With the grant of
Ministry of the University and Scientific and Technological Research Ministero dell'UniversitĂ e della Ricerca
Biodiversity and Maritime Traffic Ballast waters as vectors for the introduction of alien species
Phooto of A. Grassi - Ecotaras S.p.A.
Ballast water This is water transported by ships in special reservoirs to provide stability, order, and structural integrity. Ships use water as ballast since it is much easier to load and unload. When a ship does not have cargo, it fills its ballast tanks and vice-versa. The ballast waters are essential for the security of the ship, but can constitute a serious threat to the environment, the economy, and human health.
The bio-invasions in the Mediterranean Sea are on the increase due to the high maritime traffic and the degradation of the environment. Cargo ships transport the non-native species settled on their hulls or in the ballast waters that are taken on board in special reservoirs for reasons of stability and structural resistance. The problem of the introduction of allochthonous species by way of the ballast waters is particularly important for planktonic organisms, since many species, throughout their life cycle, produce resting stages that can survive in the sediments of the ballast tanks, even though the environmental conditions here are harsh.
The reccomendations of IMO
IMO, International Maritime Organization, recommends that the discharge of ballast waters is carried out in open sea or in far areas 200 nautical miles from the nearer coast and in deep waters at least 200 meters. Moreover it would have to avoid the cargo of waters of ballast in presence of algal bloom and during the night, when zooplancton get up in sea surface; to use pumps of cargo and drainage to high speed in order to increase mortality of the organisms, and at last to subject waters of ballast to a mechanical treatment of filtering and centrifuge. In the February of the 2004 International Maritime Organization has adopted a convention that it has the objective to define common rules of uniform implementation in order to prevent upgrades them determined harmful effects from the organisms transported in the ballast waters. The “convention for the control and the management of ballast waters and sediments of the ships� previews that all the ships must have a plan of management of ballast waters and sediments, must have a registry of ballast waters and manage them according to determined standards and procedures. The Convention establishes, moreover, that the ports must have adequate systems for the collection of ballast waters and sediments.
Realized by
Maritime Admiral Michelagnoli Foundation NGO non-profit Fondazione Marittima Ammiraglio Michelagnoli Onlus - Taranto - Italy
In the past 50 years, the volume of ship movements and loading and unloading at ports in the Mediterranean Sea has increased by 77%. Every year, around 200,000 commercial ships cross the Mediterranean Sea, 30% of which head towards one of the 300 ports within the basin. It is estimated that over the next 20 years naval traffic in the Mediterranean will increase some 3 to 4 times.
Ballast waters cycle Engine room Upper deck
Stern water tank
1. The cargo ships take on ballast water in special reservoirs in the departure ports when they need to travel with empty holds or, however, to improve their stability during navigation; 2. During the voyage many organisms that are taken on board with the ballast water die, but many others survive, especially in a dormant phase; 3. In the port of arrival the ballast water is discharged and with it the organisms that would have survived; 4. The ship departs with its holds full of cargo and heads towards its next destination.
Tank for ballast
Discharge of the holds
Charge of ballast waters 1. Starting port
Photo archive "Mare Nostrum" , property of Fondazione Michelagnoli & Giuseppe Pignataro (international champion) www.fondazionemichelagnoli.it English version translated by Dr Adrian Mallia - Adi Associates Environmental Consultants Ltd - Malta
Side tanks for ballast
Empty holds
Full tank of ballast waters 2. During the navigation
Lower tanks
Bilge
Charge of the holds
Discharge of the ballast waters 3. in the port of destination
Bow water tank
Full holds
Completely empty tank of ballast waters 4. During the navigation
In agreement with
National Interuniversity Consortium For Marine Sciences - Italy Co.N.I.S.Ma. - Consorzio Nazionale Interuniversitario di Scienze del Mare