Sewage effluent, the water that passes through municipal wastewater treatment, and urban runoff, the water than collects off of paved surfaces and flows through municipal sewers, represent two of the largest forms pollution that human beings introduce into the marine environment. Earlier in 2011, I published research that indicates both sewage effluent and urban runoff were limiting the ability of sea stars in Southern California to exchange larvae between populations. This reduction of larval exchange limits gene flow between populations and makes them effectively smaller and more vulnerable to extinction. This summer, I travelled to New South Wales (NSW) Australia to further test this hypothesis. The coastline of NSW and the wastewater disposal system of Sydney Water offers a unique opportunity to investigate the specific influence of sewage effluent on marine populations. Sydney Water has five major wastewater treatment facilities for the greater Sydney area that serve an estimated 3.19 million people and discharge and estimated 992 million liters of wastewater into the Tasman sea every day. Additionally, the oceanography of this area is much simpler than Southern California, with a predominant North to South current that flows along a largely linear coastline. This coastline is also ripe with rocky intertidal habitat with dense populations of a related sea star species to my previous study. This provides an excellent natural laboratory to specifically investigate the role of wastewater in limiting larval exchange. To accomplish this, I spent the majority of my EAPSI fellowship in the intertidal of NSW. I collected over 600 tissues samples (one sample = one individual sampled) across 10 different sites that bracket every major sewage outfall of NSW (See Map). This fieldwork covered over 50 km of coastline and was accomplished in the most environmentally friendly way possible. I accomplished ~90% of this field research via bicycle or public transportation. When a car was necessary, I carpooled with other students in my lab and exchanged help with their fieldwork for a ride. I collect a small, non-lethal tissue biopsy from each of the sea stars and quickly return them to the location that they were found. These wounds quickly heal and regenerate completely. Samples were labeled, preserved, and transported back to my lab at the Hawaii Institute of Marine Biology. Unfortunately, my lab underwent a 10 week renovation shortly after my return from Australia and only reopened on Nov 14. Because of this, most of the genetic work for the project is still on going, but should be completed by this spring.