Mary Wilcox Silver, a native of San Francisco, is a professor in the Ocean Sciences Department@the University of California, Santa Cruz. She has mostly worked on the microbial communities that live on floating "marine snow" and studied how these ubiquitous particles transport materials into the ocean's deep interior. In the past decade she also has become interested in the role of toxic microalgae in coastal oceans, and especially how the toxins may be permeating marine ecosystems, affecting animals living both in the water and on the seafloor. This article is adapted from the Winter 2006 Synergy Lecture@UCSC. Address: Ocean Sciences Department, University of California, Santa Cruz, CA 95064. Internet: msilver@ucsc.edu