What is measured
This indicator measures the number of detected and established marine non-indigenous (exotic) species new to Aotearoa New Zealand each year. It also measures how far key marine non-indigenous species have spread.
We report baseline estimates (up to and including 2009) and subsequent estimates (from 2010-2022) for the following:
- cumulative number of new-to-New Zealand marine species
- north-south extent (that is, maximum spread of these species between the north and south of New Zealand) of nine key non-indigenous species covering the periods 2009 or earlier, 2010 to 2015, 2016 to 2018, and 2019 to 2022.
We also report the spread of key non-indigenous species to additional locations since the beginning of 2018.
Why it is important
Many marine non-indigenous species arrive in New Zealand waters and have little impact or cannot survive; others establish and have a negative impact on our native habitats and species.
Established non-indigenous species can compete with and prey on indigenous species, modify natural habitats, and alter ecosystem processes. This can threaten marine biodiversity, our cultural and natural heritage, as well as economic activities such as commercial and recreational fishing and boating, shellfish harvesting, and aquaculture.
Non-indigenous species arriving in New Zealand may quickly spread if they establish. Early detection helps in managing spread and the possible impacts associated with establishment.
Key findings
In 2009, when the baseline surveys and national review were completed across New Zealand, 355 non-indigenous species had been found, and 222 of these were considered established.
Between 2010 and 2022, a further 73 non-indigenous species were found; 44 of these showed established populations in our waters.
| 2009-01-01 | 222 |
|---|---|
| 2010-01-01 | 225 |
| 2011-01-01 | 227 |
| 2012-01-01 | 229 |
| 2013-01-01 | 232 |
| 2014-01-01 | 235 |
| 2015-01-01 | 240 |
| 2016-01-01 | 242 |
| 2017-01-01 | 245 |
| 2019-01-01 | 257 |
| 2020-01-01 | 259 |
| 2021-01-01 | 263 |
| 2022-01-01 | 266 |
| 2009-01-01 | 133 |
|---|---|
| 2010-01-01 | 133 |
| 2011-01-01 | 141 |
| 2012-01-01 | 142 |
| 2013-01-01 | 146 |
| 2014-01-01 | 149 |
| 2015-01-01 | 151 |
| 2016-01-01 | 152 |
| 2017-01-01 | 162 |
| 2019-01-01 | 162 |
| 2020-01-01 | 162 |
| 2021-01-01 | 162 |
| 2022-01-01 | 162 |
Some key non-indigenous species have been found in new locations since the beginning of 2018:
- The Asian paddle crab (Charybdis (Charybdis) japonica) was found in Tauranga Harbour for the first time in January 2018.
- The Mediterranean fanworm (Sabella spallanzanii) was found in the Bay of Plenty for the first time in 2018.
- The fragile clam (Theora lubrica) and Asian kelp or Wakame (Undaria pinnatifida) were first found in Napier in 2021. However, it is unclear how long they had been present there as the Port of Napier and Ahuriri Inner Harbour weren’t added to the National Marine High-Risk Site Surveillance programme until November 2021.
In 2021 two species of sea mustard, Caulerpa brachypus and Caulerpa parvifolia, were found in Aotea Great Barrier Island. Since the data for this indicator was extracted, these species have been found in several additional sites, including in the Bay of Islands, Great Mercury Island, and Kawau Island in the Hauraki Gulf (for an up-to-date list of sites from the Ministry for Primary Industries, see Exotic Caulerpa seaweeds in New Zealand).
Text alternative for Increase in the north-south extent (area covered) of nine non-indigenous marine species, 2009-2022
Nine maps of New Zealand show the north-south (latitude) extent (area covered) for each of nine key species at the 2009 baseline, and any subsequent expansion of area covered between 2010 and 2022. The nine species are Asian bag mussel, Asian paddle crab, Australian droplet tunicate, clubbed tunicate, fragile clam, greentail prawn, Indo-Pacific ascidian, Mediterranean fanworm, and Wakame. For each species, a coloured vertical bar indicates the maximum north-south extent for each of the following periods: up to and including 2009, 2010 to 2015, 2016 to 2018, and 2019 to 2022. The colours graduate from purple (2009 baseline) through blue and green to yellow (2022). The data is available from Increase in north-south extent (area covered), 2009-2022 (CSV, 1.6 KB).
Where this data comes from
Ministry for Primary Industries; National Institute of Water and Atmospheric Research Ltd (NIWA)
Related content
Surveillance programmes for pests and diseases
Technical report
Updating Marine Non-Indigenous Species Indicators
About the data
The National Institute of Water and Atmospheric Research (NIWA) collated data on marine non-indigenous species from a number of sources. The 2009 baseline estimates draw from two national synthetic reviews (Cranfield et al., 1998; Kospartov et al., 2010). These reviews used Port Biological Baseline Survey (PBBS) data, a series of 43 surveys conducted between 2001 and 2007 throughout New Zealand, including repeat surveys of our 13 major shipping ports and three marinas of first entry for recreational yachts. They also included data from vessel biofouling surveys, targeted surveillance, delimitation surveys, museum records, published literature, and personal communications from expert taxonomists in New Zealand and overseas (Seaward et al., 2015).
More recent data comes from National Marine High-Risk Site Surveillance (NMHRSS) programme records, as well as records submitted to the Marine Invasives Taxonomic Service (MITS), and other verified information.
The NMHRSS and MITS are funded by the Ministry for Primary Industries (MPI) as part of its post-border biosecurity surveillance and are delivered under contract by NIWA. The NMHRSS programme aims to detect incursions of new-to-New Zealand non-indigenous species listed as unwanted on the Official New Zealand Pest Register (Woods et al., 2023). MITS provides taxonomic identification and collection management of marine organisms relevant to marine biosecurity management in New Zealand. Regional councils also contribute to the detection and identification of and response to non-indigenous species (but their data are not included in this review).
The NMHRSS monitoring programme started in 2002 and is targeted at high-risk ports and marinas around New Zealand. This means that our reporting of marine non-indigenous species in New Zealand focuses on sites where incursions are most likely to occur in order to identify the arrival of new species and respond early to their presence. Marine non-indigenous species are often introduced to New Zealand among other species growing or living on the hulls of vessels (biofouling) or in discharged ballast waters. They commonly spread between New Zealand ports and harbours on commercial or recreational craft. These species may also be present at other locations beyond the ports and marinas in the NMHRSS.
In November 2021, the Port of Napier and Ahuriri Inner Harbour were added to the NMHRSS programme as the 12th high risk monitoring site (Woods et al., 2021).
Alongside estimates for new-to-Aotearoa New Zealand marine species and north-south extent of nine key non-indigenous species, we provide the following data:
- Port survey datasets (2009 baseline to 2022): Search effort (every position that was searched in each port in each year), key species found (where key species were found each year), and grid summary (annual presence-absence information for each grid cell). Search effort and key species found include partial data for 2023.
- Porthole dataset: All records of non-indigenous marine species found in NZ coastal waters with a known location dating back to 1800. This is collated from the Port Biological Baseline Surveys, the NMHRSS, the Marine Invasive Taxonomic Service and other verified observations of non-native marine species (for example, literature).
- Timeseries data: Records of first detection of all marine non-indigenous species (including those without a known location) dating back to 1800.
- North-south extent data: North-south extent data for nine key non-indigenous species (annually from 2009 baseline to 2022).
Key non-indigenous species
We report on the following key species:
- Asian bag mussel, Arcuatula senhousia
- Asian paddle crab, Charybdis (Charybdis) japonica
- Australian droplet tunicate, Eudistoma elongatum
- Greentail or ‘greasy-back’ prawn, Metapenaeus bennettae
- Mediterranean fanworm, Sabella spallanzanii
- Clubbed tunicate, Styela clava
- Indo-Pacific ascidian, Symplegma brakenhielmi
- Fragile clam, Theora lubrica
- Wakame, Undaria pinnatifida
- Sea mustard species, Caulerpa brachypus and Caulerpa parvifolia.
These species were chosen because they have a wide range of impacts: some modify natural habitats (Asian bag mussel, Mediterranean fanworm, and Wakame), some are predators of native species (Asian paddle crab), some are pests to marine industries (Australian droplet tunicate, clubbed tunicate, Mediterranean fanworm, and Wakame), one is an indicator of pollution (fragile clam), and others affect the cycle of nutrients in marine ecosystems (Mediterranean fanworm and Wakame). Some arrived in New Zealand recently, while others are long established (Seaward & Inglis, 2023).
Species are considered established if found on natural or permanent artificial habitat (Seaward & Inglis, 2018). We assume that any previously established species have not been eradicated, and therefore present the cumulative number of species found by year.
Changes from previous version of the indicator
Since this indicator was last updated in October 2019 with data to 2018, two species, Caulerpa brachypus and Caulerpa parvifolia have been added to the list of key species. The two species are indistinguishable in the field, so this indicator reports data for both green algae species C. brachypus and C. parvifolia.
Caulerpa brachypus was first recorded and confirmed in New Zealand around Aotea Great Barrier Island in 2021 (D’Archino et al., 2021). During subsequent surveys for Caulerpa brachypus on Aotea, a second, morphologically similar non-indigenous alga, Caulerpa parvifolia, was also discovered.
While the two species of Caulerpa were confined to Aotea Great Barrier Island when the data was extracted, these species have since been found in several additional sites, including in the Bay of Islands, Great Mercury Island, and Kawau Island in the Hauraki Gulf (Ministry for Primary Industries, n.d.).
The number of non-indigenous species reported in this indicator differs from the previous version of the indicator because some species had their names or status changed, and some species were added to the list in this update.
Non-indigenous species identification is a complex and evolving scientific field, and species are often reclassified, renamed, and/or re-identified over time. All identifications have been made with the best national and international taxonomic knowledge at the time of data production. Updating Marine Non-Indigenous Species Indicators provides more details.
Data quality
The accuracy of the data source is of medium quality.
Marine non-indigenous species is a direct measure of the ‘Pests, diseases, and exotic species’ topic.
Stats NZ and the Ministry for the Environment must report on topics related to the five environmental domains: air, atmosphere and climate, fresh water, land, and marine. These topics identify key issues within each domain.
Topics for environmental reporting describes the topics for each domain.
Data quality information has more information about the criteria we use to assess data quality.
References
Cranfield, H., Gordon, D., Willan, R., Marshall, B., Battershill, C., Francis, M., Nelson, W., Glasby, C., & Read, G. (1998). Adventive marine species in New Zealand (NIWA Technical Report 34). NIWA. https://docs.niwa.co.nz/library/public/NIWAtr34.pdf
D’Archino, R., Evans, O., & Nelson, W. A. (2021). Notes on Caulerpa brachypus, Harvey (1860) collected from Great Barrier Island, New Zealand. (Marine Exotic Species Note). National Institute of Water and Atmospheric Research Ltd.
Kospartov, M., Inglis, G., Seaward, K., Van Den Brink, A., D’Archino, R., & Ahyong, S. (2010). Non-indigenous and cryptogenic marine species in New Zealand – Current state of knowledge: Interim report. NIWA.
Ministry for Primary Industries. (n.d.). Exotic caulerpa seaweeds in New Zealand. https://www.mpi.govt.nz/biosecurity/exotic-pests-and-diseases-in-new-zealand/pests-and-diseases-under-response/exotic-caulerpa-seaweeds-caulerpa-brachypus-and-caulerpa-parvifolia-in-new-zealand/
Seaward, K., Acosta, H. S., Inglis, G. J., Wood, B. L., Riding, T. a. C., Wilkens, S., & Gould, B. (2015). The Marine Biosecurity Porthole – a web-based information system on non-indigenous marine species in New Zealand. Management of Biological Invasions, 6(2), 177-184. https://doi.org/10.3391/mbi.2015.6.2.08
Seaward, K., & Inglis, G. (2018). Long-term indicators for nonindigenous species (NIS) in marine systems. Updated 2018: Prepared for Ministry for the Environment October 2018 (NIWA Client Report No: 2018310CH). https://environment.govt.nz/publications/long-term-indicators-for-non-indigenous-species-in-marine-systems/
Seaward, K., & Inglis, G. (2023). Updating marine non-indigenous species indicators: Prepared for Ministry for the Environment June 2023 (NIWA Client Report No: 2023131CH). https://environment.govt.nz/publications/updating-marine-non-indigenous-species-indicators/
Woods, C., Seaward, K., Pryor Rodgers, L., Lane, H., & Inglis, G. (2021). National Marine High Risk Site Surveillance programme: Design Report for Napier Port and Ahuriri Inner Harbour (Biosecurity New Zealand Technical Paper No: 20212/10). Ministry for Primary Industries. https://www.mpi.govt.nz/dmsdocument/53818-National-Marine-High-Risk-Site-Surveillance-programme
Woods, C., Seaward, K., Pryor Rodgers, L., Buckthought, D., Carter, M., Middleton, C., Olsen, L., Smith, M., & Tait, L. (2023). National Marine High Risk Site Surveillance: Annual Synopsis Report for all High Risk Sites 2022-23 (Biosecurity New Zealand Technical Paper No: 2023/03). https://www.mpi.govt.nz/dmsdocument/59008-National-Marine-High-Risk-Site-Surveillance-Annual-Synopsis-Report-for-all-High-Risk-Sites-202223-SOW23030
Archived pages
Archived March 2024:
Marine non-indigenous species – published October 2019
