The Mediterranean, despite the high level of pollution, is home to a multitude of ‘wildlife’, some of which can be dangerous.
Jellyfish, of both harmful and harmless varieties, are a fairly common sight along the Mediterranean coast. They generally occur in swarms, making them readily visible and, in theory at least, easily avoided. Jellyfish are normally to be found between 20 and 40 miles from the coast where the waters are warmer and saltier, coastal waters being generally colder and less salty and acting as a sort of natural barrier.
Concentrations of jellyfish in any given year are dependent on several factors. A warm, dry winter and spring inland, for example, will normally lead to a high build-up of jellyfish at sea. However, when freshwater river input into the sea is lower due to lack of rain, salinity increases and this allows them to breach the barrier. Other factors include winds and sea currents as jellyfish just drift along in the currents.
Hot summer weather also brings them in, the time when millions are bathing, so sting numbers increase dramatically. Tourism being of great importance to the Spanish economy, jellyfish swarms are regularly reported in the local press in summer. However, despite these warnings, hundreds of people are stung every day up and down the Spanish Mediterranean coast.
One of the most common jellyfish in the Spanish Mediterranean is the Mauve Stinger (Pelagia noctiluca). It may grow up to 10 cm in diameter and is distinguished by a mushroom shaped, deep bell. It has 8 hair-like tentacles, extending as far as 3 metres, and all are covered in nematocysts (stinging cells). Its sting is both potent and painful, but short-lived.
The Compass jellyfish (Chrysaora hysoscella) is readily identifiable by a ring of brown dots around a flattened white saucer-shaped body. It has 32 semi-circular lobes around the fringe, each one with a brown spot. On the upper surface of the bell, 16 brown v-shaped marks radiate outwards from a dark central spot. There are also 24 tentacles around the edge of the bell, grouped in threes. It has a potent sting that can produce extremely painful and long lasting weals.
The Portuguese Man-of-War (Physalia physalis) is undoubtedly a name that almost everyone has heard of. Technically, it is not actually a true jellyfish but a hydrozoan, a floating colony of four types of polyps! But it stings like any other jellyfish so we will call it one. Its highly potent sting can, in extreme cases, provoke cardiac arrest and death in particularly sensitive persons. The nematocysts retain their potency long after death, as many have discovered to their cost after handling specimens washed up on the shore.
If you are unlucky enough to be stung by a jellyfish, seek proper medical treatment, either from a doctor or local hospital casualty unit, as soon as possible. Never rinse jellyfish stings with freshwater as this will re-trigger the stingers.
There are many species of shark to be found along the coastal regions but, fortunately, there have only been 2 documented ‘shark attacks’ in the past one hundred years, so the chances of meeting one whilst swimming are, I’m glad to say, minimal. However, they are quite common and are regularly caught by fishermen, either intentionally or by accident.
The Bluntnose SixGill (Hexanchus griseus) is fairly common along the Mediterranean coast and specimens of 2–3 metres in length (it can grow to 5 metres) are a regular catch by fishermen. They are grey-brown in colour and are paler underneath. They have a single (and small) dorsal fin near the end of the body, a blunt snout, and small eyes in front of the mouth. It has six rows of saw-like teeth positioned in the side of the lower jaw. The upper jaw has smaller, curved, single-cusped teeth. It has a toxic liver but edible flesh and is fished by man for its oil and meat. Being a deep (up to 1500 metres), bottom-feeder, contact with bathers is most unlikely.
Amongst many others, the coastal regions of Spain are home to the Common Thresher (Alopias vulpinus), Basking Shark (Cetorhinus maximus), Hammerhead (Sphyrna zygaena), Small Spotted Catshark (Scyliorhinus canicula), Porbeagle (Lamna nasus) and the very common (and much hunted for its fins) Blue Shark (Prionace glauca).
Shark fins, the bulk being for the Asian food market, are big business and two of the world’s leading ‘players’ are Japan and Spain. It is estimated that, worldwide, about 100 million sharks are killed each year in the fishing and finning industry.
On November 17th 1992, a male Great White measuring 4.75 metres in length and weighing 1000 kilos was washed ashore at Tossa del Mar in Cataluña. Being a very tourist oriented area, and fearing a cry of ‘JAWS’, the local Guardia Civil staged a midnight swoop and carted this huge beast off in a flatbed truck to the local rubbish tip! Of course, no-one was going to notice a 15 foot stinking carcass with huge teeth, were they???
Sea Urchins, although not particularly common along Spanish coasts, are nonetheless out there. They are not poisonous, but stepping on one can lead to infection as the spikes tend to break off and stay in the foot. Again, medical treatment is advisable if you are unfortunate enough to tread on one.
Spanish coastal waters are also home to several species of Rays, especially in shallow sandy areas. Although basically non-aggressive, they can lash out with their sting-laden tail if annoyed, resulting in lacerations, local irritation and the risk of infection.
More common, and a serious danger, are Weaver fish. They bury themselves in the sand to wait for their prey, smaller fish, and if trodden on they erect their poison-laden dorsal fin in defence. Every year in Spain people are stung by these fish, the venom causing intense pain and, in a few cases, deaths have been recorded. Soaking in hot water removes the toxicity of the venom. Iberian weavers include: the Lesser Weaver (Echiichthys vipera), the Greater Weaver (Trachinus draco) and the Spotted Weaver (Trachinus araneus).
The spiny fins of the Large Scaled Scorpionfish (Scorpaena scrofa), which hide amongst the rocks, also give painful, though generally less serious stings when stepped on. These fish are masters of camouflage.