Category Archives: Fish

Amusing Monday: Researchers untangle the mystery of hagfish slime

“Hundreds of meters deep in the dark of the ocean, a shark glides toward what seems like a meal. It’s kind of ugly, eel-like and not particularly meaty, but still probably food. So the shark strikes.

“This is where the interaction of biology and physics gets mysterious, as the shark finds its dinner interrupted by a cloud of protective slime that appears out of nowhere around an otherwise placid hagfish.”

I don’t usually begin my “Amusing Monday” blog posts with a quote from a news release, but writer Chris Barncard has described precisely what leads up to an encounter between a fish predator and the mysterious hagfish. Biting a hagfish sends a shudder of revulsion through an enemy trying to eat it. The news release, found on the website of the University of Wisconsin – Madison, describes the research that has led to a mathematical description of an attack by hagfish slime.

“In the blink of an eye (or the flash of attacking tail and teeth), the hagfish can produce many times its own body’s volume in slime,” writes Chris Barncard. “The goop is so thick and fibrous, predators have little choice but to spit out the hagfish and try to clear their mouths.”

Jean-Luc Thiffeault, a UW-Madison math professor, has been working to mathematically model the hagfish response, which can occur in half a second.

“The mouth of the shark is immediately chock full of this gel,” he said. “In fact, it often kills them, because it clogs their gills.”

I’ve pulled together some amusing videos of hagfish to show this strange fish in action. The video at the bottom of the page was offered by the researchers to show how the slime is able to expand so suddenly. As usual, go full-screen for the best view.

When the hagfish is attacked, gel is ejected from glands in its skin. The gel consists of seawater-trapping threads that are coiled up into “skeins” each having a diameter about twice the width of a human hair. Each tiny skein is coiled so tightly that it can release up to six inches of thread.

Previous researchers found that it took several hours for the skeins to unwind if they were placed in still water, whereas stirring the water speeded up the process.

Study collaborators Randy Ewoldt, a mechanical engineering professor at the University of Illinois, and his graduate student Gaurav Chaudhary studied the process under a microscope and worked with Thiffeault to describe the fluid dynamics.

“Our model hinges on an idea of a small piece that’s initially dangling out, and then a piece that’s being pulled away,” Thiffeault was quoted as saying. “Think of it as a roll of tape. To start pulling tape from a new roll, you may have to hunt for the end and pick it loose with your fingernail. But if there’s already a free end, it’s easy to catch it with something and get going….

“The main conclusion of our model is we think the mechanism relies on the threads getting caught on something else — other threads, all the surfaces on the inside of a predator’s mouth, pretty much anything — and it’s from there it can really be explosive.”

Improving the hydrodynamics of the system are proteins found in mucous that can help break apart the skeins.

“Nothing is going to happen as nicely as in our model — which is more of a good start for anyone who wants to take more measurements — but our model shows the physical forces play the biggest role,” Thiffeault said.

While hagfish may act like an alien creature, understanding the behavior of tangled threads in a microscopic world could lead to new applications for gel technology in the world of industry and medicine, according to the researchers. At least one company, Benthic labs, is working on developing a synthetic slime that could be used in consumer products, such as packaging and clothing, in place of materials derived from petroleum.

One species of hagfish, Pacific hagfish, can be found off the West Coast from Canada to Mexico in waters from 50 to 3,000 feet deep.

Amusing Monday: TED Ed video features Southern Resident orcas

Last week, a new animation was posted online describing the matriarchal social structure of our beloved killer whales, in which elder females serve as guides for generations of their living descendants. (See first video.)

The new video, part of the TED Ed collection of animations, focuses on the 74 Southern Resident orcas and how they stay with their mothers for life. The video’s creator, animal behaviorist Darren Croft, credits the Center for Whale Research with studies that have successfully identified every filial relationship among the Puget Sound orcas for more than 40 years.

The TED Ed collection includes hundreds of animations created by TED Conferences LLC, the media organization responsible for nearly 3,000 online TED Talks. TED combines the concepts Technology, Entertainment and Design (TED) and operates under the slogan “ideas worth spreading.” An annual conference is held in Vancouver, B.C., with smaller events held throughout North America, Europe and Asia.

The Ted Ed series was started six years ago to inspire students to discuss creative ideas, develop innovative concepts and become young leaders. TED Ed has developed a flexible curriculum that can be used by teachers or students themselves. Each video has a “create a lesson” button for teachers or students to adapt the video to their own situation and branch out into other ideas.

Students can organize themselves as a club in an after-school setting, work with a teacher in a classroom, become part of a larger ongoing program. or develop an idea alone or with a partner. The program is designed to teach students from ages 8 to 18 and welcomes participants over age 13. See “Get involved” or review the “frequently asked questions.”

The TED Ed videos cover a multitude of topics, including science, technology, health, history, art, literature, health and even riddles. Some are better than others, but the best ones provide tidbits of information that can actually cause one to change his or her way of thinking. YouTube has a large collection of TED Ed videos.

The new video about orca matrilines offers possible explanations for why female whales have been known to live well beyond their reproductive lifespan. Males and females tend to stay with their mothers for life, although males will interact with other pods for mating. As older females die off, their daughters become the new leaders of the matrilines, which together make up larger pods.

The video, called “The Amazing Grandmothers of the Killer Whale Pod,” has more than 142,000 views so far and more than 300 comments.

Other TED Ed videos I found worth watching include the second video on this page, “When will the next ice age happen?” and the third, “Jellyfish predate dinosaurs. How have they survived so long?” Also check out the following or search for subjects from the full list:

McNeil Island becoming known for fish and wildlife, not just prison

If you’ve heard of McNeil Island, you are probably thinking of a former federal or state prison in South Puget Sound — not the rare and exclusive habitat that has won high praise from fish and wildlife biologists.

A derelict boat, estimated at 100 years old, is removed from the McNeil Island shoreline.
Photo: Monica Shoemaker, DNR

I never realized that McNeil Island was such a gem until I learned about state restoration plans that could lead to near-pristine conditions for the island, located about seven miles southwest of Tacoma.

To be sure, more than 90 percent of the island’s 12-mile-long shoreline remains in a natural state, including large trees bending over the water . The restoration — the result of a longtime planning effort — will focus on discrete areas that have been highly degraded by human activities, some for more than a century.

The first project, completed this week, was the removal of shoreline armoring, creosote pilings and debris in six locations. Close to 1,000 tons of concrete was hauled away by barge along with 55 tons of scrap metal and more than 51 tons of pilings. A 557-foot bulkhead was pulled out along with a derelict boat.

“You can already see how much better the habitat appears with all that armoring and debris gone,” said Monica Shoemaker, restoration manager for the Department of Natural Resources’ Aquatic Restoration Program.

“I’m super excited about it,” she added, as she wrapped up the site work. “It takes a lot of planning and permitting, and when you work on something awhile, it is great to see it completed.”

Metal anti-submarine nets, added years ago to McNeil Island’s shoreline, were hauled away during the removal project.
Photo: Monica Shoemaker, DNR

The concrete debris included what looked like an old building, demolished and tossed down the bank, Monica told me. What appeared to be ceramic tiles from a bathroom were scattered among the pieces of concrete. Metal debris included multiple layers of twisted and tangled anti-submarine netting, apparently brought to the site following World War II.

The accomplishment goes well beyond appearances. The shoreline is important rearing habitat for juvenile salmon, including threatened Chinook. Portions of the beach will provide excellent spawning habitat for forage fish, such as surf smelt and sand lance, according to Doris Small of the Washington Department of Fish and Wildlife.

Much of the island contains moderate to low-bank waterfront, with about 25 percent identified as “feeder bluffs,” which provide sand and gravel to keep the beaches suitable for forage-fish spawning. Wetlands across the island provide habitat for a multitude of species.

Doris said the ongoing restoration effort has been the result of exceptional collaboration between DNR, WDFW and the state Department of Corrections.

McNeil Island served as the site a federal penitentiary from 1875 to 1979. It was the first federal prison in Washington Territory. In 1981, after the federal government decided it was too expensive to operate, the facility was leased by the state of Washington.

In 1984, the state Department of Corrections took ownership of the prison site with 1,324 acres used for buildings and infrastructure. The remainder of the island’s 4,413 acres was dedicated as a permanent wildlife sanctuary under control of WDFW. The deed also transferred ownership of Gertrude and Pitt islands to the state for conservation purposes.

The prison was upgraded during the 1990s with new buildings to serve up to 1,300 inmates. But in 2011 the prison was closed as a cost-cutting measure. Today, the facility houses about 300 inmates in a Special Commitment Center for sexually violent offenders who have been civilly committed.

McNeil, Gertrude and Pitt Islands remain closed to public access to protect breeding populations of wildlife. A 100-yard safety zone goes out into the water with warning signs for boaters.

In 2011, DNR established the Nisqually Reach Aquatic Reserve, which edges up against Nisqually National Wildlife Refuge and includes Anderson Island, McNeil Island and surrounding waters. The idea is to protect shoreline ecosystems in the reserve.

A feasibility report (PDF, 6.3 mb), developed by WDFW and DNR, includes a shoreline survey that identified 10 sites where debris removal would improve the nearshore habitat. Although contractors removed more material than originally estimated for the first six sites, bidding was favorable and costs were held to about $450,000, Monica said. Funding is from DNR’s aquatic restoration account.

The next project, to get underway in January, involves removal of a concrete boat launch, concrete debris and log pilings from the so-called Barge Landing Site at the southern tip of McNeil Island. Funding will come from an account that provides money from a pollution settlement with Asarco, a company that operated a Tacoma smelter that released toxic chemicals over a wide area.

Other projects on McNeil Island involve removing road embankments constructed across three estuaries along with work to restore natural functions. Estuaries provide rearing habitat for salmon and other aquatic species. State or federal restoration grants are needed to proceed with those projects. For ongoing information, check out DNR’s website about McNeil Island.

Environmental volunteers needed in Kitsap County

I thought I would offer a quick note on some volunteer opportunities in Kitsap County, based on an email from WSU Kitsap County Extension. By the way, Kitsap and King county governments are among the best in connecting people with opportunities where they can spent quality time together while helping their community. Check out Kitsap County Volunteer Services and King County volunteer calendar and opportunities.

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Legal settlement could help protect salmon eggs incubating in gravel

Washington Department of Ecology has agreed to take steps to protect wild salmon eggs incubating in gravel by developing entirely new water-quality standards to control fine sediment going into streams.

The new standards, yet to be developed, could ultimately limit silty runoff coming from logging operations, housing construction and other operations that can affect water quality. The idea is maintain adequate oxygen to salmon eggs, thus increasing the rate of survival as well as the health of the young fish.

The legal agreement with Ecology grew out of a lawsuit brought by Northwest Environmental Advocates against the federal Environmental Protection Agency. NWEA claimed that the EPA had failed to consult with natural resource agencies while reviewing changes in state water-quality standards, as required by the Endangered Species Act.

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Hood Canal avoids a major fish kill following unwelcome conditions

Southern Hood Canal avoided a major fish kill this year, but for a few days in September it looked like conditions were set for low-oxygen waters to rise to the surface, leaving fish in a critical state with no place to go, experts say.

Data from the Hoodsport buoy show the rise of low-oxygen waters to the surface over time (purple color in top two graphs). // Graphic: NANOOS

Seth Book, a biologist with the Skokomish Tribe, has been keeping a close watch on a monitoring buoy at Hoodsport. Dissolved oxygen in deep waters reached a very low concentration near the end of September, raising concerns that if these waters were to rise to the surface they could suddenly lead to a deadly low-oxygen condition. This typically happens when south winds blow the surface waters to the north.

“I started asking around the community to see if anyone had seen evidence of low DO (fish at surface; dead fish; deep fish being observed or found in fishing nets at surface; diver observations) and luckily I had no reports,” Seth wrote to me in an email.

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New film celebrates the history of the Wild and Scenic Rivers Act

Today marks the 50th anniversary of the Wild and Scenic Rivers Act, and I was pleased to see that producer/director Shane Anderson and Pacific Rivers are allowing the documentary “Run Wild Run Free” to be shown online for three days before the film goes back into limited showings.

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Getting lost in the tangle of connections called the Puget Sound food web

I’m increasingly amazed at the interwoven nature of the Puget Sound food web. Whenever I become focused on a specific species — Chinook salmon, for example — one of the first questions I ask is: What is this species eating?

I soon learn that the answer depends on the size of the individual doing the eating. Prey for a baby salmon is much different from prey for an adult.

If you really want to learn about why a species is doing well or poorly, you need to look beyond prey availability for your species of interest and find out what the prey are eating as well. Healthy prey must be abundant for any species to do well, so the prey of the prey must also do well.

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Amusing Monday: Salish Sea photo contest shows diversity of local species

Nearly 900 photographs highlighting the diversity and biodiversity of our inland waterways were submitted to the “Salish Sea in Focus” photo contest, which just announced the winners yesterday.

“One Fish, Two Fish” by Nirupam Nigam of Hoquiam
First place in Fish category, “Salish Sea in Focus” photo contest

“We’re thrilled with the quality and diversity of the photos — not only the winners but throughout the whole contest,” said Justin Cox, communications director for The SeaDoc Society, which sponsored the contest. “They capture the Salish Sea beautifully, which is everything we hoped for when we envisioned ‘Salish Sea In Focus.’”

The Grand Prize in the contest was awarded to Bruce Kerwin of Bainbridge Island, whose photo shows the furled tentacles of a giant Pacific octopus at Sund Rock on Hood Canal. Other winners were named in five categories plus an additional award for photographers under age 18.

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Amusing Monday: Ten new species, each with unique stories to tell

An international team of taxonomists has chosen the “Top 10 New Species of 2018” from among some 18,000 new species named last year.

They range from the large — a majestic tree that is critically endangered — to the small — a microscopic single-celled organism discovered in an aquarium with no obvious connection to any known species.

They include a fish that has survived in the deepest, darkest part of the Pacific Ocean — at record depth — with credit for its discovery going to a team of scientists led by a University of Washington researcher.

The list of new species also includes a rare great ape — an orangutan that has been identified as a separate species — as well as a prehistoric marsupial lion identified from fossils found in Australia.

The 11th annual list is compiled by the International Institute for Species Exploration at the College of Environmental Science and Forestry at the State University of New York.

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