The world devotes more phosphorus to producing fish than it gets from fishing

12/02/2020

Human activity devotes more phosphorus to producing fish than it obtains from fishing, which is equivalent to saying that a shortage of phosphorus could even threaten global food production, according to a study by the Centre for Ecological Research and Forestry Applications (CREAF-UAB).

The world uses more phosphorus to produce fish than it gets from fishing. Photo: Pxhere/CC0 Public Domain
The world uses more phosphorus to produce fish than it gets from fishing. Photo: Pxhere/CC0 Public Domain

The study, published by Nature Communications, indicates that in order to return the flow of phosphorus to equilibrium, aquaculture must increase the average efficiency of phosphorus use from the current 20% to at least 48% by 2050.

In addition, the work warns that the contribution of phosphorus to the biosphere has quadrupled since pre-industrial times due to food production, fisheries, and aquaculture, with a consequent environmental imbalance.

The report, entitled "The shift of phosphorus transfers in global fisheries and aquaculture", concludes that humans devote greater amounts of phosphorus to the production of fish and shellfish, - necessary for their growth and the development of their skeletons and shells - than they obtain through fishing.

CREAF researchers Josep Peñuelas and Jordi Sardans have warned that the rapid increase in world fish production has altered the consumption of this mineral, which has a limited presence on the planet and is essential for all forms of life on Earth.

"This is a radical change in the global transfer of phosphorus and is another of the great impacts that we humans cause," said Peñuelas, who insists that "until now fishing has provided us with phosphorus, but we have reached the point where the balance is negative.

According to the researcher, the action that should be taken to reverse this situation is to increase the efficiency of the use of fish farms.

"One way to return the balance in the flow of phosphorus would require that the average efficiency of aquaculture use of this mineral increase from the current value of 20% to less than 48% in 2050, which is a great challenge," says Peñuelas.

According to the paper, in 2016, 2.04 teragrams (1 trillion grams) of phosphorus were used in the aquaculture sector to increase fish production, while 1.10 teragrams were recovered from aquatic systems in the form of feed, adding up the aquatic products from traditional fisheries and aquaculture.

Food production is the major cause of anthropogenic phosphorus release into aquatic ecosystems and agriculture.

In total, 82.4% of phosphate fertilizers are used for farming and pasture.

This high use of manure and phosphorus fertilizers in agriculture means that half of this mineral is not absorbed by plants and consequently increases the risk of transfer to aquatic ecosystems.

Aquaculture - the fastest growing food production sector in the last decade - depends on external supplies of phosphorus, through feed or fertilizers that increase productivity.

By Mexicanist Source EFE