How might trawling affect marine biodiversity?

It decreases biodiversity by harvesting everything in its path, so that unwanted fish are unnecessarily killed.

Explanation:

Trawling is the method of fishing with the help of using a trawl net which is pulled by a boat. This method of fishing traps everything that comes in its path.

While marine biodiversity refers to the number of different species present in a particular ecosystem.

Since trawling catches everything which comes in its path so a lot of unwanted species also get caught, thus affecting the marine biodiversity.

i think its the first one