The Madang Lagoon on the north coast of PNG holds 11% of the world's reef fish species and is an important biodiversity site. But the populations who live there are suffering from poverty due, in part, to rapid population growth and declining natural resources. Locally managed conservation projects have helped to increase dwindling fish stock but the increases are largely of algae-eating fish because the water quality in the lagoon has been altered by upstream activities and a coastal fish cannery. High levels of coliform bacteria entering the lagoon through rivers indicate that the people upstream have practices that are polluting their streams. The fish factory hires young women from all the nearby villages, but never makes their jobs secure, keeping them on a temporary basis and vulnerable to advances from the men, some of whom offer the young women a tin of fish as the price for sex. As HIV spreads in PNG, environmental degradation and increasingly poor families drive young women into selling sex for commodities and cash. HIV/AIDS programs are essential at such workplaces, but addressing the water pollution as well as the population growth and conservation management is a better, more sustainable solution than only to offer condoms and information.