The Surfrider Foundation dedicated to cleaner oceans has a website with lots of great tips for landscaping to keep storm water run-off from washing into the oceans, alternatives to lawns, great household fertilizers (human hair can be used!), as well as plants that naturally repel insects so that pesticides aren't needed.
From their website, .
CPR stands for Conservation, Permeability, and Retention, and when fully employed, it has one of two outcomes: Water run-off is either eliminated or cleaned.
Gardeners greatly affect the ocean, and we do so in two distinct ways. First, we influence the amount of water running off a landscape. Between 30% and 80% of an urban/suburban homesite is comprised of impermeable surfaces, and besides the roof, most of this area can be changed. And second we influence the quality of water running off our properties and landscapes. Rain falling into an ocean is not inherently harmful, it is the stuff attached to it that is. Fertilizers, pesticides, oils, cleaning solutions, and organic debris all runs off our landscapes during rain. These chemicals and organic substances are the culprits that encourage harmful algae and bacteria.