This is hard to say. Sharks are very sensitive to changes in the local magnetic
field. You have probably seen the footage of sharks attacking metal cages because
they disturb the magnetic field.
In the early days of seismometry, magnetometers were used in much the same
way we use seismometers today. They recorded a magnetic disturbance at the
time that waves passed through a region. Could it be that the sharks are
picking up on these disturbances - I don't know. Anybody out there an expert
on sharks??

The attacks have occurred in waters off Virginia Beach which is 105 degrees from
the PAR event. Seismic waves are concentrated in this area. The coincidence
is interesting, but a lot more data would be needed to make any kind of
determination.