A Carnival cruise ship sets sail in Miami, Florida.

(Photo: Joe Raedle/Getty Images)

Princess Cruise Lines Ltd. has been hit with a record-setting criminal penalty for deliberate pollution. The California-based cruise line — a subsidiary of Carnival Corporation, the largest cruise company in the world — pled guilty to felony charges for illegal dumping of oil contaminated waste. It will pay a $40 million fine as part of a plea agreement, the Department of Justice reported.

The case came to light after an engineer reported that employees aboard the Caribbean Princess were using a “magic pipe” to dump oily waste off the coast of England in 2013 in order to save money. It is inarguably troubling, not least because the chief engineer’s response to the whistleblower was to attempt a cover up. (The same man was known by the crew as a broccino corto, the DOJ notes, an Italian phrase for an exceptionally frugal man whose arms are too short to reach his wallet.) The ship had a long history of environmental violations, going back at least to 2005.

What sets this infraction apart is the deliberateness of its nature. A 2000 paper from the General Accounting Office found that, between 1993 and 1998, just 15 percent of the cases of illegal discharge in American waters were intentional, 72 percent were accidental, and 13 percent could not be determined. Even cruise ships that attempt to follow the environmental regulations, laid out by a patchwork of international and domestic laws, produce massive quantities of waste.

Cruise ships are just a small fraction of the shipping industry, but perhaps the fraction most visible to the public, carrying the equivalent of a small town directly into some of the world’s most beautiful — and vulnerable — ecosystems. (See, for example, Eva Holland’s piece for Pacific Standard on the booming cruise business emerging in the Northwest Passage.) And, in such environments, even standard operating procedures can do damage.

Cruise ships generate about 15 gallons of hazardous chemical waste every day, according to environmental group Friends of the Earth. The passengers and crew aboard the biggest ships can produce 210,000 gallons of sewage and almost five times as much graywater—from sinks, showers, laundry, and so on—in a single week. And, in a year, 100 million gallons of petroleum products from cruise ships seep into our oceans. Then there’s the air pollution.

“These ships burn as much fuel as whole towns,” Bill Hemmings, the director of aviation and shipping at Transport & Environment, told the Guardian earlier this year. “They use a lot more power than container ships and even when they burn low sulphur fuel, it’s 100 times worse than road diesel.”

When it comes to dealing with sewage and graywater, ships are only strictly required to treat waste by using Marine Sanitation Devices, a catch-all term for technology that often leaves behind contaminants like bacteria, heavy metals, and nutrients that can throw marine ecosystems off kilter.

But the adoption of more advanced technologies that better screens for such contaminants and catches them before waste is dumped in the ocean could be a step in the right direction. Ideally, cruise ships should not dump even treated sewage along sensitive coastlines or marine protected areas at all. But cruise line companies are not always transparent about their environmental practices.

In 2016, Princess Cruise Lines received a “C” rating on Friends of the Earth’s cruise ship report card, which grades companies on sewage treatment, air pollution reduction, water quality compliance, and transparency—the same grade the cruise line received in 2014, and a full grade below the B it received in 2013. Of the 17 cruise lines evaluated, only Disney Cruise Lines received above a C in 2016 (it earned an A-); the majority scored below that, with eight Ds and four Fs. These environmental concerns will only become more pressing as the industry grows. Demand for cruise ships has grown by nearly 70 percent over the last 10 years, according to the Cruise Lines International Association. In 2014, more than 22 million people boarded cruise ships around the world, about half of them from the United States.

On an individual level, each passenger’s carbon footprint while cruising is roughly three times what it would be on land — something to think about this winter when temperatures drop and the appeal of a Caribbean cruise begins to rise.