Dreams about fish are generally considered a positive sign, so if there were many fish to catch, this can denote profits and pleasures to come.
If you were catching fish from a river or lake, it could mean that you will experience some obstacles at work that are created by someone senior to you.
If the fish you caught died quickly, or they were already dead in the water, this is thought to be linked to sadness, loneliness and hopelessness.
Another thought process is that you are finally bringing your feelings to the surface and have a better understanding of them. However if you put the fish back in the water after catching them then perhaps you feel uncomfortable that you've opened up to someone lately or don't want to deal with the emotions you have realised.
If you caught a fish, this could also mean that you have a firmer grasp on an idea and are now able to move it forward.
The fish could be about your ability to embrace or immerse yourself in your feelings and carry on regardless. Perhaps you are open and honest with yourself about your reactions to situations and your feelings surrounding certain things. You may not get bogged down by the meanings of it all and simply go with the flow.
One final viewpoint is that small fish are representative of semen and reproduction. If you have been talking about starting a family with your partner- the fish can be interpreted as sperm and your desire for offpsring.
The Complete A-Z Dictionary of Dreams by Ian Wallace.