(Press-News.org) The most aggressive largemouth bass in the lake are also the ones most prized by anglers. These are the fish that literally 'take the bait' and put the fun into both competitive and casual sport fishing.
Then, according to the rules of catch-and-release, the captive is unhooked and tossed back to swim away without any lasting consequences. But a new UConn study says there is an impact; the evolutionary path of a species may be on the line.
In a recent paper published in the journal PLOS ONE, a team of researchers led by Jan-Michael Hessenauer and Jason Vokoun of the Department of Natural Resources and the Environment, found the practice of catch-and-release appears to influence which fish are the species' fittest.
"This scenario genetically favors the fish with lower metabolisms, the fish that are less likely to be caught by anglers," Vokoun says. "It suggests that we may be permanently changing exploited fish populations over the long term."
The potential for recreational fishing to act as an evolutionary force is well established in theory. But this is the first study to identify outcomes of selection from recreational fishing of wild populations using unfished populations as a reference.
Researchers compared populations of largemouth bass in two lakes that are open to recreational fishing and two that have been undisturbed for hundreds of years. Connecticut has significant wild populations of largemouth bass living in protected bodies of water due to stringent management practices enforced by local water companies.
The researchers collected baby fish from the fished and unfished lakes and transferred them to a protected location with no anglers and no predation from larger fish. Prior to being released into the pens, each fish was tagged so it could later be identified by its place of origin.
Despite their different origins, the two populations grew up in the same environment and experienced the same rearing conditions. After one year, the researchers measured the fishes' resting metabolism.
They found that a significantly higher number of fish taken from the lakes where fishing was allowed had lower metabolic rates compared with the fish taken from protected bodies of water.
"The results point to a reduction in the type of behavior that is so prized by anglers," says Hessenauer, a doctoral student.
Several factors may be influencing this, according to Vokoun, associate professor of natural resources and the environment and director of UConn's Wildlife & Fisheries Conservation Center. Male Largemouth Bass are aggressive nest guarders, and if they are removed permanently, the nest will likely fail.
More aggressive females that are caught and released may suffer physiological stress that results in egg resorption and the production of fewer offspring, he says. If the same fish are caught more than once, their energy levels may be depleted, and typical behavior altered.
Vokoun adds that catch-and-release practices put physiological stress on the fish that can result in the disruption of reproductive behavior, as well as some unintended post-release mortality.
While a catch-and-release strategy may have some unintended drawbacks, Hessenauer and Vokoun don't dispute that it is well intended, or that it does make a contribution to the conservation of freshwater fish populations.
The next step in the research will be to breed fish that come from protected areas with those that come from unprotected areas, with the hope that the offspring will inherit some of the vigor and persistence of their wild kin.
The current findings may have implications for the catch-and-release strategy, says one of the study's co-authors, Robert Jacobs, Eastern District supervisor for the Inland Fisheries Division of the Connecticut Department of Energy and Environmental Protection (DEEP), which funded the study.
"People affect the genetics of plant and animal populations just by the way we interact with them, and this study contributes to a body of knowledge that will help us truly understand how traditional management strategies may become less relevant over time," he says. "The findings in this study may be a strong signal that we need to be much more creative in the ways we manage our inland fisheries."
INFORMATION:
Armed with new knowledge about how neurodegenerative diseases alter brain structures, increasing numbers of neurologists, psychiatrists and other clinicians are adopting quantitative brain imaging as a tool to measure and help manage cognitive declines in patients. These imaging findings can help spur beneficial lifestyle changes in patients to reduce risk for Alzheimer's disease.
The concept that cognitive decline can be identified early and prevented by applying quantitative brain imaging techniques is the focus of "Hot Topics in Research: Preventive Neuroradiology ...
ATLANTA - June 4, 2015- Screening for colorectal cancer increased in lower socioeconomic status (SES) individuals after 2008, perhaps reflecting the Affordable Care Act's removal of financial barriers to screening according to a new analysis. The study, by American Cancer Society investigators, appears online in the journal Cancer.
The Patient Protection and Affordable Care Act (ACA) included a cost-sharing provision intended to reduce financial barriers for preventive services, including screening for colorectal cancer (CRC) and breast cancer (BC). To investigate whether ...
Withholding angiotensin receptor blockers (ARBs) for longer than two days after surgery is associated with a significantly increased risk of postoperative death, according to a study of more than 30,000 patients in the VA health care system by researchers at UC San Francisco and the San Francisco VA Medical Center (SFVAMC).
ARBs are prescribed for high blood pressure, heart disease and kidney disease, explained lead author Susan M. Lee, MD, an SFVAMC anesthesiologist and UCSF clinical instructor.
"For non-cardiac surgery, ARBs are commonly stopped on the day of surgery ...
Researchers at the University of Tokyo have succeeded in developing a new microscope capable of observing the magnetic sensitivity of photochemical reactions believed to be responsible for the ability of some animals to navigate in the Earth's magnetic field, on a scale small enough to follow these reactions taking place inside sub-cellular structures.
Several species of insects, fish, birds and mammals are believed to be able to detect magnetic fields - an ability known as magnetoreception. For example, birds are able to sense the Earth's magnetic field and use it to ...
The advent of online social networks has led to the rapid development of tools for understanding the interactions between members of the network, their activity, the connections, the hubs and nodes. But, any relationships between lots of entities, whether users of Facebook and Twitter, bees in a colony, birds in a flock, or the genes and proteins in our bodies can be analyzed with the same tools.
Now, research published in International Journal of Data Mining and Bioinformatics shows how social network analysis can be used to understand and identify the biomarkers in ...
SEATTLE - Physical activities, such as walking, as well as aerobics/calisthenics, biking, gardening, golfing, running, weight-lifting, and yoga/Pilates are associated with better sleep habits, compared to no activity, according to a new study from researchers at the Perelman School of Medicine at the University of Pennsylvania. In contrast, the study shows that other types of physical activity - such as household and childcare -- work are associated with increased cases of poor sleep habits. The full results of the study (Abstract #0246) will be presented during the poster ...
ITHACA, N.Y. - A new Cornell study of New York state apple orchards finds that pesticides harm wild bees, and fungicides labeled "safe for bees" also indirectly may threaten native pollinators.
The research, published June 3 in Proceedings of the Royal Society B, finds the negative effects of pesticides on wild bees lessens in proportion to the amount of natural areas near orchards.
Thirty-five percent of global food production benefits from insect pollinators, and U.S. farmers have relied exclusively on European honeybees, whose populations have been in decline for ...
CINCINNATI - Researchers have identified that parent-reported responses to a questionnaire called the Pediatric Eosinophilic Esophagitis Symptom Score (PEESS® v2.0) correspond to clinical and biologic features of eosinophilic esophagitis (EoE) - a severe and often painful food allergy that renders children unable to eat a wide variety of foods.
This study, published online in Journal of Allergy and Clinical Immunology, was led by researchers at Cincinnati Children's Hospital Medical Center.
Eosinophils are normal cellular components of the blood, but when the body ...
ITHACA, N.Y. - Ask a plant researcher how the sex of a cucumber plant is determined and the person will tell you, "It's complicated." Depending on a complex mix of genetic and environmental factors, cucumbers can be seven different sexes. Some high-yield cucumber varieties produce only female flowers, and a new study identifies the gene duplication that causes this unusual trait.
The study, led by Zhangjun Fei of the Boyce Thompson Institute at Cornell University, and Sanwen Huang of the Chinese Academy of Agricultural Sciences, in Beijing, appeared recently in The Plant ...
Chicago - June 4, 2015 - It may be better for patients to resume taking their blood pressure medication sooner after surgery than previously thought. A new study published in the Online First edition of Anesthesiology, the official medical journal of the American Society of Anesthesiologists® (ASA®), found resuming angiotensin receptor blockers (ARBs), common medications used to treat high blood pressure, within two days after surgery decreased death rates in the first month following surgery.
"Sometimes doctors briefly stop ARB medications around the time of ...
