Tag Archives: Rockfish in Alaska

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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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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