Lakes Versus Rivers

I have to admit that this lake throws me for a loop.

Mostly, I understand how rivers work--how, as dynamic systems, they shift and change in character, size, flow, temperature, nutrient content, and inhabitants in space and time, from season to season and from headwaters to estuary. That's what pulls me to rivers: the way they are, by definition, always changing, never static. Whether I am kayaking, pulling online streamflow data off a USGS gauge to make a graph, or diving in my drysuit to count spawners, the river keeps me on my toes, looking for what's around the next bend. Rivers are and will continue to be central features in my life because of the way they serve to engage me, emotionally, intellectually and physically. You can't step in the same river twice, as they say.

But lakes? How the heck does a lake work? To me, a lake looks like a big static puddle-- an unmoving, unchanging, and, the lazy part of my brain would like to label it, boring body of water, good for swimming in and not a lot else. But that's where I'm desperately hoping (and strongly suspecting) I'm wrong. Lake Aleknagik may look like a giant silvery puddle with ripples on it, dark and mysterious and totally unrevealing of its secrets, but that's just because I'm so far part of the uninitiated. While they might not move tons of sediment, undercut their banks in an attempt to shape the landscape, boast dangerous rapids, threaten to flood your neighborhood in the wet season, etc. (you get the idea--rivers are powerful in a way that's obvious on a human timescale), that doesn't mean lakes are wimpy or ecologically unimportant. They're just more subtle about the ways in which they change daily, seasonally, and yearly.

Limnology explores the layers of temperature and nutrients present in a lake and how they appear and disappear with the seasons, the ebb and flow of lake levels, the waxing and waning of algae, plankton, and all the other organisms that form the base of the lake food web, how lake currents work (one word: slowly), and more. I have no prior experience with limnology, so
I am patiently exploring the idea of lakes with an open mind--or trying to, anyway. Part of me relishes the opportunity to study and understand a new kind of aquatic ecosystem. Even the streams draining into Lake Aleknagik are completely unlike any streams I have ever seen before.....low-gradient, very low-energy, clear and oxbowed, sinuously and serenely making their way just a few kilometers from the base of the mountains through wet meadows until they meet the lake. But simultaneously, even while wondering about how the lake works as an ecosystem, part of me screeches Where's the current? This thing isn't moving! What is there to look at? That's where I have to slow down and let go of the ridiculous expectation I have for the lake: that it be a river.

Actually, the Wood River System of four interconnected lakes draining into Bristol Bay sort of is uniquely like a river (of immense pools connected by short sections of flowing current) because it starts at one freshwater end and drains into a saltwater end. It's just unlike any "river" I've ever studied or played in. One other unique thing about the Wood System I haven't mentioned yet is that it forms a significant part of the spawning and rearing grounds for the largest intact, unspoiled sockeye salmon fishery on the planet. No conventional river could support a fishery this huge. It takes several giant lakes, with all their spaciousness, availability of spawning habitat, rearing habitat, nutrients and prey, and relative lack of predators to nurture several tens of millions of sockeye salmon (which, by the way, are a lake-specific species, returning exclusively to lakes at the end of their lives to spawn).

I might miss rivers, but rivers will still be there in the lower 48 when I fly south for the winter. I can't stand here with my arms crossed challenging the lake to prove to me that it is just as ecologically amazing and nuanced as any river. The lake isn't going to make the first move. That's my job.