Sharkdefense

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SharkDefense is a research organization and think tank focused on shark bycatch reduction. Its core research involves chemical and electrochemical shark repellent technologies. SharkDefense's repellent experiments have been featured extensively in the US and European media. [1]

Contents

SharkDefense is the discover of the permanent-magnetic and electrochemical repellent effects on sharks. These findings represent the first research efforts focused exclusively at selectively repelling sharks from commercial fishing gear without affecting the target catch. The repellent effect of electropositive metals on sharks was confirmed by the National Marine Fisheries Service, notably, Stoner and Kaimmer, [2] and studies completed by Brill et al. (2008) [3] and Wang et al. (2008) [4] also support the repellent effects. The preliminary research results on permanent magnetic shark repellents were reviewed, judged, and awarded the first place 2006 WWF SmartGear award. [5] In 2008, the Department of Primary Industries and Fisheries (DPI&F) and James Cook University (JCU), Australia confirmed that permanent (ferrite) magnets technology repel grey reef sharks, hammerheads, sharp-nosed sharks, blacktip sharks, the vulnerable sawfish and the critically endangered spear tooth shark.

In 2014, SharkDefense partnered with SharkTec LLC to commercialize an aerosol semiochemical shark repellent product. Both companies are working to broaden the commercial use of SharkDefense's technologies.

History

SharkDefense was formed in September 2001 by Eric Stroud and Jean Stroud. Its research program began at the Oak Ridge Shark Laboratory with a search for trace chemical messengers present in decayed shark tissue. In 1943, Burden et al. from the Woods Hole Oceanographic Institution (WHOI) had reported that decayed shark tissue was successful at halting feeding in captive dusky smooth-hound sharks (Mustelis canis). In the efforts to develop and test a chemical shark repellent package led by Dr. Harold Coolidge of the Harvard Museum, the WHOI team selected ammonium acetate as the active in the decomposing shark tissue, however, instrumental analysis by the Oak Ridge Shark Lab in 2002 failed to find ammonium acetate. It was hypothesized by SharkDefense that ammonium acetate was an approximation of the ammonium cation (based on the ammonia-like smell of the shark tissue or a urea-urease reaction), and the acetate conjugate base (based on the acetic acid which WHOI had already found to have repellent properties). After 2002, many new compounds were found and catalogued by SharkDefense, who maintains a repellent compound database.

Milestones

1. Apr. 15, 2003 – First successful field test of a semiochemical shark repellent, Triangle Rocks, South Bimini, Bahamas

2. May 2004 – A gustatory shark repellent (“5ISO”) is isolated and successfully tested

3. Nov. 2004 – Accidental discovery of the repellent effects of a rare-earth magnet is made at the Oak Ridge Shark Lab

4. Jul 12, 2005 – Testing at Achotines, Panama on captive yellowfin tuna (T. albacares) confirms that both semiochemical mixtures and the gustation compound are selective shark repellents and do not repel a commercially-valuable fish species.

5. Sep. 15, 2005 - A 0.1ppm solution of a synthetic shark repellent compound terminates tonic immobility in juvenile lemon sharks (N. brevirostris).

6. Nov. 16, 2005 – Chemical repellents are successfully incorporated into a time-release gel matrix, providing more than 4 hours of protection time.

7. May 1, 2006 – Accidental discovery is made using an electropositive metal as an experimental control at South Bimini, Bahamas.

8. May 11, 2006 – SharkDefense is the grand prize winner of the 2006 WWF Smart Gear competition for its proposal on permanent magnet shark repellents. [6]

9. Aug. 31, 2007 - Fish attractant qualities of the gustation compound are confirmed.

10. Jun. 2007 – SMART Hook technology developed.

Current members

2001 – Present. Mr. Eric M. Stroud (Seton Hall University, Ph.D. candidate) was the co-founder of SharkDefense and led the initial research to identify chemical repellent actives. He is the managing partner and is researching chemical signals and necromones as part of his PhD.

2006 – Present. Dr. Patrick H. Rice (University of Miami, RSMAS), partner, joined the SharkDefense team in 2005 while researching the repellent effects of permanent magnets. He is the director of marine sciences at Florida Keys Community College and is senior marine biogist with SharkDefense.

2006 – 2012. Mr. Craig P. O’Connell (Coastal Carolina University, Ph.D. student), partner, joined the SharkDefense team as marine biologist in 2006 while working on a contract shark repellent-sunscreen project at South Bimini, Bahamas. He is researching magnetoreception as a shark bycatch mechanism for his Ph.D.

2010 - 2011. Mr. Conrad Eskelinen (DiveBum Studios), partner, joined the SharkDefense team as creative director in 2010.

2003 – Present. Dr. Samuel H. Gruber (University of Miami, RSMAS, professor emeritus), consultant, has assisted and supervised many SharkDefense repellent trials at the Bimini Biological Field Station.

2003–Present. Mr. Grant T. Johnson (South Bimini, Bahamas), consultant, providing field and testing support.

2004 – Present. Ms. Katie Grudecki (South Bimini, Bahamas), consultant, providing field and testing support.

2004 – 2010. Mr. Sean Williams (Bimini Biological Field Station), consultant, providing field testing support.

Related Research Articles

In chemistry, a salt is a chemical compound consisting of an ionic assembly of cations and anions. Salts are composed of related numbers of cations and anions so that the product is electrically neutral. These component ions can be inorganic, such as chloride (Cl−), or organic, such as acetate ; and can be monatomic, such as fluoride (F−) or polyatomic, such as sulfate.

Bimini Third-Scheduled District in Bahamas

Bimini is the westernmost district of the Bahamas and comprises a chain of islands located about 80 kilometres (50 mi) due east of Miami. Bimini is the closest point in the Bahamas to the mainland United States and approximately 210 km (130 mi) west-northwest of Nassau. The population is 1,988 as of the 2010 census.

Elasmobranchii Subclass of fishes

Elasmobranchii is a subclass of Chondrichthyes or cartilaginous fish, including the sharks and the rays, skates, and sawfish. Members of this subclass are characterised by having five to seven pairs of gill clefts opening individually to the exterior, rigid dorsal fins and small placoid scales on the skin. The teeth are in several series; the upper jaw is not fused to the cranium, and the lower jaw is articulated with the upper. The details of this jaw anatomy vary between species, and help distinguish the different elasmobranch clades. The pelvic fins in males are modified to create claspers for the transfer of sperm. There is no swim bladder; instead, these fish maintain buoyancy with large livers rich in oil.

Cetacean bycatch

Cetacean bycatch is the incidental capture of non-target cetacean species such as dolphins, porpoises, and whales by fisheries. Bycatch can be caused by entanglement in fishing nets and lines, or direct capture by hooks or in trawl nets.

Greenland shark Species of shark

The Greenland shark, also known as the gurry shark, grey shark, or by the Kalaallisut name eqalussuaq, is a large shark of the family Somniosidae, closely related to the Pacific and southern sleeper sharks. The distribution of this species is mostly restricted to the waters of the North Atlantic Ocean and Arctic Ocean.

A shark repellent is any method of driving sharks away from an area. Shark repellents are a category of animal repellents. Shark repellent technologies include magnetic shark repellent, electropositive shark repellents, electrical repellents, and semiochemicals. Shark repellents can be used to protect people from sharks by driving the sharks away from areas where they are likely to kill human beings. In other applications, they can be used to keep sharks away from areas they may be a danger to themselves due to human activity. In this case, the shark repellent serves as a shark conservation method. There are some naturally-occurring shark repellents; modern artificial shark repellents date to at least the 1940s, with the United States Navy using them in the Pacific Ocean theater of World War II.

Ammonium acetate, also known as spirit of Mindererus in aqueous solution, is a chemical compound with the formula NH4CH3CO2. It is a white, hygroscopic solid and can be derived from the reaction of ammonia and acetic acid. It is available commercially.

Nurse shark Elasmobranch fish in the family Ginglymostomatidae

The nurse shark is an elasmobranch fish in the family Ginglymostomatidae. The conservation status of the nurse shark is globally assessed as being data deficient in- the IUCN List of Threatened Species owing to the lack of information across its range in the eastern Pacific Ocean and eastern Atlantic Ocean. They are considered to be a species of least concern in the United States and in The Bahamas, but considered to be near threatened in the western Atlantic Ocean because of their vulnerable status in South America and reported threats throughout many areas of Central America and the Caribbean. They are directly targeted in some fisheries and considered as bycatch in others.

Ammonium alum Chemical compound

Ammonium aluminium sulfate, also known as ammonium alum or just alum (though there are many different substances also called "alum"), is a white crystalline double sulfate usually encountered as the dodecahydrate, formula (NH4)Al(SO4)2·12H2O. It is used in small amounts in a variety of niche applications. The dodecahydrate occurs naturally as the rare mineral tschermigite.

Bioconversion of biomass to mixed alcohol fuels

The bioconversion of biomass to mixed alcohol fuels can be accomplished using the MixAlco process. Through bioconversion of biomass to a mixed alcohol fuel, more energy from the biomass will end up as liquid fuels than in converting biomass to ethanol by yeast fermentation.

Samuel H. Gruber was a shark biologist and founder of the American Elasmobranch Society. He was a Professor at the University of Miami's Rosential School for Marine and Atmospheric Science and the founder of the Bimini Biological Field Station Foundation.

Mike Rutzen South African conservationist and shark cage diving operator

Michael Rutzen is a South African conservationist, film maker, cage diving operator.

1-Octen-3-ol Chemical compound

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Electropositive metals (EPMs) are a new class of shark repellent materials that produce a measurable voltage when immersed in an electrolyte such as seawater. The voltages produced are as high as 1.75 VDC in seawater. It is hypothesized that this voltage overwhelms the ampullary organ in sharks, producing a repellent action. Since bony fish lack the ampullary organ, the repellent is selective to sharks and rays. The process is electrochemical, so no external power input is required. As chemical work is done, the metal is lost in the form of corrosion. Depending on the alloy or metal utilized and its thickness, the electropositive repellent effect lasts up to 48 hours. The reaction of the electropositive metal in seawater produces hydrogen gas bubbles and an insoluble nontoxic hydroxide as a precipitate which settles downward in the water column.

Magnetic shark repellents utilize permanent magnets, which exploit the sensitivity of the Ampullae of Lorenzini in sharks and rays (electrosense). This organ is not found on bony fish (teleosts), therefore, this type of shark repellent is selective to sharks and rays. Permanent magnets do not require power input, making them ideal for use in fisheries and as bycatch reduction devices. Sharkbanz, released in 2014, is a wearable commercially available device intended for recreational users. However independent tests of Sharkbanz products in 2018 highlighted that they did not work.

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<i>The Sharkfighters</i>

The Sharkfighters is a 1956 American adventure film about U.S. Navy scientists working to invent a shark repellent to protect military personnel down at sea. Directed by Jerry Hopper, it stars Victor Mature, James Olson, and Claude Akins. The fictional storyline is based on the invention of "Shark Chaser", an historical shark repellent developed by researchers during World War II.

Brown whipray Species of cartilaginous fish

The brown whipray is a species of stingray in the family Dasyatidae, common in inshore, muddy habitats along the northern coast of Australia. It has often been confused in literature for the honeycomb stingray and the black-spotted whipray, which until recently was thought to be the same species. This species has an angular, diamond-shaped pectoral fin disc and a long, very thin tail without fin folds. It is plain brown above, sometimes with white dots or flecks near the edge of the disc, and white below; the tail is dark all over, with alternating dark and light bands near the tip. The maximum recorded disc width is 74 cm (29 in).

Shark attack prevention

There are a range of shark attack prevention techniques employed to reduce the risk of shark attack and keep people safe. They include removing sharks by various fishing methods, separating people and sharks, as well as observation, education and various technology-based solutions.

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References

O’Connell, C.P., D.C. Abel, and E.M. Stroud. 2011. Analysis of permanent magnets as elasmobranch bycatch reduction devices in hook-and-line and longline trials. Fish. Bull. 109(4): 394-401.

O’Connell, C.P., S.H. Gruber, D.C. Abel, E.M. Stroud. and P.H. Rice. 2011. The responses of juvenile lemon sharks, Negaprion brevirostris, to a magnetic barrier. Ocean Coast. Manag. 54(3): 225-230.

O’Connell, C.P., Abel, D.C., Rice, P.H., Stroud, E.M. and Simuro, N.C. 2010. Responses of the Southern Stingray (Dasyatis americana) and the Nurse Shark (Ginglymostoma cirratum) to Permanent Magnets. Mar. Freshw. Behav. Phy. 43: 63-73.

O'Connell, C.P. 2008. Investigation of Grade C8 Barium Ferrite (BaFe2O4) Permanent Magnets as a Possible Elasmobranch Bycatch Reduction System. In: Swimmer, Y., J.H. Wang, and L. McNaughton. 2008. Shark deterrent and incidental capture workshop, April 10–11, 2008. U.S. Dep. Commer., NOAA Tech Memo., NOAA-TM-NMFS-PIFSC-16. 72p.

Stroud, E. M., C. P. O’Connell, P. H. Rice, B. B. Barnes, M. Elshaer, N. H. Snow, J. E. Hanson (Submitted). “Chemical Shark Repellent: Myth or Fact? The effect of a shark necromone on shark feeding behavior”. Ocean Coast. Manag.

O’Connell, C.P., P. He, T.J. O’Connell, M.K. Maxwell, R.C. Reed, C.A. Smith, E.M. Stroud and P.H. Rice. (In Preparation). The Use of Permanent Magnets to Reduce Elasmobranch Encounter with a Simulated Beach Net. 2. The Great Hammerhead Shark (Sphyrna mokarran).

O’Connell, C.P., P.He, J. Joyce, E.M. Stroud, and P.H. Rice. (In Preparation). Effects of the SMART Hook™ (Selective Magnetic and Repellent-Treated Hook) on Spiny Dogfish Catch in the Gulf of Maine.

O'Connell, C.P., E.M. Stroud, P. He, T.J. O'Connell, P.H. Rice, G. Johnson, and K. Grudecki. (Submitted). The Use of Permanent Magnets to Reduce Elasmobranch Encounter with a Simulated Beach Net. 1. The Bull Shark (Carcharhinus leucas). Ocean Coast. Manag.

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