Number 12
November 5, 1997

Link to NJ Fishing Consumer Alert page Link to NJ Fishing Consumer Alert page

[Link to OBM Impacts review articleLink to a more detailed OBM Impacts review article]
Boating impacts - Just fun on the water?

Outboard motor imageIn the 1963 article "Pollutional Effects of Outboard Motor Exhausts - Laboratory Studies" published in the Journal of the Water Pollution Control Federation, a water body was considered to be at an  "extreme critical" boating level, one showing  significant toxic effects on fish life, if the boats on it burned 18 gallons of fuel per acre-foot of water (about a third of a million gallons) per year.

Eleven years later in a study funded by the U.S. Environmental Protection Agency and contracted to the recreational boating industry titled "Analysis of Pollution from Marine Engines and Effects on Environment" the saturation boating use level determined for Lake Geneva, Wisconsin was reached when boating fuel use reached 15 gallons/acre-foot/year.

Today in Barnegat Bay, a typical Mid-Atlantic estuary in New Jersey, the calculated recreational boating fuel use is 50 gallons/acre-foot/year. This is at least a threefold increase over what were considered maximum levels of boating two decades ago. If the fuel efficiency of outboard motors has improved significantly in this period, the levels are even higher than the fuel use per acre-foot would indicate. Levels of recreational boating that were unthinkable a few years ago are now accepted as being normal and, considering the dearth of research on the impacts, evidently considered of little or no environmental consequence.

“You’ve been waiting all week to get out on the water. Now you’re idling until you’re out of the marina. In just a few minutes you’ll be able to slam down the throttle. To release your troubles in a single blast. To experience Mercury power - undaunted….More speed. More power. No worries....” (Link to Mercury Marine's siteFrom Mercury Marine’s website)


In Polluting for Pleasure (W.W. Norton & Company, 1993) author Andre Mele states that in a technical paper prepared for the Society of Automotive Engineers two outboard motor industry employees report "...a 70 horsepower outboard spews out 1,529 grams (3.37 pounds, or slightly more than half a gallon) of unburned hydrocarbons per average hour, based on the University of Wisconsin's duty-cycle studies". He then speculates on the fuel use of such a motor and concludes that, assuming it is 5 to 6 gallons an hour, " the very least 1/12th, or 8.3 percent, of supplied fuel and lubricating oil is blown out unburned."

Mele then discusses an EPA report that concludes "...two-stroke outboard motors pass fully 25 percent of their total hydrocarbon intake, fuel and lubricating oil, out the tailpipe and into the environment."  The E.P.A. has also reported that in one hour an outboard powered boat emits, on the average, as many pollutants as an automobile does in 700 miles of driving.

A high-performance hybrid...produces an adrenaline-pumping 803 pounds of thrust to blow the runabout performance envelope to shreds. (from the Kawasaki Personal Watercraft website Link to Kawasaki site)

From another perspective, at a normal cruising speed of 30 mph the blades of the 14" diameter propeller of an outboard or inboard/outboardpowered boat passes directly through 150,000 cubic feet, roughly a million gallons, of water during every hour of operation. A typical generating station pumps a million gallons of water a minute, sixty boat’s worth, for condenser cooling. The hydraulic forces generated are comparable. If you've ever observed the turbulence from an outboard motor's propeller at speed (at 2500 rpm, a point on a 14" propeller's periphery is slicing through the water - and anything else it encounters - at over 100 miles per hour), you can imagine the devastating impact it must have on the delicate, slowly swimming organisms that hatch and mature in our estuaries.

Based on an annual average of 40 hours of cruising, the 10 million outboard and inboard/outboard powered pleasure boats in use in the U.S. impact as much water - and the fragile eggs, larval and juvenile fish and shellfish living in it - as 800 base load nuclear and fossil fueled generating stations would in a year, but the boating activity is concentrated in a short boating season which is also the time of maximum biological activity in our estuaries.

To bring this closer to home, in 1990 there were 158,000 power boats registered in New Jersey. Of these, 92,000 used outboard motors (with a median size of 60 horsepower). There are approximately 20,000 boat slips and racks, most of them occupied by outboard powered boats, on Barnegat Bay, one of New Jersey's largest and most heavily used estuaries. If it takes only 60 of these boats to impact as much Barnegat Bay water, and the rich estuarine life contained in it, as the Oyster Creek nuclear generating station uses for condenser cooling over an equivalent time period, what is the combined impact of all of them? Upwards of 30 million gallons of fuel are used by New Jersey pleasure boaters every year, about 20 million by boats powered by outboard motors. The residue from this fuel, estimated by author Mele to be 8% to 25% of the total amount used, is injected directly into the water column in these estuaries, and has been for several decades. It appears as if outboard motors might well be adding one Exxon Valdez equivalent of hydrocarbons to New Jersey's coastal waters every two to six years.

What are the implications of this? Billions of dollars have been and are continuing to be spent on protecting our estuaries and the fish and shellfish in them from the impacts of generating stations. Ditto to control non-point source pollution. Each and every citizen has been paying for this, and what has been the result? In the past ten years production in many of our estuarine-dependent fisheries has steadily declined, and the number of recreational boats has increased just as steadily.

Most importantly, who's doing anything about it? So far, surprisingly, no one. Perhaps because of the influence of recreational boating interests, perhaps because of their importance to the coastal economy, perhaps because public utilities are better targets for “environmental activists” than the average suburban family out for a day of fun at the shore, or perhaps because of some blatant public funding conflicts (see box on left), this issue has been almost completely ignored by the people, the agencies and the organizations with a supposed interest in preserving the ecological integrity of our estuaries for over a decade.

Outboard motors used recreationally last for decades. Fiberglass boats are virtually indestructible. Every year we are adding significantly to what might very well be an environmental catastrophe in the making.

Emissions standards for outboard motors were put in place several years ago. According to Earth Island Institute “These rules will accelerate the introduction of alternative cleaner outboard engine configurations (four-stroke engines, direct-injection two-strokes and engines with catalytic converters) starting in model year 1998, reducing the average HC emissions of new motors by 75% by 2006, after an absurdly lengthy eight-year phase-in. The regulations will be implemented through a system of tradable emission credits among manufacturers. However, the final rulemaking is highly favorable to industry and fails to sufficiently protect the marine environment from petrochemical discharges. While manufacturers had anticipated a complete ban on the sale of new carbureted two-strokes, the regulations instead effectively sanctioned their continued sale through the averaging provision. As a result, up to 15% of all new marine engines will be completely uncontrolled. In addition, there are no plans to institute a retirement or buy-back program for the 12 million carbureted two-stroke motors already in use. As a consequence, these motors will continue to pollute for up to thirty years, the average life of a motor.” (From Earth Island Institute’s website Link to Earth Island Institute site)

New Jersey FishNet is supported by the Cape May Seafood Producer’s Association, The Family and Friends of Commercial Fishermen, the Fishermen’s Dock Cooperative, Lund’s Fishery, the National Fisheries Institute and Viking Village Dock