On Doldrums and Dementors

We are fast approaching the doldrums of summer, when tomatoes and sweet corn ripen, cicadas and crickets sing, and a string of oppressively hot days suck the energy from us.  Mere months ago we were preparing garden soil for seed, concerned about late frosts, and now the thought of delightfully cool, fall air and the smell of crisp dying leaves is a cruel and unimaginable tease.  On a shaded limb of the white pine a squirrel lies prostrate, legs hanging limply, offloading excess heat.  Birds at the feeders gape.  The air, laden with moisture, seems to have weight, and in the blistering sun there is a nearly audible sizzle.

A fine harvest of onions has been laid out in the shade of the barn for curing, joining the garlic from a couple weeks ago.  Pantry space is filled with canned green beans, pickles, and jams, cabbage is turned to kraut, sweet and crunchy carrots pack the refrigerator vegetable drawer, packaged zucchini and broccoli are added to the freezer.  Other crops, including some that welcome a relentless heat, march on towards maturity. 

In an effort to control mold and buckling floors, and with incidental consideration for our own comfort, we are running the AC like never before, and it is a godsend. Our trips outdoors have grown brief and largely limited to mornings and evenings when the heat subsides, except for our daily swims in the pond, to which we remain stubbornly dedicated.  Like any exercise routine it is not always easy to be willing and ready, but also like exercise routines it leaves us with a feeling of vitality and renewed vigor.  

During the summer doldrums there is a strong inclination to get the swimming done early in the day when the water is a tad cooler and photosynthesis is just gearing up.  We have, as do all untreated ponds, a healthy crop of string algae, as well as chara, a branched, bristly form of algae that is anchored in the soil and spreads arms upward to three feet.  We have stretched a 100 yard swim rope across the pond to keep us in line and measure distance, where it crosses shallow areas we apply a band of copper crystals to control the chara so we don't have to fight our way through it.  

String algae floats by day, the result of oxygen generated by photosynthesis being trapped and providing buoyancy so the plant rises to the surface.  At night, no longer held up by oxygen, the plants usually sink.  Some of it lands on and entangles dead and dying chara, so when daylight comes and photosynthesis resumes, the ballooning string algae brings with it a decaying chara skeleton.  Viewed from below water, the scene holds a similarity to a floating jellyfish with long tendrils trailing.  Sometimes the chara is black and putrid with decay, reminding us of the Dementors from the Harry Potter movies, so that is the name we give it.  It appears with increased frequency as the day rolls on, and drifts aimlessly with the wind.

When chara is in a state of advanced decay, it can be on the verge of disintegration, so when bumped by a focused swimmer it collapses in a cloud not unlike the ejected ink from a retreating octopus. Sulphuric compounds stored in the chara are rapidly released, leaving a stench that cannot go unnoticed by anyone with a functioning olfactory. 

But wait, there is more.  Hidden in the detritus are microscopic cercariae, the larvae of a parasitic trematode, or blood fluke, that spends its adult stage in waterfowl.  There are different kinds of trematodes and the details of their life cycles vary, but generally go something like this: Fluke eggs are passed in the bird’s feces and hatch into miracidia, which have no mouth so can't feed and must quickly find their way to an intermediate host, typically a snail.  Once inside the snail the miracidia develop into free swimming cercariae that are eventually released, swim about, and ideally penetrate the skin of a waterfowl where they then migrate to the blood vessels and become adults, completing the life cycle. 

It turns out that cercariae, in their zeal to find a suitable host, will latch onto almost anything, including people.  After penetrating our skin they do not develop into adults but instead die, leaving a tiny bite known as swimmer's itch.  It's not a serious problem and the bites clear up in a few days, and it's a sporadic event, so not always an issue. Cercariae can be anywhere in the water, but do seem to prefer hanging out on vegetation, or with Dementors, whom as Harry Potter fans know, feed on human happiness even without the aid of cercariae.

There are flukes that pose serious risks to man but this one does not, so in what would broadly be considered a warped viewpoint, there can be a tinge of excitement in being included in its world. With that annoying itch comes an invitation to learn of its life cycle, to appreciate its incredible adaptive behaviors and anatomical features that have allowed it to find a niche and live a life that does not weaken or kill its hosts.  In waterfowl it finds a free ride to new frontiers where it can inhabit new waters and recruit new snails to assist in its survival.  True, it's a parasite, a freeloader, but faces its own risks, and those that burrow into our skin have reached their end.

The doldrums of summer, the magic and bounty in a vegetable garden, photosynthesis, the Dementors, blood flukes, all invite us to be better aware. Weather conditions and mind boggling intricacies in the natural world are not always physically enjoyable, but do beg our appreciation and understanding.  It’s about seeing and seizing the wholeness of life. The more familiar we are, the more respectful we’ll be.