A couple days ago, I found the majority of my fish belly up. Not a good sight to see. My first call was to our friend Fred S. Conte Ph.D. Extension Aquaculture Specialist at University of California, Davis. He knows just about everything and everybody in the fish world and is a pretty neat guy to have in the aquaponics industry. Since almost all of the fish died at once, he figured it might not be a pathogen. Perhaps something mechanical?

Just after our conversation, I determined that the diaphragm in the air pump failed and there was no aeration in the fish tanks. They all died of suffocation. An incredible bummer, but a great opportunity to investigate a couple of things. First, after knowing it was a mechanical issue, it would be a really good idea to look into battery back up systems for the air pumps and water pump so something like this doesn’t happen again. Although, in this case, a simple battery back up would not have prevented the fishkill from happening since the pump motor was running just fine. As I mentioned above, it was the diaphragm that pushes the air through the tubes that failed. Adding a pressure switch to the battery back up would probably do the trick. I’ll let you know what we build.

Secondly, if this fish kill happened to be a pathogen, what would be the protocol to send them to a pathologist? Fred introduced me to Esteban Soto, MSc, DVM, PhD, Dipl. ACVM, CertAqV, Associate Professor of Aquatic Animal Health, Department of Medicine & Epidemiology, School of Veterinary Medicine, UC Davis. I’m excited to work with Esteban to see if we can develop a protocol for aquaponicists in our region to send their fish to the lab for a diagnosis.

So what happened to the fish?

As much as I would’ve liked to have kept them in our little loop, we had to act fast and I don’t have enough freezer space for 400 lbs of fish! Mostly, because the freezer space I do have is occupied by frozen crickets. So we had to take them to the neighboring farm where they will be consumed by their chickens.

Ideally, we would’ve been able to keep the fish to dry and grind them to make our own fish meal or even feed some of them to soldier fly larvae. The black soldier fly larvae project got put on hold due to the crickets taking up a good portion of my time, but it is going get restarted very soon now that I have the crickets going full swing. They would’ve loved the fish! My hope is to get a grinder soon so that I can grind a whole bunch of different things to make feed. That’s all part of the master plan. Until then, I’m grinding by hand. Just not 400 lbs of fish by hand. 🙂

Now I gotta get some new fish!