Landfast ice is sea ice that is attached to the coastline via its tensile strength, grounding to the ocean floor from pressure ridges in the Stamukhi region, or anchoring on offshore islands. Fast ice is a platform used by local communities for hunting, traveling and a place for oil and gas drilling and scientific observation. Previous work shows that adding tensile strength to sea ice in regions of shallow bathymetry in order to simulate represent landfast ice in models improves the simulation of the halocline and thermohaline circulation by changing the location of new ice formation and brine rejection at the edge of landfast ice in coastal polynya. However, the impact of fast ice presence or absence in coastal regions with deeper bathymetry (e.g. Kara Sea) on the Arctic hydrography remains unknown. In this contribution, we compare the simulated hydrography in the full Arctic with and without landfast ice parameterization that allows for a landfast ice cover in deep coastal region through lateral anchoring with land --- something not resolved in coarse ice-ocean models. Results show a fresher upper ocean signal when landfast ice is present --- because of the isolating effect of stable ice cover --- that is advected eastward from the Kara Sea to the Makarov Basin (north of the Laptev Sea) via Vilkitsky Strait, suggesting a proper landfast ice simulation in the Kara Sea influences the hydrography in the Arctic and the circulation of Atlantic and Pacific water below the halocline.