What is left when the tower goes quiet?
The Nushagak sonar site works June and July, and it estimates three species: sockeye, king and chum. Pink and coho arrive in late summer, after most of the earlier fish have already passed the counting tower, so the drainage’s main instrument is quiet before they come. What is left of the season is still worth reading, but it is read differently. The page that explains how a run is counted also names the species it estimates, and the late fish are not among them. The Nushagak produces more king and pink salmon than any other river in the Bristol Bay region, and in recent years the department has noted a growing interest in coho and pink as a commercial fishery. The fish are there. The count, for them, is not.
Three doors into the river
Three species open the late season, each through its own door. Coho enter spawning streams from July to November, usually during periods of high runoff, and the female digs a redd and deposits her eggs in the gravel. Chum spawn in the fall, in two races the profiles call “summer chum” and “fall chum”, mostly at river mouths and in lower sections, though some travel as far as the headwaters of the Yukon. Pink return to the small coastal rivers and the estuaries, most of them within forty miles of salt water. Behind all three stands the earlier water, the first kings of June and the sockeye behind them, and by late summer that water has passed.
What does cold water do to the calendar?
It lengthens it. Chum embryos hatch after three to four months, depending on water temperature, and the hatchlings stay in the gravel, living on the yolk, before they emerge and start downstream. Pink eggs incubate through the winter and hatch in late winter or early spring. Coho eggs develop over the winter, hatch in early spring, and the fry emerge in May or June. The adults are burning stored fuel long before that: chum stop feeding when they re-enter fresh water, the digestive tract degrades, and fat and muscle carry the spawning run. The profiles tie entry to runoff and to season. None of the three ties it to day length, so this almanac does not either.
Where do the late fish hold?
In the quiet water. Coho fry occupy ponds, lakes and the pools of streams, usually around submerged woody debris, out of the current, and they defend their ground against other salmonids. In the fall, juvenile coho may travel miles to reach off-channel habitat where they pass the winter free of floods, and some rear in brackish estuarine ponds instead. Chum fry go the other way: they leave fresh water within days or weeks of emerging, one or two inches long, and hold in shallow eelgrass beds near shore for their first months at sea. Adult chum choose small, slow, spring-fed side channels and the gravel below the high-tide line, a trait the profile says they share only with pink salmon. Pink adults spawn over clean gravel with little silt, in shallow water with current.
The silver fish with the white gums
A late coho in salt water is bright silver, with small black spots on the back and on the upper lobe of the tail only, and white gums. A king carries spots on both lobes and black gums, and that is the whole separation. Adults run eight to twelve pounds. The males that come home after six months at sea, about twelve inches long, are jacks, two-year-old spawners, and the department’s coho profile treats them as a normal part of the run rather than an oddity. Most coho stay eighteen months at sea. Their ocean travels are close to unread. The profile says little is known about them, and high seas tagging shows maturing Southeast fish gathering in the central Gulf of Alaska in June before dispersing toward the shore.
The numbers the bay does not publish
The Bristol Bay escapement page carries the goal ranges river by river, Ugashik to Togiak, and every line of that table is a sockeye line, with one king range for the Nushagak. The page also links a daily run summary and preliminary in-season estimates. It publishes no goal for coho and none for pink. On the Nushagak, the department keeps management plans for sockeye and king, and none for chum, even though chum are one of the three species the sonar estimates. This is the honest edge of the record. When a rumor puts a number on the late fish, the question to ask is which document published it, and the answer, usually, is none.
Why is one pink year thick and the next one thin?
Because the species keeps two separate books. Pink salmon mature and die on a two-year cycle, and the odd-year and even-year populations do not interbreed, even when they spawn in the same stream. Many streams lean toward one of the two lines, and the profile records that the weak line can later become the strong one. So a quiet year on a pink stream is not a collapse; it is the other half of the calendar. A rumor reads silence as decline. The document reads it as a year class. This is what a published life history is for: it turns a season’s silence into a question with a known answer.
How to follow a run the documents stop counting
Open the Bristol Bay escapement page and the coho species profile in two windows. On one side, rivers and their goal ranges, all sockeye with a single king line. On the other, a fish whose Alaska populations the department describes as healthy, with a life history that runs from July entry to spring emergence. Read the two lists against each other and write down which species each document will answer for. That habit, kept through a season, is the difference between a report and a rumor: the report names its document, its species, and the gap, and the rumor names none of the three.
The coho species profile
The coho species profile is a page of the Alaska Department of Fish and Game, the state agency whose sonar and escapement documents this almanac also reads. It carries a general description, life history, range and habitat, status and threats, and a fast facts list, and it gives the fish’s other name, silver salmon. The desk reads it for the run window, July to November, and for the gums.