One might think that it would be difficult to get algae to stay in place once quantified, but we have developed a protocol that seems to do the job.... well, at least for a couple of low tides when we can still see what's going on. The key is to get rid of the air bubbles lodged in the algae. After these are gone, it becomes negatively buoyant, and hopefully a significant amount is retained within the corral by the structure itself, and the eelgrass shoots. There are a couple of key moves to employ, and best be on top of these as soon as the tide starts to flood!
The initial Poke-Down (using bamboo spears) gets out most of the air bubbles, and we trap some of the algae by pinning it down in the sediment with the spears. This move is followed by the...
Shimy Shake. See Wyatt's manual force-down using his bare hands. See also Sea-oh's poke-down/half twist manoeuver. Seda (back right), is using the individual poke for find-tuning.
The Final Fling occurs when the tide is over the top of the corral structure. At this point its important to keep proding the algae, while at the same time flinging escaped algae back into the corral. Don't get me wrong, we can't get to every little fragment of ulvoid, but we can keep most of it at bay. It especially likes to accumulate in the back corners of the corral where it is pushed by the incoming tide. It tries to escape here, but using the Final Fling, you can make sure it stays where its meant to be. Usually, at this time, I am still final flinging while the rest of the crew has given up and has headed for high ground. I call it quits once I feel like I can do no more to help out the macroalgae addition treatment, or the allure of the coffee shop wins me over.
Tuesday, July 14, 2009
Nutrient Diffusers
During the last tide series we spent a good deal of time fabricating nutrient diffusers out of 2 ft sections of PVC. I bribed the nice young men at Home Depot with cookies and juice to cut up the PVC, which they did by hand, only to find that I could operate the power saw at the OIMB shop with ease. We then drilled big holes into the side of these (Wyatt was the master of this), then suspended 500g of slow release fertilizer within them using women's panty hose. I had a hard time figuring out how other experiments had added the little fertilizer pellets without them spilling out all over the eelgrass bed. I had to e-mail a researcher to find the solution... apparently you aren't aloud to mention nylons in a scientific publication!
This is what the "nut diffs" look like once installed in the field. We also installed "blanks" in the non-nutrient corral plots. The goal is to see if the algae and eelgrass respond to a heavy additional dose of nutrients. This is already a nutrient rich locale, and there is a lot of mixing, so it may be hard to detect a response, but will be very cool if get one! We're going to replace the osmocote fertilizer in August and perhaps September so that there is a constant influx of nutrients available to the corrals.
This is what the "nut diffs" look like once installed in the field. We also installed "blanks" in the non-nutrient corral plots. The goal is to see if the algae and eelgrass respond to a heavy additional dose of nutrients. This is already a nutrient rich locale, and there is a lot of mixing, so it may be hard to detect a response, but will be very cool if get one! We're going to replace the osmocote fertilizer in August and perhaps September so that there is a constant influx of nutrients available to the corrals.
The Finished Product
After fabricating all that algae I realized we needed even more! Luckily, as I was purchasing another round of expensive silicon impregnated algae at the Rain Shed the lady there suggested that I use zap straps (aka zip ties in american lingo). Why hadn't I thought of that!!!!!! So we assembled the remaining algae during the last tide series in about a quarter of the time. There are now over 200 fake algae hanging out the estuary in the corral experiment - this probably amounts of over a grand in material costs!!!! They are doing what all good algae with fake holdfasts do - accumulate sediment, make habitat for polychaetes, and will hopefully do something to change the light environment of their co-habitants, the eelgrass (the goal of this crazy fake algae production).
Monday, June 1, 2009
Fake Plastic Algae Instruction Manual
In case you've ever wanted to make fake ulvoid algae here's how:
1. Cut out one yard (wide) pieces of green silicon impregnated nylon, cut these in half, then in half again.
2. Add rocks as anchors
3. Sew rocks into nylon
Voila, the finished product!
1. Cut out one yard (wide) pieces of green silicon impregnated nylon, cut these in half, then in half again.
2. Add rocks as anchors
3. Sew rocks into nylon
Voila, the finished product!
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