How can I find articles on pollution of oceans by trash?
Yes, there are more, a lot more. One search tip I can give you is to be flexible withe your search term. I tried the same search term you did, pollution of oceans by trash and also got almost no results. But then I experimented withe the terms. I tired oceans pollution trash. I got more, but I felt I could still get better results. Then I tried oceans AND trash and I got good results. Sometimes you just have to experiment a little.
To narrow down after you get a good list of results, see the tips in our How To Use EBSCO LibGuide (link below).