Neglecting smaller polluters

By Jan TenBruggencate
Advertiser Staff Writer

We've done a good job in removing the big, visible polluters of our ocean waters, like sewage outfalls and industrial discharges, but we have missed smaller polluters, whose role has been growing.

It's like fighting off the big sharks and not noticing the schooling piranhas.

The Pew Oceans Commission in April issued the first of its reports on the condition of the oceans, and it dealt with marine pollution. The commission held hearings in the Islands, and although Hawai'i was not featured in the report, its findings on a national basis hold true for Hawai'i.

The problem is that many of the smaller sources of pollution add up to a huge toxic load for the sea to bear.

Regulators refer to this as nonpoint source pollution. The Pew commission calls it "hard-to-control, diffuse sources."

Despite curbs during the last three decades on significant pollution from ocean dumping, sewage, industrial sources and the most toxic substances, Pew said "inputs of pollutants from diffuse sources — including land runoff — were largely unabated or actually increased during the same 30 years. Diffuse sources now contribute more than direct discharges."

Some of these issues are well known to Island residents.

When the ocean near shore turns brown after a rain, that's it. Soil running off eroded hillsides, agricultural fields and open construction sites is hazardous to the health of the reefs.

When rain washes nitrogen off fertilized lawns, farms and golf courses, that's it.

"Overenrichment by plant nutrients, particularly nitrogen, has emerged as the most pervasive pollution risk for living resources and biodiversity in coastal ocean ecosystems," Pew said.

When there is a sheen on the water running into the storm drain, which dumps into a streambed and eventually into the ocean, that's it. A blend of spilled oil, industrial chemicals, automotive repair fluids, landscaping pesticides and the like flows down our city streets to the sea when it rains.

"It is clear that toxic contaminants chronically affect marine organisms at least over limited, but widely distributed areas in U.S. coastal waters near heavily populated areas," Pew said.

The solution is also evident in Hawai'i, although it's just getting started. Pew said "reversing and controlling diffuse sources of pollution, including nutrients, requires an integrated approach on the scale of an entire drainage basin."

Some in the Islands call it an ahupua'a approach: Taking care of your own back yard.

Learn about the Pew Oceans Commission at www.pewoceans.org.

Jan TenBruggencate is The Advertiser's Kaua'i bureau chief and its science and environment writer. You can call him at (808) 245-3074 or e-mail jant@honoluluadvertiser.com.