Definition of Invasive Species
Click here for more information.
The term “invasive species” is used in a variety of ways, but in Hawaii this term typically refers to species that are both harmful to the environment, economy, and/or human health, and
not native to Hawaii (i.e., species that were introduced by human assistance rather than by their own means of introduction).
It is important to note that not all nonnative species are considered invasive, only those that cause environmental or economic harm, or harm to human health. While there is currently no official designation of invasive species in Hawaii, the HISC is working on an effective way to define and classify these species for the State of Hawaii. Federally, Executive Order 13112 authorized by President Bill Clinton defines invasive species as “alien species whose introduction does or is likely to cause economic or environmental harm or harm to human health.”
INVASIVE SPECIES AS A PROBLEM IN HAWAII
Hawaii is a very unique place, due in part to its geographic isolation and volcanic origin. What we refer to as Hawaii’s native plant and animal species are those that arrived here without the assistance of humans: seeds for Hawaii’s first plants arrived here by floating on the waves, being blown by the wind, or transported by traveling birds. Likewise, Hawaii’s native animal species are those that flew here on the wind or swam here on the water. Introduction events like these are very rare, and so the species that made it to Hawaii lived here in relative isolation over the 70 million years of Hawaii’s volcanic history. Those original introductions spawned, through the course of evolution, native Hawaiian species that are often found nowhere else in the world. Our ohia and koa forests are uniquely Hawaiian, as are the hoary bats, ‘i‘iwi, and ‘apapane that once filled those forests.
Species that evolve on islands do so in the absence of some of the world’s more competitive species, such as sharp-hooved ungulates, carnivorous predators, or thorny or toxic plants. Because island species do not have to defend themselves against such threats, they lose (or fail to evolve) the defensive mechanisms often found in their distant mainland relatives. The result is a relatively benign environment: the koa is a thorn-less species of the genus Acacia, distantly related to the more prickly acacias found elsewhere in the world. Likewise, birds in pre-contact Hawaii could nest on the ground, since they didn’t have to worry about predators.
The problem, then, arises when we bring nonnative, competitive species from other parts of the world into our Hawaiian ecosystems. In today’s globalized society, it’s easy for humans to move species from one place to another, and this has resulted in the introduction of species such as deer, goats, ants, coqui frogs, miconia, and others into Hawai‘i. Hawaii’s native species haven’t evolved to compete and coexist with these species, and the result is that these new introductions become “invasive.”
The effects of invasive species are wide ranging. Miconia, an invasive plant from South America, quickly spreads throughout forests and prevents the growth of other plants, increasing the risk of erosion with its shallow root systems. Axis deer browse on a variety of native plants and agricultural goods, and their hooves break up soil and increase erosion. Little Fire Ants infest beach parks, homes, and habitats for native species, resulting in painful stings, lost crops, and injured pets. If brown tree snakes were introduced to Hawaii, they could potentially cause the extinction of our native bird species, and could cost an estimated $2.14 billion a year in damages to electrical infrastructure and medical costs associated with snake bites.
OFFICIAL DESIGNATION OF INVASIVE SPECIES
The HISC is in the process of drafting and adopting administrative rules to formally define species that are invasive in Hawaii. While no official designation currently exists, the species listed below are a sample of high-profile species that are informally considered to be invasive due to their ability or potential to cause harm to Hawaii’s environment, economy, or way of life. The description of these species as “invasive” is for educational purposes and is not related to regulatory restrictions. Our website has more information on the legal status of invasive species in Hawaii and current regulations in place to protect Hawai‘i from harmful species.
Click here for more information.
The term “invasive species” is used in a variety of ways, but in Hawaii this term typically refers to species that are both harmful to the environment, economy, and/or human health, and
not native to Hawaii (i.e., species that were introduced by human assistance rather than by their own means of introduction).
It is important to note that not all nonnative species are considered invasive, only those that cause environmental or economic harm, or harm to human health. While there is currently no official designation of invasive species in Hawaii, the HISC is working on an effective way to define and classify these species for the State of Hawaii. Federally, Executive Order 13112 authorized by President Bill Clinton defines invasive species as “alien species whose introduction does or is likely to cause economic or environmental harm or harm to human health.”
INVASIVE SPECIES AS A PROBLEM IN HAWAII
Hawaii is a very unique place, due in part to its geographic isolation and volcanic origin. What we refer to as Hawaii’s native plant and animal species are those that arrived here without the assistance of humans: seeds for Hawaii’s first plants arrived here by floating on the waves, being blown by the wind, or transported by traveling birds. Likewise, Hawaii’s native animal species are those that flew here on the wind or swam here on the water. Introduction events like these are very rare, and so the species that made it to Hawaii lived here in relative isolation over the 70 million years of Hawaii’s volcanic history. Those original introductions spawned, through the course of evolution, native Hawaiian species that are often found nowhere else in the world. Our ohia and koa forests are uniquely Hawaiian, as are the hoary bats, ‘i‘iwi, and ‘apapane that once filled those forests.
Species that evolve on islands do so in the absence of some of the world’s more competitive species, such as sharp-hooved ungulates, carnivorous predators, or thorny or toxic plants. Because island species do not have to defend themselves against such threats, they lose (or fail to evolve) the defensive mechanisms often found in their distant mainland relatives. The result is a relatively benign environment: the koa is a thorn-less species of the genus Acacia, distantly related to the more prickly acacias found elsewhere in the world. Likewise, birds in pre-contact Hawaii could nest on the ground, since they didn’t have to worry about predators.
The problem, then, arises when we bring nonnative, competitive species from other parts of the world into our Hawaiian ecosystems. In today’s globalized society, it’s easy for humans to move species from one place to another, and this has resulted in the introduction of species such as deer, goats, ants, coqui frogs, miconia, and others into Hawai‘i. Hawaii’s native species haven’t evolved to compete and coexist with these species, and the result is that these new introductions become “invasive.”
The effects of invasive species are wide ranging. Miconia, an invasive plant from South America, quickly spreads throughout forests and prevents the growth of other plants, increasing the risk of erosion with its shallow root systems. Axis deer browse on a variety of native plants and agricultural goods, and their hooves break up soil and increase erosion. Little Fire Ants infest beach parks, homes, and habitats for native species, resulting in painful stings, lost crops, and injured pets. If brown tree snakes were introduced to Hawaii, they could potentially cause the extinction of our native bird species, and could cost an estimated $2.14 billion a year in damages to electrical infrastructure and medical costs associated with snake bites.
OFFICIAL DESIGNATION OF INVASIVE SPECIES
The HISC is in the process of drafting and adopting administrative rules to formally define species that are invasive in Hawaii. While no official designation currently exists, the species listed below are a sample of high-profile species that are informally considered to be invasive due to their ability or potential to cause harm to Hawaii’s environment, economy, or way of life. The description of these species as “invasive” is for educational purposes and is not related to regulatory restrictions. Our website has more information on the legal status of invasive species in Hawaii and current regulations in place to protect Hawai‘i from harmful species.
Swimming under the radar targeting invasive species in coastal brackish water habitats in Hawaiʻi by Hawaiʻi Invasive Species Council - Support Program
Feb 20, 2021
Troy Sakihara, Cris Teague, Megan Lamson, & Dena Sedar take you on a virtual Huakaʻi across the state to look at brackish water systems and the invasive species impacting them for this Hawaiʻi Invasive Species Awareness Month webinar. Originally recorded on February 5, 2021.
Feb 20, 2021
Troy Sakihara, Cris Teague, Megan Lamson, & Dena Sedar take you on a virtual Huakaʻi across the state to look at brackish water systems and the invasive species impacting them for this Hawaiʻi Invasive Species Awareness Month webinar. Originally recorded on February 5, 2021.
Estuaries in Hawaii are highly invaded by non native fishes; presented by Kim Peyton - Hawaiʻi Invasive Species Council - Support Program
Feb 19, 2021
Learn about the space where freshwater meets saltwater in our estuarine systems of Hawaiʻi and all the creatures that inhabit these easily overlooked, but important systems. Special focus on the invasive species that are impacted these systems and native fauna as part of the Hawaiʻi Invasive Species Awareness Month webinar series. Originally recorded on February 4, 2021.
Feb 19, 2021
Learn about the space where freshwater meets saltwater in our estuarine systems of Hawaiʻi and all the creatures that inhabit these easily overlooked, but important systems. Special focus on the invasive species that are impacted these systems and native fauna as part of the Hawaiʻi Invasive Species Awareness Month webinar series. Originally recorded on February 4, 2021.
History of Invasive Species in Hawaiʻi; presented by Franny Brewer from BIISC - Hawaiʻi Invasive Species Council - Support Program
Feb 19, 2021
Check out this webinar from Franny Brewer at the Big Island Invasive Species Committee as she takes you through a short history of invasive species in Hawaiʻi from their introduction to their spread and the folks working to keep them in check. This is a great Invasive Species in Hawaiʻi 101 and part of the Hawaiʻi Invasive Species Awareness Month webinar series. Originally recorded on February 2, 2021.
Feb 19, 2021
Check out this webinar from Franny Brewer at the Big Island Invasive Species Committee as she takes you through a short history of invasive species in Hawaiʻi from their introduction to their spread and the folks working to keep them in check. This is a great Invasive Species in Hawaiʻi 101 and part of the Hawaiʻi Invasive Species Awareness Month webinar series. Originally recorded on February 2, 2021.
List of Invasive Species in the State of Hawaiʻi
Click here for more information from the Cabinet-level direction on invasive species issues - Hawaii Invasive Species Council
The species below are those for which the HISC has directed funding for prevention, control, and/or research. Though the HISC is still in the process of creating administrative rules to officially designate species as invasive, the species below are well-described by the federal definition of invasive species: alien species whose introduction does or is likely to cause economic or environmental harm or harm to human health (E.O. 13112).
The federal and state definitions for “invasive species” are broad, non-regulatory terms that describe any non-native species that causes or could cause harm to agriculture, natural resources, economy, or human health. In Hawaii, there are thousands of species that fit this broad definition of “invasive species.”
There is currently no regulatory list of “invasive species” in Hawaii. The HISC is in the process of developing administrative rules that would describe a small subset of species for which control and eradication over a large geographic area are still possible. This will include species like miconia, or little fire ants, which have substantial negative impacts but can still be managed at island-wide scales or on large geographic areas within islands.
They are not meant to represent a regulatory intent, nor is this a comprehensive list of species fitting the state “invasive species” definition. The species below are those for which the HISC has directed funding for research, and/or prevention and control actions.
Vertebrates
Invertebrates
Click here for more information.
Click here for more information from the Cabinet-level direction on invasive species issues - Hawaii Invasive Species Council
The species below are those for which the HISC has directed funding for prevention, control, and/or research. Though the HISC is still in the process of creating administrative rules to officially designate species as invasive, the species below are well-described by the federal definition of invasive species: alien species whose introduction does or is likely to cause economic or environmental harm or harm to human health (E.O. 13112).
The federal and state definitions for “invasive species” are broad, non-regulatory terms that describe any non-native species that causes or could cause harm to agriculture, natural resources, economy, or human health. In Hawaii, there are thousands of species that fit this broad definition of “invasive species.”
There is currently no regulatory list of “invasive species” in Hawaii. The HISC is in the process of developing administrative rules that would describe a small subset of species for which control and eradication over a large geographic area are still possible. This will include species like miconia, or little fire ants, which have substantial negative impacts but can still be managed at island-wide scales or on large geographic areas within islands.
They are not meant to represent a regulatory intent, nor is this a comprehensive list of species fitting the state “invasive species” definition. The species below are those for which the HISC has directed funding for research, and/or prevention and control actions.
Vertebrates
- Axis Deer (Axis axis)
- Barn Owl (Tyto alba)
- Brown Tree Snake (Boiga irregularis)
- Coqui (Eleutherodactylus coqui)
- Feral cats (Felis catus)
- Jackson’s Chameleon (Chameleo jacksonii)
- Mongoose (Herpestes javanicus)
- Red-masked Parakeet (Aratinga erythrogenys)
- Red-vented Bulbul (Pycnonotus cafer)
- Red-whiskered Bulbul (Pycnonotus jocosus)
- Rodents
- Rose-ringed Parakeet (Psittacula krameri)
- Snakes
- Ungulates
- Veiled Chameleon (Chameleo calyptratus)
Invertebrates
- Africanized Honeybee (Apis mellifera scutellata)
- Apple Snail (Pomacea canaliculata)
- Argentine Ant (Linepithema humile)
- Big-headed Ant (Pheidole megacephala)
- Black Twig Borer (Xylosandrus compactus)
- Coconut Rhinoceros Beetle (Oryctes rhinoceros)
- Coffee Berry Borer (Hypothenemus hampei)
- Erythrina Gall Wasp (Quadrastichus erythrinae)
- Fruit Flies
- Little Fire Ant (Wasmannia auropunctata)
- Mosquitos
- Naio Thrips (Klambothrips myopori)
- Nettle Caterpillar (Darna pallivitta)
- Ramie moth (Arcte coerula)
- Rat Lungworm (Angiostrongylus cantonensis – parasitic nematode (roundworm parasite))
- Red Imported Fire Ant (Solenopsis invicta)
- Small Hive Beetle (Aethina tumida)
- Snowflake Coral (Carijoa riisei)
- Tropical Fire Ant (Solenopsis geminata)
- Varroa Mite (Varroa destructor)
Click here for more information.
Header images - Clockwise from top left:
- Gold dust day gecko (Phelsuma laticauda laticauda)
- Two-lined spittlebug(Prosapia bicincta)
- Peacock grouper (Cephalopholis argus)
- Veiled chameleon (Chamaeleo calyptratus)
- Red-whiskered bulbul (Pycnonotus jocosus)
- Coqui frog, Eleutherodactylus coqui Thomas (Anura: Leptodactylidae)
- Indian mongoose (Herpestes javanicus)