This morning I made two trips to the southern-most island we can go to within the small boating limits, which is Laggard Island. It was named that in 1955 because it is at the outer rim of the islands close to Arthur Harbor (where Palmer is now) and hence, someone thought it was “lagging” in getting here. That seems to me to be a strange way to come up with a name, but that is what the official records show as its origin.
The first trip we made was with Maggie, Craig, Bill, and me all in our dry suits but not to go diving. Our target was a tufty green alga that lives in the intertidal (part of the shore that is underwater at high tide but exposed on low tide). The alga is called Cladophora repens, and it only lives in the lowest part of the intertidal that is exposed on the lowest low tides.
The height of tides vary from day to day in a pattern correlated with the phase of the moon (and its gravitational pull on the ocean). There are periods where the high tides are higher and the low tides lower that grade back and forth into periods when the highs are not as high nor the lows as low. These periods are called “spring” and “neap” tides, respectively.
We are in a spring tide period and there was a good low tide early this morning. So we got everything together last night and at 7:30 this morning, which is when boating hours normally start, with Jim at the helm we headed off to Laggard to try to collect Cladophora.
It was a beautiful sunny early morning. The mountain ranges of Anvers Island, Wiencke Island, and the Antarctic Peninsula proper were all bathed in sunlight with crisp, bright blue sky around them. Several of us commented that if you have to go “to work” early on a Saturday morning, that we certainly picked a great “office” to work in!
The reason we want Cladophora is that many of the herbivorous amphipods that we are using in our experiments like to eat it. As we will be describing in future posts, in some of our feeding experiments we take chemical extracts from algae that other experiments have told us a herbivore (animal that eats other algae) such as an amphipod does not like to eat. The experimental question is “is it not eaten because it produces chemicals that make it taste bad?” To answer that, we need to add the chemicals to something we know that the animal does like. So we make artificial foods (similar to really, really firm jello) from Cladophora that we have ground up into a fine powder.
Cladophora is very seasonal and we have only found it in abundance in the summer. It does not start to get abundant until sometime around December and I know that it is gone by mid-April (remember that is the middle of the austral summer, just the reverse of home). One of our top priorities when we first got here was to get out and collect it, and we did have a successful collection on 26 February. But I had become concerned that we might need more before we left so to be on the safe side, wanted to get some more just in case.
This set of spring tides was the best we’ve had since I made that decision. Unfortunately, in science as in all aspects of life, things do not always work out like one would like. There was still a little Cladophora there, but so little that it really did us no good. We’ll just be careful in how we use what we have, and we will make due with it.
After we got back on board the zodiac with Jim we surveyed a new dive site that Bill and I identified using a new bathymetry chart (like a topographical map on land; in this case it is a map that shows how deep the water throughout the area is). A couple days ago, the two of us went out with our boat’s depth sounder to check it out and it looked just like what we wanted in a site to collect animals. What we look for are vertical walls in the 100 to 130 foot depth range, and that’s what this looked like.
This new (to us) wall at Laggard is very exposed to the ocean’s fury with nothing to block waves coming out of the west or south. That is the kind of place we find a type of sponge that is needed for Alan and Bill’s research. But it also means that the waves have to be very small for us to be able to dive there. Yesterday, Maggie and Bill tried to go there but it was too rough to safely make the dive. Today was different.
We motored back to the station to get our dive gear and Dave Weimer, our station support person dive tender for the morning. You may wonder why we didn’t take all the dive gear out with us in the first place. It is because we need to wear less under our dry suits when collecting on land. I got hot and sweaty crawling around on the rocks as it was with just polypro underwear and a fleece jacket and pants on under the suit. If I’d had my heavy dive underwear on instead of the fleece suit, I would have roasted. Same for Bill.
Dave, Alan, Maggie, Bill, and I motored back out to Laggard with Alan at the helm. Alan is learning the ropes as a dive boat handler and “head” dive tender, so Maggie went along as a coach rather than diver. The glorious sun we’d had in the morning was gone from the skies over us and most of Anvers Island. But the mountains on the Peninsula were still bathed in sunlight and the visual effect was beautiful.
To top that, after suiting up Bill and I dropped down on an absolutely stunning underwater wall. The water visibility was great and we could easily see 40 or 50 feet. The wall was covered with red and brown algae but also a huge quantity and variety of multi-colored sponges, lots of small soft corals, and a diverse array of other invertebrate animals.
I got a number of red algae that we are working on and a sample for Craig’s project so from my perspective it was a successful dive scientifically too. But the real mission was to find the sponge that Alan and Bill need. I’m looking forward to going diving there again when our work requires the particular invertebrates we saw today. I say that because even though there was a huge variety of invertebrates, unfortunately we couldn’t find the sponge species that Alan and Bill need right now.
As I said, in science as in all aspects of life, even at a breathtakingly beautiful place, things do not always work out as well as you hope. I guess that today, our science was lagging a bit behind our scenery.