Well today’s big event was a post-mortem investigation of a fish, well I guess it was pre-mortem until we killed the fish. Anyway, first we examined to fish’s exterior; we looked at the gills, skin, eyes, and fins. We make sure that the eyes were not bulging out or retracted into the skull. I also looked for bloody spots on the skin, a sure sign of infection.
Next we cut a big hole in the side of fish so we could see the guts. We checked to make sure everything was the correct size and color. I also saw the little heart of the fish still beating. I was poking around when I accidentally ripped the spleen open. The spleen was full of nasty green liquid which got all over my sleeve. I asked the teacher to show me where the pituitary gland of the Tilapia was, I had only seen it in a Catfish. PETA would not have appreciated my activities over the last few days, I dissected a fish just to see what was inside, and performed minor surgery for practice. While yes, they were under anesthesia it was obvious they could still feel what was going on. Almost makes me feel bad for them. Then again, their sole purpose to exist is to die so I can eat them.
After taking a group picture with the other students from the international group I worked with Tim. We walked out to the six ponds Tim is using to experiment with different stocking densities of Tilapia. Periodically throughout the week he measures pH, dissolved oxygen, nitrate, nitrite, alkalinity, temperature, hardness, phosphorus, ammonium, and mortalities. Today we measured dissolved oxygen and temperature levels of the six ponds.
Dad told me a while ago that algae in the ocean is a major contributor to the creation of global oxygen. I also learned in my marine bio class that while algae is found in every ocean around the world, sometimes it is very densely concentrated. This is known as an algae bloom. When the conditions are just right there can be an explosion of algae growth; this creates vast amounts of oxygen and sequesters large amounts of CO2 on the bottom of the ocean. I wanted to see this in the real world so when I noticed that a corner of a pond had turned dark green from an algae bloom I had to investigate. Most of the ponds we tested had a dissolved oxygen level of about 12 (ppm I assume), The algae bloom area had a dissolved oxygen level of 19ppm. That is a 58 percent increase in dissolved oxygen caused by the concentration of algae.
Today’s movie is Gladiator! Ave, Morituri te Salutant! I wonder if this is what the fish thought as they saw their impending death.
1 comment:
Now he's operating on fish with anesthesia?! Post a photo of that and the algae bloom. Speaking of blooms, there is a giant one in China right now where the Olympic boating events are to be held and they're having a heck of a time getting it cleared. Check it out, and keep the great blog entries coming'.
Happy 4th of July,
UC
Post a Comment