Ugh. Fine. I'll do the math FOR you.
Level 1 Nautilus has 576 Health base. 7% of that is 40.32
Which means his shield at level 1 is now 65+40=105. HMM. LOOKS LIKE A BIGGER NUMBER TO ME, COTTON.
The shield at level 1 will be bigger unless you have more than 62.5 bonus health. At that point, 8% of it is 5 (15% old -7% new). You may be thinking "I can break that number easy with Runes and Masteries!" Yes, you can. However, Armor is definitely better for jungle survivability than Health, even on Nautilus. His shield still benefits from Armor, so it's still better to take Armor yellows.
Let's even grab math for level 9. At level 9, Naughty G has 1156 Health. 17% of that is 196.52. So, his level 9 shield is 85+196=281. That is indeed smaller. However, at this point, your benefit from health items is greater than it was before. To reach the old level 9 shield value of 300, we need 2% of your bonus health to be 19. So, you need 950 bonus health. That's quite a bit. However, as Nautilus will build a number of Health items over the course of a game, his shield will ultimately be bigger.