making an uno with ethernetshield and sd-datalogger as a slave


I have an arduino uno with ethernetshield, running a webserver and a datalogger from the sd-card.
What I want to do is making this uno a slave and connect it with a mega2560 ‘master’ using I2C.

Is this possible or does ISP, used for the sd-card, conflict with I2C, used for the master-slave connection?