November 11, 2015 — Marine fish populations are in decline worldwide. Of the 600 marine fish stocks monitored by the Food and Agriculture Organization of the United Nations (FAO), 69 per cent are fully or over-exploited.

To rebuild fish populations, MPAs, which ban some or all fishing activities in an area, have become widely used. Under the Natura 2000 network, almost 4 per cent of European waters have been designated as MPAs .

Despite their widespread use, understanding of how MPAs affect harvested fish populations remains poor, especially for areas where some fishing is still permitted (PPAs).

This study investigated the effect of a PPA on Atlantic cod (Gadus morhua) along the southeast Norwegian coast of Skagerrak.

In 2006, a 1 km2 PPA was established in the region, where only hook and line fishing and research sampling (which involves fixed nets that do not harm the fish, so they can be captured and released alive) are permitted.

The researchers wanted to know whether implementation of the PPA changed fishing mortality proportions, and also if the protection caused survival rates to increase.

To investigate this, they collected data on live re-captures and dead recoveries of cod before and after its implementation, as well as at several unprotected sites along the coastline. Data was collected from 2005–2013 along Skagerrak.

Read the full story at The Fish Site