Category Archives: Fish

Marine Reserves for Rockfish

March 10, 2019Fish, Kodiak WildlifeMarine Protected Area, Marine Reserves, Marine Reserves for Rockfish, Rockfish Conservation, Rockfish in Alaskaadmin

Should fisheries managers implement marine reserves to protect fragile rockfish populations? This week, I’ll tackle the controversial subject of marine reserves. What are they; do they work; and should they be employed to protect rockfish populations and help already depleted populations recover?

Two weeks ago, I discussed rockfish conservation, and last week, I explained how to implement the deep-water release technique for rockfish. If you missed either of those two posts, I suggest you read them to understand the biology and physiology of rockfish and why rockfish populations are fragile and subject to overfishing.

Marine reserves have been developed in certain areas where rockfish have been over-harvested. Before I start discussing the pros and cons of marine reserves, though, I want to differentiate between a few ecological terms I find confusing.

Marine Protected Area (MPA): This broad term covers a variety of management areas, including marine sanctuaries, estuarine research reserves, ocean parks, and marine wildlife refuges. Some MPAs are established to protect ecosystems, while others preserve cultural resources such as shipwrecks and archaeological sites, and still others are established to sustain fisheries production. Nearly all MPAs in the United States allow a variety of human activities, including fishing.

Marine Reserve: A Marine Reserve is a special, restrictive type of MPA where either no or only limited fishing (sport or commercial) and development are allowed. Marine Reserves are sometimes further divided into “Marine Reserves,” and “No-Take Marine Reserves.” When used together, these two terms usually mean managers allow some fishing for certain species in a Marine Reserve but place a ban on all fishing in a No-Take Marine Reserve.

When you add terms such as Marine Parks, Marine Preserves, and National Marine Sanctuaries to the mix, you end up scratching your head, wondering what each designation means. In this post, when I discuss marine reserves, I am talking about the implementation of a distinct area closed to all fishing.

Fisheries managers in the eastern North Pacific have designated several marine reserves in critical rockfish habitat where rockfish have been overfished. By prohibiting fishing in these areas, managers hope to rebuild overfished populations and protect spawning and nursery habitat. By closing an area to all fishing, biologists can protect rockfish not only from anglers who target rockfish but also from anglers who fish for other species and harvest rockfish as by-catch.

Fishermen generally do not like marine reserves because they lose fishing areas. Reserves protecting rockfish are also controversial because studies suggest as much as 20% of rockfish habitat would have to be closed for a reserve to be effective. Also, reserves displace effort and place pressure on open areas.

Some reserves appear to have benefitted local rockfish populations, but biologists are still uncertain about the overall success of reserves for managing rockfish. Since rockfish do not reproduce until they are several years old, though, and since few larvae survive to reach adulthood, it could take years to realize the benefits of rockfish reserves. Are we willing to wait before we judge the efficacy of these protected areas?

I planned to write two posts on rockfish and ended up writing six. The more I learned about these interesting fish, the more questions I had. I hope I found a few readers who are as intrigued by rockfish as I am. Before tackling my next group of fish, I’ll write a few posts on other topics.

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Robin Barefield is the author of three Alaska wilderness mystery novels, Big Game, Murder Over Kodiak, and The Fisherman’s Daughter. To download a free copy of one of her novels, watch her webinar about how she became an author and why she writes Alaska wilderness mysteries. Also, sign up below to subscribe to her free, monthly newsletter on true murder and mystery in Alaska.

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Deepwater-Release Technique for Rockfish

March 3, 2019Fish, Kodiak WildlifeDeepwater Release, Deepwater-Release Technique for Rockfish, Protecting Rockfish, Robin Barefield, Rockfish Conservation, Rockfish in Alaskaadmin

This week, I ‘ll describe the deepwater-release technique developed for rockfish. In my last post, I wrote about rockfish conservation and talked about ways anglers can help preserve vulnerable rockfish populations. Due to their unvented swim bladder, rockfish are extremely sensitive to changes in water pressure. When an angler catches a rockfish in water deeper than 90 ft. (27.43 m) and reels it to the surface, the fish’s swim bladder rapidly expands, compressing internal organs and often pushing the stomach out through the mouth. These pressure change can also rupture blood vessels, tear the swim bladder, and cause bulging eyes or gas bubbles in the eyes.

Stomach protruding from yelloweye rockfish mouth — Distressed Rockfish

Sometimes rapid pressure changes cause physiological damage so severe it kills the fish, but in other instances, the fish can survive if the angler quickly returns it to the depth where it was caught.

Since a rockfish’s swim bladder rarely deflates on its own once the fish arrives at the surface, the fish cannot dive and instead floats until it dies or is eaten. Anglers sometimes mistakenly feel they can help the fish by either puncturing the stomach protruding from the fish’s mouth or puncturing the fish’s body to let air out of the swim bladder. This technique, called “fizzing” or “venting,” often leads to infection and eventual death.

Recently, biologists have developed a new deepwater-release technique to submerge rockfish as quickly as possible either to the depth where they were caught or 100 feet (30.5 m), whichever comes first. Research on this technique has shown a substantial increase in the survival of released rockfish. One laboratory study produced a survival rate of 96% for recompressed rockfish. Another study in the wild found only 22% of yelloweye rockfish released at the water’s surface managed to submerge, but 98% of yelloweyes survived when submerged to the depth where they were captured.

The Alaska Department of Fish and Game has now added the deepwater-release technique to its list of “best practices” for anglers to employ to minimize release mortality of rockfish. Biologists believe if they can convince anglers to use this technique, as well as follow other rockfish conservation methods, rockfish mortality will decrease significantly.

What is the deepwater-release technique? It is a simple procedure, but since time is critical, rockfish anglers should have the gear ready and be prepared to implement the technique as soon as the rockfish arrives at the surface.

Several deepwater-release devices, from simple to sophisticated, can be purchased, but you can also easily make your own deepwater-release device. Begin with a 3-lb. jig with a single hook and grind the barb off the hook. Next, take a fishing rod and attach the line to the bend of the hook. Assemble the device and have it ready to go before you start fishing. The fish is much more likely to survive if you minimize its time at the surface, so have the device assembled and make sure you know what to do before you catch a rockfish.

If you think you have a rockfish on the line, quickly reel the fish to the surface. The swim bladder will inflate regardless of your reeling speed. Remove the hook from the fish’s mouth and attach the release device. If using a homemade device, hook the barbless hook through the soft tissue of the jaw. Gently drop the fish back into the water and release the anti-reverse on the reel, allowing the line to free spool. Allow the fish to descend until either the jig hits bottom, or reaches 100 ft., whichever comes first. Then, give the rod a hard tug to release the fish. The faster you can perform this technique, the more likely the rockfish will survive.

Next week, I’ll discuss marine reserves as a possible management option to protect rockfish populations. Reserves are controversial because both sport and commercial fishing are prohibited in reserves, and many biologists question if reserves work as a form of conservation.

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y the way, Mary Ann’s books would make perfect Christmas presents!

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Rockfish Conservation

February 24, 2019Fish, Kodiak WildlifeBlackRockfish, Robin Barefield, Rockfish, Rockfish Conservation, Yelloweye Rockfishadmin

This week, I want to discuss rockfish conservation. Over the past few weeks, I’ve discussed how rockfish are more vulnerable to overfishing than most species of fish, and non-pelagic rockfish populations are particularly fragile. Rockfish prefer rocky habitats where anglers can easily find and target them, and rockfish are quick to take a lure, making them easy to catch. Also, they grow quickly but mature slowly, so they are often caught before they can reproduce and sustain their population. It is their physiology, though, not their lifestyle which makes rockfish susceptible to annihilation by anglers.

Rockfish rarely survive catch-and-release fishing because they have an unvented swim bladder. The swim bladder is a balloon-like organ which adjusts the buoyancy of a fish. As the fish ascends toward the surface, the swim bladder inflates. If the swim bladder has a vent, it can easily again deflate when the fish dives, but a rockfish cannot quickly deflate its swim bladder, and since the fish normally remains in deep water, it has no need to make large adjustments in the inflation or deflation of its bladder. When an angler catches a rockfish, though, and reels it to the surface, the gasses in the swim bladder expand and compress internal organs. Often, by the time the fish reaches the surface, the stomach bulges into the mouth cavity. Other common pressure-change injuries include ruptured swim bladders, ruptured blood vessels in internal organs, and bulging eyes or gas bubbles in the eyes.

Once the swim bladder of a rockfish has completely expanded, it will not likely deflate on its own because it does not have a vent. If the angler releases a fish with an inflated swim bladder, the fish floats on the surface until it suffocates, or something eats it. Gulls often land near floating fish and peck out its eyes while the fish is still alive.

Rockfish are good to eat and are harvested in commercial, sport, and subsistence fisheries from California to Alaska. Anglers have depleted many rockfish populations from British Columbia to California, and even when fisheries managers enact strict regulations or completely ban fishing in certain areas, these populations are slow to recover. Only older rockfish can reproduce, and few rockfish larvae survive to reach maturity.

Rockfish are not easy to manage because they live in deep, rocky spots where biologists cannot employ traditional sampling techniques. In Alaska, researchers do not know the abundance of most rockfish stocks, so fisheries managers have elected to implement strict regulations for catching and retaining rockfish, especially for yelloweye and other non-pelagic rockfish. Since even the rockfish anglers release are likely to die, though, biologists now focus on informing anglers of the fragility of rockfish populations.

The Alaska Department of Fish and Game distributes literature to sportfishing guides and posts informational signs near boat ramps to encourage anglers to follow these guidelines to avoid catching rockfish or to at least minimize rockfish harvest.

Angler's Guide to the Rockfishes of Alaska

If you are not targeting rockfish, avoid fishing where you are likely to catch them. Rockfish inhabit the steep sides of rock piles and reefs. Lingcod are found at the top of rock piles and reefs, and halibut lie on the flat bottom near a reef.
If you are targeting lingcod or halibut, keep your jig 10-15 ft. (3-5 m) off the bottom. Researchers in Oregon found this technique significantly reduced rockfish bycatch but did not affect the odds of catching halibut and actually increased the success rate for landing lingcod.
If you want to retain a few rockfish along with other species, target the other species first and retain any incidental rockfish you catch.
Fish with a circle hook. Circle hooks stick in the mouth and are not ingested, so they are easier to release and less likely to cause a serious injury.
Remember, rockfish only have a freezer life of four months, so don’t catch more than you can eat.
If targeting rockfish, implement deep-water-release methods.

In my next post, I will discuss deep-water-release techniques in more detail. This simple concept produces surprisingly successful results.

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Several weeks ago, I mentioned the Reader’s and Writer’s Book Club started by my publisher and some of my fellow authors. You can still claim your free lifetime membership to the club by following this link, but free membership will end within the next few weeks. I am currently writing a mystery with the aid of club members, and I invite you to join the fun!

As always, thanks for visiting my blog, and don’t forget to sign up for my free monthly mystery newsletter about true murder and mystery in Alaska.

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Black Rockfish

February 10, 2019Fish, Kodiak WildlifeBlack Rockfish, Black Rockfish in Alaska, Kodiak Fish, Robin Barefield, Rockfish, Rockfish of Alaska, Sebastes melonopsadmin

Black rockfish (Sebastes melonops) range from range from Amchitka Island, Alaska in the Aleutian Islands to California. Two weeks ago, I wrote about rockfish in Alaska, and I explained that biologists classify rockfish by dividing them into two groups: pelagic and non-pelagic. Last week, I wrote about yelloweye rockfish, a non-pelagic species. This week, I’ll write about black rockfish, a pelagic species and the most common rockfish in Alaskan waters.

Although not related to the bass family, anglers often refer to black rockfish as black bass because their shape resembles a bass. They have a mottled gray-black body, usually with dark stripes extending from the head to the gill cover. The sides are lighter than the back, and the stomach is pale gray. Black rockfish have a large mouth and a spiny dorsal fin. As with other rockfish, venom sacs lie at the base of each spine. The venom is only mildly toxic to humans, but it does cause pain and can lead to infection. Their light-colored stomach, the lack of pores or a knob on the lower jaw, black mottling on the dorsal fin, and their large mouth which extends past their eyes, are all features which distinguish black rockfish from similar species such as dark rockfish and dusky rockfish. Black rockfish grow to a maximum length of 29.6 inches (69 cm) and weigh up to 11 lbs. (5 kg).

Black rockfish are found anywhere from the surface to 1200 ft. (366 m) deep, but they usually inhabit water shallower than 492 ft. (150 m). They are sometimes seen in large schools at the surface when they are feeding, but they most commonly occur in rocky areas or remain above rocky pinnacles.

Black rockfish are much more mobile than yelloweye rockfish, but biologists in Oregon performed a tagging study and learned the average home range of a black rockfish is only .2 square miles (.55 sq. km). A rockfish sometimes travels outside its home range during the reproductive season or to feed.

Black rockfish reach sexual maturity between the ages of six and eight years. After mating, the female stores the male’s sperm for several months before fertilizing her eggs. Then, between January and May, she releases between 125,000 and 1,200,000 larvae. Black rockfish have a maximum lifespan of fifty years.

Black rockfish feed on zooplankton, crab larvae, and small fish species such as herring and sand lance. Predators of rockfish include sablefish, halibut, other fish species, and seabirds such as pigeon guillemots.

Black rockfish populations in Alaska are considered stable, but fisheries managers set conservative limits on all species of rockfish. Because black rockfish grow and mature slowly, live nearshore, and have small home ranges, they are susceptible to overfishing by sport and commercial fishermen. They are easy to find and easy to catch. Like other rockfish species, they have an unvented swim bladder, and when anglers reel them to the surface, they usually do not survive if released.

As I have mentioned several times over the past few posts, both pelagic and non-pelagic rockfish are highly susceptible to barotrauma, physical injuries due to rapid changes in pressure when an angler catches a rockfish and brings it to the surface. In my next post, I will discuss ways to spare rockfish from barotrauma and methods to protect fragile rockfish populations.

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Yelloweye Rockfish (Sebastes ruberrimus)

January 27, 2019Fish, Kodiak WildlifeFish of Alaska, Fish of Kodiak Island, Robin Barefield, Rockfish, Rockfish of Alaska, Sebaste ruberrimus, Yelloweye, Yelloweye Rockfishadmin

The brightly colored yelloweye rockfish looks like a fish you might expect to see swimming near a tropical reef, but yelloweyes live in the frigid waters of the northeastern Pacific Ocean, from Baja California to the Aleutian Islands in Alaska. Anglers sometimes call yelloweyes red snapper, but they are not snappers and are not related to the red snappers found in the Gulf of Mexico.

Yelloweyes are among the largest rockfish found in Alaska and can grow to 36 inches (91.44 cm) in length and weigh 24 lbs. (11 kg.). They vary in color from orange-yellow to orange-red, and they tend to become more yellow as they age. Juveniles are usually bright red and have two vertical stripes, one above and one below the lateral line. As they age, the stripes fade, and their color changes to a red-orange or orange. A very old rockfish might be yellow. While their fins tips of adults are usually black, the fins of juveniles are tipped either white or black. As their name suggests, their eyes gleam bright yellow, making them easy to identify. In addition to the spines found in their dorsal and anal fins, several small spines sprout from their head.

Adult yelloweyes are solitary fish and live in steep, rocky areas, where they can find shelter. They typically live on the ocean bottom, and they don’t venture far from their rocky homes. They usually live between 300 and 600 ft. (91.44 – 182.88 m), but they have been found in only 48 ft. (14.63 m) of water and as deep as 1,800 ft. (548.64 m). Because yelloweyes live in rocky areas near the bottom and have small ranges, biologists classify them as one of the species of non-pelagic rockfish.

Rockfish are long-lived and slow to mature. Yelloweyes can live over 100 years, and the oldest recorded was a 121-year-old individual caught in Southeast Alaska. Yelloweye males mature when they are approximately 18-years-old, while females do not reach sexual maturity until 22-years of age. Males fertilize a female’s eggs internally, and the female then carries and nourishes the eggs until they hatch into larvae. One female can give birth to as many as 2,700,00 larvae.

Since the female nourishes her eggs and gives birth to live organisms, you might expect rockfish to have a higher reproductive success rate than do other fish species where eggs receive little or no parental care, but unfortunately, only a small percentage of rockfish larvae survive to adulthood, and even fewer survive until they are sexually mature. As soon as they are released, ocean currents sweep most of the larvae out to sea, and the young fish die before they have a chance to feed and grow. Other larvae starve to death from a lack of food, while many fall prey to larger fish, seabirds, and other organisms. The few larvae that survive, drift with the ocean currents while they eat and grow into small fish. They then settle to the bottom where they can find protection from predators among rocks and under kelp. As the young grow, they move into deeper water.

Yelloweye populations are fragile and vulnerable to overfishing. Females do not reproduce until they are over twenty-years-old, and once the female releases her larvae, few of the young survive. Recruitment of young fish into the population is slow, and if a fish reaches sexual maturity and is then caught by an angler or eaten by a predator, the population suffers not only the loss of this one individual but also the loss of all the potential young this one fish could have produced during its long life.

Because yelloweyes seldom move from one area to another, they are easy targets for anglers, and they are easy to catch. Even strict regulations which prevent the retention of non-pelagic rockfish do not protect yelloweyes because when an angler reels a yelloweye to the surface from a depth greater than 90 ft., the fish usually cannot return to the bottom, and when released, it floats at the surface until it dies. Yelloweyes, like other rockfish, have an un-vented swim bladder, and as the swim bladder inflates when the fish is reeled to the surface, it compresses internal organs and often pushes the stomach out of the mouth. The fish cannot deflate its swim bladder at the surface, but the swim bladder will deflate to the normal size if the angler can return the fish to the bottom where it was caught. New deep-water release techniques have helped improve the survivability of released rockfish.

The best way to avoid killing a yelloweye is to avoid fishing in the rocky areas where they live. Fisheries biologists find it difficult and expensive to manage non-pelagic rockfish because hauling them to the surface to tag them would likely kill them. Researchers believe most yelloweye populations in Alaska remain stable, but they’ve enacted strict regulations to protect these beautiful fish.

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Rockfish of Alaska

January 20, 2019Fish, Kodiak Wildlife, UncategorizedBlack Rockfish, Fish of Alaska, Rockfish, Rockfish in Alaska, RockfishBiology, Yelloweye Rockfishadmin

Scientists have identified more than 102 species of rockfish belonging to the genus Sebastes, and over thirty species live in Alaskan waters.^] Although anglers sometimes refer to yelloweye rockfish as red snapper, and many call black rockfish black bass, there are no snapper or bass in Alaska.

Rockfish belong to the family Scorpaenidae, the “scorpionfishes.” Scorpionfish have venomous spines in their fins, and the venom in some species is extremely toxic. Rockfish venom is only mildly toxic, but it causes pain and swelling and can lead to infection. In most species of rockfish, the venom sacs are located at the base of the dorsal and anal fin spines, but in a few species, other fin spines are also venomous. They use their venom to defend themselves.

A rockfish has large scales, and in addition to its fin spines, it has smaller spines on its head and gill covers. Species range in color from bright reddish orange and yellow to gray and black. Individuals of some species grow to 40 inches (101.6 cm) in length.

Scientists divide rockfish species into two groups based upon their preferred habitats: Pelagic and Non-Pelagic. Pelagic species can be found at any depth and usually swim in large schools above rocky shelves. Pelagic species include black, dusky, dark, and yellowtail. Solitary non-pelagic rockfish remain near the bottom in rocky areas, sometimes hiding in cracks or under rocks. They usually live at a greater depth than pelagic species. Non-pelagic species include yelloweye, tiger, quillback, silvergray, China, copper, rougheye , and shortraker.

Rockfish are some of the longest living vertebrates. A yelloweye caught in Southeast Alaska was 121 years old, and shortraker rockfish can live over 150 years.^]

Some species of rockfish reach sexual maturity at five to seven years old, but others do not begin to reproduce until they 15 to 20 years of age. Most fish lay and fertilize eggs externally, but rockfish mate internally, and the female carries and nourishes the eggs for several months before giving birth to thousands or even millions of tiny larvae. The larvae are at the mercy of the ocean currents and wind, and most get swept out to sea and don’t survive. Those that do survive, are subject to predation. The larvae feed and grow in the ocean column for several months before they settle onto the ocean floor where they can seek protection in the kelp and rocks. As the young mature, they move into deeper water.

Researchers have found that while pelagic rockfish sometimes travel hundreds of miles, most maintain a range of only twenty miles. Non-pelagic species have very small ranges of only a few-hundred yards, and some spend their entire lives on the same rock pile.^] Because non-pelagic species do not travel far from their rocky homes, they are easy targets for anglers and are vulnerable to overfishing.

Rockfish eat plankton, crabs, shrimp, and small fish, including smaller rockfish. They are preyed upon by Pacific cod, lingcod, sablefish, other rockfish, halibut, king salmon, sculpins, sharks, seabirds, marine mammals, and humans.

Non-pelagic rockfish are more susceptible to overfishing than most fish species. Not only are they easy to find and catch, but they rarely survive catch-and-release fishing because their air bladder or swim bladder has no vent. A fish uses its swim bladder to adjust buoyancy, and when a rockfish is caught in its deep home and reeled to the surface, the balloon-like swim bladder rapidly expands and pushes against its internal organs. By the time the fish reaches the surface, the expanded swim bladder often shoves the stomach into the mouth. Once it is at the surface, the fish is unable to deflate the swim bladder, and if the angler releases it, the fish will float at the surface and die.

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In my next post, I will discuss yelloweye rockfish in more detail, and in the following post I’ll focus on black rockfish. Then, I’ll talk about rockfish management and techniques anglers can employ to preserve non-pelagic rockfish populations.

I have been traveling for the past two weeks and will be on the road for another three weeks, so my posts have been less frequent than usual, and I probably won’t return to a steady schedule until I get home. Thanks for reading, and I hope you are enjoying a great winter.

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Sablefish (Anoplopoma fimbria)

September 2, 2018Fish, Kodiak WildlifeBlack Cod, Robin Barefield, Sablefish, Sablefish in Alaskaadmin

Sablefish (Anoplopoma fimbria) or black cod, as they are commonly called, are not related to Pacific cod but are instead in the family Anoplopomatidae, a family with only one other species, the skilfish (Erilepis zonifer).

A sablefish is slim and long and covered with small scales. It is dark gray or grayish-green on its back and sides and light gray or white on its stomach. It has two widely separated dorsal fins and a tail which is lightly indented in the middle. Sablefish have large mouths with small teeth. They grow quite large and have been known to reach 45 inches (114 cm) in length and 50.5 lbs. (25 kg). An average-sized sablefish weighs 8.1 lbs, (3.7 kg) and is 27 inches (69.1cm) long.

Sablefish range from Alaska and British Columbia south to Baja, California, and west to Kamchatka and Japan, Alaska has the highest concentration of sablefish.

Adult sablefish live on the slopes of the continental shelf and are usually found at depths of 492 to 4921 ft. (150 – 1500 m), but they have been found as deep as 9842 ft. (3000 m). Juveniles live nearshore in much shallower water. Juveniles are pelagic, while adults live near the bottom.

Sablefish spawn in the winter, normally between January and March, but spawning is dependent upon location. They spawn along the continental shelf at depths greater than 3281 ft. (1000 m.) Sablefish become sexually mature between five and seven years, and once they reach sexual maturity, they spawn annually. A female lays 110 eggs per gram of body weight, so an average sized female weighing 3.7 kg will lay approximately 407,000 eggs.

Sablefish larvae drift inshore, and juveniles remain inshore until they reach a size of 12 to 16 inches (30 -40 cm) at the age of two to five years. They then begin to move into deeper water and settle near the bottom, where they continue to grow.

Juvenile sablefish eat zooplankton and small fish, and adults eat fish, squid, octopus, and crustaceans. Survival of juveniles varies greatly from year to year, and biologists believe this variability is linked to zooplankton abundance, which is in turn linked to environmental conditions. Zooplankton thrive during years when ocean temperatures and nutrients produce rich phytoplankton crops for them to eat, and juvenile sablefish then eat the zooplankton, such as krill. When conditions are not favorable, though, zooplankton numbers drop, and fewer sablefish survive.

Juvenile sablefish are prey for many fish species, including Chinook and coho salmon. Sperm whales are a major predator of adults. Sablefish often live as long as 40 years, and the oldest recorded in Alaska was 94-years-old.

Like halibut, sablefish bring a high price per pound to commercial fishermen, and the current value of sablefish in the U.S. fishery is approximately $50 million per year. Most of the commercial catch is exported to Asia, where it is considered a delicacy, but sablefish is gaining popularity in the U.S. Sablefish are primarily harvested by longline or trawling. A small but growing sport fishery for sablefish has developed in Southeast Alaska.
Sablefish abundance has dropped since the 1980s, but with stricter commercial regulations in place, fishery managers consider the population stable. Both state and federal agencies manage sablefish.

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Robin Barefield is the author of three Alaska wilderness mystery novels, Big Game, Murder Over Kodiak, and The Fisherman’s Daughter. To download a free copy of one of her novels, watch her webinar about how she became an author and why she writes Alaska wilderness mysteries. If you like audiobooks, check out her audiobook version of Murder Over Kodiak. Also, sign up below to subscribe to her free, monthly newsletter on true murder and mystery in Alaska.

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Lingcod (Ophiodon elongatus)

August 26, 2018Fish, Kodiak WildlifeAlaskan Fish, Fishing in Alaska, Fishing on Kodiak Island, Greenling, Kodiak Island, Lingcod, Lingcod Biology, Robin Barefieldadmin

Lingcod are not true cod and are not related to Pacific cod or pollack. Instead, lingcod are the largest members of the greenling family. Adults average 10 lbs (4.5 kg), but they can grow to over 80 lbs. (35 kg) and measure 60 inches (150 cm) in length.

A lingcod has a long body and varies in coloration from gray to brown to green or even blue on the back and sides and lighter on the stomach. It is covered with dark brown or copper blotches arranged in clusters, and it has a prominent light-colored lateral line and large, cycloid scales. A long dorsal fin spans the distance from behind the head nearly to the tail. The front part of the fin is spiny, while the posterior portion consists of soft rays. A notch connects the two sections. The anal fin has three spines. The head and mouth of a lingcod are large, and the mouth holds 18 big, sharp teeth. The head does not have scales.

Lingcod are found only on the west coast of North America, from the Alaska Peninsula and Aleutian Islands south to Baja California. They are common throughout Southeast Alaska, along the outer reaches of the Kenai Peninsula, around Kodiak Island, and in Prince William Sound. They normally live nearshore around rocky reefs from depths of 30 to 330 ft. (10 – 100m), but they have been found as deep as 1000 ft. (300 m). Lingcod usually stay in the same area and often near the same reef for their entire lives, but researchers have tagged lingcod that have moved as far as 500 miles (800 km) from where they were first observed.

Female lingcod mature between three and five years of age at a length of 24 to 30 inches (61-75 cm). Males mature when they are two years old and approximately 20 inches (45 cm) long. Lingcod nest in rock crevices or ledges with strong currents. A male leads a female to the nesting area, and the female lays between 150,000 to 500,000 eggs. The number of eggs a female lays increases with both size and age. Once the female lays her eggs, she leaves the area, and then the male fertilizes the eggs and stays to guard the nest. In Alaska, lingcod begin spawning in early December, with peak spawning from mid-January to mid-March. The eggs hatch within 5 to 11 weeks, so most hatching takes place between mid-March and mid-May.

Male lingcod guard the egg nests until the eggs hatch. If left unguarded, egg nests are usually decimated within 48 hours by rockfish, starfish, sculpins, kelp greenling, and cod. The adult male must be aggressive to drive away invading fish and invertebrates, and if something happens to him, the eggs will not survive. Unfortunately, this aggressive behavior of the male makes him more vulnerable to predation by seals, sea lions, and anglers.

Lingcod larvae measure ¼ to ½ inch (7-10 mm) in length. They drift with the ocean currents and grow rapidly by eating copepods and small fish. By mid-summer, when they are 3-inches (150 cm) long, they settle on the bottom in kelp or eelgrass beds and feed on juvenile herring or other small fish. They remain in shallow water as they grow. Adult lingcod are voracious predators and grow rapidly. They feed on invertebrates and fish, including other lingcod who are nearly their same size. Lingcod continue growing until they are 12 to 14 years old. Male lingcod have a maximum lifespan of 14 years, while females can live as long as 20 years.

Lingcod are popular for both sport and food. Their flesh is white with a natural blue-green tint. The blue coloration disappears when cooked. The flesh is dense and mild tasting and is high in protein, minerals, vitamins, and omega-3 fatty acids. Lingcod are taken by subsistence, sport, and commercial fishermen. Because they are so aggressive, they are excellent fighters for sport anglers.

Lingcod are highly susceptible to overfishing. Anglers can easily find lingcod because they live nearshore in shallow, rocky areas, and since they are so aggressive, they readily hit a lure. Once a lingcod population is overfished, it doesn’t recover for a long time. Because lingcod can be easily over-harvested, the Alaska Department of Fish and Game conservatively manages the lingcod fishery. To protect spawning females and nest-guarding males, sport and commercial fisheries are closed during the spawning and nest-guarding periods. Also, minimum size limits have been established to protect immature fish, and finally, catch limits are restricted.

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Robin Barefield is the author of three Alaska wilderness mystery novels, Big Game, Murder Over Kodiak, and The Fisherman’s Daughter. To download a free copy of one of her novels, watch her webinar about how she became an author and why she writes Alaska wilderness mysteries. If you like audiobooks, check out her audiobook version of Murder Over Kodiak. Also, sign up below to subscribe to her free, monthly newsletter on true murder and mystery in Alaska.

Mystery Newsletter

Walleye Pollock (Gadus chalcogrammus)

July 29, 2018Fish, Kodiak WildlifeAlaska Fish, Alaska Pollock, Commercial Fishing, Gadus chalcogrammus, Pacific Cod, Pollock, Robin Barefield, Walleye Pollockadmin

The walleye or Alaska Pollock (Gadus chalcogrammus) is another species in the true cod family Gadidae. For a long time, taxonomists placed walleye pollock in a separate genus from Pacific cod, but researchers have recently shown pollock are closely related to Pacific and Atlantic cod, and most taxonomists now include walleye pollock in the genus Gadus.

Pollock are more streamlined than their gray cod cousins, but like cod, pollock have olive-green to tan mottled markings their backs. This coloration helps camouflage them from predators and prey when they rest and swim near the sandy ocean bottom. Pollock have silvery sides, white bellies, three dorsal fins, and two anal fins. Pollock have either no chin barbel or only a tiny barbel.

Pollock range from the Sea of Japan and the Sea of Okhotsk west to the Bering Sea and the Gulf of Alaska and south to Northern California. They migrate in a circular pattern, moving inshore to relatively shallow waters from 295 to 460 ft. (90 to 140 m) to breed and feed in March and then returning in December to the warmer, deeper waters of the continental shelf to 525 to 984 ft. (160 to 300 m). Pollock are semi-demersal (semi-bottom dwelling) but can be found anywhere from the surface to 1640 ft. (500 m).

Pollock spawn from March to mid-June. They form dense schools when spawning and broadcast eggs and sperm into the water. Fertilized eggs are planktonic, and depending on the temperature of the water, they incubate for approximately 10 to 27 days. When the larvae hatch, they have a yolk sac and float upside down at the water surface until the sac is absorbed.

Young pollock eat zooplankton, but as they grow, they begin adding fish to their diet. Adults feed on young pollock and other fish. Pollock grow rapidly and can reach a length of 3.4 ft. (105 cm) and a weight of 13.3 lbs. (6.05 kg). They usually don’t, live more than 10 years, but biologists in Alaska have recorded pollock as old as 22 years.

Alaska pollock is the largest fishery by volume in the United States and the second most important fishery in the world. The Alaska pollock has been called, “The largest remaining source of palatable fish in the world.”

From 1964 through 1980, only foreign vessels harvested Alaska pollock. U.S. vessels began to enter the fishery in 1980, and by 1987, U.S. boats harvested 99% of the quota. Since 1988, only U.S. vessels have operated in the Eastern Bering Sea pollock fishery. From 2002 to 2006, the Eastern Bering Sea pollock catch averaged 1.48 million metric tons worth $500 million annually.

While biologists do not believe pollock have been overfished, stocks have declined in recent years. The pollock fishery was originally a bottom fishery and trawls were dragged across the ocean bottom to catch the fish. As concerns about habitat degradation from bottom trawling grew, fishermen switched to pelagic trawl gear, which is deployed above the seabed. Controversy also swirls around the use of pelagic trawl gear, though, since the trawl is not specific to pollock but catches and often kills any fish it encounters.

Pollock is an important food for Steller sea lions, and when sea lion populations began decreasing, managers reduced fishery time and implemented area closures for pollock near critical sea lion habitat.

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Next week I plan to take a short break from fish and set the stage for a wonderful guest post from a fellow author the following week. Three weeks from now, I will write about lingcod. As always, thanks for visiting my blog.

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Robin Barefield is the author of three Alaska wilderness mystery novels, Big Game, Murder Over Kodiak, and The Fisherman’s Daughter. To download a free copy of one of her novels, watch her webinar about how she became an author and why she writes Alaska wilderness mysteries. If you like audiobooks, check out her audiobook version of Murder Over Kodiak. Also, sign up below to subscribe to her free, monthly newsletter on true murder and mystery in Alaska.

Mystery Newsletter

Pacific Cod Commercial Fishery

July 22, 2018Fish, Kodiak WildlifeAlaska Fishing, Atlantic Cod, Cod, Cod in Alaska, Pacific Cod, Robin Barefieldadmin

Three weeks ago, I wrote about the collapse of the Pacific cod population in central and southwestern Alaska. Over the course of two years, cod went from one of the most prolific fish species in the area to nearly non-existent. The Alaska Department of Fish and Game slashed commercial fishing quotas in 2017, but there were so few cod, commercial fishermen struggled even to catch the allowed poundage. The economic ramifications from the crash of the Pacific cod fishery are just beginning to affect Alaska’s ports, and biologists believe it will be years before the launch of another viable cod fishery.

This week, I’ll explain more about the history of the Pacific cod fishery and commercial methods for harvesting cod in Alaska. First, though, I want to emphasize the importance of Pacific cod not only to fishermen but also to consumers. Most of us at some point in our lives have eaten cod; whether it was a fish stick, a fish sandwich, fried fish, or baked white fish, cod is one of the most popular fish served by restaurants from fast-food drive-ins to diners to gourmet bistros. Cod has a mild flavor and a dense, flaky white flesh. It freezes well and can be shipped long distances. Cod liver oil is made from cod livers and is an important source of vitamin A, vitamin D, vitamin E, and omega-3-fatty acids.

The Pacific cod fishery gained traction just as the Atlantic cod fishery began to crash. The Atlantic cod fishery lasted for more than 1000 years and was popular even during the Viking period, around 800 AD. The fishery was vital to Europe, Canada, and the U.S., but this widespread popularity of Atlantic cod led to its downfall. Atlantic cod populations survived centuries of human strife, ranging from plagues to wars, only to be fished to the point of annihilation because the many countries that commercially fished cod couldn’t agree on regulations to protect this valuable resource. With Atlantic cod no longer available, fish buyers looked to the Pacific.

Pacific cod have been commercially fished on a small scale since the 19th century, but the modern commercial fishery began in the early 1960s with the Japanese longline fishery in the Bering Sea/ Aleutian Island (BSAI) region. Between 1980 and 1989, a U.S. trawl fishery and several joint venture fisheries began in both the BSAI and the Gulf of Alaska (GOA) regions, and by 1989 the U.S. commercial cod fishery overtook the foreign fishery in both the BSAI and GOA regions.

Multiple methods are now used to harvest Pacific cod, including trawl, longline, pot, and jigging. Between 1991 and 1999, trawl gear accounted for 52% of the cod catch, longline gear took 37% of the harvest, and pot gear caught 11%. After 2000, however, longline fishing became the most productive means of landing cod. Between 2000 and 2006, longline gear accounted for 46% of the catch, trawl gear 37%, and pot gear 16%.

According to recent NOAA Fisheries Service surveys of Pacific cod stocks taken only a few years before the population collapsed, the cod stocks in Alaskan waters were stable and were not being over-fished. In 2010, NOAA estimated the BSAI stock at 1 million metric tons and the GOA stock at 0.4 million tons. Biologists have closely regulated the Pacific cod fishery and have erred on the side of caution by setting strict quotas to protect not only the cod fishery but also marine mammals such as Steller sea lions that depend on cod for food.

Researchers are now working diligently to discover what happened to the Pacific cod. Why did the cod population crash in Alaska? The leading theory is the crash was caused by warmer-than-normal ocean temperatures which in turn caused a reduction in the biomass of phytoplankton and zooplankton in the North Pacific. Juvenile cod, like most young fish, depend on zooplankton as a food source. Because of the reduction of zooplankton in the North Pacific, juvenile cod had little to eat, and many starved to death.

If the zooplankton biomass in the North Pacific has decreased to the point where cod can’t find enough to eat, we should all be concerned, not only for cod but for all animals in this portion of the sea. Marine animals from the smallest fish and birds to the largest whales depend on phytoplankton and zooplankton to survive.

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Robin Barefield is the author of three Alaska wilderness mystery novels, Big Game, Murder Over Kodiak, and The Fisherman’s Daughter. To download a free copy of one of her novels, watch her webinar about how she became an author and why she writes Alaska wilderness mysteries. If you like audiobooks, check out her audiobook version of Murder Over Kodiak. Also, sign up below to subscribe to her free, monthly newsletter on true murder and mystery in Alaska.