Cruise ships are a major source of air pollution which causes and/or contributes to a wide range of serious health problems such as respiratory ailments, lung disease, cancer and premature deaths. The pollutants from ship engines exhaust gases include sulfer oxides(SOx) as well as non-combustible particulate matter and black carbon. A video of a Carnival cruise ship, the Carnival Victory (shown below), belching bunker fuel fumes in port in Nassau a couple of months ago was widely distributed via PTZtv. It should have been an embarrasing spectacle by a cruise line on probation here in Miami for widespread water and air pollution.

Heavy fuel oil (HFO), sometimes referred to as bunker fuel, has historically been a low cost favorite of cruise ships. HFO has tar-like consistency which results from the residue of crude oil distillation  HFO is contaminated with several different compounds including sulfur and nitrogen, which makes HFO emissions far more toxic compared to low sulfur fuels.

Bunker Fuel – the “Dirtest Fuel of All”

Forbes reports that the German watchdog Nabu surveyed 77 cruise ships and found that all but one used toxic heavy fuel oil that the group described as “dirtiest of all fuels.”

Bunker fuel cannot be used without incombustible particles flying all over the place – not unlike burning a tire – with the residue burrowing deep into the mucous membranes of your lungs. It should be considered to be a public nuisance and banned as such. No one reading this article would burn bunker fuel in their house, or subject their neighbors to this toxic pollutant.  Bunker fuel is the nastiest and most toxic fuel you can use. But this fuel is the cornerstone of the cruise industry.

The IMO’s 0.5% Cap

The International Maritime Organization (IMO) adopted a sulfur cap to reduce the dangerous effects of HFO. The IMO will theoretically enforce the cap as of  January 1, 2020 when shipping companies will be required to switch from heavy fuel oil to 0.5 percent low-sulfur fuel, compared with the current 3.5 percent.  (Some Emission Control Areas have stricter caps).  But the IMO permitted a loophole requested by the shipping industry. A cruise line can continue to use the lower cost but high-sulfur fuel, as long as they install an exhaust gas cleaning system (EGCS), (i.e., a “scrubber”) on each ship to maintain emissions at the same levels as low-sulfur fuel.

A scrubber works by spraying alkaline water (usually seawater) into the vessel’s exhaust stacks, which is designed to reduce reduce carbon, sulfur oxide (SOx) emissions, and non-combustible particles from bunker fuel from the ship’s engine exhaust gases.

Money, Money, Money

The cruise industry is highly profitable. It is preoccupied with keeping its costs artificially low. The cruise business model avoids taxes, underpays crew members and provides them with few benefits, and externalizes virtually all costs of doing business. Avoiding higher fuel costs is a fundamental part of its business, irrespective of the damage caused to the environment and injury to its passengers, crew members and shore-side communities.

Around half of the cruise lines have decided to use scrubbers to comply with the new IMO rules. In other words, they have made a decision to refuse to incur the higher cost of low-sulfer fuel.

Cruise Lines Dodge Environmental Regulations with “Emission Cheat” Systems 

Many prople call scrubbers “emissions cheat” systems, which are designed to avoid the shipping industry having to buy cleaner, more expensive fuel. The Guardian newspaper called them an  “environmental dodge.” As explained by Bloomberg Businessweek, in an article published yesterday, scrubbers allow ship owners to continue buying cheaper high-sulfur fuel.  In the most used system, known as “open loop,” the waste water is discharged into the ocean. The more expensive closed-loop systems require storage of waste water to be discharged into a facility on shore, according to the Guardian. Bloomberg Businessweek points out that about half of the 268 cruise ships operated by members of the Cruise Lines International Association (CLIA) reportedly have installed scrubbers.  “Scrubbers effectively turn air pollution into water pollution,” says Kendra Ulrich, of environmental group Stand.earth.

Toxic Scrubber Sludge

The pollutants which scrubbers remove from the air are called “scrubber sludge” or simply “sludge,” an accurate description of the toxic mix of metals, such as lead, nickel and zinc, as well as hydrocarbons, sulfur, and nitrogen compounds which have been sprayed from the ship’s emission stacks.  The scrubbing also removes non-combustible particles such as soot, incompletely burned oil, and ash. The water used to spray the emission stacks become acidic and is dumped back into the ocean in the open loop systems. The sludge residue must be collected during closed loop operations and stored aboard the ship. The cruise companies are then required to dispose of the sludge at suitable shoreside facilities. Cruise lines are also requireed to maintain logs documenting the storage and disposal of the washwater residue.  But some cruise lines are suspected of dumping the sludge at sea.

Turning Air Pollution Into Water Pollution

Travel Weekly writes that “questions are being raised about where all the pollution that’s being removed from cruise ship exhaust is ending up.” Travel Weekly mentioned a case where it appears that a Princess Cruises cruise ship piped the scrubber sludge overboard while in the port of Ketchican last July. Port employees observed discharges coming from the Star Princess cruise ship in Ketchikan, Alaska and took photographs which showed “darkened splotches in the water. One shows a patch of lumpy black material floating near a piling.”

Princess Cruises, which is under probation for wide spread pollution and repeated lies to the Coast Guard and other agencies, denied any wrongdoing, stating: “Our experts believe what was viewed and photographed is most likely sea foam discolored by natural microorganisms such as algae in the seawater, which is commonly experienced in northern climates in the summer season.”

Some Ports Ban Open Loop Scrubbers

According to Travel Weekly, nearly a dozen environmental groups petitioned the IMO to prohibit the use of scrubbers. They argued that the technology isn’t always reliable, “citing an audit of the Carnival fleet from 2017-18 that turned up 30 examples of scrubbers that either weren’t turned on or had unexpectedly shut down in areas where sulfur emissions were already capped.” These environmental groups have roundly criticized the cruise industry’s plans to continue to burn high-sulfur fuel and its use of scrubbers, and have asked regulators to adopt the use of low-sulfur fuel as the only allowable method of complying with the new IMO regulations. Several international ports (but not all) have outlawed the use of scrubbers, which has alarmed cruise lines that have invested heavily in the use of scrubbers.

Carnival’s Advanced Air Quality is an Emission Cheat System

Carnival Corporation has embarked on a public relations campaign with a pro-scrubber website. Carnival argues that scrubbers, which it calls “Advanced Air Quality Systems,” are an effective way to reduce sulfur dioxide and other pollutants.

But trusting Carnival and its related brands, like Princess and Holland America Line (HAL)(which was just fined yesterday for discharging untreated grey water into Glacier Bay National Park) to comply with environmental laws seems perilous. Carnival brands have a long history of illegally discharging oily water, chemicals, bilge water, grey water, chemicals, and food mixed with plastic items, trash and garbage from numerous ships around the world, even while on probation. Given the tendency of Carnival owned ships to dump waste products overboard, rather than incurring the expenses of collecting, storing and properly disposing the pollutants ashore, the dumping of scrubber sludge seems to be a certainty.

Other cruise lines, such as Royal Caribbean and Norwegian Cruise Line, also have a history of pollution. They have both pleaded guilty to multiple environmental felonies. Royal Caribbean was seemingly the first cruise line where engineers perfected secret bypass valves (later widely used on Princess cruise ships) which permitted ship employees to bypass the oily water seperators and discharge the oil directly overboard. Royal Caribbean’s use of these illegal devices eventually ended only after it was caught repeatedly violating its probation for pollution and the DOJ fined it a total of $27,000,000.

Royal Caribbean’s Advanced Emission Purification is Another Emission Cheat System

Royal Caribbean calls scrubbers “Advanced Emission Purification” systems which have been installed in the original build of of its largest ships like the Harmony of the Seas and the Symphony of the Seas and retrofitted on many ships in its fleet over the last several years.  Watch the videos produced by Royal Caribbean “Cruising Into The Future: Royal Caribbean Initiates Advanced Emissions Purification Plans” and “Sustainability At Sea.” Royal Caribben states that between 500 and 1,500 tons of seawater and additives are sprayed into each of two emission stacks on a typical ship per hour to try and clean the emission of pollutants. Sulfur, heavy metals, and other toxic wastes are either washed overboard or collected as sludge after many thousands of tons or water are sprayed in the stacks of these ships which are still burning high-sulfur fuel.

Smoke or Water-Vapor? Either Way Cruise Ships Create Scrubber Sludge 

Earlier this week, a reader of this blog videotaped the Symphony of the Seas leaving the port of St. Thomas, U.S.V.I. He posted the video on YouTube (below) with the caption “Royal Caribbean Smoke Show.” The video is sure to create the usual debate every time I post a video of a cruise ship burning high-sulfer bunker fuel bellowing smoke from its funnels. Defenders of the polluting cruise industry (and an ocassional engineer or two employed on cruise ships) will inevitably comment that the videos do not show engine gases but condensed water vapor from the scrubber operations.

My thought is that even if what we are seeing from the Symphony of the Seas is water vapor and not smoke, the ship is creating vast quantities of toxic sludge which is routinely discharged as waste water.

In an industry well known for taking environmental shortcuts to save money, Carnival and Royal Caribbean cannot be trusted not to dump the toxic sludge into the oceans.

Have a comment or question? Please leave one below or join the discussion on our Facebook page.

We suggest reading:

The Gurdian Thousands of Ships Could Dump Pollutants at Sea to Avoid Dirty Fuel Ban.

Bloomberg Businessweek Cruise Ship Companies Are Finding It Hard to Quit Carbon.

September 29, 2019 Update: The Independent Thousands of Ships Fitted with ‘Cheat Devices’ to Divert Poisonous Pollution Into Sea. 

Video and photo credit:

Video of Carnival Victory – PTZtv; photo of scrubber sludge – City of Ketchikan, Alaska; video of Symphony of the Seas – Red Oaks YouTube.