Dr. Décima's interests include zooplankton ecology, marine pelagic food-webs, gelatinous zooplankton, and carbon and nutrient cycling. The Décima lab is currently focusing on:

• Quantifying trophic pathways within the lower pelagic food-web using experiments, stable isotopes, pigment-based estimates, and modelling approaches.
• Understanding the effects of crustacean zooplankton  on the marine food-web and carbon export.
• Understanding the role of pelagic tunicates, primarily salps and pyrosomes, in marine food-webs and their effects on biogeochemistry.
• Assessing the effects of warming and acidification on marine plankton assemblages.
• Understanding the effects of wildfires on marine pelagic biological communities.

These research areas are investigated in various regions of the world, including: the California Current, the Southwest Pacific, the Ross Sea, the Indian Ocean, the North Pacific Subtropical Gyre, and the Eastern Equatorial Pacific.

Dr. Décima is also the curator of the Scripps Institution of Oceanography Pelagic Invertebrate Collection (SIO- PIC), one of the largest and most comprehensive collections of pelagic invertebrates in the world.