20 - 27 July 2022: ... the surprise was TRACKING nautiluses in Fiji for the first time! And when tracking starts, it is a grind because we don't just start tracking only, we continue doing everything else - nautilus surveys with traps, shrimp and crab surveys, planning, photography - and my updates always seem to fall off the list at this point. So, to sum up the last week of the expedition...
To track nautiluses, you first have to catch some nautiluses using our normal, meter cubed steel framed traps. Deploying them is the easy part. Retrieving them from 300 meters is the hard part. We have some good "tricks" to getting the trap up and keeping the nautiluses safe, but towards the end, it is just muscle power to pull it up and get it on the boat. All the while, HOPING that there is at least one nautilus in there to learn from and to place a transmitter on. Transmitters are attached to a positively buoyant "saddle" so that when it goes on the nautilus shell, it is neutrally buoyant and does not significantly impact their ability to regulate their own buoyancy.
We went out to retrieve our two traps, just as usual. They aren't too far outside of Suva Harbour and pretty easy for us to see with our GPS points. We passed by our first trap and didn't see it at first, but not too big of a deal, and went to the second trap first since it was further away. Pulled up the trap, after 45 minutes, and.... ONE nautilus. Bummer. But, one more than we had. We also pulled up some crab and shrimp. Placed everything in chilled seawater on the boat and headed to find the other trap. For some reason, a large flag was added to this trap's buoy, to make it easier for us to see in the big waves and swells. We searched and searched and searched, but nothing. Had to make the call to go back to the dock, process the organisms we caught, and attach one transmitter to the nautilus. We would look for the trap when we came back out. Transmitter attached and nautilus moving around well!
The nautilus was dived down, photographed, and released at about 15-20m away from the reef wall. As it was being released, we monitored its descent which was normal, reaching the bottom (which we know using a depth sounder). Now, we just wait and follow the nautilus wherever it goes making notes of its GPS coordinates from the boat, its depth, and the temperature over time. It is exciting at the beginning but hours later, on a small, open-top boat, this is when you have to push forward to not lose focus and become complacent. For me, I like tracking. I like being at sea. I like the stillness and the time to think and just be inundated in this type of science. We did not reset any traps today.
Over the next several days, we started trapping again and continued the tracking studies. The weather was pretty good for the most part. Some light rain every now and then until... our good weather luck ran out and we got hit with some cold, tropical rain. My "rain jacket" didn't really repel much so I was soaked but the important thing was keeping some of our equipment out of the rain, which we did! Through it all, we were able to catch several more nautiluses, attach two more transmitters to two nautiluses, track them, and discover some new things about the nautiluses of Fiji! Along the way, we were invited to a Fijian lovo lunch with the Fijian Water Police - Taro leaves with corned beef and coconut milk, kasava, pork, and chicken. Later, the Fijian Water Police really saved us because our boat was working great so it was not safe to be out at night in it. The bad thing is that the sunset is crucial for testing several hypotheses about nautilus migration. Well, the Fijian Water Police offered to take us out on one of their boats on one evening! How cool!
And then just like that, the expedition was over. If everything went perfectly to plan (how can it ever), we maybe would have come away with more data, but we left with a TON more data than we came with and more importantly maybe, we came away with some stronger partnerships and collaboration opportunities to not only continue this work each year when we are there, but continue it even when we are not there on the ground. Happy last sunrise in Fiji and SAVE THE NAUTILUS!