Today On Sea World: Old Fish's Population is Declining and It's Not Looking Good

Khryss | Published 2017-09-30 10:57

Save the elderly!

A recent study showed an alarmingly drastic change on the sea creature's population.

Researchers utilized different techniques to calculate and determine the fishes' ages. They examined 63 fisheries, all with 24-140 years records. What they found? Not just a simple decline on old fish's population but a disproportionate difference compared to other age groups.

In fact, the reduction has an average of 72 per cent! “The new statistics [even] revealed that the reduction of older fish populations had actually increased by 180 per cent,” says lead author Lewis Barnett of the University of Washington in Seattle.

Moreover, older populations in certain species like Pacific cod, Pacific hake, red snapper and Atlantic cod  individuals have fallen by more than 95 per cent.

Why is this important and dangerous?

Older fishes can be so much more adapting to almost all adversities under the sea. While thought to be just "waiting" for their deaths, these fellas actually produce the largest and most offspring. They even spontaneously spawn in different times and locations, making them less likely to be severely affected by short-term environmental changes for they've become flexible through time and experiences.

Hence, this huge decrease increases the possibility of the fisheries to collapse. But there might be a solution: maintaining a healthy mix of ages. Another way to preserve our precious fishes is to either stop fishing in certain areas or have “slot limits” in order to not only regulate the sizes (age-range) harvested, but let the populations rest and recover, says Barnett.

Barnett's 2015 study, together with Marissa Baskett of the University of California, Davis, also showed that marine reserves could be of help. Results showed that when reserves had enough old population, they became more genetically diverse, consequently protecting the species.

https://www.newscientist.com/article/2147585-there-are-hardly-any-old-fish-left-in-the-ocean-and-thats-bad/

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