Biodiversity

Species Profile and Threats Database


For information to assist proponents in referral, environmental assessments and compliance issues, refer to the Policy Statements and Guidelines (where available), the Conservation Advice (where available) or the Listing Advice (where available).
 
In addition, proponents and land managers should refer to the Recovery Plan (where available) or the Conservation Advice (where available) for recovery, mitigation and conservation information.

EPBC Act Listing Status Listed as Critically Endangered
Listing and Conservation Advices Commonwealth Conservation Advice on Mathewsoconcha grayi ms (Threatened Species Scientific Committee (TSSC), 2008aen) [Conservation Advice].
 
Commonwealth Listing Advice on Mathewsoconcha grayi ms (Threatened Species Scientific Committee (TSSC), 2008aes) [Listing Advice].
 
Recovery Plan Decision Recovery Plan not required, a regional multi-species recovery plan incorporates this species and it occurs within areas currently managed as a National Park and in a reserve area. Therefore the approved conservation advice for this species provides sufficient direction to implement priority actions and manage key threats (19/12/2008).
 
Adopted/Made Recovery Plans
Other EPBC Act Plans Threat abatement plan to reduce the impacts of exotic rodents on biodiversity on Australian offshore islands of less than 100 000 hectares 2009 (Department of the Environment, Water, Heritage and the Arts (DEWHA), 2009u) [Threat Abatement Plan].
 
Information Sheets What the Environment Protection and Biodiversity Conservation Act 1999 (EPBC Act) means for Norfolk Islanders (Department of the Environment and Heritage (DEH), 2004i) [Information Sheet].
 
Federal Register of
    Legislative Instruments
Inclusion of species in the list of threatened species under section 178 of the Environment Protection and Biodiversity Conservation Act 1999 (64) (19/12/2008) (Commonwealth of Australia, 2008f) [Legislative Instrument].
 
Scientific name Mathewsoconcha grayi ms [81852]
Family Helicarionidae:Pulmonata:Gastropoda:Mollusca:Animalia
Species author  
Infraspecies author  
Reference Hyman, I. 2005. Taxonomy, systematics and evolutionary trends in Helicarionida (Mollusca,Pulmonata). Ph D thesis, University of Sydney. Pp. i-xvii, 1-583
Distribution map Species Distribution Map

This is an indicative distribution map of the present distribution of the species based on best available knowledge. See map caveat for more information.

Illustrations Google Images

Scientific name: Mathewsoconcha grayi ms

Common name: Gray's Helicarionid Land Snail

Gray's Helicarionid Land Snail was described by Hyman (2005) and is conventionally accepted, however, it is yet to be formally published.

Gray's Helicarionid Land Snail is a small land snail which usually has an orange-brown to fawn coloured shell. A typical specimen is about 15 mm in diameter and 11 mm high. There is no peripheral band (Hyman 2005).

Gray's Helicarionid Land Snail has a similar shell to Mathewsoconcha suteri, though the former's spire is a little higher and the shell is distinctly larger and more inflated (TSSC 2008aes).

Gray's Helicarionid Land Snail is likely to be extinct on Norfolk Island, but may survive on Phillip Island, which is a very restricted distribution. This distribution is based on two specimens collected in 1982 - one living specimen and the other a recently dead shell. Fossils of Gray's Helicarionid Land Snail are known from Nepean Island and the Cemetery Bay area on Norfolk Island (Varman 1991).

The type material of Gray's Helicarionid Land Snail from Norfolk Island was alive when collected and it was noted as 'very common' in subfossil deposits on Norfolk Island. However, it was recorded as 'extinct' in native forests on the main island in a survey spanning 1983 to 1990 (Varman 1991). The very small number of records of non-fossil material is not surprising if it is extinct on the main island and currently restricted to Phillip Island where very little sampling has occurred. However, given the almost complete destruction of the vegetation on Phillip Island, it is unlikely that Gray's Helicarionid Land Snail is anything other than very rare (TSSC 2008aes).

The Territory of Norfolk Island is 1700 km north-east of Sydney in the South Pacific Ocean. The Territory includes Norfolk Island, which is approximately 35 km², as well as Nepean and Phillip Islands, which are smaller, uninhabited islands to the south of Norfolk Island (DEH 2000). The islands are volcanic in origin, formed by masses of basalt which arose from the ocean floor, a process which began about 3 million years ago and extended over 700 000 years. Over time, the islands have been colonised by plants and animals (TSSC 2008aes). It is recognised that Norfolk Island has a high diversity of land snails relative to other similar sized islands (Iredale 1944).

The vegetation on Phillip Island has been dramatically altered by the introduction of pigs (Sus scrofa), goats (Capra hircus) and rabbits (Oryctolagus cuniculus). Whilst these pest species have been removed, Phillip Island remains a highly degraded habitat, and the recovery of native vegetation is threatened by invasive weed species which have become established on the island, including the African Olive (Olea europaea subsp. cuspidata) (DEH 2000). Rats, which are a threat to snail species on Norfolk Island, do not currently occur on Phillip Island, however, there is a possibility that they could disperse to Phillip Island via a boat (TSSC 2008aes).

There is insufficient data to estimate the current population numbers for Gray's Helicarionid Land Snail.

Examinations of fossil deposits suggest that Gray's Helicarionid Land Snail was once common on Nepean Island and in the Cemetery Bay area of Norfolk Island (Varman 1991). These fossil deposits date from prior to a brief period of Polynesian settlement until European settlement. However, only four non-fossil specimens of Gray's Helicarionid Land Snail have been collected and lodged at the Australian Museum and the Natural History Museum in London. The two most recent collections, from Phillip Island, were made in 1982. The species was noted as being extinct in native forests of Norfolk Island in surveys spanning 1983–1990 (Varman 1991), however very little survey work has been undertaken on Phillip Island. Therefore, the available evidence suggests that whilst the species is likely to be extinct on Norfolk Island, it may continue to survive on Phillip Island (TSSC 2008aes).

Gray's Helicarionid Land Snail is common in fossil records compared to the number of specimens collected in more recent times, which suggests that the species has undergone a reduction in numbers. This is likely to be due to habitat clearance following European settlement of Norfolk Island and habitat degradation caused by the introduction of several invasive species of plants and animals, including rats to Norfolk Island and pigs, goats and rabbits to Phillip Island. Phillip Island has suffered severe soil erosion and continues to be a highly degraded habitat (TSSC 2008aes).

Although there is likely to have been a decline in the species' numbers in more recent times due to ongoing decline in habitat quality caused by invasive weeds and feral animals, which may continue in the future, there are no quantitative data available to judge that Gray's Helicarionid Land Snail has undergone a recent reduction in numbers (TSSC 2008aes).

Norfolk Island has been intermittently occupied by various settlers who have dramatically altered the environment, predominantly by land clearing for agriculture and housing. Approximately 80% of the original vegetation has been cleared, and the invasion of remnants by weed species has been extensive. Much of the Norfolk Island landscape has been transformed from a densely vegetated sub-tropical island to a highly modified pastoral landscape characterised by grazed kikuyu pastures bordered by remnant woodland (DEH 2000, 2004i).

Phillip Island lies approximately 7 km south of Norfolk Island and is approximately 4 km². The vegetation on the island has been severely degraded by the grazing of pigs, goats and rabbits released there for food and sport during early colonisation of the islands by Europeans. Pigs and goats were removed in the early 20th century, but rabbits were not removed until 1988 (TSSC 2008aes).

Little is known about the biology and ecology of Gray's Helicarionid Land Snail. The generation length of this species is not known (TSSC 2008aes).

Gray's Helicarionid Land Snail has a similar shell to Mathewsoconcha suteri, though the spire of the former is a little higher and the shell is distinctly larger and more inflated (TSSC 2008aes).

Feral animals
The key historical threat to Gray's Helicarionid Land Snail was predation by introduced rats. The Polynesian Rat (Rattus exulans) is presumed to have been introduced thousands of years ago by Polynesian visitors to Norfolk Island. The Black Rat (Rattus rattus) was introduced later, possibly around 1943 (DEH 2000). Both species are likely to have caused a decline in the numbers of Gray's Helicarionid Land Snail by direct predation on Norfolk Island. An extensive rat control program has been operating on Norfolk Island since 1992, however, Gray's Helicarionid Land Snail is likely to be extinct on Norfolk Island, so it is unlikely to benefit from this program. Rats do not currently occur on Phillip Island, however, it is possible that they could disperse to Phillip Island via a boat (TSSC 2008aes).

Neuweger and colleagues (2001) found a higher diversity of snails in the pre-settlement cultural layer and below it. This reduction appears to have occurred as a result of human impact, combined with predation by the Polynesian Rat introduced by Polynesian settlers prior to European settlement. The Black Rat arrived later (circa 1940) and probably played a significant role in the further decline of these species and of other similar-sized snails (Neuweger et al. 2001).

Habitat degradation
A further historical threat to Gray's Helicarionid Land Snail, with ongoing effects, was the destruction of vegetation on Phillip Island by the grazing of pigs, goats and rabbits. While these animals are no longer present on Phillip Island, the landscape has suffered severe soil erosion and of the few plants that survived, many are introduced weeds. Phillip Island continues to be a highly degraded habitat, though programs to control weeds, re-establish native vegetation and protect rare plants and animals have been undertaken by Parks Australia since 1978. This degradation and associated soil erosion is likely to have drastically altered the habitat available to the Gray's Helicarionid Land Snail, and caused a decline in the species' numbers (TSSC 2008aes).

Weeds
Gray's Helicarionid Land Snail available habitat is also likely to be declining in quality due to the presence of weed species on Norfolk Island. Over 200 species of introduced vascular plants have been recorded on Norfolk Island, including Lantana (Lantana camara), 'William Taylor' weed (Ageratina riparia) and Wild Tobacco (Solanum auriculatum) (Hyman 2005). Parks Australia is currently implementing a weed control program involving the broad scale treatment and rehabilitation of weed infested areas, however it is likely that the habitat of the Gray's Helicarionid Land Snail remains threatened, as weed control is not undertaken across the entire former range of the species (TSSC 2008aes).

Land clearing
Prior to European settlement, Norfolk Island was almost entirely covered by rainforest, dominated by Norfolk Island Pines (Araucaria heterophylla); however, only 20% of the native vegetation of Norfolk Island remains intact, while vegetation on Nepean and Phillip Islands has been almost completely lost (DEH 2000). Much of the remnant vegetation is degraded owing to weed infestation and stock accesibility. Even Mount Pitt Reserve was not fenced until recently, previously being grazed by livestock. Exotic weed growth has been a major problem on the island, spreading at a rate much faster than it can be controlled (DEH 2004i). Weeds displace the natural vegetation on the island and can dramatically transform the original landscape, particularly the leaf litter and fallen bark that the snails require for survival. In addition, some weed control measures may be detrimental to land snail survival (TSSC 2008aes).

A 2001 survey of the land snail fauna in the Emily Bay region of Norfolk Island illustrates a grossly altered fauna in this area compared with archaeological samples from pre-European times (Neuweger et al. 2001). This is likely the result of habitat loss and the habitat being heavily vegetated prior to Polynesian and European settlement. Human activity on the island has led to the conversion of tracts of land to pasture and residential development, undoubtedly modifying habitat, introducing flora, reduing available moisture and possibly increasing fire frequency.

Recovery actions
The Threat Abatement Plan to reduce the impacts of exotic rodents on biodiversity on Australian offshore islands of less than 100 000 hectares(DEWR 2008) is in preparation and should provide mitigation actions for the threat posed by rats. The Threatened Species Scientifc Committee (TSSC 2008aen) outlines recovery actions, and include:

  • Survey to identify locations of current populations of the species.
  • Monitor populations in existing locations and assess the efficiency of management.
  • Investigate and monitor the impacts of rodent eradication methods on non-target species and other environmental impacts.
  • Upon completion, implement the Recovery Plan for Norfolk Island.
  • Increase quarantine and surveillance measures in relation to potential introduced threats, on Phillip Island.
  • Establish captive breeding programs and investigate establishment of additional populations.
  • Identify known sites of high conservation priority.
  • Protect areas of native vegetation that contain populations of the species or which could support populations in the future.
  • Revegetate key areas.
  • Raise awareness of the species within the local community.

Documents that may assist in the recovery of Campbell's Helicarionid Land Snail include the Norfolk Island Recovery Plan (in preparation), the Draft threat abatement plan to reduce the impacts of exotic rodents on biodiversity on Australian offshore islands of less than 100 000 hectares (DEWR 2008) and the Conservation Advice on Mathewsoconcha grayi ms (TSSC 2008aen).

The following table lists known and perceived threats to this species. Threats are based on the International Union for Conservation of Nature and Natural Resources (IUCN) threat classification version 1.1.

Threat Class Threatening Species References
Agriculture and Aquaculture:Livestock Farming and Grazing:Grazing pressures and associated habitat changes Norfolk Island Region Threatened Species Recovery Plan (Director of National Parks (DNP), 2010a) [State Recovery Plan].
Climate Change and Severe Weather:Habitat Shifting and Alteration:Habitat loss, modification and/or degradation Norfolk Island Region Threatened Species Recovery Plan (Director of National Parks (DNP), 2010a) [State Recovery Plan].
Commonwealth Listing Advice on Mathewsoconcha grayi ms (Threatened Species Scientific Committee (TSSC), 2008aes) [Listing Advice].
Ecosystem/Community Stresses:Ecosystem Degradation:Decline in habitat quality Norfolk Island Region Threatened Species Recovery Plan (Director of National Parks (DNP), 2010a) [State Recovery Plan].
Ecosystem/Community Stresses:Indirect Ecosystem Effects:Restricted geographical distribution (area of occupancy and extent of occurrence) Commonwealth Conservation Advice on Mathewsoconcha grayi ms (Threatened Species Scientific Committee (TSSC), 2008aen) [Conservation Advice].
Invasive and Other Problematic Species and Genes:Invasive Non-Native/Alien Species:Competition and/or habitat degradation Oryctolagus cuniculus (Rabbit, European Rabbit) Commonwealth Listing Advice on Mathewsoconcha grayi ms (Threatened Species Scientific Committee (TSSC), 2008aes) [Listing Advice].
Invasive and Other Problematic Species and Genes:Invasive Non-Native/Alien Species:Competition and/or habitat degradation Ageratina riparia (Mistflower, Mist Flower, Creeping Croftonweed, River Eupatorium, Spreading Mistflower) Commonwealth Listing Advice on Mathewsoconcha grayi ms (Threatened Species Scientific Committee (TSSC), 2008aes) [Listing Advice].
Invasive and Other Problematic Species and Genes:Invasive Non-Native/Alien Species:Competition and/or habitat degradation Lantana camara (Lantana, Common Lantana, Kamara Lantana, Large-leaf Lantana, Pink Flowered Lantana, Red Flowered Lantana, Red-Flowered Sage, White Sage, Wild Sage) Commonwealth Listing Advice on Mathewsoconcha grayi ms (Threatened Species Scientific Committee (TSSC), 2008aes) [Listing Advice].
Invasive and Other Problematic Species and Genes:Invasive Non-Native/Alien Species:Competition and/or habitat degradation Solanum mauritianum (Wild Tobacco Tree, Wild Tobacco Bush, Tobacco Tree) Commonwealth Listing Advice on Mathewsoconcha grayi ms (Threatened Species Scientific Committee (TSSC), 2008aes) [Listing Advice].
Invasive and Other Problematic Species and Genes:Invasive Non-Native/Alien Species:Competition and/or habitat degradation by weeds Commonwealth Conservation Advice on Mathewsoconcha grayi ms (Threatened Species Scientific Committee (TSSC), 2008aen) [Conservation Advice].
Invasive and Other Problematic Species and Genes:Invasive Non-Native/Alien Species:Competition and/or predation Rattus exulans (Pacific Rat, Polynesian Rat) Commonwealth Listing Advice on Mathewsoconcha grayi ms (Threatened Species Scientific Committee (TSSC), 2008aes) [Listing Advice].
Invasive and Other Problematic Species and Genes:Invasive Non-Native/Alien Species:Competition and/or predation Rattus rattus (Black Rat, Ship Rat) Norfolk Island Region Threatened Species Recovery Plan (Director of National Parks (DNP), 2010a) [State Recovery Plan].
Commonwealth Listing Advice on Mathewsoconcha grayi ms (Threatened Species Scientific Committee (TSSC), 2008aes) [Listing Advice].
Invasive and Other Problematic Species and Genes:Invasive Non-Native/Alien Species:Competition and/or predation by rats Commonwealth Conservation Advice on Mathewsoconcha grayi ms (Threatened Species Scientific Committee (TSSC), 2008aen) [Conservation Advice].
Invasive and Other Problematic Species and Genes:Invasive Non-Native/Alien Species:Competition, predation and/or habitat degradation Gallus gallus (Red Junglefowl, Domestic Fowl) Norfolk Island Region Threatened Species Recovery Plan (Director of National Parks (DNP), 2010a) [State Recovery Plan].
Invasive and Other Problematic Species and Genes:Invasive Non-Native/Alien Species:Grazing, tramping, competition and/or habitat degradation Capra hircus (Goat) Commonwealth Listing Advice on Mathewsoconcha grayi ms (Threatened Species Scientific Committee (TSSC), 2008aes) [Listing Advice].
Invasive and Other Problematic Species and Genes:Invasive Non-Native/Alien Species:Grazing, tramping, competition and/or habitat degradation Sus scrofa (Pig) Commonwealth Listing Advice on Mathewsoconcha grayi ms (Threatened Species Scientific Committee (TSSC), 2008aes) [Listing Advice].

Department of the Environment and Heritage (DEH) (2000). Norfolk Island National Park and Norfolk Island Botanic Garden Plans of Management. Canberra, ACT: DEH.

Department of the Environment and Heritage (DEH) (2004i). What the Environment Protection and Biodiversity Conservation Act 1999 (EPBC Act) means for Norfolk Islanders. [Online]. Available from: http://www.environment.gov.au/biodiversity/publications/norfolk-island/pubs/norfolk-island.pdf.

Department of the Environment, Water, Heritage and the Arts (DEWHA) (2009u). Threat abatement plan to reduce the impacts of exotic rodents on biodiversity on Australian offshore islands of less than 100 000 hectares 2009. [Online]. Available from: http://www.environment.gov.au/biodiversity/threatened/publications/tap/exotic-rodents.html.

Hyman, I. (2005). Taxonomy, systematics and evolutionary trends in Helicarionida (Mollusca, Pulmonata). Page(s) 1-583. Ph.D. Thesis. University of Sydney.

Iredale, T. (1944). The Land Mollusca of Lord Howe Island. Australian Zoologist. 10(3):299-330.

Neuweger, D., P. White & W.F. Ponder (2001). Land snails from Norfolk Island sites. Atholl Anderson and Peter White, eds. The Prehistoric Archaeology of Norfolk Island, Southwest Pacific. Records of the Australian Museum. 27:115-122. Sydney: Australian Museum.

Threatened Species Scientific Committee (TSSC) (2008aen). Commonwealth Conservation Advice on Mathewsoconcha grayi ms. [Online]. Department of the Environment, Water, Heritage and the Arts. Available from: http://www.environment.gov.au/biodiversity/threatened/species/pubs/81852-conservation-advice.pdf.

Threatened Species Scientific Committee (TSSC) (2008aes). Commonwealth Listing Advice on Mathewsoconcha grayi ms. [Online]. Department of the Environment, Water, Heritage and the Arts. Available from: http://www.environment.gov.au/biodiversity/threatened/species/pubs/81852-listing-advice.pdf.

Varman, R.V.J.P. (1991). Conchological Survey 1983-90: Manuscript of Land Mollusca Fossiliferous and Present Day. Unpublished manuscript.

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This database is designed to provide statutory, biological and ecological information on species and ecological communities, migratory species, marine species, and species and species products subject to international trade and commercial use protected under the Environment Protection and Biodiversity Conservation Act 1999 (the EPBC Act). It has been compiled from a range of sources including listing advice, recovery plans, published literature and individual experts. While reasonable efforts have been made to ensure the accuracy of the information, no guarantee is given, nor responsibility taken, by the Commonwealth for its accuracy, currency or completeness. The Commonwealth does not accept any responsibility for any loss or damage that may be occasioned directly or indirectly through the use of, or reliance on, the information contained in this database. The information contained in this database does not necessarily represent the views of the Commonwealth. This database is not intended to be a complete source of information on the matters it deals with. Individuals and organisations should consider all the available information, including that available from other sources, in deciding whether there is a need to make a referral or apply for a permit or exemption under the EPBC Act.

Citation: Department of the Environment (2014). Mathewsoconcha grayi ms in Species Profile and Threats Database, Department of the Environment, Canberra. Available from: http://www.environment.gov.au/sprat. Accessed Wed, 23 Jul 2014 22:21:46 +1000.