Dear Editor,

Roland Seguin's comment [Nature leaks more than pipelines, Aug. 2 Letters, Langley Advance] is demonstrative of an emerging trend on the part of the proponents of increased oil exports through B.C. to frame examples of existing occurrences of oil in nature as an argument in favour of their cause.

His "radical hair-on-fire eco-saviours" reference to those on the other side of the argument from his does as little to prop up his argument as does his lack of understanding about the impact these naturally occurring phenomena have on the local ecosystems in which they exist.

The seeps and oil ponds he refers to have been around for thousands of years, that's true. What his argument fails to recognize is that, over time, the environment around them has adjusted to their presence by developing phenomena such as oil-eating enzymes that actually end up becoming a source of food for creatures higher up in the food chain. In essence, the seeps have become one with their environment.

On the other hand, if an oil pipeline crossing a salmon-bearing stream suddenly bursts and releases thousands or tens of thousands of gallons of crude oil into the waterway, or a tanker splits up and spills its entire cargo into a pristine oceanic environment, the impact would be devastating, simply because the ecosystem in which it happens has not evolved over time to deal with it.

I don't think most people have a difficult time agreeing with that logic.

Notably, this same type of argument used by Mr. Seguin was used recently in an article by Stephen Hume that appeared in the Vancouver Sun on July 27.

In his article, Mr. Hume made the statement that Metro Vancouver contributes, quote, "the equivalent of an Exxon Valdez (worth of oil) to the environment every two years." That comment formed the nexus of his argument, which is stated in the headline of his column: "Oily truth: Urban run-off a greater threat to ocean."

I work in the civil engineering field, dealing with urban runoff on a daily basis. When I did the math, I observed that what he was saying is that every man, woman, and child living in the Greater Vancouver region and Fraser Valley were contributing almost 2.5 gallons of oil to the urban runoff stream that finds its way into the waters of Georgia Straight.

That didn't seem reasonable to me, so I decided to look into the numbers that formed the basis of his argument.

A few Google searches brought me to the web page that quite obviously formed the basis of his argument (http://seawifs.gsfc.nasa.gov/OCEAN_PLANET/HTML/peril_oil_pollution.html/).

The information he used was extracted from an archived version of the script of "Ocean Planet," a 1995 Smithsonian Institution travelling exhibition. The disclaimer at the top of the web page read, "The content reflects the state of knowledge at the time of the exhibition, and has not been updated." Indeed.

A graph on the web page claims that 363 million gallons of oil finds its way into the world's oceans worldwide each year from urban runoff, and a hyperlink beside a written statement to that effect referenced a 1985 research article put out by the National Research Council as its source.

Another statement on the page - and this is the statement on which Stephen Hume bases his assertion that the equivalent of an Exxon Valdez spill occurs in the ocean surrounding Vancouver every two years - is that, "Every year oily runoff from a city of 5 million could contain as much oil as one tanker spill". Considering the population of the lower mainland at 2.3 million and a commonly accepted minimum spill of 11 million gallons that came from the Exxon Valdez, the math works out to about 2.5 gallons per year for each resident of the Vancouver regional district.

Oddly enough, the only statement on the web page that doesn't reference the National Research Council as its source was the one on which Mr. Hume based his argument. A mouse click on the reference hyperlink for that statement simply says, "footnote not available."

I can't speculate on the reason for this anomaly, but it was the thing that heightened my curiosity about the other numbers.

When I looked closer at the notion that 363 million gallons of oil finds its way into the world's oceans from urban runoff each year and compared it to the sum of the populations of the world's cities, I began to see why that footnote wasn't available. No one wanted to lay claim to the obviously flawed logic.

When you consider just the total population of the world's 100 most populous cities (722.5 million) and multiply it by 2.5 gallons per person, you come to 1.59 billion gallons. That's almost 4.5 times the 363 million gallons that the Smithsonian article claims enters the world's oceans each year.

Notably, Vancouver doesn't even come close to making that list - in fact, considering that the population of the 100th most populous city in the world (Naples at 3 million) is greater than the population of the entire lower mainland, it can be appreciated that there are in fact hundreds more cities on the planet that must be contributing an 'Exxon Valdez' worth of oil to the oceans every two years if you believe Mr. Hume's logic. In fact, with an estimated 70%of the world's population (some 4.9 billion people) living in urban areas of the planet, Mr. Hume's logic says that we should see about 12.5 billion gallons of oil from runoff in the world's oceans each year, not the 363 million number put forth by the Smithsonian article.

More importantly, when you look at the dilution of 363 million gallons (or even 12.5 billion, if you want to believe that number) of oil into the world's oceans, which contain some 1.3 billion cubic kilometres of water (1.3 x 1015 gallons - that's 13 followed by 14 zeros), it becomes apparent how insignificant urban runoff really is when compared to the devastation that would result from an Exxon Valdez sized spill in the Georgia Straight.

When a highly respected columnist of Stephen Hume's calibre can be duped into using a statistic with such dubious credibility to form the heart of an argument of such importance as the one he offers, it comes as no surprise that some believe, as Mr. Seguin does, that there is no difference between a catastrophic oil spill in a sensitive ecosystem and the oil that's already in the world's ecosystems. Such an argument just doesn't stand up to the tiniest modicum of scrutiny and is, by far, more radical than the opinion of those who see the very real danger in large oil spills.

Marshall Neuman, Langley