"The number of people who go on a cruise each year more than trebled – from 1.4 to 4.5 million – between 1980 and 1993. The largest cruise ship built so far, the Carnival Destiny, carries 3,400 passengers and 1,040 crew, and is taller than the Statue of Liberty and longer than three football fields.
Cruise ships, on average generate about 4,400 kg of waste a day, compared to the 60 kg a day produced by cargo ships and 10 kg a day by fishing vessels.
About a third of the waste from cruise ships visiting the Caribbean is deliberately dumped, because many ships do not have incineration units (or they are faulty) or because ports do not have adequate facilities for unloading it.
Indeed, even when the waste is properly received by ports, this is often only the beginning of the problem: many countries, particularly small islands, do not have enough disposal sites to deal with it."
Source: GESAMP70:24
GESAMP (IMO/FAO/UNESCO-IOC/WMO/WHO/IAEA/UN/UNEP Joint Group of Experts on the Scientific Aspects of Marine Environmental Protection). 2001. A sea of troubles. Rep. Stud. GESAMP No. 70, 35 pp. ISBN 82-7701-010-9