It was a small move that made a big difference in the battle of truth versus perception.

The FAO has been categorising the sustainability of fisheries around the world into three compartments; over-exploited, under-exploited, and fully exploited.

While it is clear that over-exploited means a fishery that has been over-fished and needs to be left alone to recover, and under-exploited indicates a fishery that has not been fished to its potential, the use of ‘fully-exploited’ to describe a sustainable fishery has been confusing and problematic.

The decision by the FAO to change from ‘fully exploited’ to ‘maximally sustainably fished’ is cause for celebration as the previous description has been misused, intentionally or not, by the opponents of commercial fishing globally.

The facts are, according to the latest FAO report on the state of the world’s fisheries, that 11 percent of the world’s fisheries are under fished, 58 percent are maximally sustainably fished and 31 percent are overfished.

The use of ‘fully exploited’ has led to mischievous reports declaring that 90 percent of the world’s fisheries are overfished.  Just weeks ago, and long after the term was clarified and revised by the FAO, the United States-based NGO Pew was still adding the 58 percent that was sustainably caught to the 31 percent that was actually overfished to demonstrate the collapse of global fisheries. Until the use of ‘maximally sustainably fished’, as clumsy as it is, is in widespread use they will continue to do this.

The FAO is the only body that monitors global capture of fish, mostly through the official statistics supplied by member countries, and it details the findings in an annual report; The State of World Fisheries and Aquaculture. 

The three categories determine whether the amount caught in a fishery is compromising future harvests - based on data collected in that fishery. This is broken down to a Maximum Sustainable Yield (MSY) which is the level to which the greatest number of fish can be caught without compromising the fishery’s sustainability.

So it is science, to a point. Many developing countries lack the skill and resources to accurately collect and report the data that is needed to assess fish stocks.

However, there is an even greater divide between the developed world and developing countries. While, through management and sustainability measures, fishing in the developed world has decreased by about 50 percent from its peak in 1988, the fish effort in developing countries rises every year.

So, despite developed countries significantly improving their fisheries management, the overfished stocks globally continue to rise.

Some 97 percent of New Zealand’s catch is now from sustainable stocks but the FAO says unless the countries that are doing the right thing, such as New Zealand, assist those countries still struggling with the pursuit of sustainability the UN goal of zero over-fishing by 2020 will remain elusive.