Trophic connections between ecosystems are key to understanding food webs and predicting their responses to a changing environment. The overall focus of this interdisciplinary study is quantification of trophic connectivity between the highly productive giant kelp forest (Macrocystis pyrifera; donor ecosystem) and the practically non-productive sandy beach (recipient ecosystem). Kelp forests export large amounts of drift kelp to sandy beaches. This beached kelp is necessary and sufficient fuel for a diverse and productive intertidal food web. The coastal ocean circulation, through its transport of kelp from forest to shoreline, is key to the health of sandy beach ecosystems. The transport of drift kelp from coastal ocean kelp forests to sandy beaches is being investigated in Southern California as part of the larger ecosystem study. Nearly 2000 kelp plants attached to the ocean floor were tagged with drift cards over a two-year period. The distribution of beached drift cards (tagged kelp plants) quantifies the connectivity between kelp forests and sandy beaches. A smaller set of kelp plants was tagged with GPS devices to quantify transport pathways (and transport times) from forests. GPS tracking allows trajectories of non-beaching plants to be quantified. Finally, transport pathways from kelp forests are quantified with trajectories computed from ocean circulation model results. Drift cards, GPS tracking and model trajectories all indicate that only about 25% of kelp plants removed from a forest land on beaches. The majority of kelp plants (~75%) move into open ocean waters where they presumably decay and sink. High levels of variability in loss of tag kelp plants and kelp delivery to beaches are observed. First, there is a strong seasonal cycle in kelp removal from forests and deposition on beaches, with the majority of plants leaving forests during the winter months when surface gravity wave energy is largest. Second, the spatial distribution of beached kelp depends on the location of a forest relative to a curved coastline. Transport is directly shoreward from one forest. For another forest, initial transport is alongshore with subsequent deposition most often in the lee of headlands. The majority of kelp plants beach within ~5 km of their source forests. However, tagged kelp plants are observed to beach more than 100 km from their forests in both the upcoast and downcoast directions. The addition of Stokes drift to ROMS surface current solutions gives a significant improvement in kelp-transport compared with observations.