Thanks for waiting patiently, but I have some good news! After 3 failed attempts to get Macrocystis spores to settle, germinate into male and female gametophytes, reproduce sexually, out compete benthic diatoms (Navicula sp.) for space/light/nutrients, and develop into embryonic sporophytes, I finally have some babies growing! It has been 41 days since the sporophylls these little asexual beings were released from, were collected from approximately 40ft deep in the Point Loma kelp forest. After collecting the sporophylls (specialized blades containing the reproductive matter of giant kelp) on June 4th, these blades were wiped down with fresh water to remove diatoms (1st line of defense), then dessicated in between filtered sea water moistened paper towels in our lab fridge for 5 hours. We call this process “making lasagne” due to the act of layering sporophylls between paper towels over and over again, and the fact that it makes you really hungry for lasagne. Dessicating them in essence “stresses out” the sporophylls which makes them more readily release their spores when we rehydrate them later. To rehydrate them, you prepare three tubs of filtered sea water, remove a handful of slimy but now more manageable sporophylls into each tub and start your stop watch. It took me a few tries to learn to have three batches of sporophylls rehydrating at once. It is always possible that your randomly chosen sporophylls won’t cooperate, so having more than one tub of spores to select from is a smart move. After about 15 minutes, agitate the water in one of the tubs. If you can see some visible murk, the water looks slightly golden and there are little particles swirling around, now is a good time to check for competent spores. If you are lucky enough to own/be in a lab that owns a hemocytometer (sweet little expensive glass microscope slide that has been modified so you can count tiny things in a fixed volume of liquid) you can then look for the microscopic pear-shaped single cell spores zipping around and figure out how many millions you need to add to your aquaria.
I wanted quantities that would equate to 50/mm^2, 100/mm^2, and 200/mm^2, because this is what Dan Reed suggested was best some 25 years ago. Luckily for us, these little spores tend to settle uniformly, so I added the polypropylene mats I wanted them to settle on to three large tanks. Using the hemocytometer I was able to determine my stock spore solution contained 26,000,000 spores per ml, therefore I needed to add between 2-8ml of spore solution to each tank to get my desired low, medium, and high densities. Then you turn off the lights and cross your fingers for 3 days! After 3 days, turn the lights on but keep your fingers crossed for the next 37 days and you might be as lucky as I just was. Also adding a little GeO2 to my water and creating an alter to Tim Howard so he would protect my kelp babies from Navicula certainly helped.
I will show you some baby pictures later, but for now its time to celebrate with some fish tacos!