Well, they say smoking reduces the volume, as does age. Also, if you are having a lot of sex, that could affect it. But there may also be a blockage somewhere so if none of these factors apply, then I would check with a urologist.

should i see a urologist or endocrinologist for this ?

when i was younger i used to masturabate frequently. that is when i noticed the decrease in fluid. something just seems very unnatural when very little is released.

I did a quick check round google and it seems it is a urology problem, as the semen could be going back down the tube towards the bladder, though why I am not sure.

There is a posting already on this site about it, though both the question and the Doctor's response are a little scary!

http://This link has been removed/forums/urology/messages/30804.html

But if you google 'low ejaculate volume' you will get lots of returns.

Good luck.