Dangerous Reef

Dangerous Reef is an island and reef system located in Spencer Gulf in the Australian state of South Australia about 32.5 kilometres (20.2 mi) east-south east of the city of Port Lincoln. It is the southernmost member of the Sir Joseph Banks Group. It has been the site of a navigation aid since 1911. It is notable as the site of a breeding colony of Australian sea lions. The waters adjoining its shore are notable as a place to view great white sharks to the extent that it was both a popular gamefishing and shark cage diving venue during the twentieth century, and was used to film footage for the following motion pictures – Blue Water White Death and Jaws. The island has enjoyed protected area status since 1900 and it has been part of the Sir Joseph Banks Group Conservation Park since 1989.

For other uses, see Dangerous.

Dangerous Reef
Dangerous Reef, near Pt. Lincoln, a bird colony and seal habitat. Circa 1932.
(State Library of South Australia PRG PRG-458-1-1-9)
Dangerous Reef
Geography
Coordinates34°49′03″S 136°13′03″E
ArchipelagoSir Joseph Banks Group
Adjacent bodies of waterSpencer Gulf
Area12 ha (30 acres)[1]
Highest elevation3 m (10 ft)[1]
Administration
Australia
Demographics
Population0
Coordinates[2]

Description

Dangerous Reef is located in Spencer Gulf about 32.5 kilometres (20.2 mi) east-south east of the city of Port Lincoln, about 17 kilometres (9 nmi) north-northeast of Observatory Point on the northeast coast of Thistle Island and is about 17.5 kilometres (10.9 mi) east of the nearest point of the mainland on the Eyre Peninsula.[1][3][4] Officially, it is described in one source as being a "reef."[2] In another official source, it is considered to be an island as it is listed as being part of the island group known as the Sir Joseph Banks Group despite being located about 15.5 kilometres (9.6 mi) south-southwest of Stickney Island, the nearest group member.[1][5] Dangerous Reef itself is described as consisting of "a chain of four large rocks" with the tallest reaching a height of 3 metres (9.8 ft) with the remainder being "barely dry" at low tide as well as some other "small rocks."[1][4] At high tide, the island/reef system has an area of dry land covering about 12 hectares (30 acres) while at low tide, the system dries to an area of about 40 hectares (100 acres).[2] Access to the island/reef system which is subject to permission by the responsible government agency due to the island group's protected area status (refer below) is either via boat or helicopter.[6]

Formation, geology and oceanography

Dangerous Reef was formed about 8400 years ago following the rise of sea levels at the start of the Holocene.[7] The island/reef system consists of an "isolated inselberg ridge" formed of "much eroded peneplained granite or granite gneiss belonging to the Lincoln Complex of granitic rocks intruded during the Kimban Orogeny, 1600 to 1800 Ma." As of 1982, it was reported that the island/reef system has no soil apart from that derived as the "broken down by-product of sea-lion and seabird excrement".[1][8] The island/reef system extends from the "largest rock" for a distance of 1.39 kilometres (0.75 nmi) to the west and for a distance of 4.6 kilometres (2.5 nmi) to the south-east. The south-eastern end of the reef system is reported as experiencing waves that "break heavily."[3][4] Water depths greater than 18.3 metres (60 ft) are reported within 4.6 kilometres (2.5 nmi) of the reef system.[4]

Flora and fauna

Flora

As of 1982, only the "largest rock" was vegetated and this consisted of two plant species – Mueller's Saltbush and Leafy Peppercress.[9]

Fauna

Australian sea lions (referred to as "hair seals" at the time) were abundant at Dangerous Reef in 1904.[10] Photographs from the 1907 show Australian sealions and cormorants inhabiting the reef[11] and are supported by written accounts.[12] Early 20th century descriptions note cormorants and terns there as "prolific", and detail gulls preying on unattended cormorant eggs,[13] while the eggs of terns appeared untouched. Also noted were the presence of Greater crested terns, Little terns and Pacific gulls.[14] In 1913, the island was known to support a breeding colony of cormorants.[15]

In the 1930s, the reef was reported to host "plentiful" birds and seals,[16] and photographs show the presence of Australian sealions,[17] which were reportedly abundant there.[18] A written account of a landing party there noted the dominance of Australian sealions and relatively few Long-nosed fur seals. It said of the sealions:

"Huge old bulls had their harems and offspring grouped around them, while all the young bulls kept at a respectful distance. The air was full of the sound of their coughing barks."[19]

In the 1950s, Dangerous Reef was a popular destination for shark fishermen to catch Great white sharks.

In 1982, Dangerous Reef was known to support breeding colonies of black-faced cormorant, silver gull and Pacific gull.[9]

In 1994, the breeding colony of Australian sea lions on the "largest rock" was reported as being the second largest colony for this species of pinniped.[1]

History

Discovery

Dangerous Reef was discovered and named by the British navigator, Matthew Flinders, on 19 March 1802.[2] While the name of the reef is attributed to Flinders in official sources, it has been suggested by Ernest Scott, the historian and the author of book, The Life of Captain Matthew Flinders R.N., that Dangerous Reef is an example of a feature for which Flinders wrote a descriptive remark about on his charts, i.e. to identify it as a navigation hazard. The descriptive remark for this and other features have been retained and subsequently used as the name of the features on charts and maps.[20]

Capturing animals

Attempts were made in the late 1800s to capture animals from Dangerous Reef for zoological displays. Captured animals included seal pups and terns.[21] The seals were well known residents of the reef,[22] and were described as "plentiful" there in the 1930s.[23]

Guano mining

Dangerous Reef is one of the island sites from which guano was mined under licence from the South Australian Government prior to 1919.[24] The activity was controversial for the disturbance that it caused to roosting and breeding seabirds.[25]

A navigation aid has been in place on the "largest rock" since 1911.[26]

Great white sharks

The waters adjoining Dangerous Reef are notable as a place of aggregation for great white sharks. It was a popular site for gamefishing[27][28][29] from early in the 20th century[30] until 1997 when the great white shark became a protected species in Australia.[31][32] Dolphins were sometimes used as bait.[30] A whole seal was found in the stomach of one shark, caught in 1907.[33] Notable gamefishers who visited the waters around Dangerous Reef included the Australian radio personality, Jack Davey, in 1952 and the American novelist, Zane Grey, in 1939.[34][35]

In 1969, the island/reef system was one of the sites used for filming of the great white shark documentary, Blue Water White Death.[36] In 1974, footage of live sharks used in the 1975 American film, Jaws was filmed at Dangerous Reef by Ron Taylor.[37] Great White of Dangerous Reef, hosted by game-fisherman Malcolm Florence was filmed there in the late 1980s. In the film, sharks are fed from the safety of a shark cage before a shark is caught on a line.[38][39][40] From the 1970s up until 2002, Dangerous Reef was one of the sites where tourists could try shark cage diving[41] and observe sharks from within the water.[42] In more recent years, shark cage diving for tourists has been offered near the Neptune Islands instead, with tours departing from Port Lincoln.

Protected area status
Further information: Sir Joseph Banks Group Conservation Park

Dangerous Reef first received protected area status on 29 April 1909 as a bird protection district declared under the Birds Protection Act 1900.[43][44] It was further publicized as a sanctuary in 1933, noting that seals there were also protected.[45] Since 1989, it has been part of the Sir Joseph Banks Group Conservation Park including the waters within 2 kilometres (1.2 mi) of the island group's shoreline for the purpose of managing shark cage diving activity.[46][47][48] Since 2012, the waters adjoining the island group have also been part of a sanctuary zone within the Sir Joseph Banks Group Marine Park.[48]

See also

References

Citations
  1. Robinson et al, 1996, page 271
  2. "Search result for "DANGEROUS REEF (REEF)" (Record no SA0017837)". Department of Planning, Transport and Infrastructure. Retrieved 19 January 2016.
  3. DMH, 1985, chart 31
  4. Sailing Directions (Enroute), Pub. 175: North, West, and South Coasts of Australia (PDF). Sailing Directions. United States National Geospatial-Intelligence Agency. 2017. p. 186.
  5. "Search result for "SIR JOSEPH BANKS GROUP (ISLAND GROUP)" (Record no SA0061743)". Department of Planning, Transport and Infrastructure. Retrieved 20 January 2016.
  6. Robinson et al, 1996, pages 271 & 437
  7. Robinson et al, 1996, Page 11
  8. Robinson et al, 1996, page 253
  9. Robinson et al, 1996, pages 271, 427 & 432
  10. "YACHTING NOTES". Express and Telegraph (Adelaide, SA : 1867 - 1922). 30 January 1904. p. 3. Retrieved 12 July 2020.
  11. "CRUISE OF SCIENCE CONGRESSMEN IN THE GOVERNOR MUSGRAVE". Observer (Adelaide, SA : 1905 - 1931). 2 February 1907. p. 29. Retrieved 23 May 2020.
  12. "GULP BIRDS. DISTURBED BY EXCURSIONISTS". Observer (Adelaide, SA : 1905 - 1931). 25 May 1907. p. 52. Retrieved 22 June 2020.
  13. "A SCIENTIFIC CRUISE". Advertiser (Adelaide, SA : 1889 - 1931). 19 January 1907. p. 4. Retrieved 23 May 2020.
  14. "GULF BIRDS". Evening Journal (Adelaide, SA : 1869 - 1912). 18 May 1907. p. 7. Retrieved 23 May 2020.
  15. "CAMERA ON THE WEST COAST". Observer (Adelaide, SA : 1905 - 1931). 15 February 1913. p. 29. Retrieved 23 May 2020.
  16. "Trip to Dangerous Reef". Port Lincoln Times (SA : 1927 - 1954). 16 February 1934. p. 5. Retrieved 23 May 2020.
  17. "UNUSUAL VISITORS". Chronicle (Adelaide, SA : 1895 - 1954). 14 May 1931. p. 35. Retrieved 23 May 2020.
  18. "Seeing The Islands Of the S.A. Coast". Advertiser (Adelaide, SA : 1931 - 1954). 13 April 1935. p. 9. Retrieved 22 June 2020.
  19. "Seeing The Islands Of the S.A. Coast". Advertiser (Adelaide, SA : 1931 - 1954). 13 April 1935. p. 9. Retrieved 22 June 2020.
  20. Cooper, 1953, page 130
  21. "Sealing on Dangerous Reef". Express and Telegraph (Adelaide, SA : 1867 - 1922). 14 June 1886. p. 2. Retrieved 23 May 2020.
  22. "TRIP OF THE MORIALTA ROUND SPENCER GULF". Chronicle (Adelaide, SA : 1895 - 1954). 10 February 1912. p. 31. Retrieved 23 May 2020.
  23. "Seals Plentiful". Port Lincoln Times (SA : 1927 - 1954). 10 January 1930. p. 8. Retrieved 23 May 2020.
  24. Robinson et al, 1996, Page 134
  25. "DANGEROUS REEF". Register (Adelaide, SA : 1901 - 1929). 16 January 1909. p. 8. Retrieved 23 May 2020.
  26. Robinson et al, 1996, Page 129
  27. "3 Sharks Caught At Dangerous Reef". Port Lincoln Times (SA : 1927 - 1954). 9 December 1954. p. 1. Retrieved 23 May 2020.
  28. "Three More Sharks From Dangerous Reef". Port Lincoln Times (SA : 1927 - 1954). 9 March 1950. p. 6. Retrieved 23 May 2020.
  29. "1,000 1b. Shark Landed Near Dangerous Reef". Port Lincoln Times (SA : 1927 - 1954). 17 February 1949. p. 1. Retrieved 23 May 2020.
  30. "MORE LARGE SHARKS CAUGHT WITH RODS". News (Adelaide, SA : 1923 - 1954). 7 December 1938. p. 9. Retrieved 23 May 2020.
  31. "Sharkfishing Extraordinary". The Observer. Adelaide. 5 March 1910. p. 43. Retrieved 21 January 2016 – via National Library of Australia.
  32. DSEWPaC), 2013, page 26
  33. "MONSTER SHARKS". Observer (Adelaide, SA : 1905 - 1931). 6 April 1907. p. 28. Retrieved 23 May 2020.
  34. "Jack Davey to fish at Dangerous Reef". Port Lincoln Times. SA. 10 April 1952. p. 1. Retrieved 21 January 2016 – via National Library of Australia.
  35. "Zane Grey's first S.A. Shark". The Advertiser. Adelaide. 30 March 1939. p. 18. Retrieved 21 January 2016 – via National Library of Australia.
  36. "Blue Water, White Death (1971)". Turner Classic Movies. Retrieved 21 January 2016.
  37. Davies, Nathan (19 June 2015). "How a big shark and a little man forced Spielberg to make Jaws even better". The Advertiser. Retrieved 21 January 2016.
  38. "Great Whites of Dangerous Reef (1988)". The Courier-News. 2 October 1988. p. 80. Retrieved 29 June 2020.
  39. "Great whites of Dangerous Reef (1992)". The Charlotte Observer. 17 July 1992. p. 51. Retrieved 29 June 2020.
  40. "Great whites of Dangerous Reef (1992)". The Morning Call. 19 January 1992. p. 210. Retrieved 29 June 2020.
  41. "The Great Australian Bite (2000)". The Age. 30 July 2000. p. 88. Retrieved 29 June 2020.
  42. DSEWPaC), 2013, page 43
  43. "Bird Protection District" (PDF). South Australian Government Gazette. Adelaide: Government of South Australia. year 1909 (23): 847. 6 May 1909. Retrieved 22 January 2016.
  44. Robinson et al, 1996, Pages 138 & 140
  45. "Animals and Birds Protected by Law". Port Lincoln Times (SA : 1927 - 1954). 13 October 1933. p. 9. Retrieved 23 May 2020.
  46. Robinson et al, 1996, Page 272
  47. Baker (Part 4), 2004, page 455-456
  48. DEWNR, 2012, page 26

Sources
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