GLOSSARY

After Walters, S (1996) Ballast Water, Hull Fouling and Exotic Marine Organism Introductions via Ships - A Victorian Study. EPA

Aft: Towards the stern; near the stern.

After: Further aft; nearer the stern.

Ballasting and de-ballasting: Ballasting is the process of taking sea water (or fresh water) on board where the water is gravity fed or pumped into the ships' ballast tanks and/or specially strengthened cargo holds. The process of pumping out or discharging the water is called de-ballasting or ballast discharge.

Ballast water volume/tonnage: Ballast water capacity on ships is expressed in terms of tonnes of seawater (1.025 specific gravity).

Bending moments: Moments of forces capable of bending a vessel. A ship is subject to varying loads due to the distribution of forces of upthrust (due to buoyancy) acting vertically upwards and downwards.

Benthic: Living on the bottom of sea, lake, river etc.

Bulk carriers: This classification includes woodchip carriers. Bulk carriers are designed to carry a wide range of cargo types, depending on the size of the vessel. Bulk carriers vary from about 10,000 to 200,000 dwt; all have similar designs but differ in scale. In addition to ballast tanks, one or more of the cargo holds is usually designed to carry ballast for when the ship needs to be heavily ballasted.

Bulkhead: Transverse, or fore and aft, vertical partition in a vessel which subdivides the interior into compartments.

Coastal vessels: Australian ships which visit domestic ports only.

Container: A portable compartment (case) for the repeated carriage of cargo in bulk or package form. Rigid and collapsible types are available.

Container ships/cellular container ships: Ships designed to carry containers both on deck and in cargo holds. In the holds there is a cellular structure of angle bars forming guides into which the containers are stored one on top of another.

Deadweight tonnage (dwt): Is the weight in tonnes (1000 kg) of cargo, stores, fuel, passengers and crew carried by a ship when it is loaded to the maximum summer loadline. The dwt or deadweight carrying capacity is the difference between the light and loaded displacements of a ship.

Displacement: The light displacement is the weight of the vessel either in long tons of 2240 lbs or in metric tonnes of 1000 kgs. The loaded displacement is the weight of the vessel plus stores, cargo, the weight of officers, crew members and passengers.

Domestic vessels and visits: Ships (and visits) which had a domestic port of call as their last port of call - they include international vessels calling at multiple Australian ports.

Draft/Draught: The distance from the bottom of the ship to the waterline. The amount of draft affects the ease with which ships can be steered and their stability, particularly in heavy weather.

Established species: Species which have established self-reproducing populations.

Exotic species: Species which originate from another country.

Eutrophic: Rivers, lakes etc. having high levels of nutrients, as oxidised nitrogen and inorganic phosphorous, encouraging the growth of algae.

Fecundity: Ability of a species to multiply rapidly; capacity to produce large numbers of offspring.

Flow-through ballast water exchange: Where ballast tank inspection hatches on the deck are opened and ballast pumps are run for a period equivalent to allowing three times the volume of the tank to flow through the hatch and out over the ship's side.

Fore: In or towards the forward part of a ship.

Fore and Aft: 1. Leading or lying in the same direction as the length of a ship.

2. Embracing the whole length of a ship.

General cargo ships: Vessels ranging between 5,000 - 20,000 dwt which carry a variety of different cargoes. In Australian trades for example, they may handle timber, palletised goods or machinery.

Indigenous species: Species which are native to a particular region or country.

International vessels and visits: Ships (and visits) made by vessels with an overseas last and next port of call.

International/multiple vessels and visits: Ships (and visits) made by vessels which travel to and from overseas ports and which have visited or will be visiting more than one Australian domestic port on their current trip to Australia.

Introduced species: Exotic species currently living in Australia, including species which may not yet have become established.

List: A measured angle indicating the degree to which a vessel is heeled port or starboard from the vertical.

Load lines or Plimsoll lines: Lines drawn on the side of ship and marked:

TF	-	Tropical fresh water
F	-	Fresh water
T	-	Tropical water
S	-	Summer season
W	-	Winter season
WNA	-	Winter in North Atlantic

They indicate the maximum legal draught to which a ship may be loaded under specified conditions in accordance with the Merchant Shipping Act 1932.

Marks: Same as load lines above.

Marina: A boat basin offering dockage and other service for small craft.

Mid-ocean ballast exchange: The total or partial exchange of ballast water in a vessel while it is in deep ocean water. Ballast exchange (as recommended by the International Maritime Organisation (IMO) International Guidelines and AQIS) aims to minimise the risk of organism transfer by replacing coastal ballast with ocean ballast. Most deep sea organisms are unlikely to adapt readily to coastal environments. In addition to posing many practical difficulties and safety concerns, the effectiveness of ballast exchange has been questioned.

n.m: Nautical Mile. The international nautical mile is 1852m (6,076.12 ft), it is equivalent to the average length of a minute of latitude, and corresponds to a latitude of 45^o.

Pathogen: Any disease causing micro-organism.

Port: Left side of a ship when looking forward, opposite to Starboard.

Re-ballasting: Emptying ballast tanks sequentially and then refilling them with clean oceanic water.

Reefer cargoes: Refrigerated cargoes.

Roll on, roll off (ro/ro) cargo ships: Ro/ros are designed to carry cargoes which include palletised goods, trucks, cars, refrigerated containers, break bulk and cars and machinery. Passenger ferries (such as The Spirit of Tasmania) are included in this category. Ro/ros take on and discharge ballast in very small quantities (if at all).

Shearing stresses or forces: Forces exerted on the bulkheads of a vessel as the result of external forces perpendicular to the ship.

Slack ballast tanks: Tanks which are partially, rather than completely full of water.

Slipway: An inclined plane or ramp, sloping to the water, serving as a landing place or a site on which vessels are built or repaired.
Starboard: The right hand side of a ship when looking forward. Opposite to port.

Stern: After end of a vessel.

Tankers: The classification used in this report includes Liquefied Petroleum Gas (LPG) tankers, chemical tankers and oil tankers. A crude carrier is designed to carry crude oil from producer to refinery and a product carrier is designed to carry a range of refined products to end user markets.

Translocated species: Indigenous or introduced species which have been transferred to waters outside their natural or previous distributions.

Trim: The difference between the forward and aft draft of the vessel. "Trimming" is the process of transferring ballast water from one tank, usually carried out while loading or unloading cargo. This manoeuvre is necessary to ensure that safe bending moments and stresses in the vessel are not exceeded or to minimise draft for port entry or departure.