SEIGNOSSE, Landes Coast : A Blue Shark Paying a Visit on the Estagnots Beach in May, 2019

On Sunday May 12, 2019, at Seignosse, a sea resort located in the South-West of France (Landes county), a Blue Shark (Prionace glauca) was seen swimming in the shore, subtidal zone of the Estagnots beach. A short video was uploaded in the social networks (e.g., Facebook), which was filmed by a surf-club trainer.

I quickly investigated the video and, although some said that the shark was a Thresher one, however, it is clear that he or she's a Blue Shark. Hereafter is a short documentary video about this news (© France 3 Aquitaine) :

Identification of the Shark species was very easily done : he or she was not a Thresher shark, because his or her tail is very much too small in fact compared to a Thresher shark tail. The body of the shark, the colour of the skin, the pattern of the dorsal fin, the tail ... all these features indicate that they saw a Blue Shark, no doubt about it. Hereafter, I give two detailed pictures of the Prionace glauca body and some highlights of the Blue Shark to prove this simple species investigation.

Now , the questions everybody seems to have in mind on the Aquitaine littoral : is it usual to find sharks in this area, in particular in the shore ? If yes, are they dangerous for people going into the ocean, either for swimming, surfing, diving, or any other leisure activities ?

Concerning the first question, i.e. sharks in this area, the answer is : yes, as everywhere all around the world, even in the Amazonia river, no more no less. Bottom topography, major currents, and also eddies are present here, including the "Gouf", a big canyon, with its apex just a few hundred meters offshore Capbreton, a little harbour (and sea resort too) close to Seignosse. The canyon, the Gouf, is the same as the one offshore Portugal (e.g., Nazaré), Spain and extends through Ireland too according to maps. Le Gouf is a reknown fishing area (now, probably, overfishing is in progress), mainly because the Landes and French Basque coasts, or shallow waters, were and still are often overfished zones. Besides, this area is also known for encounters, as well as migration paths, of Tunas species (e.g., Atlantic Bluefin Tuna - Thunnus thynnus), sea mammals, including Whales, Dolphins, Pilot Whales (or Globicephala) and Killer Whales (see URL: itsasarima.com) ). A slope current is present, leaning on the continental shelf, with a South-North direction. Local and industrial professional fishermen sometimes catch : Blue Sharks, Short-Fin Makos, Catsharks, Thresher Sharks, Hammerheads Sharks, Basking Sharks, among others.

However, as everywhere on the planet, many of these species are in a critical danger of extinction, or in the way of extinction. As an example, Angel Sharks (Squatina squatina) is extincted in the area I am studying in the scope of SHARK RESEARCH: Silver & Opal Coasts (EU), since at least some tenths of years (NB Testimonies taken from local individuals).

Overfishing is the main reason of the modification of the ocean(s) trophic chain, from the bottom to the top of it, so evidently at the Apex Predators level (namely: sharks, elasmobranchs), a highly critical level for the survival, and the "health", of the seas and the oceans. As a proof (necessary but not yet sufficient in a mathematical sense, so the need to study furthermore), in the 2018-9 winter, many gelatinous zooplanktons (salps) were catched in some nets of fishermen in the Bay of Biscay. This is in accordance with the scientific community taht says : the presence of salps proves an overfished activity. In our case, in the Bay of Biscay. Again, may I recall this rule of thumb,

No Sharks, no Fishs.

As a hint, hereafter one may find a simple way to understand why sharks, as apex predators, are important, and why it is a challenge to reorient our mind :

About the danger of sharks or, more precisely and adequately, the human-shark interactions, one has to remember that we are not in our common environment. As a Primate species (Homo sapiens sapiens), our common one is : country, or land. Not the water medium. Sharks, in their "modern" forms, live in the oceans since at least 250 millions years, probably more (NB Proof: fossils). In fact, this is very likely because sharks, contrary to humans (again, primates, or big apes family) who need to eat after 8 hours, can eat only after several weeks and even 3 to 4 months of diet. Sharks are often great migrators, and site faitfhful, with a short-, and long-term memory, as this is the case of other elasmobranchs (e.g., Manta rays).

Human people are, and never were, part of the shark diet. When a man or woman dies after or during a human-shark interaction, often following a lethal injury such as the cut of the femoral artery, this is an accident or the consequence of having not followed usual precautions, or ignorance. Below, look a while a picture showing, with statistical numbers, the human death rates according to different living species involved (NB Not an exhaustive list - © Geobuzz).

Besides, the likelihood to die from car accidents is very much more than dying from a human-shark interaction (© Sécurité routière, France) ->

Even in mass-tourism area such as the Aquitaine territory, one has to always apply usual precautions. Besides, it will be a good habit to apply these simple rules here (e.g., do not swim or surf early in the morning, or when the afternoon decreases, more likely because too much people are in the shore making too much noise ; be quiet ; do not wear yellow or red swimsuits/wetsuits) for other forecasted travels in, for example, Hawaii, Australia, Florida, California ...

Eventually, for this Blue Shark "encounter" at Seignosse, the shark seems - apparently, at a first sight - to be in good health, and having a - young - adult size. Probably, he or she lost the way to return offshore (e.g., he or she followed a shoal close to the beach), approaching too close the very shallow waters, not fish (overfising) to eat, boat noise may have disturb him or her, and so on.

Such facts to be collected is a task duty within the SHARK RESEARCH: Silver & Opal Coasts (EU) . A further investigation will be made for this shark, in particular should he or she be killed or saved after the video was filmed. In fact, the Blue Sharks are also strongly decreasing in their population, in particular in the Mediterranean Sea.

Eventually,

always follow the common rules when you enter in the sea (and before),

to avoid critical human-shark interactions, and useless further shark culls.

Remark : a typical image and condition when shark culling (NB SHARK RESEARCH: Silver & Opal Coasts (EU) is opposed to such unnecessary, lethal, and counterproductive practices) ->

Map for the Estagnots beach: https://www.google.com/maps/place/Plage+des+Estagnots/@43.6867531,-1.4582306,4106m/data=!3m1!1e3!4m5!3m4!1s0xd515bf4da2e50bb:0x979d78ac0fff14b6!8m2!3d43.686755!4d-1.44072