The Cod is perhaps the best known of all Irish sea fish, thanks to its traditional place over the last several decades as the staple of fish suppers.

The Cod is instantly recognisable due to the barbel or “beard” which protrudes from its lower jaw. The barbel is used as a sensor, to help enable the Cod find food among the murky depths, and around the sea-bed. The Cod is a fast growing fish with a huge mouth and even bigger appetite and is known as both “old bucket mouth” and “hoover of the sea” due to its habit of just opening its jaws and sucking everything before it into its giant mouth.

Most Cod are around 2 to 3 feet long and about 10 pounds in weight when caught by fishermen, but there are places in the North Atlantic , where adults up to 6 feet in length and over 100 pounds weight have been found!

Cod have been very heavily fished over the past few decades, and this has led to a decline in numbers in many of their more coastal habitats. However, Cod produce an incredible number of young, with a single female able to produce up to 9 million eggs in one season! This allows the Cod to regenerate their numbers very rapidly if allowed to do so. However, Cod also appear to be suffering due to changes in their food chain caused by environmental influences: as Atlantic currents moves northwards (possibly due to global warming), these currents bring with them the tiny animals (plankton) which begin the food chain on which the Cod depends. An example of such a food chain could be

Plankton -> Sandeel -> Whiting -> Cod

Clearly if there is a shortage of plankton, then this will affect all other fish in the food chain, right up to Cod. Trying to determine what effect environmental change has on Cod numbers, and how much is caused by over-fishing, is one of the major challenges facing Irish marine scientists today.

At Atlantaquaria, we have both wild caught and farmed Cod on display. The farmed Cod are from the National University of Ireland’s Marine Laboratory at Carna, Connemara , which is trying to develop a method of rearing Cod to a marketable size in captivity, with the long term aim of reducing the pressure on wild stocks.