Any Fishing Changes Sex Ratios in Fish

[n2doc]

A reduced population leads to more males - and fewer eggs laid.


By Rachel Cernansky | Thu Jul 29, 2010 10:22


We know overfishing has a devastating impact on the environment, and we've seen weird things happen to fish as a result of a changing environment before, but a new finding has perplexed scientists.

A researcher in Australia, Stefan Walker, has found that fishing may cause the male-female ratio to change in sex-changing fish populations.

New Scientist reports:

Walker saw more sex changes in regions where fish populations were low. This led to more males holding court to fewer females and a drop in the number of eggs laid per square metre of lagoon.

Surprisingly, instead of freeing up resources for the fish to thrive and reproduce more, a reduced population seems to be a trigger for the population to reduce even further

more

http://planetgreen.discovery.com/travel-outdoors/forget-overfishing-any-fishing-changes-sex-ratios-in-fish.html