If you blank you still get 5 points for attendance, hence Tom has 5 points from only fishing 1 match and blanking.
Seventh at Deganwy would earn you 29 points, plus 1 point per species, which i would assume was just 1.
Thats 35 points to drop from 210 leaving you 175, which would put you in provisional 2nd, assuming all the other scores are correct.
It will all change again over the next 3 matches.
Thats what you get for rushing him