Board Thread:Questions and Answers/@comment-24439089-20140119020839

And if you ask why because Isshin Shiba(kurosaki)'s shikai release was Burn, Engetsu which does heavily imply him as Fire not to mention that ability he used with his blood when fighting against the hollow (chapter 532).

Then we have Kaien Shiba and his water element-type Zanpakuto so he would be Water.

Next we got Ganju who is Earth from his turning things to sand ability this description taken from his own page it is what seppa is derived from--->(Earth Magic: Ganju's earth magic doesn't seem to operate on the same principal as standard Shinigami Kidō, as it is used without incantation and is unnumbered.)

Finally we have Kūkaku Shiba who used a level 63. Hado spell which happened to be lightning based the Raikoho so she must fall into the lightning category.

personally i find this very interesting despite its irrelevance to the story i like the depth it gives to the Shiba clan that is if it was purposefully plotted by Kubo. But still I'd liked to know others opinions not to mention it would pretty cool if it was true (though i truly couldn't care to its relevance in the story). not to mention the elements really compliment each of the character well. And what could Ichigo's element be? 