Black Sea Sealife

The Black Sea forms a natural border for both Bulgaria and Europe as West meets East. The picturesque coastline of Bulgaria stretches 378 km from Turkey in the South to the Romanian border in the North and is home to a vast array of aquatic species as well as areas of natural beauty

The Black Sea, although originally a large inland fresh water lake, is thought to have been created by the same natural disaster associated with the “Noah’s Flood”, around 7,500 years ago. The huge tidal wave entered via the area around the Bospherus, near Turkey, burying villages and towns below tons of water as the new inland sea was created. The low salinity of the water is attributed to this event as well as the fact that there are several rivers flowing into the Sea. At lower depths there is a complete lack of oxygen in the water and therefore many artefacts have been extremely well preserved. The water column is unique in having two layers, an oxygenated upper layer, about 200m deep, teeming with life, and a `dead' lower layer, where until recently nothing was thought to be able to survive, stretching to almost 2000m.

Fifteen thousand years ago, during the last Ice Age, what we call the Black Sea was actually an enormous freshwater lake. It was about two-thirds its current size, hundreds of feet shallower, and completely cut off from the Mediterranean and the world's oceans. The Ice age ended and global temperatures rose as the polar ice caps began to melt, the sea level of the Atlantic started to rise, and the only thing separating the fresh water “Black Lake“from the saltwater Mediterranean was the tiny Bosphorus valley.

7000 years on and 8,000 years ago, the Black Lake would have had an anoxic zone of its own, simply because it was so deep, but this lakes anoxic zone would've been nothing like the queen of all anoxic zones we find in the Black Sea today, eventually, the saltwater rose over the land and connected the Black Lake to the Mediterranean, creating the narrow, 17-mile long Bosphorus strait we see today. The Black Sea was created.

According to Greek mythology, on the eastern shores of the Black Sea, was the kingdom of Kolchis. The home of the Golden Fleece, which Jason and his Argonauts set out to find and bring back to Greece.
 
Long an important trading center and crossroads of human civilization, the Black Sea has seen the rise and fall of nations over thousands of years. Although its vast waters may have daunted ancient explorers, the Black Sea is, in fact, only barely a sea. Bordered by modern-day Bulgaria and Romania to the west, Turkey to the south and Ukraine to the north, it is nearly landlocked, connected to the Mediterranean Sea only through the narrow, dangerous Bosporus and Dardanelles straits.

Fed by several major European rivers, the surface waters of the Black Sea are also only half as salty as the ocean. To a depth of about 50 meters, these waters support abundant marine life, from zooplankton and mollusks to fish and dolphins. Below that surface layer, however, lies denser, saltier water. From about 200 meters all the way down to the sea’s bottom — about 2,000 meters at its deepest point — the water is almost completely oxygen-free, or anoxic. This layer gives the Black Sea the distinction of being the largest anoxic body of water in the world: Because the density difference between the two layers is so large, they rarely mix, and the colder, denser waters of the bottom rarely receive any influx of oxygen from above.

These conditions make the Black Sea a unique laboratory for scientists to study its physical, chemical and biological properties, but the low-oxygen conditions also offer something to archaeologists and historians, ships’ hulls and other often-fragile clues to ancient civilizations are likely still well-preserved and intact under the sea’s dark waters, a veritable museum.

The Black Sea is absolutely fascinating, and largely unexplored, in part because the region only opened up to Western scientists at the end of the Cold War in the late 1980s, but the region still retains much of its mystery, and although the Golden Fleece is long gone, the sea still holds plenty of treasure.

In most aquatic situations, ancient shipwrecks on the seafloor don't look like ships (with hulls and masts and all that nautical paraphernalia), but mere piles. That is because tiny creatures in the sea, some not visible to the naked eye, eat all the organic matter that's left on their plate (the entire seafloor). Not only do we have hungry bacteria (the same kind that decompose things on land), the sea is also home to a particularly unfortunate yield of evolution called the Teredo worm. This mollusc consumes wood like a starving monkey in bannana heaven. If you submerge a log in the ocean for a week, when you pull it up you'll find significant holes bored out of it. Multiply that weekly effect by 52,000, and you see that there probably won't be anything organic left from a Roman shipwreck

Back in the 1970's, the oceanographer Willard Bascom suggested that the anoxia of the Black Sea could house an astounding collection of intact ancient shipwrecks. He argued that crafts from throughout history that foundered here actually sank into a natural freeze-drier, where they were preserved for thousands of years. Direct investigations of the Black Sea's depths have only begun recently. We don't know if we'll find ships from the second millenia BC with sails and lines still on them, with food still in the galley, with ancient clothes still in the seachests, and we don't know if we'll find human remains from over 4000 years ago, still intact, preserved eeirily since before Rome was built.

The Black Sea's anoxia is like Mount Vesuvias, which preserved the city of Pompeii: in both cases, people and architecture were frozen by acts of immense natural violence. But in case of the anoxic zone, victims have fallen into this spider's nest of preservation not just in one day, but from throughout recorded history. It also so happens that the Black Sea was a major crossroads of the ancient world. So not only do we expect to find well-preserved wrecks in the Black Sea, we expect to find a lot of them.

The Bulgarian Coastline Beautiful Scenic Views

Archaeological research along the Bulgarian Black Sea coast has revealed many finds from submerged and partly submerged settlements, harbors and harbor facilities, and shipwrecks.
Mediterranean ships sailed the Black Sea for the first time in the 16th c. BC. After this point, the population of the western Black Sea maintained trade contacts with the populations of the eastern Mediterranean, including the Achaeans, Trojans, and Cretans in the 16th-12th c. BC, and the Carians in the 12th-11th c. BC.

Due to mutual or complementary material needs, trading networks were established and in some regions, trade was probably very active. Metals such as copper, tin (both components of bronze), and eventually, iron and lead were important as exports and imports.

Archaeological evidence along the shores of the western Black Sea has thrown up anchors and anchor material; remains of cargo and ships, metal objects and amphorae from the Bronze age. Submerged settlements along the Bulgarian Black Sea shoreline have led to the discovery of 10 submerged neolithic settlements and at least 29 sites dating from the Bronze age.

Bronze Age water transport was of paramount importance for establishing trade relations that continued through the Classical era. Despite temporary lulls in trade resulting from such factors as military and political unrest, trading maintained economic equilibrium throughout the eastern Mediterranean lands for many centuries. During the Greek and Hellenistic periods, at western Black Sea markets imported goods came from Miletos, Heraclia Pontica, and from the islands of Chios, Rhodes, Cos, Thasos, and, during the Roman Age, from Sinope. Also, wine, olive-oil, and clay lamps came from Egypt, Athens, and Corinth, and glass came from Syria and Asia Minor. Goods entered the interior of ancient Thrace via the road network along the Black Sea coast. Later on, Thrace became a Roman province and, after that, part of Bulgaria.

The local Sea life offers an interesting range of species, including Scorpion Fish, Dragon Fish, Mackerel, Turbot, the Dog (Black Sea) Shark, Jellyfish, Skate as well as up to another 180 species of local fish.  Sea Horses in particular can be seen in June performing their synchronized mating rituals found, while in August, plankton can be seen in the evening lighting up the Sea!

Although it may come as a surprise the Black Sea plays host to The Black Bottlenose Dolphin as well as other species and along with the Black Seal these are protected species. In August 2009, while on a dive in Kaliakra, we actually had a confirmed sighting of a Black Sea. This was the first such sighting for some years.

The corrals and fauna have developed independently of other eco systems due to the isolated nature of this inland sea and the influence of a large inflow of fresh water from the European Rivers and as such may be of interest to those with a greater appreciation of ecosystems.

The best conditions for diving are found between March and November. The temperatures quickly rise in summer to over 35°C with a water temperature varying from 22 - 27°C.

Delphinus delphis Linnaeus, 1758

Synonyms: Delphinus delphis ponticus Barabasch-Nikiforov, 1935
Common names: Engl: Common dolphin; Bulg: Obiknoven delfin
Order: CETACEA
Family: DELPHINIDAE

Taxonomic descriptions: It is one of two Delphinidae species and single representative of the genusin Black Sea cetacean fauna. The Black Sea common dolphin is distinguished by some authorities as the endemic sub-species D. delphis ponticus. According to the recent studies, the genus Delphinus include two nominal species, the long-beaked and short-beaked common dolphins. It is very possible that the Black Sea population could be referred to the short-beaked species.
External distinctions: prominent beak with numerous small, conical teeth; tall, falcate dorsal fin; hourglass-like pattern (complex composition of grey, white, black and yellowish stripes and areas) on both sides of the body.

Habitats type, Critical habitats, Limiting factors: D.delphis is distributed predominantly offshore, but also visits precoastal waters following on seasonal aggregations and mass migrations of small pelagic fishes. Cross-relations including both side movements between the Black Sea and Mediterranean populations seem to be possible, but no direct evidence obtained up to now. Critical habitats are not so clear as dangerous zones (e.g., Black Sea straits), which could harm animals due to heavy marine traffic, fisheries and water pollution.

Biology: Black Sea individuals seem to be the smallest representatives of this species anywhere in the world: the average length is 1.5-1.7 m (maximum 2.0 m) for adult females, and - 1.7-1.8 m (maximum 2.2 m) for males. According to dentinal growth layers, females and males attain sexual maturity at 2-4 and 3-4 years; the life span is 20-22 years or even more (probably 25-30 years). The mating period - late spring-early autumn - peaks in July-August. The annual pregnancy rate of the population (46-75% of fertilizing females) depends on the duration of calving intervals, estimated from 1.3 to 2.3 years. The gestation (one foetus) and lactation periods take up 10-11 and 14-19 months respectively, but calves feed on the mother’s milk only for the first 5-6 months of their life. Small pelagic fishes, forming large aggregations (sprat, anchovy, pipefish), are the basic prey for subadult and adult animals (daily ration - 4-10 kg).

Population trends: The common dolphin population still seems continuing to be the most abundant cetacean population in the Black Sea despite of its over-exploitation (mass direct kills on an industrial basis) during 1930s-early 1980s. However, this point of view is not more than a speculation circulating instead of reliable scientific data. The stock of common dolphins in Romanian waters is estimated at 600-800 individuals.

Conservation measures taken: The common dolphin is listed in the IUCN Red Data Book and Red Data Book of Ukraine, and all six Black Sea states have stopped commercial hunting in their waters: Turkey in 1983, other countries in 1966. This species together with other cetacean species in the region is protected by the Berne and Bonn conventions, CITES and ACCOBAMS. The UNEP Marine Mammal Action Plan and IUCN/SSC Action Plan stress that the Black Sea population is at risk

Conservation measures proposed: Adoption of ACCOBAMS by Black Sea countries; establishment of a regional program for marine mammals research and conservation, including a monitoring study on common dolphin population.

Mediterranean Monk Seal Monachus monachus, 1779

The Mediterranean monk seal (Monachus monachus) is a sea mammal, listed among the six most endangered sea mammals in the world  and the most threatened of the seal species.

The classification of the monk seal (Monachus monachus) is as follows: 
Class: Mammalia
Subclass: Eutheria
Order: Carnivora
Suborder: Pinnipedia
Family: Phocidae
Subfamily: Monachinae
Genus: Monachus
Species: Monachus monachus

The name monk was attributed to this species of  seal  because it does not living in large groups preferring solitude and isolation from human presence and/or its head resembles the typical hood of some Catholic monks.

Once found throughout the Mediterranean and Black Seas, and the North African Atlantic, the Mediterranean Monk Seal is now restricted to a few isolated stretches of coastline. Around 200 remain in the Aegean and along the Mediterranean coast of North Africa, and perhaps a further 450 or more on the Atlantic coast of Morocco and Mauritania (Luke, 1993). Although at one time commercially exploited, its decline over the past 30 years is attributable to human disturbance (including tourism) and increased urbanisation of coasts, which caused it to abandon many breeding beaches in favour of caves, where breeding success is poor; persecution by fishermen; and new fishing methods which have depleted prey stocks. The species occurs in several protected areas, but more is required to safeguard its future.

Description: Males are on average 241 cm long and weigh 315 kg. Females are 238 cm long and weigh 300 kg. Pups are 88-103 cm at birth and weigh 16-18 kg. Pups have a black woolly coat with a white or yellow patch on the belly. The adult monk seal can be any colour from dark brown or black to light grey. It is often lighter ventrally.

Distribution: The monk seal was formerly widespread throughout the Mediterranean, the Northwest coast of Africa, and the Black Sea, where it hauled out on sandy and rocky beaches as well as in caves. Now they are confined to remote and undisturbed areas where they breed in caves. The monk seal now occurs in countries around the Mediterranean Sea, on islands in the Adriatic Sea and Aegean Sea, on Madeira (Desartas Islands), the Atlantic coast of Morocco, and Mauritania. There have been no sightings in the Black Sea during the past five years.
Population dynamics: There is little information about this seal. One four-year-old female was observed to be sexually mature.

Population size: The total population size is probably no larger than several hundred and is declining. Estimates made for parts of the Mediterranean monk seal's range give the following: Albania 20; Algeria 10-30; Cyprus and Turkey 20-50; Desertas 8-10; Greece 200-250; Libya 0-20; Mediterranean Morocco 10-20; peninsula of Cap Blanc (Mauritania) 130; Croatia 25.
Feeding: Almost nothing is known about the diet of the Mediterranean monk seal, but it has been observed to feed on both fish and cephalopods.

Trophic relations: There is probably no competition for food; Killer whales (Orcinus orca) and sharks are believed to prey on the seals in some areas.

Human impacts: The Mediterranean monk seal is perceived as a competitor by fishermen in the eastern Mediterranean where seals are killed deliberately. Throughout its range there are reports of death following entanglement in fishing gear. Locally, food availability may have been reduced by overfishing. Disturbances during the pupping season may result in desertion and high pup mortality.

Exploitation: The Mediterranean monk seal is protected throughout its range. There are two protected areas created especially for monk seals, Desertas Islands in Madeira and the marine park Northern Sporades in Greece. There are future plans to set up nature reserves to protect the seals' habitat. Despite the protection, monk seals are still killed by fishermen.

Threats to the population: This small population of secretive animals, spread out over a large area is very vulnerable. Important threats are deliberate killing, loss of habitat, incidental entanglement, and disturbance. Threats from pollution, disease, and reduction in food supply should not be ignored. Monachus monachus is included in the IUCN Red List as being Endangered.