 pounds.
    ● They're also native to Northwest Pacific, likely introduced due to shellfish aquaculture and recreational boating.
    ● Green Fleece attaches to hard surfaces in tide pools and shallow coastal waters, including shells of shellfish.
    ● Tolerant of various water conditions and 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 exist currently as this is a recently known issue.
    ● Performing checks of ballast water may 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

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

Japanese Skeleton Shrimp
(Caprella mutica)

  • ● It is a long, thin shrimp with mottled red body and spines along its back.
    ● They can be over 2 inches long.
    ● These shrimps are native to Northwest Pacific, first introduced to Northwest Atlantic in 1988, likely from ballast water and/or Pacific oyster imports.
    ● They are typically found in anthropogenic areas on manmade structures or algae.
    ● Skeleton shrimp 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.
    ● You can 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.

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)

  • ● Bryozoan is a colony of zooids that form a flat, brick-like pattern on things like kelp, ships, hulls, etc.
    ● They are white or light grey in color with rounded edges.
    ● This creature has an 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

“Mystery” Colonial Tunicate
(Didemnum vexillum)

  • 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 seabed

    ● 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 to get rid of Tunicate.
    ● 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 and inspecting your vessel to remove 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

  • ● 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

  • ● Pepperweed is a non-native herb that can grow in various levels of saturated soil, allowing it to thrive along coasts.
    ● They have tall stems with clusters of four-petal white flowers.
    ● These plants are native to Europe, and western Asia.
    ● They can displace native species by changing soil composition to the point that it must be remediated manually.