Tag Archives: Robin Barefield

Osmoregulation in Salmon

July 5, 2020Fish, Kodiak WildlifeKodiak Wildlife, osmoregulation in salmon, Osmoreulation, Pacific Salmon, Robin Barefieldadmin

Osmoregulation is the process of maintaining salt and water balance across the body’s membranes. Any fish faces a challenge to maintain this balance. A freshwater fish struggles to retain salt and not take on too much water, while a saltwater fish tends to lose too much water to the environment and keeps a surplus of salt. Fish have developed behaviors and physiological adaptations to survive in their environments, whether fresh or marine water, but how do fish manage to thrive in both fresh and saltwater?

A catadromous fish spends most of its life in freshwater and then migrates to the ocean to breed. Eels of the genus Anguilla represent catadromous organisms. Anadromous fish begin life in freshwater, spend most of their lives in saltwater, and then return to freshwater to spawn. Pacific salmon and some species of sturgeon are anadromous fish.

How does a salmon maintain the composition of its body fluids within homeostatic limits? How does it reverse its osmoregulation physiology when it swims from a freshwater environment into the ocean or from the ocean to freshwater?

In the ocean, a salmon swims in a fluid nearly three times more concentrated than the composition inside its cells. In such an environment, the fish tends to take on salt from the water and lose water to the denser ocean. This exchange would result in severe dehydration and quickly kill the salmon if the fish did not adequately deal with the issue.

A Salmon faces the opposite problem in freshwater, where it lives in a solution nearly devoid of salts. In this case, the fish has more salt in its body than in its environment, presenting the problem of losing salt to the environment while flooding its body with water.

How does a salmon deal with these two warring issues of osmoregulation? The salmon has evolved behavioral and physiological adaptations to allow it to live in both fresh and saltwater habitats.

In the ocean, a salmon drinks several liters of water a day to maintain its water volume, but in freshwater, it does not drink at all, except for what it takes on during feeding. In freshwater, a salmon’s kidneys produce a large volume of very dilute urine to offset the excess water diffusing into its body fluids. In the ocean environment, though, a salmon’s urine is highly concentrated, consisting mostly of salt ions, and it excretes very little water.

A salmon also has a remarkable adaptation that allows osmoregulation by the fish in both marine and freshwater environments. A salmon uses energy to actively pump Na and Cl ions across the gill epithelial cells against their concentration gradients. In saltwater, the fish pumps NaCl out of its blood and into the surrounding ocean. In freshwater, the pump works in reverse, moving NaCl out of the water, over the gills, and into the blood.

These amazing behavioral and physiological adaptations allow a salmon to move from fresh to saltwater when the fish leaves its nursery area to travel to its ocean feeding grounds and then back from its marine habitat to freshwater when the salmon returns to spawn. The critical changes in osmoregulation are not immediate, though. When a salmon smolt first leaves its home stream, it must rest in brackish water for several days or weeks while it adjusts, and then it will slowly move into water with higher salt concentrations. As the smolt adjusts, its kidneys begin producing more-concentrated urine while the NaCl pumps in its gills reverse direction and start pumping NaCl out of the blood. When the salmon returns to its natal stream to spawn, it must again remain in brackish water for a period while its kidneys adjust, and the NaCl pump changes direction to pump NaCl out of the water and into the blood.

I am always amazed by how animals and plants adjust to the demands of their environment. Anadromous and catadromous fish, however, must adapt to two environments with opposite physiological requirements, and to do this, they flip the switch on osmoregulation from one extreme to the other.

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Robin Barefield is the author of four Alaska wilderness mystery novels, Big Game, Murder Over Kodiak, and The Fisherman’s Daughter, and Karluk Bones. Also, 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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Incredible Spot Shrimp

June 14, 2020Kodiak Wildlife, ShrimpKodiak Wildlife, Robin Barefield, Shrimp, Shrimp in Alaska, Spot Shrimpadmin

Spot shrimp are the largest wild species of shrimp found in Alaska, with females reaching more than 12 inches (30 cm) in length. Because of their large size, marketers often refer to them as “spot prawns,” but they are not prawns.

What is the difference between a prawn and a shrimp? They might look similar, but shrimp differ from prawns in many ways. Prawns and shrimp are both decapod crustaceans, but they belong to separate sub-orders. Shrimp have plate-like gills and a set of claws on their front two pairs of legs, while prawns have branching gills and claws on three sets of their legs. Shrimp have three body segments, with the middle segment overlapping the front and rear sections, causing their bodies to curve. Prawns, however, lack the body segmentation and have straighter bodies than shrimp. Shrimp and prawns vary in many other ways too, including their reproductive habits. Prawns release their progeny into the water to survive on their own, while a female shrimp carries her eggs on her abdomen for five months.

Spot shrimp range from Southern California to the Aleutian Islands to the Sea of Japan and the Korea Strait. They occupy a variety of habitats and water depths from very shallow to 1510 ft. (460 m), but they most commonly live at approximately 300 ft (90m.). They usually remain close to the bottom and stay near rock piles, crevices, under boulders, or in other areas where they can seek protection from predators. Juvenile spot shrimp remain in shallow, inshore areas and migrate offshore when they mature.

Spot shrimp appear reddish-brown to tan and have horizontal bars on the carapace. The distinctive white spots, from which they derive their common name, are located on the first and fifth abdominal segments. The slender body of a spot shrimp has five pairs of swimmerets on the underside of its abdomen. A spot shrimp repeatedly molts throughout its life and grows larger with each molt.

The most amazing fact about spot shrimp is, like some other shrimp species, spot shrimp are protandric hermaphrodites. They mature as males and later transform into females. They reach sexual maturity at age three when they can produce sperm and spawn as males. As they grow, they pass through a transitional stage and become females capable of producing eggs. Research indicates not all spot shrimp follow this pattern, though. Some skip the male-phase of the life cycle and develop directly into females.

Before mating, a female molts into a shell specialized for carrying eggs. Each egg attaches to her abdomen by a hair-sized structure called a seta, and she carries the eggs from October to March. Biologists believe each spot shrimp spawns once as a male and one or more times as a female. They spawn at depths of 500-700 ft. (152.4 m to 213.4 m).

Spot shrimp are bottom feeders, and they feed at night. They eat a wide variety of bottom organisms, including worms, diatoms, dead organic material, algae, mollusks, and even other shrimp. Fish such as halibut Pacific cod, pollock, flounders, and salmon pursue and eat spot shrimp. Spot shrimp can live seven to eleven years.

Due to destructive fishing methods used to catch shrimp in many areas of the world, biologists consider the commercial harvest of shrimp to be one of the most unsustainable of all global fisheries. Bottom trawls destroy everything in their path. In Alaska, the shrimp harvest is mainly restricted to pot fisheries in certain areas.

In Southeastern Alaska, the Alaska Department of Fish and Game closed the spot shrimp fishery to commercial and sport fishermen in 2013, but the spot shrimp population in the area has continued to decline. Biologists wonder if recent warmer, more-acidic ocean waters could be the cause for dwindling spot shrimp numbers, and they are beginning to research the issue. Shrimp remain most vulnerable to acidification during early life stages when they rely on calcification to build their exoskeletons.

Robin Barefield is the author of four Alaska wilderness mystery novels, Big Game, Murder Over Kodiak, and The Fisherman’s Daughter, and Karluk Bones. You are invited to 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, and listen to her podcast, Murder and Mystery in the Last Frontier.

Alaska Wilderness Mystery Novels by Author Robin Barefield: Big Game, Murder Over Kodiak, The Fisherman's Daughter, and Karluk Bones.

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Whale Season

May 24, 2020Fin Whale, Humpback Whale, killer whale, Kodiak WildlifeFin Whale, Grey Whale, humpback whale, Minke Whale, Robin Barefield, Sei Whale, Whale Biology, Whale Evolution, whales, whales in Alaska, Wildlife of Kodiak Islandadmin

Spring marks the beginning of whale season here in Alaska. The humpbacks and grey whales begin arriving from their long migrations north from their wintering grounds, and the north Pacific Ocean teems with life as the waters warm and phytoplankton blooms. Swarms of krill and other zooplankton feast on the abundant plant life, and fish such as herring, eulachon, and similar species follow the zooplankton into the bays on Kodiak Island. In turn, huge baleen whales, including fin, sei, and humpback, gather to eat the krill and small fish. I am thrilled any time I see a whale, but I think it’s a special treat to stand in my front yard and watch these magnificent creatures feed and blow.

Sea mammals evolved from land mammals, and they resemble us in many ways. Whales, like humans, have lungs and must breathe air to survive. They are warm-blooded, and they bear live young. Whales nurse their young with milk, and while you might not think of a whale having hair, all whales do have hair at some stage in their development. All members of the order Cetacea evolved 45 million years ago from hoofed mammals, such as cows, sheep, and camels. Comparisons of specific milk protein genes indicate the hippopotamus is the closest, living, land relative to whales.

The order Cetacea contains more than eighty species; although, taxonomists debate the precise number. Biologists have recorded thirty-nine cetacean species in the North American Pacific.

Cetacea comes from the Greek word “ketos,” which means “whale.” All cetaceans have forelimbs modified into flippers and no hind limbs. They have horizontally flattened tails, and they breathe through a nostril, or blowhole, located on the top of the head. A blowhole has a nasal plug that remains closed except when forced open by muscular contractions to breathe. This plug seals when the whale dives. A whale has internal sensory and reproductive organs to reduce drag while swimming, and they do not have external ears but instead have a complex internal system of air sinuses and bones to detect sounds.The lungs of a cetacean are relatively small, highly elastic, and elongated. A whale has a muscular diaphragm, allowing the animal to purge a large amount of air in a short time. With each respiration, a whale replaces 80% to 90% of the air in its lungs. During a deep dive, a cetacean slows its heart rate and decreases blood flow to peripheral tissues.

Cetaceans living in the cold ocean waters of the North Pacific must somehow maintain a body temperature nearly the same as a human’s body temperature. A whale uses several mechanisms to accomplish this feat. First, it has a thick layer of blubber with few blood vessels, reducing the heat loss at the body surface. A whale has a counter-current heat exchanger, with arteries surrounding veins at the periphery. Hence, vessels flowing from the cold periphery to the warm core partially absorb heat lost by vessels flowing from the core toward the surface. A cetacean also has a high metabolic rate to produce heat, and it has a low body surface to volume ratio, which conserves heat. Finally, a whale has a slower respiration rate than a land mammal, so the whale expels warm air less frequently.

Most cetaceans produce large calves, and the large body volume relative to surface area minimizes heat loss in the calf. Calves are born tail first, and as soon as the calf emerges from the birth canal, the mother or another whale nudges it to the surface for its first few breaths.^[3]Cetacean mothers nurse their calves with a pair of teats concealed in slits along the body wall. The milk has a high-fat content, and the calves grow at a rapid rate. Whale mothers tend and guard their calves closely, and a calf often rides the bow wave or the convection currents produced by its mother or another adult when the whales travel. This method of travel is so efficient that the calf barely needs to move its flukes to keep up with the group.

Two suborders comprise the order Cetacea: The Mysticeti or baleen whales and the Odontoceti, or toothed whales. We most commonly see fin whales in Uyak Bay, but we also spot sei, humpback, minke, and killer whales. No matter the species, whenever I see a spout of water, excitement buzzes through me while I watch one of the largest animals on the planet.

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Mammalian Diving Reflex

May 3, 2020Harbor Seal, Kodiak WildlifeDiving Reflex in Humans, Harbor Seals, Mammmalian Diving Reflex, Robin Barefieldadmin

The mammalian diving reflex is a fantastic biological adaptation intrinsic not only to marine mammals but also to land mammals, including humans, whose ancestors once lived in the ocean. I am currently editing my wildlife book and was once again awed by how deep some marine mammals dive and how long they can stay below the surface without breathing. I think the mammalian diving reflex represents one of nature’s most incredible adjustments for air-breathing mammals required to find food in an inhospitable environment void of air.

What is the mammalian diving reflex? Biologists mostly have studied the reflex in harbor seals, so I will use a seal to explain the elements of the physiological changes. A harbor seal can dive as deep as 1640 ft. (500 m) and stay submerged for over twenty minutes. When it dives, a harbor seal’s heart rate slows from its normal rate between 75 to 120 beats per minute down to just four to six beats per minute. Blood shunts from peripheral tissues tolerant to low oxygen levels and flows to the heart, brain, and tissues dependent on a constant supply of oxygen to survive. These adaptations allow the seal to conserve oxygen while it dives and searches for food.

Seals utilize additional adaptations to conserve oxygen and withstand the rigors of increased pressure when they dive. Before a deep dive, seals exhale several times to collapse their lungs, and they then store their oxygen in blood and muscle tissues instead of in the lungs. Harbor seals have a proportionately higher blood volume than land mammals of the same size, and seals also possess ten times more myoglobin than humans. This oxygen-binding protein helps prevent muscle oxygen deficiency.

Researchers originally believed the diving reflex was an automatic response triggered by breath-holding and submergence in cool water. In recent studies, though, scientists attached a device similar to a Fitbit to harbor seals. The device records blood flow and oxygen levels in the seal’s brain, and the study produced some interesting results. Seals can control their diving reflex. Seals contract their peripheral blood vessels beginning 15 to 45 seconds before they dive, and they restore normal blood flow to their blubber several seconds before they reach the surface. When seals are feeding, they return to the surface to breathe but often don’t stay there long enough to restore normal oxygen levels. Researchers also learned that seals slow their heart rates more if they plan to stay underwater longer.

Biologists hope to learn if other animals, including humans, can also consciously control their dive reflex. The world’s top freedivers can descend to a depth of 426 ft. (130 meters) and return to the surface, and the record for breath-holding without moving tops 11 minutes. Are these free divers able to control the physiology of the diving reflex to accomplish these incredible feats?

The next time you see a harbor seal, pause for a moment to consider the rigors this animal must endure just to eat dinner.

I hope you are well and navigating our changed world. Life remains quiet here in the wilderness of Kodiak Island, and we feel oddly removed from the biological havoc wreaked by this virus. Even here, though, we have been touched by the economic disaster the world faces. I look forward to better times for all of us soon! Take care.

Join the Battle of the Books contest, and you could win a $500 Amazon Gift Card! I am very excited to have my novel, Karluk Bones, included in this contest.

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Writing

April 12, 2020WritingAuthor advice, How to become an author, Robin Barefield, Writing, Writing Advice for authorsadmin

Are you thinking about writing a book, or maybe you’ve already started one? A few weeks ago, Dee S. Knight wrote a guest post for my blog, and in it, she offered great advice to beginning novelists. I know she learned much of this information the hard way, just as I did. As soon as I read her bulleted points, I decided to expand on Dee’s wise words and tell you about the emotions I experience when I write a book.

My education is in biology, and I knew very little about the mechanics of writing a novel. I love to learn, though, so I read every book and magazine I could find on writing. Much of the advice was good; some was not. I am still learning how to tell a story, build compelling characters, put it all together, and polish it. Writing a novel requires fortitude and diligence.

I jokingly tell friends that all authors are delusional. When I begin writing a novel, I’m confident I’m about to tell a fantastic story, and my creation will top the best-seller list. By the midway point, my book doesn’t seem so great anymore. Toward the end, I’m optimistic I’ve written a reasonably good book, but by edit number seven, I am sick of reading this piece of junk I wrote. When My publisher sends me the completed and published novel, I hold it in my hands and wonder if it’s any good and if anyone will read it. After this rollercoaster ride of emotions, you’d think I’d never want to write another novel, but I can’t wait to tell the next story bursting to escape my brain. It’s no wonder so many famous novelists had severe mental problems or were alcoholics or drug addicts. We authors lack sanity.

Before I wrote my first novel, I read some great advice from a well-known author. I think the author was Mary Higgins Clark, and she said if you want to write books, begin by writing 15 minutes a day – every day. You might think you need great chunks of time to write, and perhaps a lack of time is your excuse for not writing a novel. Not many of us can carve out big pieces of our day to write. We have jobs, we have families, we have lives. I guarantee if you follow Ms. Clark’s advice and manage to write 15 minutes a day, soon you will find 30 minutes a day to write, and before long, you’ll manage to write an hour a day. You might not write for an hour in one sitting, but if you can write 10 minutes here, 20 minutes there, and so on, you will make progress.

Writing is like exercise. You must do it consistently to keep your mind sharp and to stay focused on your story. I hear authors talk about “writer’s block,” and I don’t know what they mean. Somedays, my brain feels so sluggish I write mush, but I write something. I can always delete it the next day if it’s terrible.

In her post, Dee encouraged beginning novelists to spend time learning the craft of storytelling. Read books on the subject or take an online class. Storytelling has rules, and sure, you can break the rules, but you should know what the rules are before you break them.

Once you complete your manuscript, you must edit it, and you cannot skip this step. You need to edit your book until you can’t stand to look at it anymore. Once I’ve read through it repeatedly, I send it to a professional editor. Yes, professional editors are expensive, but you want your masterpiece expertly polished before you send it out into the world. When the manuscript comes back from the editor, I go through it again and try to understand the changes the editor has made. I do this edit not only to make myself a better writer but also to be sure the editor hasn’t changed the voice or meaning of my book. Next, I send my novel to other authors I know will give me honest feedback. I then do one more read through and send it to my publisher. He will e-mail the galleys back to me for one or two more edits. Yes, editing is not for the faint-hearted, but skip any step in this process, and you risk releasing a book full of embarrassing errors. Even after you’ve done all the above, your novel will still have errors – I guarantee! I want to cry when I find a mistake in one of my published books, and it’s even worse when someone else points out the error to me.

If you want to write a book, and if you have a story you must tell, then I encourage you to do it. Dee is correct, though. Writing is a business, and you need to think of yourself as a professional. If you are determined to become an author, then you will succeed, but to be victorious, you must write every day. Nobody has enough time to write a novel, but if you plan to become a published author, you must find the time.

Thank you, Dee, for letting me borrow your wise advice!

Happy Easter and Passover to everyone who celebrates these holidays. My wish for all the world is that a year from now, these terrible days will be only a hazy memory. Stay well!

Join the Battle of the Books contest, and you could win a $500 Amazon Gift Card! I am very excited to have my novel, Karluk Bones, included in this contest.

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Jumping Hurdles

March 29, 2020Living in the wilderness on Kodiak IslandAlaska, Coronavirus, COVID-19, Pandemic, Robin Barefield, Small lodge, Tourismadmin

Sometimes, life seems like a series of hurdles, and this winter, a new, huge hurdle appeared out of nowhere, catching most of us by surprise and forcing us to re-evaluate our priorities.

I hope you and your loved ones are well. We don’t know what will happen in the coming days, and many of us are struggling to cope with the present. As some of you know, my husband, Mike, and I own a small lodge in the wilderness on Kodiak Island, Alaska, and a few days ago, the Governor, in effect, closed Alaska to visitors for at least the next month. I know he made the right decision. I am sure the coronavirus will eventually spread to all areas of the state, but we need to do everything we can to slow its rate of infection. Folks who don’t need to travel should stay home. Even though Mike and I feared the Governor might halt travel to Alaska, his mandate still hit hard, and we find ourselves trying to decide what to do to survive economically.

This is not the first time a national or world event has impacted us. The 1989 Exxon Valdez oil spill and the 9-11 terrorist attack both nearly decimated tourism in Alaska. Economic downturns always hurt the travel industry, and during one of the many budget squabbles in the U.S. Congress, the Kodiak National Wildlife Refuge closed, and we had to cancel goat hunts already in progress. The COVID-19 threat differs from previous disasters, though. During earlier crises, I focused my anger on one person or a group of people. Whether it was a drunk captain, deranged terrorists, or spoiled politicians, I could always picture the cause of our near-economic destruction.

Unfortunately, a pandemic is no one’s fault. We can’t blame anyone for the coronavirus. Our government could and should have acted faster, but even with the best response, a very infectious, novel virus is hard to stop. We have no idea when this virus will run its course, but until then, we remain at its mercy.

I find the economics of our situation disheartening and depressing, and I know the government won’t miraculously bail us out of our financial woes. Even in the past, when the government caused our economic problems, we never received assistance to help us rebound. I certainly don’t expect help this time, but I know we will be okay. We will jump over this hurdle. As long as our family, friends, and we stay healthy, all else becomes insignificant.

I thank the health care workers and first responders who are fighting on the front lines of this pandemic. They take incredible chances every day.

Stay well, and we will get over this hurdle, and hopefully, something good will come from the pain. As you can see from the photo, I have a beautiful place to self-isolate.

Join the Battle of the Books contest, and you could win a $500 Amazon Gift Card! I am very excited to have my novel, Karluk Bones, included in this contest.

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Dungeness Crab for Dinner

January 26, 2020Crab, Kodiak WildlifeCommercial Fishing for Dungeness Crab, Dungeness Crab, Dungeness Crab and Domoic Acid, Dungeness Crab and Paralytic Shellfish Poisoning, Dungeness Crab In Alaska, Dungeness Crab Management in Alaska, How to cook Dungeness Crab, Robin Barefieldadmin

Dungeness crab is a favorite dinner menu item from the docks of San Francisco to Fisherman’s Wharf in Seattle to the top restaurants in Anchorage. With its sweet meat and delicate flavor, Dungeness crab ranks as one of the world’s finest delicacies. So how are Dungeness caught commercially, and are they susceptible to shellfish poisoning?

The commercial Dungeness crab fishery in Alaska began around 1916, and Dungeness crabs were first commercially canned in Seldovia in 1920. Today, Dungeness crabs are canned, frozen, shipped fresh, or shipped live to market.

Commercial fishermen catch Dungeness crabs in circular, steel pots, usually baited with herring or squid. The pots measure 40 inches (101.6 cm) in diameter and 14 inches (35.6 cm) in height. The round steel frames of the pots are wrapped in rubber tubing and then covered with stainless steel mesh. According to regulations, the pots must include two escape rings large enough to allow the undersized crab to exit the pot. The fishing season and the number of pots a vessel can deploy varies by management area in Alaska, but regulations throughout most of the state for pot numbers remain lenient.

Biologists manage the commercial Dungeness fishery by the three S’s: size, sex, and season. Only male crabs over 6.5 inches (165mm) can be harvested, and the fishery is closed during the female molting and mating period from mid-August until the end of September. Because biologists do not survey Dungeness crab populations in much of Alaska, recent research near Kodiak focused on whether legal male crabs have reached sexual maturity and had the chance to mate once or twice. The results of the study indicated the current minimum size limit of 6.5 inches (165 mm) is appropriate for Dungeness crabs in Alaska. Males are approximately four-years old at 6.5 inches, and they have probably mated two or three times.

The meat of a Dungeness crab tastes sweeter than the flesh of either a tanner (snow) or king crab. Approximately one-quarter of the crab’s weight is meat. You cook a Dungeness crab by boiling it in the shell for 20 minutes. Crabs can ingest poisonous algae such as the algae that produce domoic acid or the algae which carry the paralytic-shellfish-poisoning toxin. These toxins are found only in the internal organs of the crabs, so biologists recommend butchering a crab before cooking it. You can butcher the crab by cutting it in half and removing the internal organs and gills. Once you’ve boiled the crab and melted butter for dipping, you are ready to feast!

As always, thank you for reading. I am currently on the road. We had a nice vacation and family reunion in Hawaii, and we are now preparing to return to Anchorage, where we will buy supplies and take our Wilderness First Responder Recertification course. We’ll fly back to Kodiak in early March and then home a few days later. I enjoyed getting away and finding the sun for a few weeks, but I can’t wait to get home and dive into new projects.

In the meantime, I’ll feature two, wonderful authors who have graciously agreed to write guest posts while I finish my travels. I’ll introduce them to you in my next post.

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Range and Commercial Fisheries for Tanner and Snow Crabs in Alaska

December 15, 2019Crab, Kodiak WildlifeCommercial Snow Crab Fishery, Commercial Tanner Crab Fishery, Robin Barefield, Snow Crab Management, Tanner Crab Management, Who Manages Tanner and Snow Crab?admin

Tanner crabs range from Oregon to the Gulf of Alaska and the Bering Sea, as far north as Cape Navarin in Russia and west to Hokkaido, Japan. Snow crabs inhabit colder waters than tanner crab, but the ranges of the two species overlap, and where they occur together, they interbreed and produce hybrids. Snow crabs inhabit waters from Japan to the Bering and Beaufort Seas. Snow crabs also occur in the Atlantic Ocean from Greenland to Maine.

In my last post, I described the biology and life cycles of tanner crabs (Chionoecetes bairdi) and snow crabs (Chionoecetes opilio). A valuable market exists for both species, and a robust but limited fishery occurs in the Gulf of Alaska and Bering Sea.

NOAA Fisheries, the North Pacific Fishery Management Council, and The Alaska Department of Fish and Game jointly manage the tanner and snow crab commercial fisheries. As with king crab, biologists manage the tanner and snow crab fisheries according to the “three S’s.” These are size, sex, and season. Fishermen can keep only male crabs over a specific size, and fishing is not allowed during the mating and molting seasons. These restrictions enable crabs to grow to reproductive age and preserve females so they can reproduce. Managers gauge crab abundance during the current season and then adjust quotas accordingly for the following season.

In 2005, the Crab Rationalization Program was implemented, directing fisheries managers to allocate shares of the overall quota of tanner and snow crabs among harvesters, processors, and coastal communities. Fishing vessels must have satellite communications systems, so the captain can report the number of crabs caught daily. This real-time reporting allows fisheries managers to monitor the catch and to close the fishery when fishermen reach the harvest limit.

Crab pots must have escape panels and rings, which employ biodegradable twine. When a fisherman loses a pot, the twine will disintegrate, rendering the pot incapable of trapping crab and other organisms. Regulations also require observers to join the crew and collect data on the catch and bycatch and document any violations on a randomly chosen twenty percent of all fishing vessels.

Happy Holidays! I won’t have a podcast episode or a blog post next week, but I’ll be back on December 29^th with a post to review my year, make resolutions for next year, and most importantly, wish all of you a Happy New Year!

Whose bones lay scattered in the Kodiak wilderness? My latest novel, Karluk Bones, is now available.

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Tanner Crab and Snow Crab(Chionoecetes bairdi and Chionoecetes opilio)

December 1, 2019Crab, Kodiak WildlifeAlaska Snow Crab, Bairdi, Chionoecetes bairdi, Chionoecetes opilio, Opis, Robin Barefield, Tanner Crab, Tanner crab Biologyadmin

Whenever I mention tanner crabs to our guests, they return a questioning look. “What is a tanner crab?” “I’ve never heard of a tanner crab.” If you enjoy eating crab, you’ve undoubtedly consumed tanner crab at a restaurant, but the menu probably listed the delicacy as “Alaska Snow Crab.”

In the 1960s and 70s, when the king crab fishery exploded, commercial fishermen considered the smaller tanner crabs pests worth nothing. A decade later, though, when the king crab fishery failed in many areas, savvy industry marketers began advertising tanner crabs as snow crabs, and suddenly, their value soared as demand grew.

To make the tanner crab – snow crab situation more complicated, fishermen call Chionoecetes bairdi by the common name, “tanner crab,” but they refer to Chionoecetes opilio as “snow crab.” To further confuse things, where the two species’ ranges overlap, they can interbreed, producing offspring bearing characteristics of both parents. For this article, I will refer to Chionoecetes bairdi as tanner crab and Chionoecetes opilio as snow crab.

Tanner crabs (Chionoecetes bairdi) and snow crabs (Chionoecetes opilio) are considered short-tailed or “true” crabs. A tanner crab’s body is a chitinous carapace with a small abdominal flap. A male’s flap is triangular, while a female has a broad, round abdominal flap. A tanner crab has five pairs of legs and the first pair sports pincers. By the time it reaches adulthood between the ages of seven to eleven years, a tanner crab weighs from two to four pounds (0.91 to 1.81 kg).

Unlike king crabs, tanner crabs do not continue to molt (shed their old shell and grow a new one) throughout their lives. Once they reach sexual maturity, both males and females undergo a terminal molt, after which they will never again shed their shell. A female tanner crab mates for the first time during her terminal molt. She releases pheromones to attract a male and remains receptive for 21 days. The male crab clasps the female and inserts his sperm into her. Laboratory observations suggest this clasping embrace can last as long as 14 to 151 hours.

After her first mating session, biologists think a female tanner crab produces another four clutches of eggs before dying. During subsequent mating sessions, the female has a hard shell, and in the absence of a male, she can produce an egg clutch with sperm she stored from a previous mating. A female tanner deposits between 85,000 to 424,00 eggs in a clutch. She extrudes the eggs within 48 hours of fertilization onto her abdominal flap, where they incubate for a year.

The eggs hatch the following spring from April to June, and hatching usually coincides with the peak of the spring plankton bloom, providing ample food for the larvae. At first, the larvae are free-swimming, and they molt many times as they grow. The swimming phase lasts about 63 to 66 days, and then the larvae settle to the bottom. The young crabs continue to molt and grow for several years. Females reach maturity at approximately five years of age, while males mature at six years. Tanner crabs can live 14 years.

Biologists do not fully understand the migration patterns of tanner crabs, but they know the sexes remain separated during most of the year and move into the same areas only during the mating season.

Tanner crabs eat a wide variety of organisms, including worms, clams, mussels, snails, crabs, and other crustaceans. They are preyed upon by fish, sea otters, and humans.

Tanner crabs are susceptible to an illness called Bitter Crab Disease, caused by a specialized dinoflagellate from the genus Hermatodinium. As its name suggests, crabs infected by Hermatodinium taste bitter, and the meat appears chalky. The disease is often fatal, and dying crabs release spores which infect nearby crabs.

Snow crabs are smaller than their tanner crab cousins and reach a maximum of only one to three lbs. (.5 to 1.35 kg). Females carry up to 100,000 eggs, and biologists estimate snow crab can live up to twenty years. Snow crabs and tanner crabs have similar life cycles.

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Mystery Newsletter

Safety Regulations Forced Upon the Commercial Fishing Industry

November 3, 2019UncategorizedCommercial Fishing, Dangers of Crab Fishing, Fishing in Alaska, Making Fishing Safer, Manditory safety regulations for commercial fishermen, Robin Barefield, Safety for Commercial Fishingadmin

In the 1970s and 80s, commercial crab fishing earned a deadly reputation, but fishermen opposed mandated safety regulations. With powerful politicians behind it, the commercial fishing industry fought against government interference of any kind, but when a bereaved mother took up the fight, Congress finally forced safety upon the most dangerous occupation in the United States.

Each summer, young men and women flock to Alaska, looking for adventure and a chance to make good money for a few months of work. They’ve heard the stories and watched shows like The Deadliest Catch, and they dream of adventure and riches. Unfortunately, though, the truth is not nearly as glamorous as the shows they’ve watched or the stories they’ve read. Topline fishing operations only want to hire experienced crew members who know what they are doing. The least appealing hire to the owner of a fishing boat is a kid out of college for the summer who wants to “experience life.” These eager young people are likely to find jobs on lower tier boats, the ones struggling to make ends meet.

In 1985, Peter Barry, a 20-year-old Yale anthropology student, flew to Kodiak Island for a summer adventure. He was one of the annual 15,000 summer workers in the Alaska fishing industry. Barry met Gerald Bouchard on a dock in Kodiak, and Bouchard, the captain of the Western Sea, offered Barry a job as a crewman on his salmon seiner. Peter jumped at the opportunity to work aboard a fishing boat in Alaska, and he called his parents with the good news.

After a few days aboard the Western Sea, Peter sent his parents a letter, and his tone sounded much less optimistic. He reported the boat didn’t seem seaworthy, and the captain’s temper often flared, his behavior erratic. Peter wanted to leave the vessel, but the captain threatened him, and Peter decided to stay aboard awhile longer.

On August 20, 1985, a fisherman spotted the body of a young man floating in the water near Kodiak Island. In the man’s pocket they found a letter addressed to Peter Barry. The Western Sea was lost, and out of a six-man crew, searchers found the bodies of only two other men. One of the bodies recovered was Captain Gerald Bouchard’s, and a toxicology exam on Bouchard’s body indicated he was high on cocaine the day the Western Sea went down.

Peter Barry’s father, Bob, flew to Kodiak and demanded answers. Bob Barry was the former U.S. Ambassador to Bulgaria and the current head of the U.S. delegation to the Conference on Disarmament in Europe. When Barry asked questions, he expected answers, but what he learned in Kodiak appalled him. The crewman Peter had replaced on the Western Sea told Barry the old wooden boat, built in 1915, was rotten and leaky and had no pumps. The captain refused to spend money on safety gear, so the vessel had no life raft, survival suits, life preservers, nor an EPIRB to transmit a distress signal. The Western Sea was nothing more than a death trap with a captain fueled by rage and cocaine.

What shocked Bob Barry and his wife, Peggy, more than anything, though, was when they learned commercial fishing boats were not required to carry safety gear or have annual inspections. Even though it was the most dangerous industry in the United States, commercial fishing remained mostly unregulated from the standpoint of safety.

Peggy Barry sank into depression after her son died, but then she began to receive phone calls from others who had lost loved ones on fishing boats. Peggy decided she needed to spearhead the movement to incite change. Something needed to be done to regulate safety equipment and procedures on commercial fishing boats.

Fishermen did not appreciate Peggy Barry’s interference, and she was thought of by the industry as a “privileged outsider.” National Fisherman quoted a lobbyist as saying, “Fishermen have been dying for years, then one Yalie dies, and the whole world seems up in arms.”

Peggy ignored the push-back from fishermen and continued to approach senators and representatives with her concerns. Representative Gary Studds from Massachusetts agreed with Barry and took up her cause.

Because so many fishing boats, especially in Alaska, sank in the mid-eighties, insurance premiums for commercial fishing boat owners jumped dramatically. Insurance premiums on an average fishing vessel rose from $34,000 in 1976 to $169,000 in 1986. Congressmen from states supporting robust fishing industries rushed to pass a bill for insurance relief. Studds saw this as a chance to further his cause. If Congress could agree on a law requiring stiffer safety regulations along with lower insurance premiums, perhaps it could mandate safety for crew members on fishing boats.

Peggy Barry contacted the parents and wives of young men (most lost crew members were young men) who had died on fishing boats, and with an unflinching Peggy Barry by their sides, they addressed the Congressional subcommittee on merchant marine and fisheries. Each loved-one told his or her story and pleaded with the congressmen for safety reform in the commercial fishing industry.

In the end, Peggy Barry and her comrades made some progress. The Coast Guard could not support a provision in the proposed bill requiring all fishing vessels to undergo stability tests. The Coast Guard also felt it could not demand licensing for captains and crews. The final law required commercial fishing vessels to carry life rafts, survival suits, and emergency radio beacons. All crewmen must also take safety training, and a $5,000 penalty could be imposed for failure to comply. The bill ordered the Coast Guard to terminate the unsafe operation of any fishing vessel.

While this bill was a watered-down version of what Peggy Barry wanted, it brought much-needed safety regulations to the most dangerous industry in the U.S. While fishermen were not happy with the new law, indisputable proof shows the new measures made their jobs less deadly. In the year 1983, long before the bill demanding new safety measures, 245 commercial fishermen died at sea. Over time, the death rate has dropped. Between 2000 and 2014, over 14-years, 179 individuals died in fishing-related incidents in Alaska. The mortality rate has fallen to an average of 13 crew members per year. While this number is still too high, it is an improvement.

If you would like to read more about the dangers of commercial fishing, I suggest the book, Lost at Sea by Patrick Dillon. He tells the true story of two ships mysteriously capsizing in the Bering Sea. I’ve read the book three times and was captivated each time by the way Dillon recounted this tragic tale.