Tracking genetically modified animals

New CSI-like methods for detecting artificial transgenes

Peer-Reviewed Publication

MCGILL UNIVERSITY

 

IMAGE: GLOFISH TETRNECTIA GENETICALLY MODIFIED FISH. view more 

CREDIT: CHARLES XU

McGill University researchers have discovered a new way to track genetically modified animals using the artificial transgenes they leave behind in the environment. The discovery provides a powerful new tool to locate and manage genetically modified animals that have escaped or been released into the wild.

The magic of eDNA

In a study published in PLOS ONE, the researchers show for the first time that artificial transgenes from a variety of genetically modified animals like fruit flies, mice, and tetra fish can be detected and sequenced from the DNA left behind in soil, water, and in the form of feces, urine, or saliva. These findings could be used, for example, to detect the transgenes of genetically modified mosquitoes from pools of standing water in areas where they were recently released.

Compared to traditional animal monitoring methods, environmental DNA (eDNA) has proven to be more accurate and efficient, requiring less time and lower costs.

“Until now no one had applied these environmental DNA methods to genetically modified animals, even though they are already in the wild,” says Charles Xu, a PhD student in Department of Biology at McGill University. “Detection of animal transgenes from eDNA can be very useful because it can tell you whether genetically modified animals are there without the need to find them.”

An explosion of genetically modified animals

Advances in genome-editing technologies like CRISPR have dramatically simplified the process of creating genetically modified organisms, leading to an explosion in the number and types of genetically modified animals being produced around the world. With them come concerns about the ecological, evolutionary, and bioethical implications of these new creatures. Some genetically modified animals, like glowing aquarium fish, can be purchased by the public, while others, like mosquitos, have been released into the wild. The creatures carry artificial transgenes, or genes that have either been altered by scientists or introduced from another species by artificial means.

“Because genetically modified animals are often indistinguishable from their natural counterparts based on appearance alone, environmental DNA or eDNA methods could be especially useful for early detection and monitoring purposes,” he adds. “That is especially true in cases where these animals may escape from the lab or the farm, move to places they don’t belong, or crossbreed with natural animals.”

In the future, labs, companies, and governments involved in producing and managing genetically modified animals will be able to use eDNA methods to detect and track them in real-life contexts.

CAPTION

Researchers have discovered a new way to track genetically modified animals using the artificial transgenes they leave behind in the environment.

CREDIT

About this study

“Transgenes of genetically modified animals detected non-invasively via environmental DNA” by Charles C.Y. Xu, Claire Ramsay, Mitra Cowan, Mehmoush Dehghani, Paul Lasko, and Rowan D.H. Barrett was published in PLOS ONE. The research was supported by Natural Science and Engineering Research Council, Discovery Grant Canada, Canada Research Chair, Vanier Canada Graduate Scholarship, Quebec Fonds de recherche du Quebec – Nature et technologies.

DOI: https://doi.org/10.1371/journal.pone.0249439

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JOURNAL

PLoS ONE

DOI

10.1371/journal.pone.0249439 

METHOD OF RESEARCH

Experimental study

SUBJECT OF RESEARCH

Animals

ARTICLE TITLE

Transgenes of genetically modified animals detected non-invasively via environmental DNA

ARTICLE PUBLICATION DATE

26-Aug-2021

Companion dogs may be a key to solving dementia

The data support that cognitive dysfunction in dogs models several key aspects of human dementia

Peer-Reviewed Publication

EÖTVÖS LORÁND UNIVERSITY (ELTE), FACULTY OF SCIENCE

 

IMAGE: NEW RESEARCH MEASURED AN ALZHEIMER’S DISEASE-ASSOCIATED PEPTIDE (AΒ42) IN COMPANION DOG BRAINS AND FOUND THAT HIGHER ABUNDANCE IS ASSOCIATED WITH INCREASED COGNITIVE DECLINE. (EÖTVÖS LORÁND UNIVERSITY) view more 

CREDIT: PHOTO: KUBINYI

New research measured an Alzheimer’s disease-associated peptide (Aβ42) in companion dog brains and found that higher abundance is associated with increased cognitive decline. The data support that cognitive dysfunction in dogs models several key aspects of human dementia, underscoring the suitability and usefulness of companion dogs as an animal model for aging studies.

Dementia is an umbrella term for loss of memory and ability to learn, deterioration in thinking, behaviour, and the ability to carry out daily tasks. The chance of getting dementia rises as one gets older: In general, 5-8% of people over 60 are thought to have some degree of dementia. The most common cause of dementia is Alzheimer’s Disease, for which unfortunately no cure exists yet. One main limitation in Alzheimer’s research is the lack of useful animal models that develop dementia spontaneously, without genetic engineering, and also adequately reflect the genetic and environmental complexity of humans. Companion dogs recently emerged as exciting new models for human aging because they share the human environment, they are exposed to similar risk factors, they age roughly ten times faster than humans, and a subset of dogs spontaneously develop canine dementia in old age. “When an old dog shows decreased ability to learn, increased anxiety, loss of normal sleep patterns, and aimless wandering, he may be struggling with Canine Cognitive Dysfunction,” said Silvan Urfer, a veterinarian and researcher at the University of Washington, who is the first author of the study published in GeroScience. “It can be reliably diagnosed using a validated questionnaire that assesses the dog’s cognitive function. Scores of 50 points and above are indicative of a diagnosis of cognitive dysfunction.”

Molecular features of Alzheimer’s disease in humans include the deposition of a peptide in the brain, called amyloid beta 42 (Aβ42). The canine Aβ42 peptide is identical to the human form. “We were interested in whether Aβ42 levels in companion dog brains are linked to cognitive function and age. In collaboration with Martin Darvas, our laboratory developed a new assay to measure Aβ42 in primate and canine brains and cerebrospinal fluid (CSF), but we did not yet have access to enough samples” said Matt Kaeberlein, one of the founders of the Dog Aging Project. This is where Urfer and Kaeberlein turned to Eniko Kubinyi, who has established the Canine Brain and Tissue Bank together with Kalman Czeibert, veterinarian, and Sara Sandor, geneticist, at the Department of Ethology, ELTE in Budapest. “We developed a unique pet dog body donation protocol for owners who, in agreement with their veterinarians, voluntarily offer their dog’s body for research after medically reasoned euthanasia.” said Kubinyi. The Hungarian researchers collect the brain and cerebrospinal fluid of the deceased subjects, together with thorough documentation of the dogs’ previous cognitive performance. This system allowed the team to correlate the post-mortem histological and molecular data with the behavioural measurements. They found significant positive correlations between Aβ42 and age in all three investigated brain regions (prefrontal cortex, temporal cortex, hippocampus/entorhinal cortex) while Aβ42 in the cerebrospinal fluid negatively correlated with age. Brain Aβ42 abundance in all three brain regions was also correlated with the Canine Cognitive Dysfunction Scale score. The relationship between cognitive impairment and Aβ42 abundance may mirror a similar trajectory in the aging dog, as in humans. It is well established that Aβ42 and other Alzheimer’s disease-related pathologies emerge in the brain years or even decades before clinical symptoms manifest. 

CAPTION

Dogs can help study human dementia

CREDIT

Photo: Kubinyi / Eötvös Loránd University

Both the Dog Aging Project and the Senior Family Dog Project aim to leverage privately owned companion dogs as models for aging and age-related disease in humans. Companion dogs living with their owners capture the genetic and environmental diversity that is impossible to recapitulate in laboratory animals.  To investigate aging in dogs, an important aspect is the availability of biospecimens from various organs for research, which should also include clinical and demographic information for these animals. Both the existing Canine Brain and Tissue Bank (CBTB) at ELTE and the Dog Aging Project Biobank at Cornell University address this emerging need by allowing citizen scientist owners to donate their dog’s body at the time of its natural end of life. These resources will be useful to conduct larger-scale studies in the future as more specimens become available.

The correlation between Aβ42 in dog brains and the cognitive scores supports the suitability of the companion dog as a model for Alzheimer’s disease. Besides, it illustrates the utility of veterinary biobanking to make biospecimens available to researchers for analysis. In the future, dogs could be used to study interventions aimed at preventing or treating Alzheimer-like pathology. Such research can also contribute to increasing the healthy lifespan of our pets.

  

CAPTION

Dogs can help study human dementia

CREDIT

Photo: Kubinyi / Eötvös Loránd University

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JOURNAL

GeroScience

DOI

/10.1007/s11357-021-00422-1 

METHOD OF RESEARCH

Experimental study

SUBJECT OF RESEARCH

Animal tissue samples

ARTICLE TITLE

Canine Cognitive Dysfunction (CCD) scores correlate with amyloid beta 42 levels in dog brain tissue

ARTICLE PUBLICATION DATE

19-Aug-2021

 

High cod catches could have been sustained in Eastern Canada for decades, simple stock assessment method shows

Peer-Reviewed Publication

UNIVERSITY OF BRITISH COLUMBIA

A simple fish stock assessment model applied to over 500 years of catch data demonstrated that if Canadian authorities had allowed for the rebuilding of northern Atlantic cod stock off Newfoundland and Labrador in the 1980s, annual catches of about 200,000 tonnes could have been sustained.

A new study by researchers from the Sea Around Us initiative at the University of British Columbia, the GEOMAR Helmholtz Centre for Ocean Research and Dalhousie University modelled the cod population trajectory for the entire period from 1508 to 2019. 

“Our assessment suggests that the biomass—the weight of the population in the water— of northern cod is currently around 2 per cent of what it was earlier,” said Rebecca Schijns, lead author of the study and a researcher with the Sea Around Us at UBC’s Institute for the Oceans and Fisheries.

“The interesting thing is that we got to these results by applying a computer-intensive but very simple stock assessment methods—known as CMSY—to catch data for five centuries. Different from previous assessments that required large amounts of information, this method basically requires only a time series of annual catches,” Schijns said. “The other information that is required is available from the scientific literature, and from people with knowledge of the fishery.”

Working with such a long time series allowed the researchers to reliably estimate maximum sustainable yield–or the highest catch that a fish stock can support in the long-term, given that environmental conditions remain more or less constant– for northern cod at 380,000 tonnes per year.  

But such high catches are now only a dream.  

Fisheries used lines and later traps for 400 years and were sustainable, generating catches of 100,000 to 200,000 tonnes per year. However, in the mid-1950s the introduction of bottom trawlers reduced northern cod biomass to levels that could not sustain high catches.

Although Canada declared a fishery exclusion zone in 1977, fishing did not actually halt to allow the stock to rebuild. This led to a final collapse of the northern Atlantic cod fishery, which remained open to small-scale fishers even during a moratorium imposed in 1992.

And in recent years, every time northern cod populations appear to increase, the fishing quota is raised.

“As a student, I was on board a German trawler fishing off Newfoundland and Labrador in 1973 and I have vivid memories of this cod rush,” said Dr. Daniel Pauly, co-author of the study and the Sea Around Us principal investigator.

“If artisanal fishers in the outports had been listened to when they warned about running out of cod to catch, things would be different now,” said Dr. Pauly. “The scientists then monitoring the cod stock ignored small-scale fishers and relied only on the data from trawlers which, however, did not reflect the cod stock’s decline because the trawlers could follow the cod further out than the small-scale fishers.”

Paying attention to what local and/or Indigenous fishers have to say—and integrating centuries-old catch data into stock assessments— can help manage marine populations more effectively for the long term. This approach is also helpful to understand the total impact of fisheries on marine ecosystems, Dr. Pauly noted.

“The CMSY method proved to be useful to assess the data-rich cod stock, but it also works with stocks for which we have only a catch data. This method is able to provide more reliable estimates of stock status by incorporating past data-limited periods,” Dr. Pauly said.

The CMSY method offers researchers, fisheries managers and policymakers the possibility of taking a comprehensive look into the status of the world’s most important fish stocks.

“Ancient catch data exist for several stocks, such as bluefin tuna in the Mediterranean, which started being commercialized around the 8th century, Atlantic herring in the Baltic Sea, whose fishery started in the 13th century, and Atlantic salmon in the Celtic Sea, whose fishery started in the 14th century," said Dr. Jeffrey Hutchings, co-author of the study and a researcher at Dalhousie University. “There is a real opportunity to use these data to design policies that prevent collapses similar to that of the cod stock.”

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JOURNAL

ICES Journal of Marine Science

DOI

10.1093/icesjms/fsab153 

METHOD OF RESEARCH

Data/statistical analysis

SUBJECT OF RESEARCH

Animals

ARTICLE TITLE

Five centuries of cod catches in Eastern Canada

Bowfin genome reveals old dogfish can teach researchers new tricks

International team of researchers sequence genome of the enigmatic bowfin fish

Peer-Reviewed Publication

HARVARD UNIVERSITY, DEPARTMENT OF ORGANISMIC AND EVOLUTIONARY BIOLOGY

 

IMAGE: FRESHLY DEPOSITED BOWFIN EGGS ATTACHED TO NEST MATERIAL. MALE BOWFIN BUILD NESTS IN WHICH FEMALES LAY EGGS. AFTER THE MALE FERTILIZES THE EGGS, IT WILL REMAIN WITH THE NEST TO GUARD THE YOUNG view more 

CREDIT: M. BRENT HAWKINS

The fish species Amia calva goes by many names including bowfin, freshwater dogfish, grinnel, and mud pike. No matter what you call it, this species is an evolutionary enigma because it embodies a unique combination of ancestral and advanced fish features.

In a paper published August 30 in Nature Genetics an international and collaborative team of researchers, headed by Ingo Braasch and Andrew Thompson of Michigan State University, have begun to unravel the enigma by sequencing the genome of the bowfin fish. Their collaborative analysis yielded unexpected insights into diverse aspects of the biology of this mysterious, ancient lineage.

The bowfin is a bony fish endemic to eastern North America and is the sole surviving member of a once large lineage of many species that are now known only from fossils. Scientists have long been fascinated with the bowfin because it bears a combination of ancestral features, such as lung-like air breathing and a robust fin skeleton, and derived features like simplified scales and a reduced tail. The bowfin also occupies a key position in the fish family tree, where it sits between the teleosts, a large and diverse group that arose recently, and more ancient branches that include sturgeons, paddlefish, and bichirs.

Due to this special position in the fish family tree, the bowfin can help scientists understand how aspects of modern fishes evolved from their ancient antecedents. By examining the bowfin genome, scientists can investigate the genetic basis of the unique set of old and new features of the bowfin. They can also use this genomic information as a framework to better understand the origin of the teleosts, which have duplicated and extensively modified their genomes since separating from the bowfin lineage and emerging as the dominant lineage in most aquatic habitats.

As a doctoral candidate in the Department of Organismic and Evolutionary Biology at Harvard University, study co-author M. Brent Hawkins (PhD ’20) examined the evolution and development of the bowfin pectoral fin. Hawkins’ doctoral thesis, conducted with Professor Matthew P. Harris, Harvard Medical School and Boston Children’s Hospital, and Professor James Hanken, Department of Organismic and Evolutionary Biology at Harvard university, contributed some of the study’s most surprising findings.

Hawkins focused on the pectoral fin of the bowfin because of its ancestral configuration of the skeleton. The bowfin retains the metapterygium, which is a portion of the fin skeleton that is homologous to the limb bones of tetrapods. Model organisms such as the widely used zebrafish and medaka have lost the metapterygium, which makes comparisons between the fin and the limb difficult. By studying the bowfin fin, scientists can use knowledge of bowfin development as a steppingstone to bridge teleost fin development to tetrapod limb development and help explain the evolution of the fin-to-limb transition.

CAPTION

Schematics show the arrangement of bones in fins and limbs. Elements that are derived from the ancestral metapterygium are shown in magenta. The tetrapod limb and a portion of the bowfin fin arose from the metapterygium, while teleosts have lost the metapterygial components

CREDIT

M. Brent Hawkins

With co-authors Emily Funk and Amy McCune, both at Cornell University, Hawkins collected young bowfin embryos from nests in the wild in upstate New York. Hawkins raised the embryos, collecting pectoral fin samples as they developed. He extracted mRNA from the samples and performed Transcriptome Sequencing with the help of the Harvard University Bauer Core to determine which genes are turned on in the developing fin by parsing the transcriptome data using the genomic reference sequence. Once identified, he used in situ hybridization to visualize where these genes are activated during fin outgrowth. Initially, Hawkins expected the bowfin gene data to look very similar to other fins and limbs. “As a field, we have characterized many of the genes involved in appendage patterning. We have a good idea of what the essential fin and limb genes are and where they should be turned on,” said Hawkins. However, when he analyzed the fin data he was shocked by the results.

While the bowfin pectoral fins did express many of the expected appendage growth genes, some of the most critical of these genes were in fact entirely absent. One such gene called fibroblast growth factor 8 (Fgf8) is turned on at the far tip of developing fins and limbs and is required for the outgrowth of these appendages. When Fgf8 is lost appendage outgrowth is impaired, and if extra Fgf8 is applied to an embryo, it can cause a new limb to form. “Every other fin and limb we know of expresses Fgf8 during development,” Hawkins said. “Discovering that bowfin fins don’t express Fgf8 is like finding a car that runs without a gas pedal. That the bowfin has accomplished this rewiring indicates unexpected flexibility in the fin development program. With the genome in hand, we can now unlock how this flexibility evolved.”

While some genes like Fgf8 were mysteriously absent from the bowfin fin, other genes were unexpectedly activated in the fins. The HoxD14 gene is expressed in the fins of fishes from the deeper branches of the fish family tree, such as paddlefish, but this gene was lost in more recent branches including the teleosts. When the authors found this gene in the bowfin genome data, they thought it must not be expressed because the DNA sequence did not encode a functional protein. Surprisingly, Hawkins and colleagues found that bowfin fins made HoxD14 gene transcripts at high levels, even though it did not code for a protein. “The fact that the HoxD14 gene can no longer make a protein, but it still transcribed into mRNA at such high levels suggests that there might be another function that we do not yet understand. We might be seeing a new level of Hox gene regulation at play in the bowfin,” said Hawkins.

CAPTION

A recently hatched bowfin larva facing to the left as seen through a microscope.

CREDIT

M. Brent Hawkins

Taken together the Fgf8 and HoxD14 results indicate that genetic programs, even those that guide the formation of important structures such as fins and limbs, are not as invariable as previously thought. “By studying more species, we learn which rules are hard and fast and which ones evolution can tinker with. Our study shows the importance of sampling a broader swath of natural diversity. We might just find important exceptions to established rules,” said Hawkins.

Hawkins also suggests that the results of the bowfin study serve as a warning against treating members of deeper branches of the tree of life as stand-ins for actual ancestors. “Some people might describe species like the bowfin as a ‘living fossil’ that reliably represents the ancestral condition of a lineage. In reality, these deeper branches have been evolving past that ancestor for just as long as the more recent branches, doing their own thing and changing in their own ways. In evolution, old dogs do learn new tricks.”

Hawkins is currently a postdoctoral researcher in the lab of Matthew P. Harris at Harvard Medical School and Boston Children’s Hospital.

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JOURNAL

Nature Genetics

DOI

DOI: 10.1038/s41588-021-00914-y 

ARTICLE TITLE

The bowfin genome illuminates the developmental evolution of ray-finned fishes

ARTICLE PUBLICATION DATE

30-Aug-2021

Learning from a ‘living fossil’

A Spartan-led team has probed the genetics of bowfin fish like never before to reveal insights about human health and evolutionary history

Peer-Reviewed Publication

MICHIGAN STATE UNIVERSITY

As we live and breathe, ancient-looking fish known as bowfin are guarding genetic secrets that that can help unravel humanity’s evolutionary history and better understand its health.

Michigan State researchers Ingo Braasch and Andrew Thompson are now decoding some of those secrets. Leading a project that included more than two dozen researchers spanning three continents, the Spartans have assembled the most complete picture of the bowfin genome to date.

“For the first time, we have what’s called a chromosome-level genome assembly for the bowfin,” said Braasch, an assistant professor of integrative biology in the College of Natural Science. “If you think of the genome like a book, what we had in the past was like having all the pages ripped out in pieces. Now, we’ve put them back in the book.”

“And in order,” added Thompson, a postdoctoral researcher in Braasch’s lab and the first author of the new research report, published Aug. 30 in the journal Nature Genetics.

This is really important information for a few reasons, the duo said, and it starts with the bowfin being what Charles Darwin referred to as a “living fossil.” The bowfin, or dogfish, looks like an ancient fish.

This doesn’t mean that the bowfin hasn’t evolved since ancient times, but it has evolved more slowly than most fishes. This means that the bowfin has more in common with the last ancestor shared by fish and humans, hundreds of millions of years ago, than, say, today’s zebrafish.

Zebrafish — which are modern, so-called teleost fishes — are a notable example because they’re widely used by scientists as a model to test and develop theories about human health. Having more genetic information about the bowfin helps make the zebrafish a better model.

“A lot of research on human health and disease is done on model organisms, like mice and zebrafish,” Thompson said. “But once you identify important genes and the elements that regulate those genes in zebrafish, it can be hard to find their equivalents in humans. It’s easier to go from zebrafish to bowfin to human.”

For example, one particularly interesting gene is one that’s used in developing the bowfin’s gas bladder, an organ the fish uses to breathe and store air. Scientists believe that the last common ancestor shared by fish and humans had air-filled organs like these that were evolutionary predecessors to human lungs.

In their new study, the Spartan researchers could see that a certain genetic process in the bowfin’s gas bladder development bore striking similarities to what’s known about human lung development. A similar process is also present in the modern teleost fishes, but it’s been obscured by eons of evolution.

“When you looked for the human genetic elements of this organ development in zebrafish, you couldn’t find it because teleost fishes have higher rates of evolution,” Thompson said. “It’s there in modern fishes, but it’s hidden from view until you see it in bowfin and gar.”

The gar is another air-breathing fish with “living fossil” status that’s studied by Braasch and his team. With both the gar and bowfin genomes, the team was able to show where these genetic elements linked to gas bladder and lung formation were hiding out in the modern teleost fishes. The ancient fish enable researchers to build a better bridge between the established modern fish model organisms and human biology.

“You don’t want to base that bridge on one species,” said Braasch, who added this finding also strengthens the implications for evolutionary history. “This is another piece of the puzzle that suggests the common ancestor of fish and humans had an air-filled organ and used it for breathing at the water surface, quite similar to what you see in bowfin and gar.”

Although these findings have insights that are pertinent to all of humanity, Spartans might feel a special affinity for the bowfin. For starters, male fish turn their fins and throats a bright shade of green during spawning season. Also, famed biologist William Ballard of Dartmouth College studied bowfin development from eggs to larval fish at Michigan State’s W.K. Kellogg Biological Station during the 1980s. This was what he called his “Odyssey of Strange Fish,” and Braasch’s team now uses his work to guide their genomic analyses of bowfin development.

Bowfins are native to Michigan. They could be in the Red Cedar River on MSU’s campus now, according to Thompson, but they also can be quite elusive and, sometimes, very aggressive. This made collaborations essential for securing specimens. With colleagues at Nicholls State University in Louisiana, the team caught bowfins for genome sequencing. Amy McCune, a collaborator and professor at Cornell University, knew where to find bowfin eggs in upstate New York and had a graduate student gifted at securing these unique samples for investigating bowfin development.

The Spartans also had connections at other universities and institutions with experts in bowfin biology, chromosome evolution and more. All told, the team included researchers from six states as well as France, Japan and Switzerland. Back in East Lansing, graduate students Mauricio Losilla and Olivia Fitch, research technologist Brett Racicot, and Kevin Childs, director of the MSU Genomics Core facility, also contributed to the study, which comes with an interesting twist at the end.

Almost all vertebrate creatures that grow paired limbs or fins share a common gene.

“Humans use it, mice use it. All fishes that have been studied so far use it,” Braasch said. “The naïve expectation would be that bowfin do, too.”

But that’s not what the team found. The bowfin, the “living fossil,” has evolved a different way of growing its paired fins.

“For whatever reason, it changed its genetic programming. Even ‘living fossils’ keep evolving. They’re not frozen in time,” Braasch said. “It’s sort of a cautionary tale that we shouldn’t take these things for granted. You have to look trait by trait, gene by gene and across many different species to paint the complete picture.”

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JOURNAL

Nature Genetics

DOI

10.1038/s41588-021-00914-y 

ARTICLE TITLE

The bowfin genome illuminates the developmental evolution of ray-finned fishes

ARTICLE PUBLICATION DATE

30-Aug-2021

Minnesota Sea Grant launches egg-to-market yellow perch project

Project aims to develop producer-scale methods for raising Yellow Perch fish from egg to market size using a recirculating aquaculture system (RAS)

Grant and Award Announcement

UNIVERSITY OF MINNESOTA

 

IMAGE: YELLOW PERCH. view more 

CREDIT: IMAGE CREDIT: ROBERT COLLETTA/U.S.DEPARTMENT OF AGRICULTURE, AGRICULTURAL RESEARCH SERVICE.

“Many Minnesota fish farmers are looking for a species that has a much higher market value than Tilapia; Yellow Perch might fill that niche,” said Amy Schrank, MNSG fisheries and aquaculture extension educator and project lead. “Minnesota Sea Grant has been actively engaged with Minnesota fish farmers since 2017 and raising Yellow Perch is one of the problems they asked us for help with.”

Yellow Perch, also known as Lake Perch, has a mild, sweet flavor with firm, flaky white flesh. They are highly sought after by ice anglers, according to the Minnesota Department of Natural Resources. 

“Consistent availability of juvenile Yellow Perch, called fingerlings, has limited Yellow Perch aquaculture in Minnesota and the Great Lakes region and these limitations became more severe during the COVID-19 pandemic,” said Schrank.  

MNSG’s Yellow Perch project is funded by a $134,879 grant from the National Sea Grant Office and is one of 13 nationwide projects designed to address ongoing and long-term impacts associated with the COVID-19 pandemic on seafood resources, including aquaculture and the connection between aquaculture and wild-caught fisheries.

“We are partnering with a Yellow Perch producer from Minnesota to compare methods and costs of rearing Yellow Perch in two different styles of indoor, biosecure production systems,” said Schrank. “We will compare fish growth, mortality rates, and production costs between systems for both fingerling and market-size fish.” 

The two types of indoor fish-rearing systems the project will compare are a flow-through and a recirculating aquaculture system or RAS. The main difference between the two systems is that in a flow-through system the water is not reused and in a RAS the water is filtered and is reused within the tank. The two test systems will be located on the University of Minnesota St. Paul campus.    

“Moving production of Yellow Perch from outdoor pond rearing to indoor RAS could increase overall production, increase growth rates, and expand the season when fresh Yellow Perch fillets would be available to consumers,” said Schrank. “We hope this project will also help increase the availability of biosecure fingerlings that fish farmers need.” 

Once the project is complete, the project team, which includes Don Schreiner, Minnesota Sea Grant fisheries specialist, and Marie Thoms, communications manager, plans to develop and distribute a guide and outreach materials for producers on how to raise Yellow Perch that describe best practices and cost estimates for production in RAS.

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CONTACT:

Amy Schrank, fisheries and aquaculture extension educator, Minnesota Sea Grant, University of Minnesota and University of Minnesota Duluth, aschrank@umn.edu.

Don Schreiner, fisheries specialist, Minnesota Sea Grant, University of Minnesota and University of Minnesota Duluth, schr0941@d.umn.edu

Marie Thoms, communications manager, Minnesota Sea Grant, University of Minnesota and University of Minnesota Duluth, methoms@d.umn.edu

Seaweed farms in river estuaries significantly reduce nitrogen concentrations and prevent environmental pollution

Research conducted by Tel Aviv and Berkeley Universities

Peer-Reviewed Publication

TEL-AVIV UNIVERSIT

 

IMAGE: THE CULTIVATION REACTOR THAT WAS USED AS THE BASE OF THE MODEL. view more 

CREDIT: MEIRON ZOLLMANN

A new study by Tel Aviv University and University of California, Berkeley proposes a model according to which the establishment of seaweed farms in river estuaries significantly reduces nitrogen concentrations in the estuary and prevents pollution in estuarine and marine environments. The study was headed by doctoral student Meiron Zollmann, under the joint supervision of Prof. Alexander Golberg of the Porter School of Environmental and Earth Sciences and Prof. Alexander Liberzon of the School of Mechanical Engineering at the Iby and Aladar Fleischman Faculty of Engineering, Tel Aviv University. The study was conducted in collaboration with Prof. Boris Rubinsky of the Faculty of Mechanical Engineering at UC Berkeley. The study was published in the prestigious journal Communications Biology.

 

As part of the study, the researchers built a large seaweed farm model for growing the ulva sp. green macroalgae in the Alexander River estuary, hundreds of meters from the open sea. The Alexander River was chosen because the river discharges polluting nitrogen from nearby upstream fields and towns into the Mediterranean Sea. Data for the model were collected over two years from controlled cultivation studies.

Researchers explain that nitrogen is a necessary fertilizer for agriculture, but it comes with an environmental price tag. Once nitrogen reaches the ocean, it disperses randomly, damaging various ecosystems. As a result, the state local authorities spend a great deal of money on reducing nitrogen concentrations in water, following national and international conventions that limit nitrogen loading in the oceans, including in the Mediterranean Sea.

 

"My laboratory researches basic processes and develops technologies for aquaculture," explains Prof. Golberg. "We are developing technologies for growing seaweed in the ocean in order to offset carbon and extract various substances , such as proteins and starches, to offer a marine alternative to terrestrial agricultural production. In this study, we showed that if seaweed is grown according to the model we developed, in rivers’ estuaries, they can absorb the nitrogen to conform to environmental standards and prevent its dispersal in water and thus neutralize environmental pollution. In this way, we actually produce a kind of "natural decontamination facility" with significant ecological and economic value since seaweed can be sold as biomass for human use.

 

The researchers add that the mathematical model predicts farm yields and links seaweed yield and chemical composition to nitrogen concentration in the estuary.  "Our model allows marine farmers, as well as government and environmental bodies, to know, in advance, what the impact will be and what the products of a large seaweed farm will be – before setting up the actual farm," adds Meiron Zollman. "Thanks to mathematics, we know how to make the adjustments also concerning large agricultural farms and maximize environmental benefits, including producing the agriculturally desired protein quantities."

 

"It is important to understand that the whole world is moving towards green energy, and seaweed can be a significant source," adds Prof. Liberzon, "and yet today, there is no single farm with the proven technological and scientific capability. The barriers here are also scientific: We do not really know what the impact of a huge farm will be on the marine environment. It is like transitioning from a vegetable garden outside the house to endless fields of industrial farming. Our model provides some of the answers, hoping to convince decision-makers that such farms will be profitable and environmentally friendly. Furthermore, one can imagine even more far-reaching scenarios. For example, green energy: "If we knew how to utilize the growth rates for energy in better percentages, it would be possible to embark on a one-year cruise with a kilogram of seaweed, with no additional fuel beyond the production of biomass in a marine environment."

 

"The interesting connection we offer here is growing seaweed at the expense of nitrogen treatment," concludes Prof. Golberg. "In fact, we have developed a planning tool for setting up seaweed farms in estuaries to address both environmental problems while producing economic benefit. We offer the design of seaweed farms in river estuaries containing large quantities of agriculturally related nitrogen residues to rehabilitate the estuary and prevent nitrogen from reaching the ocean while growing the seaweed itself for food. In this way, aquaculture complements terrestrial agriculture."

 

Link to the article:

https://www.nature.com/articles/s42003-021-02371-z#Sec2

 

 

 

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JOURNAL

Communications Biology

DOI

10.1038/s42003-021-02371-z 

ARTICLE TITLE

Multi-scale modeling of intensive macroalgae cultivation and marine nitrogen sequestration

ARTICLE PUBLICATION DATE

6-Jul-2021

Recreational marijuana legalization and co-use with alcohol among adolescents

Peer-Reviewed Publication

PACIFIC INSTITUTE FOR RESEARCH AND EVALUATION

A new study from the Prevention Research Center of the Pacific Institute for Research and Evaluation finds that recreational marijuana legalization may increase the risk of alcohol and marijuana co-use among adolescents.

The study examined the association between recreational marijuana legalization in California in November 2016 and alcohol and marijuana co-use among underage youth. The study is based on data from 7th, 9th, and 11th graders who participated in the statewide California Healthy Kids Survey from 2010–2011 to 2018–2019 school years.

Key findings include:

• Recreational marijuana legalization was associated with greater odds of past 30–day alcohol and marijuana co-use among adolescents after 2016-2017
• Legalization was more strongly associated with co-use among adolescents who reported past 30–day alcohol use and heavy drinking
• Legalization was inversely related to co-use among past 30–day marijuana users
• Among past 30–day co-users, there was a positive association between legalization and the frequency of marijuana use

Study co-author, Dr. Mallie J. Pachall, notes that:  “Our study shows that marijuana legalization may increase the risk of alcohol and marijuana co-use among adolescents. To combat this negative public health effect, greater restrictions on the numbers of alcohol and marijuana retail outlets, hours of operation, advertising, as well as imposing higher taxes on alcohol and marijuana products may help reduce their availability to adolescents.”

Source:  Paschall, Mallie J., Grisel García-Ramírez, and Joel W. Grube. "Recreational Marijuana Legalization and Co-use With Alcohol Among Adolescents." American Journal of Preventive Medicine (2021). https://doi.org/10.1016/j.amepre.2021.06.003Get rights and content

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PIRE is an independent, nonprofit organization merging scientific knowledge and proven practice to create solutions that improve the health, safety and well-being of individuals, communities, and nations around the world. www.pire.org

The Prevention Research Center (PRC) of PIRE is one of 16 centers sponsored by the National Institute on Alcohol Abuse and Alcoholism (NIAAA), of the National Institutes of Health, and is the only one that specializes in prevention. PRC's focus is on conducting research to better understand the social and physical environments that influence individual behaviors that lead to alcohol and drug misuse. www.prev.org

The Resource Link for Community Action provides information and practical guidance to state and community agencies and organizations, policy makers, and members of the public who are interested in combating alcohol and other drug abuse and misuse. https://prev.org/community-action/

Facebook:  facebook.com/PrevResources

Twitter:       twitter.com/PrevResources 

LinkedIn:   linkedin.com/company/PrevResources

If you would like more information about this topic, please call Sue Thomas at 831.429.4084 or email her at thomas.pire.org

 

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JOURNAL

American Journal of Preventive Medicine

DOI

10.1016/j.amepre.2021.06.003 

METHOD OF RESEARCH

Data/statistical analysis

SUBJECT OF RESEARCH

People

ARTICLE TITLE

Recreational Marijuana Legalization and Co-use With Alcohol Among Adolescents