Before East Honolulu was paved over to build houses, stormwater runoff from the Ko'olau mountains would be absorbed by marshlands before reaching the ocean. Now much of that water, falling on pavement and channeled by concrete storm drains and hardened stream beds, runs directly into Maunalua Bay. Along the way, that water picks up the detritus of civilization — fertilizer, pesticides, rubbish. The result: tons of silt and pollutants settling on the fragile coral reefs.

It's a problem that's not confined to developed areas. On Moloka'i, feral goats have denuded hillsides, exposing soil that rainfall washes downhill into the ocean on the leeward side of the island. As Advertiser reporter Rob Perez describes in today's paper, the results can be devastating. Tons of silt and pollutants settle on the reef flats, smothering corals and crippling a fragile ecosystem upon which marine life, and our economy, rely.

Controlling a problem that begins in the mountains and ends in the ocean is not easy. Disparate and often conflicting interests are at play. The need to protect homes from flooding, or to allow subsistence hunting, are legitimate concerns. But the state's environmental and economic health depends on protecting both the land and sea — something Hawaiians of old understood when creating the ahupua'a system.

The answers to curbing nearshore pollution require more than the rules already on the books. Mother Nature won't observe them. The effort can begin close to home, with a concerted public education effort, so the next generation of Hawai'i residents will understand and more readily adopt a more sustainable lifestyle. It can be as simple as a homeowner recycling rainwater. Wendy Wiltse, an Environmental Protection Agency official on O'ahu, redirects rainwater to a garden instead of her driveway. And keeping home-use fertilizer and pesticides from entering storm drains should be a basic habit.

But broader solutions require cooperation and coordinated efforts among public and private agencies, landowners and interest groups united in a common purpose: to redirect and absorb stormwater before it reaches the sea. These efforts cross jurisdictional lines. Reforestation of denuded hillsides, changing agricultural practices and improving county planning and zoning rules can all contribute to reducing nearshore pollution — but only if the different agencies responsible for them work together. Leadership, beginning at the top, can set the agenda. The offices of the governor and county mayors should work together to make nearshore pollution a priority for the agencies they control.

The land above particularly at-risk reefs — those that are still pristine, and those in sheltered areas with poor circulation — deserve closer attention, and perhaps, tighter regulations on how the land is used.

Community groups, such as Malama Maunalua, can help develop comprehensive plans that have crucial buy-in from local residents and provide a clear, sensible guide for policymakers to follow.

In the end, it will take a broad effort from all stakeholders — that's all of us — to protect our nearshore reefs and aquatic life from crippling pollution. The result will be a priceless legacy to hand down to our children and grandchildren.