New study suggests catching the slowest swimmers, commercial fishermen are inadvertently helping fish species evolve to swim faster.

Dr. Killen and his colleagues investigated whether commercial fishing was prompting physiological changes, as faster fish had better chances of evading capture by . “Over time, the selective removal of poor-swimming fish could alter the fundamental physiological makeup of descendant populations that avoid fisheries capture,” explains Killen.  “Fish being trawled will try to swim at a steady pace ahead of the mouth of the net for as long as possible, but a proportion will eventually tire and fall back into the net,” said Killen Read the rest here 12:24

One Response to New study suggests catching the slowest swimmers, commercial fishermen are inadvertently helping fish species evolve to swim faster.

  1. DickyG says:

    Trawling causes evolutionary changes?

    Aside, perhaps, from “Peeping Tom” drones and drugs that cure yellow toenails…”but could cause pancreatitis”, can the results of this world obsession with STEM (Science, Technology, Engineering, and Math) get any more bizarre than this study? Are the researchers running out of hypotheses that make even a little bit of sense? Say, for instance, hypotheses pertaining to some accurate and intelligent fish behavior research as it might be influenced by environmental factors—factors other than fishing?

    This study spends money on the hypothesis which suggests that fishing is causing evolutionary changes to the fish as they swim faster and get in better anaerobic shape to stay ahead of the “controversial trawling nets”? (Wow!)

    From the article:

    “Though controversial, trawling nets play a large role in the commercial fishing industry; the speed of a trawling net is species-specific, typically determined by the maximum speed of the fish.” “Fish being trawled will try to swim at a steady pace ahead of the mouth of the net for as long as possible, but a proportion will eventually tire and fall back into the net,” said Killen in a press release from the University of Glasgow.

    “The study mimicked commercial trawling practices with schools of wild minnows in a laboratory, to observe how the fish interacted with the nets.”

    “The researchers measured many traits in the 43 fish studied, including swimming ability, metabolic rate, and indicators of aerobic and anaerobic physical fitness. They found that high anaerobic capacity – which allows fish to swim rapidly for short bursts – was most helpful for fish in evading capture.”

    Now maybe the purpose for this article (and study) was to provide a setting for a few of the anti-fishing talking point phrases: “Conservationists and fishermen alike are concerned about rapidly decreasing fish populations.”

    And

    “There is a lot of concern on how overfishing is affecting the abundance of wild fish, consequences for the economy, employment, and the ecosystem as a whole,” said Killen in the press release. “But one aspect that is often overlooked is that intense fishing pressure may cause evolutionary changes to remaining the fish that are not captured.”

    Or maybe the study was Pew funded (and directed) and part of an “emergency measure” deal to sustain an Ocean Biology Department and its resident scientists and take a shot at fishing in the bargain? But really, studying 43 minnows in a tank and extrapolating that out to suggest the question, “Are fish evolving to outswim trawlers?

    Regardless of the motivation for these absurd scientific adventures might be, what’s really sad and frustrating is that the money used here might be put to far better use researching some of the cliché misinformation gems that the article presents as established fact and actually uses as a basis for the research.

    These bogus anti-fishing talking points are worn threadbare in the eco-NGO media campaigns to retire the independent small boat fishing industry. They emerge again here in this article regarding “rapidly decreasing fish populations” and “…how overfishing is affecting the abundance of wild fish” and that “…the speed of a trawling net is species-specific, typically determined by the maximum speed of the fish”. (I guess our “highly sophisticated fish-finding electronic equipment has an app for fish speed…just enter the species and Bingo!)

    The presumption that “overfishing” is so intense that it is “…affecting the abundance of wild fish, consequences for the economy, employment, and the ecosystem as a whole”, is a completely false narrative.

    However, on the basis of studying 43 minnows in a tank, to suggest that fishing is so “high-volume” that it is capable of changing the genetic makeup of the vast number of fish in the vast oceans, is truly preposterous—if not delusional.

    But Wait! It seems all is not lost: “The research team now plans to study fish in the wild to see if they find the same behaviors that they observed in laboratory conditions.”

    That should prove to be a challenging study.

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