Ad
related to: why ballast water is important
Search results
Results From The WOW.Com Content Network
Ballast water discharges are believed to be the leading source of invasive species in U.S. marine waters, thus posing public health and environmental risks, as well as significant economic cost to industries such as water and power utilities, commercial and recreational fisheries, agriculture, and tourism. [11]
Cross section of a vessel with a single ballast tank at the bottom. A ballast tank is a compartment within a boat, ship or other floating structure that holds water, which is used as ballast to provide hydrostatic stability for a vessel, to reduce or control buoyancy, as in a submarine, to correct trim or list, to provide a more even load distribution along the hull to reduce structural ...
Timescales are very important when considering regrowth. For instance, if ballast water is treated at intake and held in ballast tanks for over a week before discharge, then the organisms surviving the treatment could have enough time to increase in numbers and potentially exceed discharge standards before the end of the voyage.
The advantage of water ballast is that the tanks can be emptied, reducing draft or the weight of the boat (e.g. for transport on ground) and water added back in (in small boats, simply by opening up the valves and letting the water flow in) after the boat is launched or cargo unloaded.
Before the final ruling in ballast water standards in 2012, many vessels arriving from outside the EEZ were able to be exempted from safety regulations by exchanging ballast water mid-ocean. Vessels also had to report number of ballast water tanks, each tank's volume, and origin of the ballast water to be discharged.
Ballast, other than cargo, may be placed in a vehicle, often a ship or the gondola of a balloon or airship, to provide stability. A compartment within a boat, ship, submarine, or other floating structure that holds water is called a ballast tank. Water should be moved in and out from the ballast tank to balance the ship.
The International Convention for the Control and Management of Ships' Ballast Water and Sediments (Ballast Water Management Convention or BWM Convention) is a 2004 international maritime treaty which requires signatory flag states to ensure that ships flagged by them comply with standards and procedures for the management and control of ships' ballast water and sediments. [2]
Approximately 10 billion tons of ballast water is transported each year, accounting for 90% of our world trade. [2] Typically, ballast water discharge contains a variety of biological materials including non-native, invasive, and exotic species that can cause extensive ecological and economic damage to aquatic ecosystems.