Drum line (shark control)

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A drum line is an unmanned aquatic trap used to lure and capture large sharks using baited hooks. They are typically deployed near popular swimming beaches with the intention of reducing the number of sharks in the vicinity and therefore the probability of shark attack. Drum lines are often used in association with shark nets, with the intent of killing sharks. However SMART drum lines can be used to move sharks, which greatly reduces shark and bycatch mortality. The use of drum lines has been successful in reducing shark attacks in the areas where they are installed.[1][2][3][4] The topic of shark culling became an international controversy and sparked public demonstrations and vocal opposition, particularly from environmentalists, animal welfare advocates and ocean activists.[5][6][7][8]

Description[edit]

The drum line consists of a floating drum (a barrel) with two lines attached to it. One line is attached to an anchor on the sea floor, while the other features a large baited shark hook. The drum is filled with a rigid polyurethane foam, which keeps it buoyant and prevents it from being stolen for use as a storage vessel.[9] To attract sharks, the hooks are baited with red mullet and false jacopever. Since the objective of the drum line is to prevent sharks from approaching popular beaches (and not to attract them) only about 500 grams of bait is added to each hook. Thus only sharks from the immediate vicinity are attracted to the baits.[10]

History[edit]

Drum lines were first deployed to prevent shark attacks in Queensland, Australia in 1962.[11] They continue to be used in Queensland and continue to kill sharks (and also kill by-catch species such as dolphins).[12][13] They were then used by KwaZulu-Natal (South Africa), and continue to be used there.[14] They were used intermittently in Western Australia in an "imminent threat" policy, having previously been used there for 4 months in 2014.[15][7] The use of drum lines in Western Australia ceased in March 2017 following a change in the state government,[16] but there is a plan to reintroduce them there (though, this time the plan is to install "SMART" drum lines).[17] Since 2014 Réunion Island has used drum lines in conjunction with long lines and shark barriers.[18]

Advantages[edit]

Permanent or semipermanent deployment of shark-fishing gear off high-use beaches (which includes drum lines) has been very successful in reducing the incidence of shark attack at protected beaches,[19][20] though this has been disputed.[21][22] While shark nets and drum lines share the same purpose, drum lines are more effective at targeting the three sharks that are considered most dangerous to swimmers: the bull shark, tiger shark and great white shark.[9] Drum lines physically attract sharks from within the immediate vicinity using bait[23] while shark nets allow the sharks to swim over or around them.[24] Additionally, the bycatch, or unintended catch, of drum lines is considerably less than that of shark nets.[25]

SMART drumlines can also be utilised to move sharks, which greatly reduces mortality of sharks and bycatch. In the New South Wales North Coast SMART drumline trial (Australia) 99% of targeted sharks and 98% of other animals caught were released alive.[26]

Drum lines and long lines have also been used with great success in Recife, Brazil where the shark attack rate dropped by 97%.[27][28] The purpose of the program was to relocate sharks 8 kilometers from beaches.[29][30][31]

Disadvantages[edit]

Recife, Brazil data, October 2007 to December 2011[32]
Common name Total
caught
% released
alive
Spotted eagle ray 4 100%
Marine catfish 244 75%
Blacknose shark 26 12%
Silky shark 2 50%
Bull shark 4 50%
Blacktip shark 3 33%
Caribbean reef shark 1 0%
Marine turtles 4 100%
Barred grunt 3 67%
Sting rays 14 93%
Atlantic goliath grouper 13 100%
Tiger shark 34 82%
Nurse shark 130 99%
Moray eels 11 18%
Snappers 6 67%
Devil rays 6 50%
Brazilian sharpnose shark 1 0%
Total: 506[33] 77%

Drum lines can result in the death of sharks and bycatch. During a shark attack mitigation program off Recife, Brazil over a 4-year period (October 2007 to December 2011) the total sharks caught, as well as bycatch and the percentage released alive is shown in the table.[27][32]

During the same period in Recife, 44 potentially aggressive sharks were also hooked, including 34 tiger sharks and 4 bull sharks. The overall survival rate of potentially aggressive sharks was 70% (relocated and released).[27] Out of all the animals caught, 22.7% of them died.[32] Unlike in Queensland, the objective of the Recife program was to relocate potentially aggressive sharks.[32]

The combination of drum lines and shark nets does not directly lead to extinction, but they also may not give the population room to recover from being endangered of extinction.[34]

Using drum lines to kill sharks negatively affects the marine ecosystem.[21][22] The Australian Marine Conservation Society said, "the ecological cost of drum lines is high, with 97% of sharks caught [in Queensland] since 2001 considered to be at some level of conservation risk."[35] Jessica Morris of Humane Society International says, "sharks are top order predators that play an important role in the functioning of marine ecosystems. We need them for healthy oceans."[36]

Drum lines have been claimed to be an ineffective strategy to keep people safe, while simultaneously killing thousands of sharks and other wildlife in the marine ecosystem.[21][37] Western Australia Fisheries Minister Dave Kelly said "there is currently no scientific evidence to show that drumlines reduce the risk of a [shark] attack".[38][note 1]

The ongoing killing of sharks in Queensland (under a "shark control" program) has been criticized.[11] This program has been called a cull.[5] From 1962 to the present, the government of Queensland has targeted and killed sharks in large numbers by using drum lines[40] — this program has also killed large numbers of other animals such as dolphins; it has also killed endangered hammerhead sharks.[13][41][37] Queensland currently operates the largest shark culling program in Australia.[35] In the first 11 months of 2013, 633 sharks were captured in Queensland — more than 95% of those sharks were killed.[42] From 2013 to 2014, 667 sharks were killed in Queensland's "shark control" program, including great white sharks and critically endangered grey nurse sharks.[35] From 2014 to 2015, 621 sharks were killed in Queensland.[43] From 2017 to 2018, 218 sharks were killed, including 75 tiger sharks and 41 bull sharks.[44] From 2001 to 2018, a total of 10,480 sharks were killed on lethal drum lines in Queensland.[45]

In 2015, the following was said about bycatch in Queensland's "shark control" program (which uses drum lines):

[Data] reveals the ecological carnage of [Queensland's] shark control regime. In total, more than 8,000 marine species with some level of protection status have been caught by the Queensland Shark Control Program, including 719 loggerhead turtles, 442 manta rays and 33 critically endangered hawksbill turtles. More than 84,000 marine animals have been ensnared by drum-lines and shark nets since the program began in 1962 [...] Nearly 27,000 marine mammals have been snared. The state’s shark control policy has captured over 5,000 turtles, 1,014 dolphins, nearly 700 dugongs and 120 whales, all of which are federally protected marine species.[46]

Shark and bycatch mortality from drum lines is minor compared to Commercial fishing. On average 15 Great white sharks are caught by the NSW and Queensland shark control programme each year, compared to 186 caught in Australia from other activities.[47] Australia's commercial shark fishing industry is catching over 1200 tonne of shark each year,[48] of which 130 are Great white sharks.[47] The NSW prawn trawling industry alone results in 64 tonne of shark as bycatch each year,[48] with two thirds dying.[49] Tuna and swordfish longline fishing off the coast of South Africa reported 39,000 to 43,000 sharks killed each year between 1995 and 2005.[49] Sharksavers estimates that in total 50 million sharks are caught unintentionally each year as bycatch by the commercial fishing industry.[50]

There is also evidence of dolphins stealing bait on numerous occasions, thus rendering the drum lines useless.[2][51]

Smart drumlines[edit]

On Réunion regular operation of "SMART" (Shark-Management-Alert-in-Real-Time)[52] drum lines began in August 2015 and they are used in conjunction with bottom long lines. A "SMART" drum line is based on the traditional drum line design, but it includes technology that can alert rangers to the capture of marine life, who can then attend the device if sea conditions permit. In Reunion, fishermen usually attend the drum lines within 90 minutes of an alert and 90 per cent of animals caught on the hooks survive.[53] There are now around 15 of these smart-drumlines along the coast of Réunion Island.[54]

Since December 2015 the New South Wales State government commenced trials of "SMART" drumlines,[52] as part of an expansion of shark attack mitigation strategies along the New South Wales North coast.[55] Twenty five drumlines were deployed at Ballina and Evans Head beaches (15 off Ballina; 10 off Evans Head).[55] Once a target shark is caught it is tagged with a transmitter, relocated approximately 1 km offshore and released. Non-targeted animals are immediately released. In addition, the tagged sharks provide an alert to the community if they pass within range of a series of listening stations located along the coast.[56] Since the start of the trial 230 target sharks (209 great white, 12 tiger, and 9 bull sharks) were caught with 99% of targeted sharks and 98% of other animals released alive.[26][56] The trial has been effective in reducing shark attacks[57][58][59] and has been expanded to other regions of New South Wales.[56]

In August 2018 a 12-month trial of "SMART" drumlines along Western Australia's South West coast, near Gracetown was announced.[60]

Environmental groups oppose "SMART" drum lines; they say that "SMART" drum lines will not reduce the risk of shark attacks, and may actually make beaches more dangerous; they also say "SMART" drum lines are dangerous to sharks.[39] In 2018, more than 7,000 Western Australians signed a petition demanding that Western Australia's "SMART" drum line trial be abandoned.[39] Humane Society International stated the following about "SMART" drum lines in Western Australia: "HSI expects the SMART drumline trial to result in the inevitable suffering and death of marine wildlife, and therefore opposes the decision to commence the trial."[61] Tooni Mahto, a spokesman for the Australian Marine Conservation Society, said the following about "SMART" drum lines: "Some species can't cope with being released after being caught [on "SMART" drum lines]. For example hammerhead sharks, when caught on hooks get very, very stressed."[62]

On the 17 January 2019 the Environmental Protection Authority of Western Australia determined that the "SMART" drumline trial would have minimal impact on the environment and therefore did not warrant a formal assessment.[63]

Controversy[edit]

Great white sharks were targeted by Western Australia's controversial shark culling policy.

Prior to 2014, drum lines were only utilised on Australia's eastern coast and in South Africa where the numbers of attacks reduced dramatically.[2][19] In 2014, the Western Australian government reacted to the loss of seven human lives in the years 2010-2013 and installed drum lines along around 200 km[64] of its 20,000 km (12,000 mi) long coastline[65] (around 1%). The policy has been the subject of national and international protests, coming under fire from marine conservationists and animal welfare advocates and their supporters. The policy is commonly referred to as the Western Australian shark cull. Following a change in the West Australian state government in March 2017,[16] the newly elected Premier Mark McGowan and Fisheries Minister David Kelly have stated that they do not support the previous governments' catch and kill policy.[66] However, in August 2018, following continual shark attacks, the West Australian state government reversed their position and announced a 12-month trial of "SMART" drumlines along Western Australia's South West coast, near Gracetown.[17]

Drum lines have been criticized on animal rights grounds, not only for their negative effect on the environment and killing of endangered species, but also for their non-scientific and speciesist approach.[6][7][8][22]

A number of people opposed to the Queensland's shark-killing program have sabotaged various drum lines throughout Queensland to save sharks, despite the risk of being fined.[67]

The current shark-killing program in Queensland has been criticized by environmentalists, conservationists, and animal rights advocates — they say Queensland's shark-killing program is unethical and harms the marine ecosystem.[35][37][6][36][21] Queensland's shark-killing program has been called "outdated, cruel and ineffective".[37] The government of Queensland currently kills sharks in the Great Barrier Reef using 173 lethal drum lines; in 2018, Humane Society International Australia filed a lawsuit (court challenge) requesting that the drum lines be removed there.[45] The case was heard in the Administrative Appeals Tribunal in January 2019, and in April 2019 the Tribunal ordered that sharks no longer be culled in the Great Barrier Reef based on the evidence that killing sharks makes no difference to swimmer safety.[68] The Queensland Government said it would appeal the decision.

See also[edit]

Note[edit]

  1. ^ After Dave Kelly said this, the Western Australian government decided to implement a "SMART" drum line trial; Kelly said in November 2018, "Hopefully at the end of the trial we will get a scientific basis for making an assessment as to whether or not these ['SMART'] drum lines actually make our beaches safer."[39]

References[edit]

  1. ^ Richard Shears (28 October 2009). "Great White Shark bitten nearly in half by an even BIGGER monster". Daily Mail.com.
  2. ^ a b c "A Report on the Queensland Shark Safety Program" (PDF). State of Queensland. March 2006. Archived from the original (PDF) on 2014-01-23. Retrieved 2016-11-26.
  3. ^ "Shark Nets, Drumlines, and Safe Swimming". KwaZulu Natal Sharks Board. Archived from the original on 2014-01-28.
  4. ^ Commonwealth of Australia (December 2017). "Senate Report:Shark mitigation and deterrent measures" (PDF): 77. Retrieved 25 March 2018. Cite journal requires |journal= (help)
  5. ^ a b "Sharks - Marine Science Australia". Ausmarinescience.com. Retrieved 2016-12-01.
  6. ^ a b c "Queensland | Overview". Seashepherd.org.au. Archived from the original on 2017-08-23. Retrieved 2016-12-01.
  7. ^ a b c Calla Wahlquist (12 February 2015). "Western Australia's 'serious threat' shark policy condemned by Senate". The Guardian. Retrieved 2016-12-01.
  8. ^ a b Carl Meyer (2013-12-11). "Western Australia's shark culls lack bite (and science)". Theconversation.com. Retrieved 2016-12-01.
  9. ^ a b Dudley, S.F.J.; Haestier, R.C.; Cox, K.R.; Murray, M. (1998). "Shark control: experimental fishing with baited drumlines". Marine and Freshwater Research. 49 (7): 653–661. doi:10.1071/MF98026.
  10. ^ "Drumlines Frequently Asked Questions" (PDF). KwaZulu Natal Sharks Board. Archived from the original (PDF) on 2010-02-15.
  11. ^ a b "Has Queensland really saved lives by killing thousands of sharks?". Brisbanetimes.com.au. 2014-02-21. Retrieved 2016-12-01.
  12. ^ "Drumlines Capture Hundreds of Sharks in Queensland". The Australian. Retrieved 2016-12-01.
  13. ^ a b Matt Watson (2015-08-25). "Dolphins, rays among hundreds of non-targeted animals killed on Queensland shark nets and drum lines, figures show". ABC News. Australian Broadcasting Corporation. Retrieved 2016-12-01.
  14. ^ Angela Pownall (2014-06-10). "Drum lines part of life in South Africa for 50 years". The West Australian. Retrieved 2016-12-01.
  15. ^ Oliver Milman (23 October 2014). "WA abandons shark culling program, but reserves right to kill again". The Guardian. Retrieved 2016-12-01.
  16. ^ a b Jacob Kagi (12 March 2017). "WA election: Mark McGowan confronts 'enormity of task' facing Labor government". ABC News. Australian Broadcasting Corporation. Retrieved 12 May 2017.
  17. ^ a b "Sharks to be caught on SMART drum lines off WA's South West after Labor U-turn". ABC News. 14 August 2018. Retrieved 14 August 2018.
  18. ^ "Reunion Shark Nets Snatch Victory From Jaws of Ruin". The Australian. Retrieved 2016-12-01.
  19. ^ a b Curtis; et al. (2012). "Chapter 31: Responding to the Risk of White Shark Attack – Updated Statistics, Prevention, Control, Methods and Recommendations" (PDF). In M. L. Domeier (ed.). Global Perspectives on the Biology and Life History of the White Shark. Boca Raton, FL.: CRC Press. Archived from the original (PDF) on 2016-11-22. Retrieved 27 November 2016.
  20. ^ Dudley, S.F.J. (1997). "A comparison of the shark control programs of New South Wales and Queensland (Australia) and KwaZulu-Natal (South Africa)". Ocean & Coastal Management. 34 (34): 1–27. doi:10.1016/S0964-5691(96)00061-0.
  21. ^ a b c d Alana Schetzer (8 May 2017). "Sharks: How a cull could ruin an ecosystem". Science Matters. University of Melbourne – via Pursuit.
  22. ^ a b c Chloe Hubbard (30 April 2017). "No Shark Cull: Why Some Surfers Don't Want to Kill Great Whites Despite Lethal Attacks". NBC News.
  23. ^ McPhee, D.P. (August 2012). "Likely effectiveness of netting or other capture programs as a shark hazard mitigation strategy in Western Australia" (PDF). Fisheries Occasional Publication. Perth, Western Australia: Department of Fisheries. 108. ISBN 978-1-921845-51-2. ISSN 1447-2058. Retrieved 2016-11-26.
  24. ^ Celia (21 September 2009). "Australian Shark Control Programs Indiscriminately Catch Marine Life". Marine Science Today. Retrieved 2016-11-26.
  25. ^ "2011 Annual Report". KwaZulu Natal Sharks Board. p. 21. Archived from the original on 2014-08-19. Retrieved 2018-07-26.
  26. ^ a b "NSW North Coast SMART drumline data". NSW Government: Department of Primary Industries. Retrieved 4 December 2018.
  27. ^ a b c Hazin, F.H.V.; Afonso, A.S. (28 November 2013). "A green strategy for shark attack mitigation off Recife, Brazil". Animal Conservation. 17 (4): 287–296. doi:10.1111/acv.12096. hdl:10400.1/11160.
  28. ^ https://www.abc.net.au/news/2015-12-23/shark-attacks-smart-drum-lines-fact-check/7030538 Fact Check: Are smart drum lines just a PR exercise? 3 March 2016. Abc.net.au. Retrieved October 21, 2018.
  29. ^ https://www.seashepherd.org.au/apex-harmony/overview/alternatives.html Alternatives to drum lines and shark nets. Seashepherd.org.au. Retrieved October 21, 2018.
  30. ^ https://www.wiley.com/WileyCDA/PressRelease/pressReleaseId-111168.html Humane Strategy Reduces Shark Attacks. August 4, 2014. Wiley.com. Retrieved October 21, 2018.
  31. ^ https://www.economist.com/the-economist-explains/2017/10/31/drones-v-sharks Drones v Sharks. The Economist. E.A.D.W. October 31, 2017. Retrieved October 21, 2018.
  32. ^ a b c d https://zslpublications.onlinelibrary.wiley.com/doi/pdf/10.1111/acv.12096 Zslpublications.onlinelibrary.wiley.com. A green strategy for shark attack mitigation off Recife, Brazil. F. H. V. Hazin & A. S. Afonso.
  33. ^ 462 bycatch
  34. ^ "Do the nets and drumlines really have a measurable impact on shark populations?". removethenets.com. 2 May 2009. Archived from the original on 2009-06-11. Retrieved 2010-02-10.
  35. ^ a b c d "Shark Culling". marineconservation.org.au. Archived from the original on 2018-10-02. Retrieved September 28, 2018.
  36. ^ a b Morris, Jessica (December 8, 2016). "Shark Nets – Death Traps For Marine Animals". hsi.org.au. Archived from the original on October 2, 2018. Retrieved September 28, 2018.
  37. ^ a b c d Phillips, Jack (September 4, 2018). "Video: Endangered Hammerhead Sharks Dead on Drum Line in Great Barrier Reef". ntd.tv. Archived from the original on September 19, 2018. Retrieved September 18, 2018.
  38. ^ Mackenzie, Bruce (August 4, 2018). "Sydney Shark Nets Set to Stay Despite Drumline Success". swellnet.com. Archived from the original on 2018-09-21. Retrieved September 28, 2018.
  39. ^ a b c https://www.9news.com.au/2018/11/29/21/48/shark-drumlines-wa-thousands-sign-petition-calling-for-end-of-practice 9news.com.au. Environmental activists demand WA shark drum line trial be abandoned. Elizabeth Creasy. November 29, 2018. Retrieved December 22, 2018.
  40. ^ "About the Campaign:Sea Shepherd Working Together With The Community To Establish Sustainable Solutions To Shark Bite Incidents". seashepherd.org.au. Archived from the original on 2018-04-08. Retrieved September 28, 2018.
  41. ^ Forrest, Alice (2014-09-10). "Shark Nets in Australia – What Are They and How Do They Work?". sealifetrust.org. Retrieved September 18, 2018.
  42. ^ "Can governments protect people from killer sharks?". ABC News. 2013-12-22. Retrieved 2018-09-27.
  43. ^ Burke, Gail (August 21, 2015). "621 Sharks Killed Off Queensland Coast Through Control Program". abc.net.au. Archived from the original on 2015-09-23. Retrieved September 29, 2018.
  44. ^ Donaghey, Kathleen (September 25, 2018). "Whitsunday Locals Resist Shark Culls After Two Attacks". thenewdaily.com. Archived from the original on 2018-10-02. Retrieved September 29, 2018.
  45. ^ a b "Queensland Government Kills Sharks, Faces Court Challenge". maritime-exeecutive.com. September 4, 2018. Archived from the original on 2018-09-04. Retrieved September 29, 2018.
  46. ^ Thom Mitchell (November 20, 2015). Action for Dolphins. "Queensland’s Shark Control Program Has Snagged 84,000 Animals". Retrieved December 25, 2018.
  47. ^ a b H. Malcolm, B. D. Bruce and J. D. Stevens (September 2001). "A Review of the Biology and Status of White Sharks in Australian Waters". CSIRO Marine Research, Hobart: 93. Retrieved 8 December 2018.
  48. ^ a b Media, Australian Community Media - Fairfax (8 November 2016). "Beyond the panic: the facts about shark nets". Retrieved 8 December 2018.
  49. ^ a b Stephanie M. Bettis (July 2017). "Shark Bycatch in Commercial Fisheries: A Global Perspective". Nova Southeastern University. Retrieved 8 December 2018.
  50. ^ "Shark fin trade myths and truths" (PDF). Sharksavers. Retrieved 8 December 2018.
  51. ^ "Dolphins take the bait from drumline on the Gold Coast". YouTube. 29 January 2014.
  52. ^ a b "SMART Drumlines". NSW Department of Primary Industries. NSW Government. Retrieved 18 April 2018.
  53. ^ "Fact Check: Are smart drum lines just a PR exercise?". ABC News. Australian Broadcasting Corporation. 2 March 2016. Retrieved 2016-11-26.
  54. ^ Andy Guinand (9 August 2016). "Innovative solutions for a global interest". Forbidden ocean in Réunion Island. Ocean71 Magazine. Retrieved 2016-11-26.
  55. ^ a b "North Coast Shark Net Trial: Summary". NSW Department of Primary Industry. NSW Government. Retrieved 23 March 2018.
  56. ^ a b c "SMART Drumlines: Frequently asked Questions" (PDF). NSW Department of Primary Industries. NSW Government. Retrieved 4 December 2018.
  57. ^ Miles Godfrey (1 September 2017). "Shark nets will return to NSW's north coast beaches". Tweed Daily News. Retrieved 23 March 2018.
  58. ^ Vucovic, Dom (17 March 2018). "SMART drumlines catching great white sharks and protecting swimmers, researchers say". ABC News. Australian Broadcasting Commission. Retrieved 21 April 2018.
  59. ^ https://www.buzzfeed.com/elfyscott/heres-what-you-need-to-know-about-australias-smart-drum Here's What You Need To Know About Australia's SMART Drum Lines Being Used To Prevent Shark Attacks. Buzzfeed.com. Elfy Scott. July 5, 2018. Retrieved October 24, 2018.
  60. ^ "Sharks to be caught on SMART drum lines off WA's South West after Labor U-turn". ABC News. 14 August 2018. Retrieved 14 August 2018.
  61. ^ https://hsi.org.au/blog/the-wa-government-cant-claim-smart-drumlines-are-non-lethal Humane Society International. The WA Government can’t claim SMART drumlines are “non-lethal”. October 26, 2018. Retrieved December 27, 2018.
  62. ^ https://www.abc.net.au/news/2018-03-20/data-shows-500-sharks-caught-in-drumlines-nets-queensland/9567022 Conservation groups call for 'archaic' shark control program to be abolished in Queensland. Kristy Sexton-McGrath. March 20, 2018. Retrieved December 25, 2018.
  63. ^ Government of Western Australia. "EPA determines SMART drumline proposal would have minimal impact". Environmental Protection Authority. Retrieved 9 February 2019.
  64. ^ "Shark strategy: baited drum lines and killing zones near popular beaches after fatal attacks". ABC News. Australian Broadcasting Corporation. 10 December 2013.
  65. ^ "Coastline Lengths". Education. Commonwealth of Australia. November 18, 2010. Archived from the original on 2011-01-22. Retrieved 2008-10-27.
  66. ^ Daniel Mercer (19 April 2017). "Premier Mark McGowan's shark plan not enough to protect us". The West Australian. Retrieved 13 May 2017.
  67. ^ Bill Hoffman (2014-05-16). "Beachgoers sabotaging shark bait hooks on Coast". Sunshine Coast Daily. Retrieved 2016-12-01.
  68. ^ "HSI wins court case against killing of sharks in Great Barrier Reef".