Clean It Out and They Will Come

When your environment is clean you feel happy motivated and healthy.

~Lailah Gifty Akita


I mentioned in an earlier post that we finally got around to cleaning out our two water gardens (aka salamander pools) in November. One had sprung a leak mid-way up its height a couple of years ago. It still held enough water for some critters but was choked with duckweed. The other sprung a leak this fall and drained, leaving a mud flat and lots of aquatic vegetation and their tangled root mats. These liners have been in for over 20 years (they are typically rated for 10) so I consider us lucky. We have a fairly narrow window for pond repairs as I want it to be late enough that cold weather has set in and numbed any Copperheads that might be hanging out in the rock walls, but before the Spotted Salamander breeding season, which can start as early as late December some years. I checked prices locally and online and purchased the liners at a place in Raleigh (prices have increased in 20 years!). I won’t bore you with the details, but I was pleased it only took us about a day each to totally re-do each pond, including cleaning out all the muck, putting in the new liner, and rebuilding and stabilizing their rock walls.

Lots of moving of rocks and debris to expose the old pond liner in the waterfall pool (click photos to enlarge)

–Removing the muck from the pools was the final step – we tried to rescue any amphibians and aquatic insects during the process

Laying out the new liners and then trimming to fit

After getting the liners in place, the difficult part is rebuilding a sturdy rock wall around each pond. Years ago, I purchased some flat rocks and then filled in with the irregular shaped stones that are so abundant on the property.

The first pool to be completed
The second pool has a small waterfall

The waterfall pool is great because we can hear the moving water from our screen porch so I like to think I am somewhere in the mountains when I hear it. The real advantage is as a possible additional attractant for birds (they love the sound of moving water), especially the neo-tropical migrants that move through our woods, so we will see what this season brings.

Our first good salamander rainfall didn’t occur until mid-February. We had a small run of salamanders and we ended up with about ten egg masses. About a month later we had a couple more nights of perfect weather for salamanders, and the bottoms of both pools were covered with spermatophores, followed a couple of nights later by lots of egg masses.

A Spotted Salamander egg mass as seen from below. The waterfall pool started off with very clear water which made observations and photography much easier (underwater photo taken with Olympus Tough camera)
Egg masses at different stages of development in the waterfall pool (underwater photo taken with Olympus Tough camera)
White embryos, as seen in the center egg mass, indicate the eggs are not viable. Studies have shown that egg mortality can be caused by a number of factors (including freezing) and may reach 20% to 40% of the total eggs laid in some years. Note that the gel of the egg mass itself can range from white-ish opaque to clear. That is the result of specific proteins in the gel. The significance and function of the opaque versus clear egg masses is unknown.
Egg masses are usually attached to twigs or underwater vegetation. I placed several tree branches in each pool for the females to utilize as attachment points for their eggs.
The egg masses grow in size over the first few days due to absorption of water
We ended up with about 100 egg masses in the two pools by mid-March!

I’ve been keeping tabs on the development of the eggs in the two pools over the last few weeks. Most have turned greenish in color due to the presence of an algae that is specific to Spotted Salamander egg masses. The algae probably gain nutrients like nitrogen from the waste products of the developing larvae and the larvae probably get oxygen from the photosynthesizing algae. Egg hatch time is temperature dependent and usually takes 4 to 6 weeks.

An egg mass a few weeks after being laid. Note the green color (due to symbiotic algae) and the progress in the development of the larvae.

The gel matrix holding the egg mass together starts to break down close to the time of hatching. I went out last week and lifted some of the twigs holding the egg masses and the jelly blobs started to fall apart. I gently placed one in a clear container and went inside to get my phone to photograph it. By the time I returned, there was a lot of activity in the container. Here is a quick video clip…

–the final stage of an egg mass – Spotted Salamander larvae breaking free of the gel matrix.

If you pause the video and look closely, you can see the tiny straight appendages dangling down near the head that serve as balancers for the newly hatched larva (there are also branched external gills at the head). After a couple of days, the balancers are reabsorbed when the larva is stronger and can swim and maintain an upright position in the water column.

I dipped in the pool yesterday and found one larva that has grown considerably and is now an active swimmer. Here’s hoping that many of them survive and transform into terrestrial juveniles in a couple of months. I look forward to their return on some cold and rainy nights in the years to come.

8 thoughts on “Clean It Out and They Will Come

  1. Beautiful pond! I loved reading about your pond reconstruction. Re-lining a small pond and moving and replacing all the rocks is hard work! We are on our third liner since we dug our pond in 1994. First one lasted about 20 years, including a patch job to repair two small cracks. Second one lasted until last spring, when we suspect that a small deer punched a hole in the side of it while climbing out! The tear was shaped exactly like the “v” of a hoof and we knew deer were drinking from the pond. Now we have an extra heavy liner and you are right, the liners are expensive! We too save all the critters that we can from the water and muck. We used a plastic kiddie pool and several aquariums and buckets as holding tanks and returned some of the muck and water to the pond after we refilled it. It’s a great place to watch birds sip from the upper level and to listen to frogs call at night.

  2. Nice close ups of the salamanders! We need to do the same to our pond but keeping putting it off. Ours is full of tree frogs. Congrats on relining your pond!

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