JupyterLab launching with multiple kernel sessions

I am launching from the terminal with “jupyter lab file.ipynb” or “jupyter lab” or launching from KDE Dolphin and I always have several “kernel sessions” open up. Is there a way to manage which ones will launch by default? It is annoying to shut them all down manually at each start up.

(I don’t know if it is relevant, but they’re julia kernels.)

Many thanks in advance!