The Gift of the Rotting Biomass
The rotting fish was a king salmon and it was upturned just below the surface. A fine fuzz had encased it like the seedlings of a dandelion. The next one was still alive. “Look at that ghost” I said. An almost entirely white king was swaying drunkenly in the current, flaps of pale skin washed over it’s back clinging and waving. It was barely alive and was hovering near what looked like a log protruding from the gravel.
“Yeah, looks like he wants to hang out with his old buddy”. Tom pointed out. I looked into the water again and noticed that the “log” wasn't a log at all. It was, or at least used-to-be a salmon and was melded to the bottom of the creek bed completely covered, decomposition in full-swing.
I took a quick lesson from Tom on using the air bag to fill the pack raft. We topped off each bladder by mouth, lashed down our packs and pushed off.
The pinks, not as far along in their schedule of decay as the kings, were nonetheless a ubiquitous force to be reckoned with. A school of them in varying degrees of disparity moved out of my way as I paddled into the current. Their white and yellow streaked bellies and patchy darkened skin are a dead give away not only to their identity as pinks, but also to the inevitability of their time clock.
The male of the species is a curious case. Somewhere along their journey, the males become grotesquely flattened and humped reaching their hideous peak as they near the spawning grounds. Ironically the waters they negotiate here are the shallowest they have encountered. This exposes their humps topside and a likeness is easily made to the movie Jaws (cue music here). The disfigurement is so pronounced it’s almost cartoon- like. It’s hard to believe that this strange evolutionary adaptation could be of any benefit. Maybe in the eyes of the female pinks these humps are a sexy indicator of fertility. Are the flattest males with the largest humps more likely to pass their seed than the ones with the more traditional salmonid shape?
Whatever the reason, the pink salmon seem to have stumbled upon a successful formula for procreation. They’re everywhere. As the kings dwindle in numbers, it seems that it’s the humpy that might inherit the earth.
With only a few bends of the creek under my belt, I was scrambling to dial-in my rookie level technique on the pack raft. A big school of chum salmon darted out from under the boat. Their green and purple stripes are unmistakable. More humpies mingled on the other side as I maneuvered the raft around a boulder.
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| Earning my junior paddlers badge. |
I quickly found my rhythm a few bends lower as I dropped into a large pool. Some dark red torpedoes moved under me. These big kings darted up the sweep I’d just conquered without so much as a goodbye kiss or second thought.
We wouldn't get a good look at the silvers until lower in the system and they were mixed in with everything else. The last to arrive at the party, the silvers were the brightest of the salmon that day. The waters were alive....at least for now.
Without a doubt, the gift of the salmon's return each year plays to the delight of the sport and commercial fishing crowds. Their postmortem gifts in the form of the nutrients they pass is nothing to snub noses at either. Good science tells us that the mass of salmon that push into their natal streams each year have significant impact upon the surrounding riparian flora. These nutrients find their way to the banks and then into the woods proper through a number of delivery systems including the gut of the bear. Birds are also diligent scavengers and account for much of the deposition and distribution of these nutrients. Trees are said to grow up to three times as fast in these areas because of the nutrients from the salmon (primarily nitrogen). That’s a good payoff for the fish because along with the clear, cold waters and clean gravel beds, they need the trees to shade the sun's heat to create ideal spawning conditions. In addition, without their roots systems in place, the streams would likely clog the spawning grounds with sediment washing away from the banks after the rains.
Stream health is also enhances by the rot. Salmon that never leave the stream, like my friend the upturned chinook, eventually break-down and distribute carbon, nitrogen, phosphorus and other micro-nutrients back into the system. It is estimated that 50% of the nutrients consumed by juvenile salmon come from their rotting parents ( and their friends).
The complex relationships between the salmon, the forest and the stream has flourished for thousands of years in the Susitna basin and it's only now in our short window of time that it's facing it's greatest threat; The proposed Susitna-Watana dam. If the construction of the dam goes through, the outlook is bleak. Currently there is no shining example to point to in the world of a successfully dammed river that can sustain its wild salmon population. Dams kill salmon.
“How many fish do you think we saw yesterday?” I asked Tom after catching up with him at school the next day. Both of us were secretly licking our wounds a bit from the trip. We’re not eighteen anymore. The 11 mile hike and 12 mile paddle is rough on us old boys. In the morning I burned my mouth a little as I washed down my ibuprofen with hot coffee but I wasn't about to admit that out loud either.
“ You mean total?” He asked. I could see his wheels turning. Tom’s a math and physics teacher.
“ Yeah, what’s your quick estimate of total fish?” The bell rang for the second time and the students were clearing out for their next class. “ Two thousand?”
“ Yeah. The biomass is in for sure.”
