Plankton fills an essential niche in Earth’s food chain and a vital role in the health of the planetary ecosystem. For several decades, however, a growing level of human impact on the biosphere has been increasingly modifying the age-old equilibrium of marine plankton. This program examines the broad implications of three major concerns: how the inadvertent transfer of invasive plankton species via ship ballast is negatively altering the biodiversity of plankton; how agricultural runoff and other pollutants are affecting plankton populations; and how rising sea temperatures due to global warming are facilitating the proliferation of toxic plankton species. Not available in French-speaking Canada. (52 minutes)