Mark and Diane Littler are marine scientists who have developed a unique husband and wife collaborative relationship. Diane is a Senior Research Scientist at Harbor Branch Oceanographic Institution and a Research Associate at the Smithsonian Institution. Mark is a Senior Scientist at the Smithsonian Institution. The team is best known for their investigations of coral-reef plant life. Their research has taken them around the globe, including field work in the Mediterranean, South Pacific, Galapagos Islands , Indian Ocean, and Caribbean Sea. Diane and Mark each have over 30 years of research experience on coral reefs resulting in more than 180 papers and books published in a wide range of disciplines. The Littlers' current research focus consists of: relative dominance theory, functional morphology, and complex top-down vs. bottom-up interactions on coral-reef systems. Other active research includes: monographic and phylogenetic systematics; seaweed experimental taxonomy; biodiversity, ecology, and conservation of tropical marine ecosystems.