Can Paritcle Effects Cause Lag?

So I have spent the last couple of hours searching for an answer related to this, and I couldn't find anything straight forward. If there is a topic similar with a solution, please feel fee to point me in its direction.

I just finished making a waterfall on my mountain scene and I have to say, I am impressed with myself! Now, the thing is, I noticed that I had to use many of the same particle effects over and over and have them overlap in certain spots to make it look more natural. Over time with doing this, I would jump in and test it with the 1st person controller to see how it would look, and everything was fine.

Once I finished the scene itself, I hopped in one last time to do a play test and I noticed that there was some lag when I would look in the direction of the waterfall, but I wouldn't experience this lag when I looked anywhere else. Can having a lot of particle effects in one area cause this? If so, I can go back and see what I can do to reduce the amount of them I had to use to achieve the look I desired.

One source suggested I adjust the clipping planes on the main camera, but that did nothing, and seemed a bit irrelevant considering the camera I see through is on the first person controller.

Any suggestions would be appreciated. It is a bit annoying have to deal with the lag after finally achieving this nice little waterfall look :)