Haystack Island

This article is about the island in South Australia. For other uses, see Haystack.

Haystack
Haystack is located in South Australia
Haystack
Haystack
Geography
LocationInvestigator Strait
Coordinates35°19′19″S 136°54′26″E / 35.32191°S 136.9071°E / -35.32191; 136.9071
Length500 m (1600 ft)
Width120 m (390 ft)
Highest elevation43 m (141 ft)
Administration
Australia

Haystack Island is an island located in Investigator Strait off the south coast of Yorke Peninsula in the Australian state of South Australia about 6 kilometres (3.7 miles) south-west of Stenhouse Bay. Since 1972, it has been part of the Althorpe Islands Conservation Park.

Description

Haystack Island is about 6 kilometres (3.7 miles) south-west of Stenhouse Bay. It is described as ‘a narrow wall of sheer cliffs, undermined, indented and marked by fresh scars and rockfalls’ and that ‘has been eroded to a series of tall lobes connected by thin necks of rock that narrow to an almost knife-edge ridge’. It is surrounded by a ‘fringing wave-cut reef’. The island is about 500 metres (1,600 feet) long by a maximum width of about 120 metres (390 feet) and with the tallest lobe having a height of 43 metres (141 feet). Its long axis is aligned in a north-west to south-east direction.[1][2]

Access is reported as best done in calm seas and that the summit ridge can be reached from the island’s east coast via a rubble cone of rubble, taking care when climbing the slope’s ‘loose and crumbling’ surface. A survey carried out in 1982 by the responsible government agency used a helicopter to access the island’s summit.[1][3] A number of sources consider Haystack Island along with the Althorpe Islands and Seal Island to be a group of islands known as the Althorpe Islands Group.[4][5][6]

Formation, geology and oceanography

Haystack Island was formed about 7350 years ago after sea levels rose at the start of the Holocene thereby separating Yorke Peninsula from Kangaroo Island.[7] Haystack Island consists of a seam of Bridgewater Formation calcarenite that sits on a largely submerged ridge of Gleesons Landing Granite.[6][8] Haystack Island rises from a depth of 20 metres (66 feet) within 300 metres (980 feet) from its southern shore.[9]

Flora and fauna

Flora

A survey carried out in November 1982 found 11 species of plants making up a shrubland covering the island’s ridge including Grey Samphire, Marsh saltbush, and Nitre-bush in the deeper soils, and Cushion-bush, Round-leaved Pigface and Southern Sea-heath in the shallower soils.[1][3]

Fauna

A survey carried out in November 1982 reported evidence of the presence of the following vertebrate animals - the White-faced storm petrel by the presence of ‘shallow burrows’ used during the ‘summer breeding season’, Pacific gull by the existence of a ‘large midden of shell fragments was found on the highest dome, indicating a feeding site…’, and the White-bellied sea eagle by the presence of a ‘maintained nest’.[1][3]

Protected areas status

Since 1972, Haystack Island has been part of the Althorpe Islands Conservation Park. Since 2007, it has been a prohibited area where access is only allowed by permit in order to protect the breeding population of seabirds.[10][11][12] Since 2012, the waters surrounding its shores are part of a habitat protection zone located within the boundaries of the Southern Spencer Gulf Marine Park.[13]

References

  1. ^ a b c d A.C., Robinson; Canty, P.; Mooney, T.; Rudduck, P. (1996). South Australia's offshore islands (PDF). Canberra: Australian Heritage Commission. pp. 287–288. ISBN 0-644350-11-3.
  2. ^ A.C., Robinson; Canty, P.; Mooney, T.; Rudduck, P. (1996). South Australia's offshore islands (PDF). Canberra: Australian Heritage Commission. p. 500. ISBN 0-644350-11-3.
  3. ^ a b c A.C., Robinson; Canty, P.; Mooney, T.; Rudduck, P. (1996). South Australia's offshore islands (PDF). Canberra: Australian Heritage Commission. pp. 445–451, 452 & 457. ISBN 0-644350-11-3.
  4. ^ A.C., Robinson; Canty, P.; Mooney, T.; Rudduck, P. (1996). South Australia's offshore islands (PDF). Canberra: Australian Heritage Commission. p. 286. ISBN 0-644350-11-3.
  5. ^ Sailing Directions (Enroute), Pub. 175: North, West, and South Coasts of Australia (PDF). Sailing Directions. United States National Geospatial-Intelligence Agency. 2017. p. 196.
  6. ^ a b Management Plan - Althorpe Islands, Goose Island and Troubridge Island Conservation Parks (PDF). Adelaide: Department of Environment & Heritage. 2009. p. 13. ISBN 978-1-921466-76-2.
  7. ^ A.C., Robinson; Canty, P.; Mooney, T.; Rudduck, P. (1996). South Australia's offshore islands (PDF). Canberra: Australian Heritage Commission. p. 12. ISBN 0-644350-11-3.
  8. ^ Fairclough, Martin C (December 2007). "KINGSCOTE Special 1:250 000 geological map" (PDF). MESA Journal. 47. Government of South Australia, DMITRE: 28–31. ISSN 1326-3544. Archived from the original (PDF) on 27 May 2016. Retrieved 18 May 2014.
  9. ^ South Australia. Department of Marine and Harbors (1985), The Waters of South Australia a series of charts, sailing notes and coastal photographs, Dept. of Marine and Harbors, South Australia, pp. Chart 23, ISBN 978-0-7243-7603-2
  10. ^ Management Plan - Althorpe Islands, Goose Island and Troubridge Island Conservation Parks (PDF). Adelaide: Department of Environment & Heritage. 2009. p. 1. ISBN 978-1-921466-76-2.
  11. ^ Management Plan - Althorpe Islands, Goose Island and Troubridge Island Conservation Parks (PDF). Adelaide: Department of Environment & Heritage. 2009. p. 28. ISBN 978-1-921466-76-2.
  12. ^ A.C., Robinson; Canty, P.; Mooney, T.; Rudduck, P. (1996). South Australia's offshore islands (PDF). Canberra: Australian Heritage Commission. p. 146. ISBN 0-644350-11-3.
  13. ^ "Southern Spencer Gulf Marine Park, Management plan summary" (PDF). Department of Environment Water and Natural Resources. 2012. p. 2. Retrieved 13 July 2014.