Answer:
Black water
Step-by-step explanation:
Cruise ships have been described as "floating cities" and like cities, they have a lot of pollution problems. Their per capita pollution is actually worse than a city of the same population, due to weak pollution control laws, lax enforcement, and the difficulty of detecting illegal discharges at sea. Cruise ships impact coastal waters in several US states, including Alaska, California, Florida, and Hawaii.
All cruise ships generate the following types of waste:
"Gray water" from sinks, showers, laundries and galleys
Sewage or "black water" from toilets
Oily bilge water
Hazardous wastes (including perchloroethylene from drycleaning, photo-processing wastes, paint waste, solvents, print shop wastes, fluorescent light bulbs, and batteries)
Solid wastes (plastic, paper, wood, cardboard, food waste, cans, and glass)
Air pollution from the ship's diesel engines
A 3,000-passenger cruise ship (considered an average size, some carry 5,000 or more passengers) generates the following amounts of waste on a typical one-week voyage:
1 million gallons of "gray water"
210,000 gallons of sewage
25,000 gallons of oily bilge water
Over 100 gallons of hazardous or toxic waste
50 tons of garbage and solid waste
Diesel exhaust emissions equivalent to thousands of automobiles
In addition, these ships take in large quantities of ballast water, which is seawater pumped into the hulls of ships to ensure stability. This water is typically taken in at one port and then discharged at the ship's destination, which can introduce invasive species and serious diseases into U.S. waters. A typical release of ballast water amounts to 1,000 metric tons.