Orpheus Island in closing

Well, Dr. Allen and I leave Orpheus Island in two days. This trip has been extremely fast!


We finally figured out how to culture the crown-of-thorns larvae. It turns out our larvae were dying from copper toxicity. The freshwater here runs through copper pipes, so when we wash our glassware in the freshwater and place larvae in it, they die.

Since we figured that out, we’ve been experimenting non-stop. We ran several trials of an egg age experiment. We were interested in how egg age affects development, so we were fertilizing eggs at different time points and scoring fertilization and developmental abnormalities. Yesterday we set up a cloning experiment. We put larvae of low, medium, or high densities into shot glasses. Some shot glasses received high food, others low food. Then today we counted the number of clones in the cultures. Our results indicate that food is more important in inducing larval cloning than density is. Larvae receiving high food and those at high densities clone more frequently.

In the last post I talked about the hypothesis regarding why so many COTS are showing up on the reef. The idea is that nutrients from agriculture fields is running off into the ocean. Those nutrients cause algal blooms, and given COTS larvae eat algae, they thrive. Our cloning results further support this hypothesis and demonstrates something no one has considered before–COTS larvae aren’t just surviving, they’re multiplying!

Yesterday we took a trip to the outer part of the Great Barrier Reef. I was astounded by how beautiful it was! There was a wall of coral, going down about 30 feet. Reef fish, sting rays, sharks, crinoids everywhere! Our main objective was to collect more COTS adults, so our collaborators can send them back to the University of Sydney. It was hard because I was getting so distracted by everything else. The only bad thing about the trip was that it was really choppy out on the water, so half of us came down with some intense sea sickness.

Tomorrow is our last day on the island, and I’m trying to come up with a way to hide in the trees so they forget to take me back to the mainland on Thursday. Our time in Australia has been exhausting but we’ve learned a lot and collected tons of data. I’m looking forward to my next trip here!