Hi Angela and thanks for your great picture and question about your marionberries. This looks like a case of scale, probably Lecanium scale, which is actually an insect that protects itself as an adult under a waxy coating, in this case a brown oblong bump. At this time of year, your best bet is to rub them off with a cloth or toothbrush so they don't lay eggs and repeat the cycle next year.

This article explains more about them but pay particular attention to the "Management/Cultural Control" section for other things you can do now. Because of the waxy coating, spraying does not have much effect and there are some predators that may move in to help control the outbreak, but you may not have much of a berry crop this year. 

https://pnwhandbooks.org/insect/hort/landscape/common/landscape-scale-insect

Good luck,