Dr Karl O'Brien
speaker
11 appearances
2 recordings
1 series
first heard Oct 2012
last heard Nov 2012
Dr Karl O'Brien’s voice in public audio — every appearance, attributed to the second.
Trend
recordings per month · last 12 monthsNo recordings in the last 12 months.Older appearances are listed below; set an alert to hear about the next one.
Appearances
Cod start to mature at ages one and two, and they're fully mature by age six.
The bulk of the mature cod in the North Sea at the moment is constituted of fish which are actually younger than seven years of age.
Cod start to mature at ages one and two, and they're fully mature by age six.
The bulk of the mature cod in the North Sea at the moment is constituted of fish which are actually younger than seven years of age.
As fisheries scientists, we do not try to count every single fish in the sea.
Instead, we collect information from three main sources, from landings at ports, from fishermen themselves, and from research vessels.
These data are used to estimate the size of commercial fish populations, such as the North Sea cod stock.
We obviously use sampling methods, and as a rough estimate, we aim to sample a minimum of roughly 200 fish per 1,000 tonnes landed.
Our methods are rigorous and robust with small errors of uncertainty.
The latest international assessment shows that there's been a gradual improvement in the status of the stock over the last few years, and the amount of mature fish has actually increased from the historic low in 2006 and does show signs of further improvement.
So although there's a long way to go, there are good indications that the stock is ready to recover.
Showing 1–11 of 11