Download PDF | Bogatova, Yu. I._ Synegub, I. A._ Vinogradov, A. K - Ecology of Marine Ports of the Black and Azov Sea Basin-Springer International Publishing _ Imprint_ Springer (2018).
420 Pages
Introduction
Modern ecology is a science about ecosystems uncovering the laws of their composition, structure, functioning and evolution.
V.D. Fedorov, T.G. Gilmanov
The present book proposes to the reader revised, expanded and improved material partly based on the previously published monograph “Ecosystems of marine ports aquatories of the Black—Azov Sea basin (introduction to marine ports ecology)” (Odessa, Astroprint, 2012). In the new sections of this edition, particular attention has been given to ecological peculiarities of organization and general ecological mechanisms of marine port (MP) aquatories ecosystems functioning.
Coastal and estuarine MPs are typically located within the sea shelf in “land— sea” and “land-river—sea” transitional zones. MPs constitute peculiar marginal ecosystems in which natural and anthropogenic components are variously combined. All MPs have unique individual features, but, at the same time, they are all created with the main objective of reducing the wave and wind influence on ships to an acceptable level. MPs of the classical type include three main components in their structure: (1) protected aquatories, (2) artificial hydrotechnical structures (HTS) located in the aquatories and protecting them; (3) access channels (AC) with depths matching those in aquatories.
In the Black—Azov Sea basin, the targeted exploitation of the shores and the construction of port cities started during the seventh—eighth centuries BC, during the period of the “great colonization” by the Greeks. After three to four centuries, several dozens of MPs were already operating on the shores of the Black and Azov Seas. The absolute majority of modern MPs are operating at the same locations as the ports existing in ancient times. Until the fourteenth—fifteenth centuries AD, the use of rowboats and sailing rowboats with draft up to 2—2.5 m has not resulted in an urgent need for the construction of harbours with deeper aquatories. During the sixteenth— seventeenth centuries, shifting to multi-decker sailing vessels with draft up to 5-6 m placed new requirements on MPs.
During the period nineteenth—-twentieth centuries, the appearance of steamships with iron and, later on, steel hulls provided an impetus for construction of berths with depths of 8—10 m in the Black and Azov Seas. Berths with depths of 15-20 m appeared in Novorossiysk, Odessa, Yuzhny and Constanza during the period from the end of the twentieth to the beginning of the twenty-first centuries. Invention of steam and diesel engines allowed to mechanize the necessary dredging activities. Over 2500 years, each of the ship dimensions (length, width and draft) has increased ten times, while draft and carrying capacity (deadweight) have increased threefold. At present, ships with lengths up to 300-320 m, drafts up to 20 m and displacements up to 220-230 thousand tonnes are considered the most economically viable for navigation in the Black Sea.
At the end of the eighteenth—beginning of the nineteenth century, merchant shipping started to develop on the Russian coasts of the Black Sea and merchant harbours were constructed along with military ones. The Treaty of Kii¢gtik Kaynarca (1774) established a “free and unrestricted navigation of Russian flagged merchant ships” sailing into the Black Sea via the Dardanelles and Bosphorus straits, thus making Russia a fully legitimate Black Sea state. The opening of the commercial ports in Kherson, Feodosiya and Sevastopol was announced in 1784 by Tsar’s manifesto and the Russian Black Sea trade started in the 1790s. Odessa was proclaimed a free trade zone (porto-franco) in 1794.
The Treaty of Adrianople (also called the Treaty of Edirne) with the Ottoman Empire (1829) granted Russia the freedom of commercial navigation in the Black Sea straits and the freedom of trade for Russian merchants within the Ottoman Empire. At the end of the twentieth century, after the collapse of the USSR, MPs located on the northern coast of the Black and Azov Seas and in Crimea, previously belonging to Russian Empire and the USSR, were acquired by Ukraine.
MPs were located in gulfs, bays, limans and estuaries already having some natural protection. Several ports were initially built for military purposes and later became merchant ports. During the period of their existence, all ports have undergone, and continue to undergo, periods of rise and fall with human activity ceasing for decades or centuries in some of them.
Dimensions, depths, peculiarities and general economical significance of each MP are primarily determined by its hinterland, or zone of economic attraction, and the influence of associated logistic. Ships, ports and cities in which they are located belong to systems centred on the flow of merchandise, cargo and freight. Shipbuilding has progressed along with navigation and port builders have been adapting ports aquatories and infrastructures to the newly originating requirements [9].
The analysis shows that there is a close direct and inverse connection between the sizes of a city and its port. Already in ancient time, MPs acted as “city-forming enterprises”. They were providing not only connections, but also economic well-being of the maritime cities. Changing of conjuncture, resource deterioration, appearance of new itineraries of transportation could all lead to reduction of the role of a port. Increase of cargo traffic creates the need for reconstruction of old berths and construction of new ones as well as dredging in MP aquatories and their AC.
There are direct and indirect ecological links and interrelationships among ships (ength, draft, number, etc.), ports (sizes, depths, access channels, number of artificial HS) and marine cities (population, communications and infrastructures). Changes in one of the above-mentioned components inevitably cause direct and indirect consequences in the others. Thus, the port city of Istria throve in ancient times and then totally declined due to sand accumulation in its navigating channel. In port cities, the growth of population and number of circulating vessels were increasing the volume of domestic effluents and faecal wastes directly discharged into the protected MP aquatories, which favoured processes of local eutrophication. The more numerous the populations of ancient port cities grew, the bigger their influence on terrestrial and aquatic ecosystems. The overgrowing of hydrobionts on ships’ hulls during more than two thousand years favoured species exchange between the aquatories of various MPs.
Various manufactures (smelting and working of metal, production of pottery and glass, leather working, etc.) developed in wealthy port cities over the centuries. These first workshops did not have a pronounced negative influence on the environment until the eighteenth—nineteenth centuries. During the nineteenth-twentieth centuries, the big Black and Azov Seas’ ports, which nowadays are located on the continental territory of Ukraine and Crimea, were connected by railway lines with industrial and agricultural regions. MPs such as Odessa, Ilyichevsk, Yuzhny, Nikolaev, Kherson, Kerch and Mariupol became big transport and industrial complexes, with evident negative impact on terrestrial and aquatic ecosystems including MPs aquatories and adjacent sea zones.
Ecosystems of the modern MPs of the Black—Azov Sea basin in general, and of Ukrainian MPs in particular, comprise three more or less autonomous subsystems: (1) the pelagial zone, (2) the periphytal zone, (3) the benthal zone [2]. In a given port, the pelagial connects all the subsystems into an integrated ecosystem. In spite of individual differences, MPs are constructed and functioning on the basis of some general principles. MPs ecosystems experience conditions of weakened hydrodynamics and water exchange.
The artificial increase in MP depths opens the possibility for the vertical stratification of water masses and the formation of a stable pycnocline. The presence of high quantities of HS (hard substrata) in MP ecosystems stimulates biological production. Accumulation of organic matter (OM) takes place as a consequence of protection and lowered hydrodynamics of MP aquatories. In MPs, the coastal shallow waters and associated biocenoses are partially or totally destroyed and the conditions of the shallow shore are substituted by deep shore ones.
On the bottom and the near-bottom layer of MPs, saprobiotic situations causing mass mortality occur quite often. At the same time, there is no fishing in MPs aquatories and their biota comprises hundreds of hydrobionts species [1, 2, 10], so that MPs ecosystems are a source of larval material for adjacent ecosystems. Given all these peculiarities, the authors consider that MPs aquatories should be regarded as complete, specific aquatic ecosystems.
Construction and operation of port moles and AC not only changes the bottom relief, but also directly and indirectly influences longshore drifts flow, processes of seashore abrasion and origin of new accumulative formations. Bottom drifts enter MPs aquatories mainly via passages in HTS, notably in the correspondence of ACs.
The problem of sediment accumulation in MPs aquatories is directly connected with that in AC.
The Romanian port of Constanza has the biggest aquatory area (26 km’) among marine ports of the Black and Azov Seas located on seashore and artificially protected. The aquatory of the Bulgarian marine port Varna-West is formed by the interconnected lakes Varna and Beloslav and has a total area of more than 20 km’. MP Sevastopol has an aquatory of the estuarine type (i.e. Sevastopol Bay) with an area of about 7 km*. The aquatories of Ilyichevsk and Yuzhny MPs, located in Sukhoy and Grigorievsky Limans respectively, both have an area of about 6 km”.
Because HTS in MPs are stationary, accumulation of drifts in aquatories and changes in water level have a significant impact on their normal functioning. Fluctuations of water level have a naturally determined character and are difficult to forecast. In MPs, offshore—-onshore phenomena and seiches can be observed all year round. The speed of water level rise in the Black Sea is 1.83 + 0.07 mm year ' or 18 cm for 100 years [6]. Ports in the Black and Azov Seas experience nearly invisible tides; contrary to many ports, located in different regions of the World Ocean, whose aquatories are regularly washed out by tides. Tidal amplitude is 7 cm in Constanza, 8—9 cm in Poti and in 5—6 cm Odessa. The tidal currents are scarcely observed [4].
In many regions of the Black Sea, anthropogenic changes affect not only MPs aquatories, but also the shores adjacent to them. From the 1960s to the 1990s, about 600 drifts-trapping groins (for a total length slightly exceeding 30 km) were constructed on the shore zone of the South Crimean Coast. In the zone of Odessa Gulf, shore protection works were carried out along more than 12 km from Cape Bolshoy Fontan to Cape Lanzheron [3, 7].
In the Azov Sea, construction of Glukhoy canal and Temryuk port caused accumulation of drifts carried by the Kuban River on the windward side of these structures. Consequently, the vast, so called Chaika sandbar has formed between Glukhoy canal and the Petrushin arm of Kuban River; with depths decreasing from 6 to 1.5 m at a distance of 1 km from the shore [11].
For many ports, the “Pilot chart of the Black Sea” [5] indicates the water depth at distances of 1 and 5 m from berths. Taking Odessa MP for example, depth changes with distance from the berths can range from 0.5 to 3.0 m; causing heterogeneous conditions at the bottom. A similar situation is observed in most ports of the Black and Azov Seas and can be connected with the constant deposition at the HTS basis of the matter formed in the fouling biocenoses of underwater surfaces. It could also be explained by the danger of damage to berths’ underwater parts during dredging and by peculiarities of the water flows in the near-bottom layer. The round form of ships’ submerged hulls is compatible with such differences because, when moored, the deepest draft is at the keel part of ships’ bottom.
According to international classification, ports of I, II and III class are accepting ships with draft up to 20, 12 and 9 m, respectively [8]. The deepest water ports of Ukraine are Yuzhny, Odessa and Ilyichevsk MP can accept vessels with draft of more than 12 m and, at some berths of Yuzhny and Odessa MPs, up to 15-17 m.
In sea ports, the patterns of hydrobionts distribution, the flows of live and dead (suspended and dissolved) OM and the formation of aggregates of living material are mainly determined by physical, physical-chemical and chemical processes.
Up to now, the ecological role of marine ports located on the shores of tideless seas such as the Black and Azov Seas is poorly described in the scientific literature. However, according to tentative estimations, the total area of anthropogenically modified MPs aquatories in this basin comprises more than 50 km”. Furthermore, the cumulative length of access channels (AC) to MPs is more than 350 km and the total extension of HTS in MPs exceeds 300 km; the area of their submerged parts being over 2 millions m7’. In MPs, moles, breakwaters, berths and floating docks represent hard substrata artificially introduced into marine coastal ecosystems and are classified as artificial reefs (AR) [2]. For fouling hydrobionts, wetted surfaces of ship’s hulls also represent HS. The ruins of ancient ports and towns submerged by the sea a long time ago (Dioskoyrias, Kallatis, Sinop and other) also serve as HS for fouling organisms. Taking all this into account, the authors consider the elaboration of general recommendations to ameliorate the ecological situation in MPs aquatories as an imperative task.
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