Nav: Home

Fishing can cause slowly reversible changes in gene expression

May 16, 2017

Cohort after cohort, fishing typically removes large fish from the population and can lead to rapid evolutionary changes in exploited fish populations. A new study from the University of Turku, Finland, shows that removing the largest individuals from the population can lead to massive gene expression changes in an experimentally exploited fish population. The study was funded by the Academy of Finland.

During the last two decades, there has been a lot of discussion on size-selective fishing causing genetic changes in exploited populations in contemporary timescales. Now, researchers have shown that fishing can cause expression changes in thousands of genes and that these changes can at least partly be associated with changes at DNA level.

"Removing the largest individuals from the experimentally exploited populations induced differences in the expression of more than 4,000 genes after five generations of size-selective harvesting," says postdoctoral researcher Silva Uusi-Heikkilä from the University of Turku.

The harvesting experiment was done in collaboration between the University of Turku and the Leibniz Institute of Freshwater Ecology and Inland Fisheries, Berlin. For five generations, experimental zebrafish populations were harvested by using two harvesting strategies: removing the largest individuals and removing individuals randomly with respect to body size. After harvesting, the populations were allowed to recover for six generations.

"Changes in gene expression help fish to adapt to different selective pressure," Uusi-Heikkilä says. "It's noteworthy, however, that the differences in expression pattern between the harvest treatments remained after the recovery."

In addition to the changes in gene expression, the expression variance was also affected by fishing: fishing decreased the variance. Gene expression variation can be important because it may help fish to adapt to changes in the environment and the climate.

"After the recovery period, the gene expression variance increased but only in randomly harvested fish. The variance continued to decrease among fish where the largest individuals had been removed," Uusi-Heikkilä says.

Reduced variation caused by size-selective harvesting in exploited populations can slow down the recovery. "Moderate fishing pressure combined with protection of large individuals may advance the recovery of fish populations."
-end-
Molecular Ecology: Link to publication: http://onlinelibrary.wiley.com/doi/10.1111/mec.14179/full

Academy of Finland

Related Fishing Articles:

Fishing can cause slowly reversible changes in gene expression
Cohort after cohort, fishing typically removes large fish from the population and can lead to rapid evolutionary changes in exploited fish populations.
New study suggests overfishing in one of world's most productive fishing regions
Scientists at Scripps Institution of Oceanography at the University of California San Diego used images from satellites and flyovers to count the number of small boats, or pangas, to find that fishing in Gulf of California, which separates Baja California and mainland Mexico, is over capacity.
Banning transshipment at-sea necessary to curb illegal fishing, researchers conclude
Banning transshipment at-sea -- the transfer of fish and supplies from one vessel to another in open waters -- is necessary to diminish illegal fishing, a team of researchers has concluded after an analysis of existing maritime regulations.
How to clamp down on cyanide fishing
Spraying cyanide in tropical seas can quickly and cheaply stun fish, allowing them to be easily captured and sold.
Unrestricted improvements in fishing technology threaten the future of seafood
A study conducted by ICTA-UAB (Universitat Autònoma de Barcelona) researcher Eric Galbraith shows that future improvement of fishing technology poses a threat for the global fishery that could be greater than climate change.
Supramolecular protein fishing with molecular baits
Scientists from the Center for Self-assembly and Complexity (CSC) successfully isolated a cancer-prone protein by fishing out the proteins using 'molecular bait'.
Hidden no more: First-ever global view of transshipment in commercial fishing industry
A new report released today presents the first global map of transshipment, a major pathway for illegally caught and unreported fish to enter the seafood market.
Climate change and fishing create 'trap' for penguins
Endangered penguins are foraging for food in the wrong places due to fishing and climate change, new research shows.
Intense industrial fishing
A new study by the Bren School examines how China maintains large catches and what it means for fishery management elsewhere
Diversification key to resilient fishing communities
Fishing communities can survive -- and even thrive -- as fish abundance and market prices shift if they can catch a variety of species and nimbly move from one fishery to the next, a new University of Washington study finds.

Related Fishing Reading:

Best Science Podcasts 2019

We have hand picked the best science podcasts for 2019. Sit back and enjoy new science podcasts updated daily from your favorite science news services and scientists.
Now Playing: TED Radio Hour

Anthropomorphic
Do animals grieve? Do they have language or consciousness? For a long time, scientists resisted the urge to look for human qualities in animals. This hour, TED speakers explore how that is changing. Guests include biological anthropologist Barbara King, dolphin researcher Denise Herzing, primatologist Frans de Waal, and ecologist Carl Safina.
Now Playing: Science for the People

#SB2 2019 Science Birthday Minisode: Mary Golda Ross
Our second annual Science Birthday is here, and this year we celebrate the wonderful Mary Golda Ross, born 9 August 1908. She died in 2008 at age 99, but left a lasting mark on the science of rocketry and space exploration as an early woman in engineering, and one of the first Native Americans in engineering. Join Rachelle and Bethany for this very special birthday minisode celebrating Mary and her achievements. Thanks to our Patreons who make this show possible! Read more about Mary G. Ross: Interview with Mary Ross on Lash Publications International, by Laurel Sheppard Meet Mary Golda...