metal piece connecting pickup and bridge in Fender azz bass

Hello.

I am wondering what is the functionality of a metal piece (copper?) connecting between the bridge-side pickup and the bridge in certain models of Fender Jazz bass. For example, the following photos of the Jaco Pastorius model clearly shows this metal piece.
http://www.fender.com/products/prod_images/basses/0196208800_xl.jpg

Thanks!

 

Dear moomoocajoo and Swlabr,
Thanks a lot for your quick reply!

Then, I have another question.

> It grounds the brigde/strings. Have you ever noticed when you touch the > strings you get a reduction in amp buzz? If the strings weren't grounded, > that buzz would stay.

The Fendar Jaco Pastorius model in fact comes with the detached metal bar for ground as an option to install it by yourself. On the other hand, I think the strings are grounded because one gets a reduction in amp buzz when the strings are touched. This implies that this optional metal ground bar is included just for cosmetic reason at least for the Jaco Pastorius model?

Thanks!