WaterNotes

20: Ten months

Well dear readers I know it seems that each month I find something to get worked up and excited over - this month is no exception. At ten months the tank is steaming along and I have made major harvests of several species, including Halodule, Caulerpa and the Halymenia. I try to spread around species as much as possible so that we can, as a community, lessen the impact seagrass aquariums might have on the wild beds. Just think how wonderful it would be if ‘grass keepers could say that 90% of all the plants in the hobby were aquacultured.. or to compose a whole tank out of aquacultured greens. It makes the wildlife conservationist in me smile!

Monterey Bay Aquarium:

I made a trip in the first week of March to San Jose, Monterey and San Francisco for a mini vacation as well as to do some professional related work. I’d never seen the Pacific before, so that was of course quite a treat. I only wish I’d had the time and resources to do diving in the kelp forests, despite their frigid temperatures.

The most amazing experience I had out in California was not getting soaked in an open air trolley during a thunderstorm in San Francisco, nor was it eating clam chowder in a bread bowl! It was visiting the Monterey Bay Aquarium (MBA). For those of you who have not read it, its on the main page here, you should all pick up a copy of David Powell’s memoirs, A Fascination for Fish. Powell is the guy who basically invented many of the ideas in aquascaping and creating large scale displays for public aquaria. He designed most of the tanks at MBA. I read the book just after it was first published and have been hoping to get out to Monterey for many years now, and seeing all the tanks described in the book in person was priceless. I have idolized Powell for several years and finally seeing his work was well worth all the time and travel associated with seeing MBA.

For those of you who are not aware, MBA is a gem among public aquariums not so much for its size or the precise animals in the collection, but for the way the tanks are integrated and attempt to be biotope specific. Many aquariums add fake decor to impressive fish displays.. not MBA. The main kelp forest exhibit is full of fish, plant and cnidarian life that boggle the mind in variety and health. The smaller coldwater displays throughout the aquarium are just as amazing.. strawberry anemones, which are fairly sensitive to water conditions and are a bit of a pain to feed (live BBS and similar items mostly) cover all the available surfaces of many of the tanks. To the uninitiated eye MBA looks like any other aquarium, but to those of us who know how hard it is to maintain full ecosystems such as these, it is a rare treat.

I found myself absolutely drawn to and inspired by several setups scattered throughout the aquarium which deserved much more attention than they were typically given. The first display I discovered had eel grass, Zostera marina, growing alongside Ulva, several cold water red macros and served as home to dwarf perch and bay pipefish. It was tranquil, elegantly conceived and really a fantastic example of what can be done with a ‘planted’ marine tank. Another, very large sunlit system, in the aviary was just as amazing - again with Zostera and Ulva dominant - and housing juvenile leopard sharks, perch and several fish species that I cannot ID from the pictures I took. If you cant tell, I wasnt particularly interested in the fish.. I just stared, entranced, at the grasses.

Phyllospadix sp. seagrass, “surf grass” was also scattered about in a number of displays as well as all of the touch tanks in the facility (and there are several). This is a cold water species, like Zostera, that anchors in very dense pockets to rubble and boulders in the tidal zones and around rock pools off the West coast. Its gorgeous and grows very long. I was not convinced that the specimens in all of the tanks were permanent residents like the Zostera exhibits clearly were. Still, all of this seagrass nearly sent me into a fit of happiness. Outside of Waikiki I had no idea that any public aquaria were maintaining seagrasses, and seeing them at MBA definitely warmed my heart. It also helped to convince me that I have not lost my marbles, and that seagrass aquaria is indeed a wonderful new concept.

CO2 is fun:

The effects of carbon dioxide dosing in the second month have been dramatic. Shoal grass growth skyrocketed to two plant per day being produced on all the established rhizomes. The left side of the tank is outstripping the right, and why I’m not really sure, but both sides are definitely showing good growth. The tank now consumes 300mg~ of nitrate per day, along with the dosed iron. pH and alkalinity values still hold out at stable conditions, which is a wonderful change for me.

To give you a quick idea of how many plants are now in the tank I have harvested well over one hundred plants of shoal grass and it hardly made an impact in the apparent density of the system. I dont even know if I could hazard a guess of how many plants are in the system. I started with an initial planting of about thirty-five.

New additions:

Unfortunately, my lovely jawfish decided to jump a few days after I returned from California, which will teach me to egg crate the tank from now on. I had been getting away without for several reasons, including the fact that he had been in the tank for so long at that point. I will miss his cute little face and his begging for mysis in the mornings.

The tank has been running without a fish or large inputs of waste for nearly two weeks now and a few days ago I noticed that growth was slowing in the grasses. I refreshed the CO2, made sure I was correctly dosing other parameters and did a full water quality test. The only thing that came back abnormal was phophate. The PO4 content of my seagrass aquaria has never wavered above or much below 0.1ppm but this tank reported zero phosphate in the water. A better kit, Salifert, told me the same thing. So, out comes a 1M KPO4 solution that I keep for experimental systems. A few drops of it into the tank and in a few hours I had pearling like champagne out of the plants and growth resumed at its impossible rate the next day. Its very encouraging to see that, in the absense of constant PO4 input from fish waste and missed-mysis, the tank can be driven into P limitation. I did not have any nuisance algaes bloom with the minimal amount of PO4 given, and that includes no cyano and no green glass algae. Very encouraging and interesting results.

For now I am quarantining a teeny tiny little cherub angelfish, Centropyge argi that will be added to the tank in a few weeks to test out their compatibility with macroalgaes and seagrasses. Its a big gamble, but one I’m willing to take. She will eventually grace a much larger tank at a friends house, but until he is ready to add the lass I’m babysitting. Why did we go to the trouble - we dont see cherubs in this area too often, at least not at this impossibly tiny size. She is super cute though, I wish I could keep her. Perhaps in my future sunlit 40gallon or larger projects a single dwarf like the cherub would be a good fit.

Pics of the tank:

2.22.06

3.20.06