Biology and Life Cycle of the King Crab

September 8, 2019Crab, Kodiak WildlifeAlaska King Crab, King Crab, King Crab Biology, King Crab Life Cycle, Red King Crab, Robin Barefieldadmin

Researchers do not fully understand the biology and life cycles of any of the king crab species, but red king crabs have been the most extensively researched. Scarlet king crabs live very deep where they are challenging to study, so biologists know little about their life history. The following describes the life cycle of the red king crab, except where noted.

Before mating, a female king crab must molt by shedding her shell. A few weeks before molting, the female begins releasing pheromones into the water, signaling to males in the area she will soon be ready to mate. When the male finds the female, he grasps her first pair of legs in his claws and holds her facing him for several days. Meanwhile, the female begins to molt. Her old shell separates, and it takes her only 15 minutes to climb out of the shell. A new, soft carapace now covers her, and she absorbs water and swells, making her appear larger.

After the female has molted, the male turns her upside down and places her beneath him. He inserts his ventral surface under her abdominal flap, where he releases strings of sperm. The female releases her ova from paired openings on the underside of her second walking legs. As soon as each ovum is exposed to seawater, a sac forms around it, and the sperm fertilizes the ovum. This process can be repeated several times over the next few hours. Once he finishes, the male releases the female and shows no further interest in her.

The female incubates the eggs under her tail flap for eleven to twelve months. A female king crab, depending on her species and her age, will carry between 45,000 and 500,000 eggs. Blue king crabs have bigger eggs and a lower fecundity than red king crabs. The female releases her larvae between February and April over a period of approximately 29 days. When they first hatch, the larvae resemble tiny shrimp. The larvae pass through four zoeal instar stages, each lasting between ten days to two weeks, and they finally transition into the stage which resembles a small crab. The larvae eat both phytoplankton and zooplankton and become more carnivorous as they age. When the young crabs finally settle to the bottom, they are about the size of a dime and are very susceptible to predation. The larvae settle from July through early September.

Young king crabs migrate to depths of 150 ft. or deeper. Red king crabs are known to form giant pods, and biologists believe they assemble in these pods to protect against predators. Other king crab species have not been observed forming pods. Around age four or five, king crabs move to shallower water during the spring migration to join the adults.

Red king crabs spawn every year, but blue king crabs reproduce every two years. After spawning, adult red king crabs settle at depths between 90 and 200 ft. for the remainder of the year. Red king crabs seem to prefer soft sand. Red and blue king crabs are known as shallow-water species, while golden king crabs settle at least 300-feet deep, and scarlet king crabs seek out even deeper habitats.

King crabs are opportunistic feeders, and they eat sponges, barnacles, sand dollars, brittle stars, sea stars, worms, clams, mussels, snails, crabs, and other crustaceans. What they eat depends on their size and available prey species.

King crabs have several predators, including fishes such as Pacific cod, halibut, sculpins, and yellowfin sole. A king crab will prey upon a smaller king crab, and octopuses and sea otters also eat king crabs. Nemertean worms consume king crab embryos.

King crabs are also susceptible to parasites and many diseases. The Rhizocehpalan barnacle invades a king crab’s internal tissues, producing an immunosuppressive agent to cloak its presence. The barnacle eventually castrates the crab and stunts its growth. Liparid fish parasitize king crabs by depositing their eggs in the gill chambers of the crabs. The egg mass interferes with respiration and can lead to death.

Biologists estimate king crabs can live twenty to thirty years.

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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Alaska King Crab

August 25, 2019Crab, Kodiak WildlifeAlaska King Crab, Blue King Crab, Golden King Crab, Red King Crab, Robin Barefield, Scarlet King Crabadmin

The family Lithodidae, known as the stone or king crabs, has 16 genera and 95 known species. Four species are commercially fished in Alaskan waters. These are the red king crabs (Paralithodes camtschaticus), the blue king crabs (Paralithodes platypus), the golden king crabs (Lithodes aequispinus), and the scarlet king crabs (Lithodes couesi). Of these, red king crabs are the most abundant and extensively studied species. Scarlet king crabs are much smaller than the other three species, and because they live in very deep water, researchers know little about their life cycle. Since scarlet crabs are smaller than red, blue and golden king crabs, they are not commercially significant.

All four species have different but overlapping distributions throughout the Gulf of Alaska, Bering Sea, and the Aleutian Islands. Red king crabs range from British Columbia to Japan and north to the Bering Sea. They are most abundant in Bristol Bay and the Kodiak Archipelago. Red king crabs exist from the intertidal zone to 600 ft. (183 m) or deeper.

King crabs receive their common names from the color of their carapaces. All king crabs are decapods, meaning they have ten legs. Unlike brachyuran crabs, which are considered “true” crabs, king crabs are not symmetrical but have an asymmetrical abdomen, asymmetrical first pair of walking legs, and modified fifth pair of walking legs. Biologists think king crabs are more closely related to hermit crabs than they are to brachyuran crabs such as Dungeness crabs.

King crabs have tails or abdomens which are fan-shaped and are tucked underneath the rear of the shell. Of their five pairs of legs, the first is their claws or pincers. The right claw is usually the largest. The next three pairs are their walking legs, and the fifth pair of legs are small and usually tucked underneath the rear of their carapace. Adult females use these specialized legs to clean their embryos, and males use them to transfer sperm to females during mating.

A crab’s skeleton is its external shell made of calcium. In order to grow, a crab must periodically shed and grow a new, larger carapace, during a process called molting. Juveniles molt frequently during their first few years but less often when they reach sexual maturity at the age of four or five years. Adult females must molt in order to mate, but a male does not need to shed his shell to mate. Adult female red king crabs molt and mate once a year, but males often keep the same shell for two years. King crabs shed their shells by absorbing water, causing the shell to crack.

Red king crabs are the largest of the king crab species. Blue crabs are the second largest, and golden king crabs are the third largest. Female red king crabs reach a maximum weight of 10.5 lbs. (4.8 kg), and males grow as large as 24 lbs. (10.9 kg). A large male has a leg span of nearly five ft. (1.52 m) and a carapace as long as 11 inches (27.9 cm). King crabs can live 20 to 30 years.

Red, blue, and golden king crabs migrate annually from nearshore to offshore. They migrate to shallow water in the late winter or early spring where the female’s embryos hatch. Adult females and some adult males then molt, and mating occurs before the crabs return to deep water. Once they have mated, adults segregate by sex. Biologists studying male red king crabs near Kodiak noted some males migrate up to 100 miles (161 km) round-trip annually, and at times, they move as fast as a mile (1.6 km) per day. While depth ranges and habitats overlap, red, blue, gold, and scarlet king crabs rarely co-exist.

In my next post, I will cover the lifecycle and feeding habits of king crabs as well as the status of king crab populations and the threats they face.

Please sign up below for my newsletter about true murder and mystery in Alaska, and I invite you to listen to my podcast, Murder and Mystery in the Last Frontier.

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Alaska Crab

August 11, 2019Uncategorizedadmin

One of the many images the name “Alaska” conjures is a platter of steaming crab legs accompanied by a ramekin of drawn butter. King crab ranks with lobster as one of the premiere shellfish delicacies in the world.

While shellfish connoisseurs have long appreciated king crab, tanner crab (snow crab), and Dungeness crab from Alaska, the television series The Deadliest Catch made folks aware of the rigors and dangers involved in catching the beautiful crabs they craved. Although the show is sometimes overly dramatic, there is no question that while crab fishing can be highly profitable, it is often dangerous.

Over my next several posts, I plan to explore in detail some of the species of crabs inhabiting Alaska’s waters, and then I will describe the seasons, techniques, and perils of fishing for these crabs.

I have been busy lately. Not only did I leap into podcasting, but I recently finished writing my fourth novel, Karluk Bones. The book is now in my publisher’s hands and should be available soon. I completed the rough draft of this novel last December and finally finished editing it in July. It is a tremendous job to write and edit a book!

I have also been working with the incredible actress Carol Herman to produce an audiobook of The Fisherman’s Daughter, and I am happy to announce Carol finished her narration, and the book should be available soon. I like to provide audiobook editions of my novels because I enjoy listening to audiobooks. Between my work at our lodge and my writing career, I have little spare time to read, so I listen to audiobooks while I work in the yard, cook, paint, or run the boat. I love listening to a good story.

With two big projects out of the way, I can now focus on new challenges. My first goal is to finish my wildlife book, and my second is to work on my next novel. Meanwhile, I will continue with my mystery newsletter, my podcast, and my blog.

I am looking forward to learning more about crab, and my next post will delve into the types and ranges of the four commercially valuable king crab species in Alaska.

As always, I would love to have you leave comments, questions, ideas, and even critiques. Thank you for reading!

If you would like to receive my newsletter on murder and mystery in Alaska, sign up below. Also, don’t forget to listen to my podcast, Murder and Mystery in the Last Frontier. I now have six episodes available to stream or download.

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What Would You Do if You Encountered a Bear in the Woods?

July 28, 2019Kodiak Bear, Kodiak WildlifeAlaska Brown Bears, Bear Encounters, Bear Protection, Black Bears, Kodiak Bears, Robin Barefield, Safety Around Bearsadmin

What would you do if you saw a bear in the woods? It’s fun to imagine hypothetical situations and wonder how you would react in a high-stress scenario, but for anyone traveling to Alaska or anywhere else with wild bear populations, you should seriously consider how you would react if you encountered a bear in the woods. Don’t venture into the Alaska bush with no bear protection plan in mind. Educate yourself, learn about bear behavior, ways to avoid bears, and what to do if you encounter a bear.

Bertie from Effortless Outdoors recently sent me a link to his article titled, What To Do If You See A Bear (And Why) and asked me to mention it on my blog. The piece is very detailed and well-researched. My one complaint is he didn’t separate Kodiak bears (or even Alaskan brown bears) from grizzly bears. While all brown bears are members of the same species, grizzlies and coastal brown bears exist in different environments and often do not react the same way to humans. Kodiak bears have more to eat and grow larger than grizzlies, but grizzlies are often more aggressive than Kodiak bears toward humans. This one criticism aside, though, Bertie’s article is good and provides some interesting facts.

Unless your goal is to see a bear, follow Bertie’s tips for avoiding a bear encounter. He helps separate fact from fiction. For example, studies show those obnoxious little bear bells that annoy your hiking companions do not deter bears and may even attract them. A whistle is also a bad idea.

Keep in mind, bears have individual personalities and do not all react to humans in the same way. A bear’s response to a person depends, in part, upon his past experiences with people. If a bear rarely sees humans, he could be startled, curious, or terrified to spot a person on his trail. On the other hand, a bear living in an area commonly visited by tourists might not even look at you as you pass him in the woods. Black bears behave differently from brown bears, and a polar bear’s reaction to a human is so dissimilar from the response of a black or brown bear, it’s a bit misleading even to include polar bears in the same article.

My husband, Mike Munsey, and I take guests bear viewing each summer. Mike knows Kodiak bears well. He understands their body language and vocalizations and can quickly spot a bear acting aggressively. He would be the first to tell you, though, that bears in other areas of Alaska often exhibit different behaviors from the ones we encounter.

If you are planning to travel in bear country, research the bears in the area you plan to visit. Contact biologists and ask what information you can download about the bears you might encounter, and inquire into methods you can use to protect yourself. If you are camping, you will want bear-proof food containers, and if you plan to camp in an area with a high concentration of bears, you might consider purchasing a portable electric fence.

If you want to see bears but don’t know anything about them, hire a guide. You have no business trying to get close to a bear on your own if you have no bear experience.

One of my favorite parts of Bertie’s article is where he uses an illustration to demonstrate the likelihood of being killed by a bear. As the graphic clearly shows, you are much more likely to be killed by a dog, a cow, or lightning than you are to be mauled and killed by a bear.

The bottom line if you encounter a bear in the woods: respect the bear’s intelligence and strength, but don’t fear the animal. The bear is likely more terrified of an encounter with you than you are of seeing him.

Robin Barefield is the author of three Alaska wilderness mystery novels, Big Game, Murder Over Kodiak, and The Fisherman’s Daughter. Sign up below to subscribe to her free, monthly newsletter on true murder and mystery in Alaska, and listen to her podcast, Murder and Mystery in the Last Frontier.

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Why are Gray Whales Dying?

July 14, 2019Gray Whale, Kodiak WildlifeBering Sea, Climate Change, Gray Whale Deaths, Gray Whales, Ocean Warming, Unusual Mortality Event, whales in Alaskaadmin

One-hundred-seventy-one gray whales have washed up on Pacific beaches from Mexico to Alaska so far this year. Seventy-eight whales were spotted off the coast of Mexico, 85 in U.S. waters, and eight near Canada. Of the whales found along the U.S. Pacific Coast, 37 dead whales were spotted in California, five in Oregon, 29 in Washington, and 14 in Alaska. Since most whales sink to the ocean floor when they die, the 171 recovered carcasses probably represent only a fraction of the number of gray whales that have died on their northward migration this spring and summer.

In my last post, I wrote about tufted puffins dying on the Pribilof Islands in the Bering Sea, and I explained how their deaths are likely linked to the warming ocean temperatures in the Bering Sea. It comes as no surprise to learn puffins aren’t the only animals affected by warming water temperatures and melting sea ice. From the smallest zooplankton to the most massive whales, all animals in the region are feeling the impact of climate change.

Gray whales have one of the longest migrations of any mammal. In the summer they feed in the Arctic in the Bering, Chukchi, and Beaufort Seas, and in the fall, they migrate to their calving grounds in the southern Gulf of California and Baja Mexico, a migration of 5000 to 7000 miles (8,050 – 11,275 km) each way. Their average swimming speed is only 3 to 5 mph (5-8 km/hr), so this migration takes a long time.

The known deaths of 171 whales have induced the National Oceanic and Atmospheric Administration (NOAA) to declare an “unusual mortality event” and launch an investigation to determine why the whales are dying. Necropsies of the whales indicate most have starved to death. Ship strikes killed four found in San Francisco Bay, and since gray whales don’t usually enter this area, researchers assume these animals were stressed and perhaps searching for food.

Investigators aren’t sure why the whales are starving, but they think it’s possible the gray whale population has exceeded its carrying capacity under current conditions. In other words, there are too many gray whales and not enough food.

We know gray whales have been impacted by ocean warming in recent years. During the summer of 2018, waters in the Bering Sea soared nine degrees warmer than average. These increasing seawater temperatures have reduced winter ice cover in the region, which has led to a reduction in productivity. Primary productivity in the northern Bering Sea declined 70% from 1988 to 2004. This previously ice-dominated, shallow ecosystem favored large communities of benthic amphipods (the favorite food of gray whales), but it has now been replaced by an ecosystem dominated by smaller species of zooplankton, such as krill. Gray whales have responded by migrating further north to the Chukchi Sea, but amphipods might now be disappearing from this region as well, forcing gray whales to consume less nutritious krill, and krill might not contain the percentage of fatty acids the whales need to build adequate blubber.

Scientists expect to find more dead gray whales this summer, and one was recently washed up on a beach on Kodiak Island. NOAA continues to monitor the mortality event and posts updates on this website.

If you enjoy listening to podcasts, I invite you to check out mine: Murder and Mystery in the Last Frontier.

http://murder-in-the-last-frontier.blubrry.net.

Mystery Newsletter

Tufted Puffins Warn Us of Our Changing Climate

June 30, 2019Birds, Kodiak WildlifeAlaska Birds, Melting Sea Ice, Puffin, Puffins warn us of our changing Climate, tufted puffin, Tufted Puffins Die in Alaska, Tufted Puffins Starving to Deathadmin

Tufted puffins are shouting a warning from the middle of the Bering Sea, and we need to listen to them. As our oceans warm, these beautiful birds are starving to death.

Alaska’s four Pribilof Islands sit between mainland Alaska and Russia. The islands support more than two million seabirds, which survive by feeding on plankton and fish in the nutrient-rich Bering Sea. With so many birds in one area, it’s not unusual to occasionally find dead ones, but alarm bells sounded when biologists learned more than 350 dead birds had washed up on the beaches of St. Paul Island, the largest of the Pribilof Islands. This number is seventy times higher than the annual average count of five bird carcasses. Stranger still, most of these dead birds were tufted puffins, a bird that rarely washes up on the beach after it dies.

Biologists knew the birds they’d found dead represented only a fraction of the total, so they applied a computer model using wind patterns and ocean currents to determine what percentage of the dead birds likely reached the shore. From this percentage, they calculated somewhere between 3,150 and 8,800 birds perished in late 2016. Even if you choose to believe the low end of this estimate, the numbers are astounding.

Two species of puffins live in Alaskan waters. The horned puffin (Fratercula corniculata) and the tufted puffin (Fratercula cirrhata) belong to the family Alcidae, which also includes guillemots, murres, murrelets, auklets, and auks. A tufted puffin has a black body, a white face, and a red and yellow bill. Its common name is derived from the long tufts of yellow feathers curling back from behind the eye on each side of the head. Adult tufted puffins measure 14 inches (36 cm) in length and weigh 1.7 lbs. (771 g).

What killed the puffins?

The dead birds recovered from the beach appeared emaciated with weak flight muscles and almost no body fat. The birds had starved to death, but why?

Puffins feed on small fish, and until recently, many resided in the Pribilof Islands so they could gorge themselves on the abundance of fish in the rich Bering Sea. The icy Bering Sea is rapidly changing, though, as the ocean warms. As the sea ice recedes and thins, pollock, cod, and other fish can no longer find the super-cooled water at the edges of the ice sheet where they like to congregate. Instead, the fish disperse, making them more difficult for puffins to find and catch. Puffins now must travel further to find food, burning precious calories.

Also, as the northern ocean warms, dominant plankton species have shifted from large, meaty forms to smaller less energy-rich species. In turn, the plankton-eating fish are also thinner and provide fewer nutrients to the animals that eat them.

Puffins molt from August to October, and as they replace their feathers, the birds can barely fly and dive, making it difficult to feed themselves unless prey species are plentiful. Biologists were not surprised to learn most of the dead puffins they found on the beaches were in the middle of molting. The birds couldn’t travel far to travel to find food while molting, and they starved to death.

Puffins are not the only species affected by the loss of sea ice in the Bering Sea, and the diminished food source is not the only issue related to the melting ice. Without sea ice clinging to the coast, winter storms now batter the rocky cliffs, causing erosion at an unprecedented rate. These cliffs provide homes for seabirds, and some of the rocky beaches are breeding sites for endangered Steller sea lions.

The Pribilof Islands are a distant place most humans will never visit, but the drama playing out on those remote islands demands our attention now. The puffins are trying to tell us our environment is changing at an alarming rate.

Mystery Newsletter

True Crime Podcasts

June 10, 2019Podcast, WritingCriminal, Generation Why, Lore, Murder and Mystery Podcast, Murder in the Last Frontier, Sword and Scale, True Crime Historian, True Crime Podcastadmin

In my last post, I announced the premiere of my true crime podcast titled, Murder and Mystery in the Last Frontier. One of the reasons I started a true crime podcast is because I am a fan of murder and mystery podcasts, so this week, I thought I’d tell you about some of my favorites and how they inspired me to begin my own podcast.

True crime podcasts take a variety of formats from a sleek sound production including interviews with those who had firsthand knowledge of the crime to dramatic recreations of events to a simple retelling of the facts of the crime. Some crime podcasts are seasonal with each season devoted to a particular murder or murderer. In these podcasts, the host breaks down the crime and the investigation. Other murder podcasts take an unsolved murder and attempt to solve it over the course of the season. Still, others involve a group of law enforcement experts discussing the pros and cons of the investigation of the crime.

The true crime genre is popular across all media formats. Take a look at the many true crime TV shows, including Dateline and 48 Hours. True crime books are immensely popular. I write a true crime newsletter, and you’ll find several true crime magazines at the newsstand. With its overwhelming popularity, it is no surprise true crime is also a major theme for podcasts.

I have not yet listened to a seasonal podcast devoted to a deep dive into one crime or one criminal, but several stand out in the rankings, including Someone Knows Something, Up and Vanished, and Accused.

If you like humor with your murder, check out White Wine True Crime or My Favorite Murder.

My favorite true crime podcasts are Sword and Scale, Criminal, Generation Why, True Crime Historian, and Casefile True Crime.

Sword and Scale is not for the squeamish. The polished, well-researched podcast takes a hard look at the most gruesome crimes.

Criminal simply does a great job of reporting well-researched crimes in a straight-forward manner.

Generation Why involves two hosts named Aaron and Justin who tell the listener the facts of a crime in a conversational manner. This is another podcast where a great deal of research is put into each episode.

True Crime Historian covers crimes from the past, and the listener not only learns about the crime but also learns a little history in the process.

Casefile True Crime is an addiction with its stellar narration and sleek production. You won’t be able to stop listening.

In the realm of “Mystery,” I highly recommend the podcast Lore. Lore looks at the creepy scary folklore legends of history to determine if there is any truth to these tales we first heard while sitting around the campfire. As the Lore website says, “Because sometimes the truth is more frightening than fiction.”

There are many more, great true crime and mystery podcasts out there, and once you hear one, you will want to hear them all. Try out the ones I’ve suggested, and while you’re at it, I hope you will give my podcast, Murder and Mystery in the Last Frontier a listen.

Mystery Newsletter

Murder and Mystery in the Last Frontier

June 2, 2019Podcast, WritingMurder and Mystery in Alaska, Murder and Mystery in the Last Frontier Podcast, Podcasting, Robin Barefieldadmin

I am excited this week to announce my new podcast: Murder and Mystery in the Last Frontier. As many of you know, I have been writing a mystery newsletter for the past three years about murder and mysterious disappearances in Alaska. A few of my newsletter subscribers encouraged me to start a podcast, and while I initially laughed at the idea, the seed took root and began to grow no matter how hard I tried to stomp on it.

At first, I didn’t believe I could upload a podcast with our slow satellite internet, but once I learned I could upload from the middle of the wilderness, I began to research what was involved in producing a podcast. Would it be expensive? Was the technology learning-curve too steep, and were my vocal skills up to the challenge?

I read everything I could find about starting a podcast, I listened to podcasts about podcasting, and I joined podcast support groups where I could ask questions. I spent less than $200 on a microphone and other necessary gear, bought audio editing software for another $100, and I signed up for a site to host my podcast.

Everything I am learning from this venture is new and challenging, and I love it all so far. I carefully chose a good microphone and headset and bought reasonably priced audio editing software that has proven to be easy to use. I also like the Hindenburg Journalist software because if I decide to take my editing to the next level, I can easily upgrade to a pro version. I chose Blubrry.com to host my podcast, mainly because it offers a free website for my podcast and all the tools I needed to learn how to publish the podcast and upload it to Apple Podcasts, Stitcher, Spotify, and other platforms.

Do I know what I am doing yet as a podcaster? Nope, not even close, but I am trying not to be hard on myself. My podcast is far from perfect, but I have plenty of room to grow and improve.

The big question is, why do I want to spend money and countless hours I don’t have to tackle yet another project? The answer to this question is simple. I hope to introduce myself and my writing to more people. If they like my podcast, perhaps they will want to sign up for my newsletter and read my books. Podcasting is an experiment for me, and I will try it for several months. If I find my podcast requires too much time with too few payoffs, I will quietly back away from the microphone and return to what works.

The downside to starting a podcast is time. As you know, there are only so many hours in the day, and I do have a hectic regular job. If I want to podcast, something must give, and unfortunately, for now, I have decided to cut back on my blog posts. Right now, I write one post a week, so for the next few weeks, I plan to scale back to two posts a month, and I will alternate weekly between a podcast and a post. Once I streamline my podcast editing, perhaps I will have time to return to a weekly post schedule.

I’ve published my first podcast episode, and you can find it here. I’m working on my second episode, and it will be available in a few days. If you enjoy my podcast, please go to Apple Podcasts and leave a comment so that other listeners can find me. If you would like to listen to all my podcast episodes, don’t forget to subscribe.

Please let me know what you think of my podcast. A few of my blog readers have been with me since I started this blog, and I appreciate you and value your opinions! Thank you for your support!

Mystery Newsletter

Commercial Herring Fishery in Alaska

May 26, 2019Fish, Kodiak WildlifeCommercial Herring Fishing, Herring, Herring Fishing in Alaska, Pacific Herring, Sac Roe Herring Fishery, Spawn-on-Kelp Herring Harvestadmin

Herring are valuable fish to commercial fishermen, and in Alaska, herring are mainly harvested for their eggs which are shipped to Japan.

In last week’s post, I wrote about the biology and life history of the Pacific herring, and I explained how important herring are to the diets of many birds, fish, and marine mammals, but herring is also a valuable commodity to humans. For hundreds of years, Alaska native populations have conducted subsistence fisheries for herring. In the spring, villagers from coastal communities harvested herring eggs on kelp or hemlock boughs, and traditional dried herring is still an important resource in Bering Sea villages near Nelson Island where salmon is not readily available.

The commercial herring fishery in Alaska began in 1878 when 30,000 lbs. were caught for human consumption. Early Alaskan settlers preserved herring by salting the fish and storing it in large, wooden barrels. Salted and pickled herring production peaked after WWI when 28 million pounds (12,700 mt) were produced annually.

Reduction fisheries, which are the production of fish oil and fish meal from ground-up fish, began in Southeast Alaska in Chatham Straight in 1882. Reduced herring became more popular in the 1920s, and reduction plants sprang up from Craig to Kodiak in areas with large herring stocks. Harvests during the 1920s and 1930s reached 250 million pounds (113,400 mt) per year, and herring stocks declined in response to this unsustainable harvest. During the 1950s, the low cost of reduced Peruvian anchovies caused the reduction market in Alaska to collapse, and the last herring reduction plant in Alaska closed in 1966.

The Alaska sac roe fishery for herring began in the 1970s when the demand for imported herring eggs in Japan increased after Japan’s herring fishery declined. The sac roe fishery targets female herring just before they spawn. Pre-spawn egg sacs are removed from the female herring and shipped to Asia where they are a highly prized delicacy called kazunoko. Most herring for this fishery are caught by purse seining with a smaller percentage caught by gill netting. Unlike any other fishery in Alaska, managers carefully monitor the quality of the herring during the fishery to obtain the highest-value product possible. Technicians periodically test the condition of the female herring as their eggs ripen, and fishery managers use this information to carefully time the opening of the fishery to within days or even hours before the females are ready to release their eggs. This scrutiny ensures the eggs are ripe and prime for the Japanese market.

Most herring fisheries in Alaska are regulated as management units or regulatory stocks, and these stocks are very specific, often to small geographical areas. While managers might open herring fishing in one bay, the fishery could be closed in an adjacent bay because the herring return to spawn in the second bay the previous year did not meet sustainable levels. The herring sac roe fishery is competitive and intense. Fishery managers often open fishing at noon and close it a few hours later when fishermen have reached the quota for the area. Herring purse seiners work together in groups called combines and hire spotter planes to search for large schools of herring. The purse seine boats stand by near a school of herring until managers declare the fishery open, and then they quickly deploy their nets to scoop up the fish.

Since fishermen are only after the eggs in a sac roe fishery, the carcasses of the females and males caught in the nets are either processed for fishmeal or are sold for bait to commercial and sport anglers. There also is still a smaller food and bait fishery for herring.

In addition to the sac roe fishery, there is another type of commercial harvest for herring eggs called a spawn-on-kelp harvest using floating pens. Herring are caught with purse seines and then confined in floating pens containing kelp. When the herring spawn, the eggs attach to the kelp and are harvested. The eggs from this type of fishery sell for a very high value.

Mystery Newsletter

Pacific Herring (Clupea pallasii)

May 19, 2019Fish, Kodiak WildlifeAlaska Herring, Clupea pallasii, Herring biology, Herring on Kodiak Island, Kodiak Alaska, Pacific Herringadmin

Last week, I mentioned how the Pacific herring (Clupea pallasii) had returned to Uyak Bay on Kodiak Island this spring in such large numbers, even bears recently out of hibernation noticed and were feeding on them in the shallow estuaries where they spawn. Pacific herring are an essential food source for many animals living in or near the North Pacific, including birds such as cormorants, murres, auklets, puffins, and bald eagles; fish, such as salmon, halibut, cod, and pollock, and marine mammals, including harbor seals, Steller Sea Lions, fin whales, humpback whales, and orcas. When a pursuing predator forces a school of herring to the surface, seagulls take advantage of the situation and can often be spotted noisily diving and feeding on the fish. Herring are loaded with nutritious oil and nutrients and are an important forage fish for many species.

A herring has a blue-green upper body, silvery sides, and large eyes. Its body is laterally compressed with large scales, protruding in a serrated fashion. It has no scales on its head or gills. A herring has a deeply forked tail, a single dorsal fin located mid-body, and no adipose fin. Pacific herring can grow to 18 inches (45.7 cm) in length, but they are usually smaller than 9 inches (22.9 cm).

Pacific herring live throughout the coastal waters of the Pacific Ocean. In the eastern North Pacific, they range from Baja California north to the Beaufort Sea, and in the western North Pacific, they can be found in the western Bering Sea to Kamchatka, in the Okhotsk Sea and around Hokkaido, Japan southeast to the Yellow Sea.

^[Pacific herring reach sexual maturity when they are three to four years old, and they spawn each year after reaching sexual maturity. Spawning occurs in the spring in shallow nearshore areas in intertidal and subtidal zones. Females release eggs at the same time males release sperm into the water, and the eggs and sperm mix, fertilizing the eggs. A single female can lay 20,000 eggs.

Spawning is precise, and while the trigger is not well understood, researchers suggest the male initiates the process by releasing milt containing a pheromone which stimulates females to release eggs. The process seems to be synchronized, and an entire school spawns in a period of a few hours, producing an egg density of up to 6,000,000 eggs per square yard (square meter).The fertilized eggs then attach to vegetation such as eelgrass or kelp or to the bottom. Eggs hatch two weeks after they are fertilized, and the larvae drift in the ocean currents. As they grow, juvenile herring stay in sheltered bays until autumn and then move into deeper water where they spend the next two to three years. Juveniles remain separate from the adult population. Biologists estimate only one herring per ten thousand eggs reaches adulthood.

Juvenile herring feed on phytoplankton and zooplankton, and adults also eat bigger crustaceans and small fish. Pacific herring travel in large schools. They migrate inshore to the heads of shallow coves and bays to spawn and then offshore to feed. They also migrate vertically in response to their prey, remaining near the bottom during the day and rising toward the top of the water column at night.

Herring are susceptible to environmental changes. Since they depend on shallow, inshore habitats to reproduce, they are affected by storms, pollution, and warming water temperatures. The Pacific herring population in Prince William Sound collapsed in 1993, four years after the Exxon Valdez oil spill, and it has still not recovered.^[

The biggest threat to Pacific herring is a loss of their spawning grounds. Spawning habitat can be degraded or destroyed by construction, dredging, log storage, oil spills or other pollution, and by global warming.^[ If Pacific herring populations crash, their loss will affect the many species of fish, birds, and marine mammals which depend on them for food.