Through the looking glasses

Hello again everyone. It has been a busy few weeks, gearing up for a presentation in Nelson, another spat rope swapping, and finally processing the first set of spat ropes. It was a bit more of an undertaking than one would expect for me to get a space and all the equipment I needed, but I got there, and had a blast going through the samples I had sieved.

To recap/explain, I set out these collectors with a piece of hairy rope in the cove where I dumped the 7 tonnes of mussels. I wanted to see if there were baby mussels settling out of the water column in the area, and hope to observe any patterns in this settlement over the next year. So every month, I venture out with my volunteers and divers collect the ropes, replace them, and then bring the dirty ropes back to me for analysis. I clean the ropes, sieve the contents down to 0.2 millimeters and then go through them with a fine toothed comb and count the number of baby mussels. Well this has been a smashing good start, and I am happy to say that there are indeed mussels. With their brown zig-zag patterns just starting to develop, something that will disappear as they grow old and take on a brown colour with a green band around the lip of the shell.

One wonderful feature of the dissecting scope I have is that I can either view them with light from above or below, as in the respective positions of the two photos. But what else is interesting are the various other organisms within the samples. I get a glimpse into a microscopic world that few get to see. A whole world of miniature organisms, and some who will never attain sizes much greater than that which I see through the looking glass of my microscope. There are many other bivalves within my samples, taking on many different shapes, some more close to my mussels, much to my dismay, and others are different yet very familiar, like the numerous baby scallops.

Brittle stars like the one just above and to the left of the leftmost scallop, are a rare but interesting find among the fibres of my hairy ropes. Much of the samples however are seemingly polluted with numerous crustaceans. From shrimp to amphipods, and the oh so misleading ostracods that look like bivalves except for the feet and antennae sticking out of the two halves of carapace (on the left hand side of the top most picture below). All kinds of different orientations of the same jointed body forms, it is truly amazing the diversity that exists, especially when one looks closely.

But sometime luckily, most of these crustaceans float, where as the mussels sink, making processing not so bad despite the high abundance of these critters. The problem comes when you look very closely, at the samples that are less than 0.5 mm but greater than 0.2 mm. These samples are heavily polluted with polychaete worm tubes, other small bivalves, and diatom plankton. But this is where the most obnoxious thing in all my samples can be found; Sand! Grains of sand bury the mussels, creating a scavenger hunt for me, picking at them with tweezers to find the buried treasures. As if lifting boulders that threaten to squash these pint-sized mussels, I sift through to find my little mussel babies.

It may not be all fun and games, but it certainly is an interesting world, our world, just smaller. I also am lucky to get to see some very interesting crabs, my other interest. There are numerous crab species, including some that would have just settled and still have their larval tails before the metamorphose to their adult form. Spindly legs and unusual shaped bodies that eventually become the robust and hardy creatures that have so successfully survived in almost every habitat, including land (Not that I found any of those species specifically).

I will continue to take pictures of unusual things I find in the miniature world and periodically post them. Until then, I will be off to a conference in Nelson to give a presentation on my work with mussel beds thus far.