Thursday, 2 July 2015

North Carolina Shark Attacks - Why So Many This Year?

Photo by Steve Bouser

With the news yesterday of a seventh shark attack, North Carolina is now having it's equal worst year since 1900 (tied with 2008) for shark bite incidents. The most recent victim, a 67 year old man, was bitten multiple times on the abdomen, hip, lower leg and both hands, is in a stable condition in hospital and eyewitnesses are reporting the incident to be very similar to most of the other incidents so this raises the question, why is North Carolina suffering an outbreak of attacks and what can be done to minimise the risk?

To begin with we need to look at the different kinds of incidents for which the term "shark attack" is used because not all incidents can be justifiably referred to as "attacks" and understanding each is key to establishing what might be causing these incidents. At this stage I should also point out that, whereby we need to address the issue objectively and having stated that not all incidents are "attacks," I do not subscribe to the recent campaign to ban the word "Shark Attack" from the media, firstly, I am uncomfortable with any kind of censorship, but moreover, I find the definitions given in the linked article, purposefully misleading and far too vague. What we need is accurate reporting, not censorship and although the 100 or so phd students, researchers and communications professionals are respected individuals in their fields, I am not aware of any whose area of expertise is actually shark attack. Whereas I agree that more should be done to increase media understanding of shark bites to aid more accurate reporting, I don't think this is the way to go about it.

Consider this, from Shark Uber-Mensch Samuel "Doc" Gruber from his 1988 paper "Why Do Sharks Attack Humans," Gruber states;

"...some attacks can be accepted as legitimate attempts by the shark to feed on humans."

For me, personally, if we are to look at the broad spectrum of what the media currently refers to as a "Shark Attack" upon an individual it can be defined most accurately as "a non-voluntary contact encounter between a human(s) and a shark" and this could range from a surfer having his board bumped by a shark to a swimmer being completely consumed and everything in between.

Regular readers will know how passionate I am about avoiding hyperbolic and simplistic reports about these incidents using lazy terminology in place of detailed analysis, I have stated here, in articles and interviews many times that each incident is dependent upon so many variables that the only way to increase understanding of these incidents is to look at every detail available to assess the incident fully. The existence of human objective input into these details is not only problematic in the media, it also leads to inconsistencies in the existing databases where some attacks are not included due to being classed as "provoked," most commonly due to the victim's activity prior to the attack, usually spearfishing.

For the purposes of accurate detailed analysis, I would like to see a "Shark/Human Incident" database which includes all non-voluntary contact encounters between sharks and humans and splits them up into the following categories;

Non-Injurious (including attacks on boats)

In each incident report, as much detail as possible would be included and where possible, a viable explanation given for the attack, on the understanding that it is impossible to always be certain on what a shark's motivation can be.

As a caveat to the above, it must be noted that, as shark attacks are so infrequent, it is impossible to collect enough reliable data to assess risks in relation to potential future incidents or, put more simply, it is impossible to create a model which will predict when a shark bite on a human will occur. Also, shark attacks are defined by many different variables from the species involved, to the victim, the victim's activity at the time of the attack, the location and various environmental factors. It is inaccurate and misleading to compartmentalise shark attacks into easily digested (pardon the pun) soundbites.

With regards to North Carolina, let's have a look at its history with shark attacks.

If we look at the current spate of attacks first:

June 11th - 13 year old received minor bites to her feet and two bites to her Body Board

June 14th - 12 year old Kirsten Yow receives serious multiple bites to her arm and leg with her hand severed. Arm is later amputated below the elbow

June 14th - 16 year old Hunter Treschl receives serious multiple bites losing his let arm above the elbow

June 24th - 8 year old boy suffers minor injuries from a bite which appears to be from a small shark at Surf City

June 26th - 47 year old man bitten on the back at Avon in Hatteras Island

June 27th - 18 year old man suffers multiple serious bites to his right calf, buttocks and both hands at Waves, also Hatteras Island

July 1st - 68 year old man receives multiple bites to abdomen, hip, lower leg and both hands at Ocracoke Island

Seven attacks in nineteen days in such a condensed geographic area is certainly a rare occurrence but it's not unprecedented. Contrary to a statement from one of the main voices behind the "ban the phrase 'shark attacks' campaign," incidents of shark bite on the same or consecutive days have actually happened multiple times around the world, including in North Carolina, prior to the events this year.

In 2001 (one fatality), 2008 and 2011 North Carolina experienced multiple attacks days and in 1995, 2000, 2004 and 2007 there were incidents on consecutive days, 1995 actually saw three attacks in 4 days.

If we look at the seven incidents so far this year, five have been confirmed as multiple bites which points towards a pronounce determination on the part of the shark, contrary to the notion that all "shark bites are a result of mistaken identity" or "curiosity," these multiple bite incidents can be more accurately described as being motivated by a degree of determination and possibly even predation. That's not to say however, that the sharks involved in these attacks are swimming around looking for people to eat, rather the unfortunate victims have encountered sharks in a natural predatory state.

Historical Statistics:

  • There have been 95 unprovoked attacks in North Carolina waters with 11 of those fatal.
  •  On average there is a fatality every 10.4 years with the most number of fatalities in a single year being two, this has happened only once (1905) since 1900.
  • The last fatality in North Carolina was the 2008 attack on Richard Snead although there is doubt whether the injuries he sustained were the cause of his death, or came after he drowned. If we place this attack as "unconfirmed," the last fatality prior to Snead came in 2001, the victim Sergi Zaloukaev.
  • Since 2000, North Carolina has seen 55 shark incidents, an average of 3.6 each year
It is also interesting that of the 95 unprovoked attacks in NC waters, 64 (67.3%) occurred in the months of June, July and August.

This can be explained firstly, by there being more people in the water due to hotter weather and also, people staying in the water for longer due to increased sea temperature. More people in the water for longer means more people exposed to sharks. The average sea temperature from early June to late August is 83.4 degrees Fahrenheit or in "real money," 28.5 degrees Celsius.

Another factor to consider is the migration and seasonal aggregation patterns of prey animals. During the warm Summer months, bait fish and other larger marine creatures move along the coastline, travelling in large numbers close to shore to try to evade predators in deeper water. This in turn attracts sharks which follow the fish into shallower water and thus, in closer proximity to bathers. Large numbers of prey means larger numbers of sharks close to shore and unfortunately, as we have seen in North Carolina this year and Florida every year, occasionally humans are getting in the way of these sharks, sharks which are in the shallows, potentially motivated by predation.

Bull Shark Photo: Andy Murch

Blacktip Shark Photo: Alexander Safonov

The most likely culprits in these attacks are the Bull Shark and Blacktip Shark. In the incidents where there have been multiple bites, I'm almost certain the attacks were carried out by Bulls. Bull Shark attacks are characterised by a propensity to bite a victim more than once, plus, their size and power often leads to serious injury and loss of limb in attacks where they are the culprit.

Blacktips are not a species often involved in shark bite incidents however they have, and do, occasionally bite people although, unlike the Bull Shark, are less likely to mount a sustained attack on a human.

Both species are regularly encountered in North Carolina waters and both will enter the shallows whilst following prey, so for me, these would be the two species most likely involved in incidents such as these in this part of the world. North Carolina is also home to Tiger Sharks, Great White, Dusky, Spinner and the most commonly encountered species there, Sandbar sharks, however, although all have historically been involved in shark bite incidents, I would be less inclined to blame any of these species above the two detailed above.

It's important to recognise a few salient points, firstly, these sharks were off these same beaches last year, the year before, the year before and so on and so on, although shark attacks in the United States have shown an upwards curve in numbers over the last 60 years, this is due solely to there being more people in the water. I've seen claims that people feeding sharks or fishing from the pier has caused the attacks but there is simply no evidence for that. Could warmer than usual water temperatures play a part? Possibly but only because it is having an effect on the migrations and seasonal aggregations of the shark's prey. Sharks go where the food is and right now, the food is close to shore off popular bathing beaches.

There will be more shark bites off America's east coast this year, Florida is unusually quiet at the moment but as the Summer gets hotter and the sea gets warmer, more people are going to be in a position where they may just get in the way of a shark following its natural prey so what can you do to minimise your risk of being bitten?

Firstly, stay out of the water, you won't get bitten by a shark on the beach! If you do however want to go into the sea and let's be honest, I don't blame you, avoid if possible, areas where the water is murky, where people are fishing, avoid swimming near the mouths of inlets or estuaries and if you can, speak to local fishermen, like sharks, they follow the fish and if the fish are in big numbers, there will be sharks there.

Most importantly though, use your brain, you know there have been incidents in North Carolina so if you must swim in those areas, realise it is your responsibility to ensure the safety of both yourself and your family, not the sharks'. Sharks do what sharks do and when you make the choice to swim in areas where you know there is shark activity, you must accept you are taking a risk, it's a small risk of course, but the responsibility is on you.

Try to be shark smart, the best people to talk to about the shark activity in your area are the people who use the beach all day every day, lifeguards and fishermen. If you're not sure whether you should be swimming somewhere, don't be afraid to ask!

Finally, don't panic, shark populations aren't exploding in numbers (quite the opposite) and moving closer to shore to eat people. Although this is a bad year for shark bites in North Carolina, it is unusual and certainly not the norm. Statistical anomalies in areas where shark bites occur, or if you want a simpler description, spikes in shark bite activity where a year's number of incidents exceeds a statistical pattern, however, are not that out of the ordinary. It happens, many places around the world have experienced a flurry of incidents followed by years, sometimes decades without a single bite.

Be safe!

Edit: Case in point regarding misleading and factually inaccurate public statements can be found in this article

"It's commonly accepted that sharks aren't intentionally trying to bite humans, either: "Scientists believe that most shark bites are a case of mistaken identity. From below, a surfer in a black rubber wetsuit looks a great deal like a seal, for example," explains David Shiffman, a PhD candidate at the University of Miami's Abess Center for Ecosystem Science and Policy."
This is quantifiably incorrect. None of the victims were surfing, none were wearing wetsuits (which incidentally are made from neoprene, not "rubber") and although some attacks throughout history have been a result of "mistaken identity," it's a tiny proportion and almost always incidents involving Great White Sharks. The notion of "mistaken identity" is misleading because it implies over 400 million years of evolution, sharks are unable to differentiate humans from their natural prey items.

None of these attacks provide any evidence that "mistaken identity" can be used as a reason, especially in the five incidents where the victim sustained multiple bites.


Michael Sealey said...

Great article David, and totally agree that the term "shark attack" should not be banned but used with great precaution.

OfficetoOcean said...

Thanks Michael and I am in total agreement, Mike's use of "Shark Strike" is a good alternative to others being suggested also.

Javier R said...

Great report and you touched in a lot of important points. I know we like to stay away from the word "attack" but sometimes we have to call a spade a spade.

OfficetoOcean said...

Thank you Javier and yes, I agree, sometimes "attack" is an accurate description. I understand the concern about its overuse and I do agree that the media should be more responsible, however, whatever phrase the media uses will have no impact on the overall narrative they employ when it comes to shark attacks. If we are asking them to change, the focus needs to be on the narrative, not just a single phrase.

Sharks don't bite humans out of anti-human malevolence or some kind of premeditated spite, it's just sharks being sharks and sometimes, sharks see humans as a legitimate source of food, not because we are humans but by virtue of us being in their natural habitat.

I'm not saying these attacks were predatory, we can never know for certain, but the incidents with multiple bites do illustrate a degree of determination on the shark's part and that is not at all in keeping with the notion of "mistaken identity."

Anonymous said...

I`ve been around for decades now, never been eaten by a shark. My secret; I dont jump into the sharks backyard. I`ll never understand you people, just dont jump into the ocean and you`ll have no shark problems. It`s just annoying, people jump in and sharks eat them. And then everyone starts making noise, omg a shark, this is terrible, bla bla bla!. They jumped into the sharks backyard, they were swiming around in the sharks foodbowl. When you walk head first into a beartrap, and you know it`s a beartrap, then you deserve everything you get. Morons.