This dataset uses the PyLag particle tracking model to simulate the ecological connectivity of benthic species in the northern North Sea during two contrasting years (2014 and 2017) to highlight seasonal to annual variability. The particles were released each day and run for 90 days. In the Retrospective Particle Tracks dataset a methodology of releasing an extensive set of particles over a wide area was used. This means the sets of particle tracks can be interrogated to understand connectivity between any two locations in the domain. This could be useful to understand if new human-made structures placed in any locations in the northern North Sea could potentially affect the ecological connectivity or different species with a maturity window up to 90 days. The particle tracks include location, time, age and water temperature. The data were generated under the Natural Environment Research Council (NERC) project CHASANS (Connectivity of Hard Substrate Assemblages in the North Sea) grant reference: NE/T010886/1.