Presentation on theme: "…in the middle of lands Mare nostrum. The only natural link to oceans is constituted by the Gibraltar Strait, which with its 15km of length and 400m of."— Presentation transcript:
The only natural link to oceans is constituted by the Gibraltar Strait, which with its 15km of length and 400m of depth, is the only way of communication, with the Atlantic ocean to the west..
In the eastern sector it is instead linked, since 1869, to the Red Sea, consequently to the Indian Ocean through the artificial Channel of Suez (161 km)
Surface 2 560 000 km2 (included the Black Sea) Lenght ( Gibraltar strait- Libanon coasts) around 3800 km Average Depth 1429 m Maximum Depth, in the Ionian sea, near Matapan cape, Peloponnesum, > 5000 m Coast extension about 46.000 km
The amount of water coming back from rivers and rainfalls is less than that which evaporates : -110 000 m3/s +38000m3/s with a sweet water deficit estimated of approximately 2.500 kilometers cubes (km3) annually If there was’nt the communication with Atlantic ocean The Mediterranean would desappear in some ten thousand years!!
At 500m of depth waters have a temperature that is about 12- 13° C Anyway the superficial strata present ample variations, which depend on seasonal changes: You can have in fact average temperatures of 10 degrees in Jenuary to average temperatures of 25°C in July. At the same time temperature varies from West to East.(15-21) Even salinity is different on the various basins: it varies from 36 to 39 ‰ according to the evaporation and the fluvial contribution. In the Adriatic sea salinity can reach 33 ‰. The Ionian sea,on surface, is more salted than Tirrenian sea.
Temperature and salinity differences between Mediterranean waters and Atlantic waters bring about a double current. It has been calculated that for the total substitution of waters 7000 years are required.! The Mediterranean waters, denser and heavier, flow in depth and enter the Atlantic through the Gibraltar Strait, whereas the ocean waters get into the Mediterranean flowing on surface.
The population of the states which look at the Mediterranean sea is about 450 millions of people. Moreover there is a remarkable touristic presence equal to a third of mondial flow seasonally concentrated on coastal areas particularly on the North Western ones.
Italy divides the Mediterranean sea in two basins,the western one and the Eastern one. The Mediterranean is subdivided in a certain numbers of independent seas: the Ligurian sea, the Tirrenian Sea and the Sardinia Sea; The Eastern Mediterranean is divided in the Sicily Sea, the Ionian sea and the Adriatic Sea.. Italian coasts stretches along 8500km, and no Italy place is more than 230km away from the coast.
Tentative reconstruction of the Mediterranean evolution for the period Oligocene-middle Miocene. This evolutionary phase has been characterised by a profound tectonic reorganisation of both the western and eastern Mediterranean regions, where the Balearic and Pannonian basins opened up. Extensional tectonics also occurred in the Northern Aegean and Northwestern Anatolian zones.
Tentative reconstruction of the Mediterranean evolution since the late Miocene, This period is characterised by a profound reorganisation of the central and eastern regions, which respectively led to the formation of the Tyrrhenian and Aegean basins. Symbols as in Fig.2. A) Late Miocene: G=Giudicarie trans-pressional fault system, NA, SA=Northern and Southern Apennines, NWT=Northwestern Tyrrhenian, Pe=Pelagian zone, SF=Selli fault. B) Late Pliocene: AE=Apulian escarpment, CR=Crete-Rhodes, CT=Central Tyrrhenian (Magnaghi- Vavilov basin), K=Kefallinia fault, I=Iblean-Ventura microplate, Me = Medina fault, NAF=North Anatolian fault system, SCH=Sicily channel fault system, SE=Siracusa escarpment, SV=Schio- Vicenza Line, Ta=Taormina fault zone, WCB=Western Cretan basin. C) Present: Ca=Calabrian wedge, ECA=External Calabrian Arc, ECB=Eastern Cretan basin, KI=Kithira trough, LP=Lybian promontory, PS=Pliny and Strabo trenches, ST=Southern Tyrrhenian (Marsili basin), VH = Victor- Hensen fault, VR=Vrancea zone.
Calabrian and Tyrrhenian sea geological evolution in the last 10 million years At the end of the Tortonian era, about 10 millions of years ago, the distribution of emerged lands and seas in the area of the mediterranean was very different from how it appears today. In that period in fact the tirrenian sea didn’t exist yet and Calabria, the northern part of Sicily, Sardinia and Corsica were joined together to form an only continental plate In the same period the Ionian sea and the Adriatic sea were much wider of the present ones.
About 7 millions of years ago, during the Miocene, the Sardinian-Corse block began to fracture and from the fractures of the crust a great quantity of basaltic lava leaked out. The fracture widened more and more until forming a deep tectonic hollow which very soon was invaded by waters from the sea. The Tirrenian sea had begun to form, while the eastern part of the old clod, contituted by the present Calabrian– Peloritan block, got away more and more from the Sardinian Corse block.
The Tirrenian sea continues its expansion still today: the present centre of expansion is at about 150 km to the west of the Calabrian Coast where the oceanic crust continues forming in correspondence with the submarine volcan of Marsili. The old expansion centres are instead represented by the submarine volcans of Magnaghi and Vavilov to the North West regarding Marsili.
While at the West of Calabria the Tirrenian sea was developing,on its eastern edge, as well as all over the edge of the Apennine, the ancient and heavy oceanic crust, which made up the sounding depth of the Ionian and Adriatic sea began to go down slowly in the mantle. The sediments which were found on the depth of the sea following the subduction process piled up ones on the others to form huge blankets of covering contributing to the formation of the Apennine Chain.
posidonia oceanica The sounding depths of the Mediterranean sea are covered with Posidonia prairies. Reduction of posidonia prairies is index of pollution marine plants The flowering is instead index of goodhealth for the ecosystem
algae Mermaid's cup (Acetabularia mediterranea) Padina pavonia Sea lettuce (Ulva lactuca) The non native introduction of species has influenced the species which were naturally present, sometimes with remarkable impacts: the tropical Caulerpa taxifolia seaweed has had catastrophic effects on the native environment The present variety of the species is correlated to the inquinameno anthropic pollution. In the lagoon of Venice, for instancee in 1938 were found 141 species of seaweed, 104 in 1962 and only 95 in 1987, and there are so polluted Lagoon areas which render the presence of some species impossible
Ligurian sea 20 % Alicante (Spain) 52 % Marseille (France) About 90 % Tolone (France). Completely desappeared Gabes Gulf (Tunisie) Completely desappeared Industrial and civil pollution Alteration of sedimentation due to drag-net fishing Competition with Caulerpa –from: UNEP-RAC/SPA, 1997a. Reduction of Posidonian prairies
sponges Axinella polypoides A. verrucosa Spongia officinalis some of them are interesting from an economic point of view Haliclona mediterranea Spongia agaricina,
Anemone sulcata Coral Corallium rubrum Cnidaria (polyp jellyfish corals anemones) Yellow gorgonian eunicella cavolinii They are represented by the red coral (facies of Corallium rubrum) and by gorgonians (Eunicella cavolinii, Paramuricea clavata). The name Cnidaria comes from the Greek word "cnidos", which means stinging nettle.
Cnidaria In the Mediterranean sea it is very easy to find the sea lung Rhizostoma pulmo. The presence of jellyfishes is index of a good quality of waters. It is the biggest jellyfish of this sea, it reaches 50- 60cm of diameter, it has a low itching power.
Carthilagineous fish (shark) Scyliorinus canicula Blue shark Prionace glauca Eggs of S.canicula
The ramarkable depth of the Mediterranean sea allows life to some great pelagic species of cetaceans dolphins The marine communities of the Mediterranean are characterized, as regards the Atlantic ones, by a greater number of species but generally with smaller individuals (Mediterranean dwarfism).
MEDITERRANEAN CETACEANS Common rorqual Balaenoptera physalus The immun-soppressive effects of contaminating agents coming from agriculture, industrial activities and demographic increase can have contributed to the decimation of marine mammalians of the Mediterranean. Delphinus delphis
Some species are in danger (Caretta caretta ) tortoise Nun seal (monachus monachus)
Owl Athene noctua The scientific name of this bird is that of the greek goddess Athena. A blue eyed owl was the symbol of Athena as we can see in the coins above
Factors that influence the Mediterranean ecosystem The eutrophization and the pollution coming from agriculture, from industrial activities, from tourism and from demographic increase The introduction of non native species through dregs ship waters, fouling, importations and biological invasions Fishing and excessive exploitation of biological resources..
La grande lentezza con la quale avviene il ricambio delle acque del Mediterraneo accentua il problema dell’inquinamento It is favoured by the continous increase of industrialization and antropization of its coasts Moreover the oil pipe lines, which carry to Europe the oil from the Sahara and the Middle East, run through the Mediterranean. 25 % of mondial oil (about 350.000.000 tonn. annue) pass trough Mediterranean sea The great slowness with which mediterranean water renewal happens icreasaes the pollution problem
The greater dangers come from the oil tankers (incidents, washing..) The pollution by domestic and industial wastes is serious in certain areas
Environmentalist organizations have often denounced the traffic and the deposit of hazardous wastes. – radiactive scum and chemical pollutants– coming from all Europe, in the Southern Mediterranean, above all along the African coast, in the Lebanon but even in Calabria. (Jolly rosso ship)
The mucillage The mucilage is constituted by gelatinous heaps produced by fitoplanctonic species (Seaweeds)) that float in the sea rendering it not transparent, moreover, joining to the nets,They make fishing possibility diminish, causing remarkable economic damages The mucilage is constituted by polisaccaridi and other substances secrete from seaweeds (diatomee...) in abnormal quantity. It is not clear if the phenomenon is connected to the pollution of the sea. Actually it existed also in pre-industrial age: scientific signallings exist since 1729 and testimony in the ever existing dialectal names (broma, brommo, sbrommo), all of which have the same root: from the Greek bromos = fetid )
Coastal erosion It is a quite diffused phenomenon on Italian coasts due to different causes: Rise of the sea level Sand removal from rivers and beaches Buildings on the beach without considering the natural variation of the coastal line
The protection of the Mediterranean Sea from pollution is guaranteed from the Convention of Barcelona of 16 February 1976, adopted under the aegis of the Intergovernment Council of the Environmental Program. It acclimatizes them of N.U. (UNEP) and in order to supply one legal instrument for the performance of the Action Plan for the Mediterranean (MAP) adopted in Barcelona in 1975. Such plan, in the second version approved in 1995, provides objects which are not limited to the single antipollution fight, and that is - to guarantee a durable management of the natural marine and land resources, - to protect the marine atmosphere and the coastal zones preventing pollution as well as reducing and if possible eliminating the contributions of polluting of whichever nature; - to defend, to safeguard and to revalue sites and landscapes of ecological or cultural interest; - to strengthen solidarity among the coastal States of the Mediterranean managing their ir common patrimony and their resources as an advantage for present and future generations; - to contribute to the improvement of life quality.
Fishing The main types of fishing diffused in our seas are: drag-net fishing pelagic fishing mollusc fishing small fishing lagoon fishing
Type of fishing The small fishing is the one carried out by boats not bigger than 10 tons of gross tonnage. The dimensions of the floating allow to be operated with contained work and investment costs. It is impossible to go further than 20 miles from the coast and this let abilities of fishing, of working, conservation and stowage of the product beby no means comparable to those of great boats. In Italy this part of the fleet is of notable importance. There are 8,680 boats of small fishing (1997 are available actually), that represent more than 53% of the national flotilla. Small fishing is particularly present in the Tyirrenian sea with 2.083 boats and in the Adriatic with 1.640 boats. The tools employed for the small fishing are above all position nets, bow-nets and palangari
The draw-net fishing is an important activity in Italy. Only the experience and a deep knowledge of sounding depths consent a ready evaluation of tools and maneuvers to be carried out. The draw net fishing can be carried out with various types of tools that vary in relation to local and regional traditions. The most used tools are the draw-nets, the rapido, the sfogliara. This kind of fishing can be dangerous if done in an uncontrolled way. It menaces the existence of marine species that lives in sounding depths Many environmental associations have required to stop this sort of fishing
SOLEA VULGARIS GADUS MORRHUA MERLUCCIUS Fish to be eaten fresh SOLES, CODS........... Diplodus vulgaris Sparus aurata Dicentrarchus Labrax - Chromis chromis
Fish to be preserved ENGRAULIS ENCRASICHOLUS THUNNUS THYNNUS SARDINA PILCHARDUS
To fishing in strict sense you can add the collection and the cultivation of seafood CHAMELEA GALLINA MYTILUS GALLOPROVINCIALIS OSTREA EDULIS
´mattanza´ Tunny fishing happens in spring time during the migration period of this fish Fishermen are divided in teams each of them chooses a leader the “rais” He has to individuate the palce from whuch the tunnies will pass and where they have to throw the nets which make up the tunny fishing net “tonnara“. ‘La tonnara’ or tunny fishing net is made up of several nets in the waters before the port, spread from the surface to the sea-bottom and set out in such a way as to convey the tunnies towards a net closed at its bottom, the net is said “chamber of death”. Established the place, the tunning fishing net is delimited holding some ropes to water surface (the ‘tintole’) within which the net that will stop the tunnies, will be thrown. The term ‘mattanza’(slaugther of tunny fish) derives from the Spanish verb matar to kill.
The tunny fishermen ability is in succedine to block the tunnies that get into this barrage and in making them flow, with the help of various nets or chambers, up to the final net called ‘chamber of death’ When tunnies are trapped, the fishermen boats encircle the ‘chamber of death); at the command of the rais (the head of fishermen), the "tonnaroti" (the fishermen) begin to lift the net that constitutes the base of the chamber forcing the tunnies to emerge on water surface. At this point the tonnaroti 8tunny fishermen) pierce the tunnies with long and sturdy iron hooks or harpoon and pull them into their boats; then they will bring them to shore to be sold or processed.
Actually the catching of hundreds of tunnies in a few hours can’t be anything but bloody, as the big fishes, pressed together in the final part of the net island (chamber of death), in a as desperate as vane struggle to escape and survive, end to kill eah other with strong tail thrusts. All around the sea is tinged with red and boils over due to the dangerous tail blows given by the hooked tunnies while are being loaded on boats. The fishermen excitement reaches paroxismand the show results to be suggestive but cruel, especially fo those who are watching it for the first time. The fishermen excitement reaches paroxismand the show results to be suggestive but cruel, especially fo those who are watching it for the first time. The fishermen excitement reaches paroxism and the show results to be suggestive but cruel, especially fo those who are watching it for the first time.
The climate is temperate mild influenced by warm air coming from the Sahara during summer and by the more humid and cold air of the Atlantic during winter. Rainfalls are scarce and seasonal. CLIMATE STATISTICS of Santa Maria di Leuca Latitude 39.82N Longitude 18.35E Altitude 104m Average data 1961-1990
The typical biome is the Mediterranean flora mainly characterized by shrubs or small evergeen trees with coriaceous leaves ( sclerophilla ) able to stand summers with very high temperatures and insufficient rainfalls.
Mediterranean flora:defence strategies Summery dryness causes strong stress for vegetable species and, just in order to limit the damages that could be provoked by excessive warmth and by water absence, the plants defend themselves with several types of adaptation. Some adaptation concern the morphology of the plant – thickening of the foliaceous cuticle (sclerophillia), reduction or disappearance of leaves (afillia), presence of hair (hairiness) or thorns (thorniness) – whereas other types involve physiology – formation of underground organs (bulbs, tubers and rhizomes ), in which the plant limits its own vital activities protecting young stems under the ground surface. Another defensive strategy is the reduction of the vital cycle (birth-life-death) of the plant in a very short period
Mediterranean typical species Broom (Spartium junceum, calicotome, ecc.), Euphorbia (Euphorbia dendroides e characias), Cistus (Cistus incanus, salvifolius e monspeliensis), Mastic (Pistacia lentiscus), Myrtle (Myrtus communis), Juniper (Juniper phoenicius), Rosemary (Rosmarinus officinalis), Pine tree (Pinus pinea, halepensis, pinaster), Carob tree (Ceratonia siliqua), Holmhoak (Quercus ilex), la roverella (Quercus pubescens). Dwarf palm (Chamaerops humilis
On the mediterranean sea spontaneously grow (PANCRATIUM MARITIMUM) TAMARIX GALLICA T. AFRICANA
EUPHORBIA POLYCROMA EUPHORBIA HELIOSCOPIA Euphorbia dendroides EUPHORBIA
Juniper ( Juniperus phoenicius ) myrtle MYRTUS COMMUNIS ARBUTUS UNEDO Strawberry tree The butcher’s broom Ruscus aculeatus
Rosa sempervirens Allium triquetrum Narcissus tazetta
Arecaceae Chamaerops humilis L. dwarf fan palm The dwarf fan palm or Saint Peter’s palm deserves a particular signal: it’s the only living palm at a spontaneous state on continental european coasts and one of the two,(the other one is Phoenix theofrasti endemic to Crete island) exclusively diffused in the mediterranean basin It is a living witness of a tropical type flora, today completely disappeared, which from the beginning of the Tertiary era (about 65 million years ago) was diffused all over southern Europe thanks to climatic conditions which where completely different from the present ones.
SweetBay Laurel Laurus nobilis Carrob (Ceratonia siliqua), Fraxinus oxicarpa
vine The shrub which produces grapes, was known in Sicily since 4000 years ago. For a long time its cultivation was confined in this area. Only after a millennium it started to spread in the rest of Italy. Anyway it was thanks to the expansion of the Roman Empire, about 300 B C, that its cultivation spread all over the Mediterranean and Europe. With the discovery of America, new species were introduced in the old Continent which demonstrated to be able to resist to a dreadful parasite, the phylloxera, which attacked European vines around the middle of 18oo BC. Today Vine is cultivated in every continent, over about 8million hectares, the 60% of which in Europe. The production is used for fresh consumption and, the great part, to be processed in wine.
The vine – vitis vinifera- is a creeping shrub because its branches, said vine shoots, clutch at walls or at appropriate supports thanks to tendrils, filiform formations coiledl to external bodies in order to support the stalk. It is well developed in limestone or silica lands and is rather demanding in fact of brightness and heat, factors that are optimal in the hilly and well exposed zones. The bloom will be in bunches, from which the grape-pip will develop. Every single grape is particularly rich water berry, containing the grape-stones inside, that is the seeds, rich of oleose substances. The grape-stones are protected outside by a waxed veil, the bloom. that has the aspect of a light powder layer and that make water to slip away.The peel of the grape-pip is made up of various layers of cells that can be found under the skin, the most external covering. the skin of the grapes is thicker in wine grapes and thinner in grapes for fresh consumption. It contains coloring substances, tannins and some aromatic substances. The juicy inside of the grape contains a great number of substances with a high nourishing value. Approximately 80% of the dry weight is constituted by carbohydrates, for the greater part sugars like glucose and fructose. The high concentration allows the fermentation of the pressed grapes, from which the wine is obtained. In the grape-pips there is also malic acid, tartaric acid, succinic acid, minerals, vitamin c and elements like potassium, iron and sodium are also present. The therapeutic virtues of the grape were exploited in the past for the cure of some diseases, like the gout, lithaemia, kidney stones, with the practice of ampelotherapy (ampelos means vine in latin). Today a high therapeutic value is granted to the flavonoids contained in the grapes, some pigments with a high anti-oxidant activity able to hinder the proliferation of tumoural cells and useful in the prevention of cardiac diseases.
In the south of Calabria th Olive trees of Rosarno and Gioia Tauro are famous with age-old specimens (300 400 years) also of twenty meters. Centuries-old olives
Olive oil composition According to oleic acid percentage we can have oils of different quality : the extra vierge oil is the best one Omerus called the olive oil “ liquid gold ”
This presentation has been done by students from Liceo Classico B. Telesio Cosenza Italy for Comenius Project 1.2 Italia -Sverige exchange With the coordination of the teachers B. Fata C. Pisani Only for educational use