This dataset contains outputs from two sets of simulations from an ocean-biogeochemistry (NEMO v.4.0.4 - ERSEM) model over the Sri Lanka region. In both simulations, the model is forced with ERA5 atmosphere, and a Nucleus for European Modelling of the Ocean (NEMO) dataset (ocean only, 3 year run) as lateral ocean boundary and initial conditions. Passive tracers (urea - organic nitrogen) are released from the region of the MV X-Press Pearl accident (approximately 7.0546N, 79.7589E). Both simulations last three months each. The outputs are stored in daily averaged grid-u, grid-v, grid-w, grid-t, and tracer variable files. For one set of these simulations, 1100T of passive tracers (urea, organic nitrogen compound) are released at different rates - over 1 day, 7 days, and 15 days. The start date of the release is 25/05/2021. These simulation start and end on: 01/05/2021 - 31/07/2021. In the other set of simulations, the release rate is over 1 day, but the date of the release is shifted from the 25th May to 25th of January, 25th February, 25th July, 25th September and 25th October (2021). These simulations start and end respectively on: 01/01/2021 - 31/03/2021; 01/02/2021 - 30/04/2021; 01/07/2021-31/09/2021; 01/09/21 - 30/11/2021; 01/10/2021 - 31/12/2021. The model configuration is named SRIL34. A complementary dataset with the hourly averaged release of tracers is also public. The outputs were generated under the Climate Linked Atlantic Sector Science (CLASS) and the South Asian Nitrogen Hub (SANH; NE/S009019/1) projects.