Because we didn’t have enough going on… a check of the fish pond yesterday revealed a rather horrid sight: about eight of the large goldfish looking very dead indeed with the rest apparently heading that way. We pulled out the dead ones and put them in a bucket (with no water, they were dead after all), pulled the heater as a possible suspect, and consulted with a local fish expert.
This resulted in a reorganizing of the afternoon to go and get an air pump for the pond (it has been running with simply the waterfall as the oxygen source for about a decade) since the consensus was low oxygen levels, likely caused by too many leaves.*
The air pump was installed a few hours later. Remember those fish in the bucket? Still sitting there by the pond? One of them twitched. So the bucket of dead fish was put back into the pond. Several dead fish promptly swam off. As of this morning only two of those ‘dead’ fish are still lying in the shallows looking dead. Another is looking ill, but the rest seem to be swimming about. I think we will wait a bit to determine the actual death count.
Apparently, asphyxiated fish in cold weather are the opposite of drowned people in cold weather. The person isn’t dead till they are warm, dry, and still dead. It would seem fish aren’t dead until they are wet and still dead. Or something. Not an experiment we are going to repeat.
*Usually the leaves are removed, for a number of very good reasons that just didn’t happen this fall. Now that we know that it really is important to do it, its priority will be bumped up for future years.