The sea in Andalusia (pelagic marine waters)

“Thalassa”: a link between the peoples of the sea – a mysterious and fertile marine ecosystem.

In Andalusia, the marine ecosystem is represented by the Atlantic Ocean and the Mediterranean Sea. The westernmost part of the Mediterranean, close to the Strait, is the so-called Alboran Sea. The sea covers more than 70% of the Earth’s surface, contains more than 96% of water reserves and is the environment where Life originated. Today, most animal groups remain exclusively marine. That’s how important the seas and oceans are in our lives. However, it is a medium that we know little, apparently far from cities and the needs of our civilization.

The main difference between seawater and most inland waters is obviously the chemical composition and the presence of mineral salts, mainly chlorine and sodium ions.


Salinity scale

Freshwater salinity (<0.5 g / l)

  • Rainwater 0.2 g / l

Salinity of brackish water (0.5–30 g / l)

  • Baltic Sea 6 g / l

Salinity of saline water (30–50 g / l)

  • North Atlantic                               30 g / l
  • Seawater                                        35 g / l (average)
  • Mediterranean Sea                     38 g / l
  • Red Sea                                          40 g / l

Water salinity hypersaline / brine (> 50 g / l)

  • Fuente de Piedra Lagoon    96 g / l (maximum in the lagoon)
  • Saturation level                      270 g / l (salt crystallization)
  • Dead Sea                                  330 g / l
The Strait of Gibraltar separates the Atlantic Ocean and the Mediterranean Sea. Punta Carnero lighthouse

The Strait of Gibraltar separates the Atlantic Ocean and the Mediterranean Sea. The Punta Carnero lighthouse is a witness to the intense maritime traffic and a mythical observation point for the observation of the migration of large gliders, birds of prey and storks.

Strait of Gibraltar, Atlantic Ocean, Mediterranean Sea, The orca, or killer whale, is a marine mammal

The killer whale is a marine mammal close to dolphins (toothed cetaceans = odontocetes) and of worldwide distribution. This species is sedentary in the Strait of Gibraltar.

sea bird, Morus bassanus, Sula bassana, sea, ocean, pelagic bird

Northern gannets (Morus bassanus) are easy to spot in winter on the Andalusian coast

Odontoceti, Spain, Andalusia, Sea, Cetaceans, striped dolphin (Stenella coeruleoalba)

The striped dolphin (Stenella coeruleoalba), species inhabiting all oceans, is commonly watched during excursions at the sea in Andalusia.

Birdlife is the easiest high seas (pelagic) biodiversity to observe in from a ship or from a cape. Seabirds are especially abundant in Andalusia during winter and migrations, Scopoli’s shearwater (Calonectris diomedea), Balearic shearwaters (Puffinus mauretanicus) and Atlantic gannets (Morus bassanus) among others are common. Offshore marine mammals are represented by bearded whales such as the common whale (Balaenoptera physalus) and by teeth cetaceans, such as oceanic dolphins: common dolphin (Delphinus delphis), striped dolphin (Stenella coeruleoalba), bottlenose dolphin (Tursiops truncatus), pilot whale (Globicephala melas) and killer whales (Orcinus orca) on one side, and sperm whales (Physeter catodon) on the other hand. Among the fish, bluefin tuna (Thunnus thynnus) and swordfish (Xiphias gladius) are large predators. Small pelagic fish such as sardines (Sardina spec.) From the large family of clupeids, anchovies (Engraulis encrasicolus), mackerels (Scomber scombrus) and curious flying fish (Cheilopogon heterurus) are their prey. Also point out the moonfish (Mola mola), of considerable size, and nothing unusual to see.

We can close this short list of marine fauna with jellyfish, increasingly frequent, and among them two very peculiar species since they are floating and drifting. Those are the dangerous Portuguese caravel (Physalia physalis) and the harmless purple sea sail (Velella velella).

And suddenly, a stain of blood on the sea appears … plus an entire family of orcas: females who were finishing hunting a tuna, a juvenile which comes to stroke the hull of the boat, and from a distance, the large fin of a careful male killer whale.

Florent Prunier