Tag Archives: Silver Salmon

Commercial and Sport Fishing for Coho (Silver) Salmon

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Last week, I wrote about the life cycle of a coho salmon, and I mentioned cohos are the most aggressive species of Pacific Salmon. Their aggressive nature makes them a favorite target for anglers. Cohos can be caught in the ocean and their spawning streams. They hit a lure or a fly hard and are tenacious fighters, often leaping out of the water and running fast both away and toward the fisherman. Coho salmon are also an important commercial species, but there are not nearly as many cohos as there are pink, chum, or red salmon, so cohos are not as economically valuable to commercial fishermen as these other Pacific Salmon species. In this post, I will cover both the commercial and sport fisheries for coho salmon, and I will discuss the current status, threats, and trends of cohos in their native range.

Commercial Fishery for Cohos in Alaska

 In most of the state, commercial fishermen catch coho salmon together with other salmon species by purse seining and gill netting. In Southeast Alaska, though, the majority of coho salmon are caught by the commercial troll fishery.[9] In 2017, commercial salmon fishermen in Alaska harvested nearly 225 million Pacific Salmon. Five million coho accounted for 2% of the harvest, but due to their large size and a price of nearly $1.20 per pound, the commercial coho catch was worth 38 million dollars, or 6% of the total salmon harvest value.[10]

Sport Fishery for Cohos in Alaska

The coho salmon is one of the most sought-after game fish in Alaska, and since the decline in king salmon numbers over the past few years, the sport fishery for cohos has become even more popular. Cohos are targeted by anglers in salt and fresh water from July through September in Alaska, and sport anglers catch nearly 1.5 million cohos every year in the state.[9]

In salt water, cohos are mostly caught by trolling or mooching. Herring is a popular bait, and any jig that looks like a small fish works well. Cohos are not particular about the bait or the jig as long as the angler keeps the jig active. The biggest challenge of catching cohos in the ocean is finding them. They may be at any depth from the surface to eighty feet or deeper.

Cohos are more finicky once they enter their spawning stream when their bodies change shape and color, and they stop eating. They will still aggressively hit a lure or a fly even after they gain their spawning colors, but they often become shy of lures, especially on a sunny day. Popular freshwater lures for spin fishing include Pixee spoons, golf tees, and spinners.

Status and Threats for Cohos

 Many coho salmon populations in California and the Pacific Northwest are threatened or endangered, but coho populations in Alaska are healthy.[9] In the southern part of their range on the west coast of the United States, humans have altered much of the coho’s habitat by urban development, constructing dams, diverting streams and rivers for agriculture, recreation, mining, logging, and other human-related activities. Studies show that in most western states, 80 to 90 percent of the historic riparian habitat has been destroyed, and 53 percent of the wetlands in the lower 48 have been eliminated. California has lost 91% of its wetland habitat, and wetlands in Oregon and Washington have been diminished by one third.[9] How can coho salmon with their complex lifecycle in fresh and salt water possibly thrive when much of the habitat they need to survive is gone?

Throughout their range, including Alaska, coho salmon will likely be impacted by warming ocean temperatures.

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I am very excited to announce my new novel, The Fisherman’s Daughter, will be available at online booksellers on November 1st. I am nervous but thrilled as I await its release. I want to again thank all of you who pre-ordered my novel.

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Coho or Silver Salmon (Oncorhynchus kisutch)

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Coho salmon, often called silver salmon due to their beautiful bright chrome color, are the most aggressive of the Pacific Salmon species. There aren’t as many cohos as there are pink salmon, chum salmon, or sockeye salmon, but coho salmon manage to spawn in tributaries and small headwaters inaccessible to other salmon species. A Coho can leap vertically six feet (1.8 m) to overcome obstacles such as rapids or waterfalls on its return journey to its spawning stream, and cohos usually migrate to their spawning streams later than other salmon species at a time when fall floods allow them to access areas not available during lower water levels.  Even young cohos are aggressive, and they often eat the young of other salmon species. This aggressive nature of coho salmon makes them excellent fighters on a rod and reel and an important species for the sportfishing industry in Alaska.

Range

The natural range of coho salmon is from Monterey Bay, California north to Point Hope, Alaska, west across the Bering Sea to the Anadyr River in Siberia, and south along the coast of Asia to Japan. Cohos have been introduced to the Great Lakes and other lakes in the Continental U.S. Cohos spawn in ponds, lakes, and pools within streams and rivers.

Description

Coho adults usually weigh between 8 and 12 lbs. (3.6-5.4 kg) and range from 24 to 30 inches (61-72 cm) in length, but fish weighing up to 31 lbs. (14.1 kg) have been caught. During their marine phase, adults are bright silver and have small, black dots on the back and the upper lobe of the tail fin. In their marine phase, cohos look very similar to king (Chinook) salmon, but king salmon have spots on both lobes of the tail, while cohos only have spots on the upper lobe. Another way to distinguish the two species is cohos have white gums, while king salmon have black gums.

When cohos return to freshwater to spawn, males turn dark to bright green on the head and back, bright red on the sides, and dark on the belly. Breeding females are not as brightly colored as males. Spawning males develop a hooked jaw called a kype.

Life Cycle

In Alaska, coho salmon return to their spawning streams from July to November, usually during periods of heavy rain and high runoff. On Kodiak, most cohos return from late August through October. A female coho selects a suitable spot and then begins to dig a nest, or redd. She turns on her side and gives several powerful flips of her tail to remove silt and other debris and then continues to dig for two to five minutes until she has a shallow nest. While she is digging her nest, she aggressively drives away other females. Meanwhile, a male coho stays near the female while she digs the nest, occasionally swimming close to her. He may also stop beside her and quiver, swim over her and touch her dorsal fin, or nudge her side with his snout. When the female has finished excavating the nest, she drops into the deepest part of the depression, and the male immediately joins her. The two fish remain side by side in the nest while they open their mouths, quiver, and release eggs and sperm. The female then moves upstream and begins digging a new nest, covering the eggs in the first nest with the gravel she dislodges from the second nest. Nest digging and spawning may continue at intervals over the next several days, until the female deposits all her eggs. The male might then leave and seek another female, but the female will continue the digging process until she grows weak and dies.

A female coho lays between 2,400 and 4,500 eggs. The eggs develop over the winter and hatch in the early spring. The alevin, with the yolk sac attached, remains in the gravel until May or June before emerging. Young silver salmon fry usually spend between one and three winters in fresh water, but some spend as many as five years in a lake before migrating to the ocean. Young silver salmon in Karluk Lake on Kodiak Island often stay two, three, or even four years in fresh water before migrating to sea. The length of time spent at sea also varies for coho salmon. Some males, called jacks, mature and return after only six months at sea, but most cohos remain in the ocean for 18 months to three years and return as full-size adults.

Prey and Predators

Cohos are aggressive feeders. In freshwater, they eat a wide range of aquatic insects and plankton. They also eat salmon eggs, and as they grow, the fry also consume smaller fry. In the ocean, cohos eat herring, sand lance, other fish, and squid.

Young coho are eaten by birds, larger fish, and a variety of other predators. Killer whales, sharks, sea lions, seals, bears, humans, and other land mammals prey on adult cohos.

Next week, I will cover commercial and sport fisheries for cohos as well as threats to coho salmon populations.

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Announcements

The publication date has changed for my novel, The Fisherman’s Daughter. Now, both the e-book and print versions of the novel will be released on November 1st. You can still pre-order the e-book, and it will be delivered to your device as soon as it is released. If you pre-ordered my novel, thank you!

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Pacific Salmon

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Five species of Pacific salmon return each summer to breed in Alaskan streams, rivers, and lakes. I will admit salmon are confusing fish. Not only do they have some of nature’s most complicated life cycles, but each species of Pacific salmon is known by two different common names. Are Atlantic and Pacific salmon the same fish? Which species of Pacific salmon is worth the most money to commercial fishermen? Do the various species taste different? Which species of salmon freezes the best? Why do some species grow larger than others, and why do salmon jump when they return to spawn?

Over the next few weeks, I hope to answer the above questions while I profile each of the five species. In this post, I will give you a generic overview of salmon and describe the life cycle of a Pacific salmon.

Pacific salmon and Atlantic salmon belong to the same family but not to the same genus. Atlantic salmon are more closely related to some species of trout than they are to Pacific salmon. One big difference between Pacific and Atlantic salmon is Pacific salmon only breed once, and then they die. Atlantic salmon return to freshwater to breed many times before they die.

The five species of Pacific salmon are pink salmon, also known as humpies; chum salmon, also known as dog salmon; red salmon, also known as sockeyes; silver salmon, also known as coho; and king salmon, also known as chinook. The five species look very similar to each other in their marine ocean phase, but once they enter fresh water, salmon go through significant physical changes, and each species has distinctive markings.

Fertilized salmon eggs incubate in the gravel of a river or lake bed for a length of time that varies depending on the species as well as other factors. Once the egg hatches, it is called an alevin. An alevin is small and has a relatively large, orange yolk sac attached to its body. The alevin receives its nutrients from the yolk sac and remains hidden from predators in the safety of the gravel bottom of the stream or lake. As the alevin grows, it depletes the nutrients in the yolk sac and begins to develop mouth parts.

Once the yolk sac is depleted, the young salmon leaves the safety of the gravel bed and must search for its food. At this point in its life cycle, the fish is called a fry. Except for pink salmon, a fry has parr marks along each side of its body. These marks provide camouflage to protect the fry from predators. Fry eat food such as insect larvae and plankton.

This is where the life cycle begins to get complicated. Fry remain in fresh water for a length of time which not only varies between species but may also vary between populations of the same species. Sockeye and silver salmon usually remain in fresh water for one or two years, while pink and chum salmon migrate to sea soon after they emerge from the gravel. King salmon fry usually stay in fresh water for one year.

Before salmon migrate to the ocean, they lose their parr marks and turn silver in color. At this stage of their lifecycle, they are called smolt. Once smolt leave their freshwater stream, they spend a great deal of time in brackish water where freshwater streams flow into the ocean. They feed and grow in the brackish water until they reach a certain size, and then they migrate to the ocean. Once they enter the marine phase of their lifecycle, they are considered adult salmon.

Adult salmon remain in the ocean for a variable amount of time, depending on the species and the population. King salmon can stay in the ocean for as long as six years, but pink salmon return to freshwater to spawn when they are only two-years-old. Once adult salmon return to freshwater, they undergo a dramatic physical change. Sockeye salmon, king salmon, and silver salmon turn dark red, while chum salmon develop calico bands on each side of their bodies. Pink salmon turn dark, and males develop a hooked jaw and a large hump on their back.

Salmon return to the stream or lake where they were born to spawn and die. At this point in their lifecycle, they are called spawners. Once the salmon reach their spawning grounds, a male and female form pair bond. The female digs a bed, called a redd, for the eggs in the gravel. She deposits her eggs in the redd, and the male swims over the eggs and fertilizes them with his sperm. She then brushes a light coating of gravel over the eggs. Once they spawn, all species of Pacific salmon slowly deteriorate and die, their bodies left to fertilize the stream or lake where they were born, ensuring the birthing grounds will remain rich in nutrients for future generations.

Every year, I watch salmon return to their natal streams to spawn. This summer, we had a huge return of pink salmon to the many streams on Kodiak Island, and at times when I sat on our boat, salmon surrounded me, jumping out of the water as far as I could see, reminding me of popcorn. I am always amazed by the incredible life cycles of Pacific salmon and how the many animals and plants on Kodiak Island depend on salmon to survive and thrive. As they return from the ocean, salmon are chased by humans, bears, eagles, seals, sea lions, sharks, and any fish big enough and fast enough to catch them. It is a wonder any salmon survives the gauntlet it must swim to reach its birth area and reproduce. Once it spawns and dies, the body of a salmon provides nutrients for the stream or lake bed and the plants and trees growing in the vicinity. It is impossible to imagine a Kodiak riparian ecosystem without salmon.

Next week, I’ll write about pink salmon, the smallest but one of the most important of the five Pacific salmon species.

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