Saturday, August 24, 2019

Weird Wild Neighbors: Bryozoans!

About a month ago while kayaking along the edge of Hammond Lake Erin and I noticed something floating in the water. It was a huge brownish-green gelatinous mass. It. was. weird.

I know I had seen them before but this one seemed bigger than others I had encountered; and even more interesting is that it was not the only one. While kayaking the perimeter of the lake we saw at least three of them and I'm sure there were many more because we weren't exactly looking for them (I'm always watching birds!).

We began to wonder...what is it? Is it native or exotic? Is it invasive?

I was able to get to the bottom of it pretty quickly by doing an internet search for "brownish-green gelatinous mass in a lake." The Lake Stewards of Maine Volunteer Lake Monitoring Program says it better than I could so I'll share what their website has to say about this weird community of creatures called bryozoans:

"Bryozoans are tiny colonial invertebrate animals belonging to the phylum ‘bryozoa’, and are also known as “moss animals”.  There are 20 freshwater species worldwide.  A bryozoan colony, consisting of individuals called zooids, may resemble a brain-like gelatinous mass and be as big as a football, and can usually be found in shallow, protected areas of lakes, ponds, streams and rivers, and is often attached to things like a mooring line, a stick, or a dock post, etc. Zooids feed by filtering tiny algae, protozoa, photosynthetic bacteria, small nematodes, and microscopic crustaceans from the water.  Tentacles help capture prey and create currents that draw food toward the mouth. Bryozoans are simultaneous hermaphrodites, with individual zooids functioning first as males and then as females.  Colonies contain zooids in both male and female stages.  Sperm from male zooids exit into the water through pores in the tips of some of the tentacles, and then are captured by the feeding currents of egg-producing female zooids. Bryozoans are usually an indicator of good water quality, and should not be disturbed or removed from the water." (https://www.lakestewardsofmaine.org/programs/other-programs/bryozoans/)

 So, if you come across a brownish-green gelatinous mass now you know that they are good to have in our lakes for the water filtering services they provide. As I seek to live into community with all that has life, now that I've taken the time to get to know it, I'm thankful for bryozoans.





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