Seafood consumption levels unsustainable

Australian scientists have warned that global marine resources cannot sustain current levels of consumption.

“The clear message is that global marine resources are finite and there are not enough to go around,” said Professor Reg Watson, from the University of Tasmania’s Institute for Marine and Antarctic Studies (IMAS).

Prof Watson said the study is the first in the world to consider changes in the efficiency of sourcing seafood to the end of this century.

“Communities will need to decide how to use accessible fish protein — either directly as protein, as a food supplement for farmed seafood species such as salmon or intensive industries like chicken and pork, or even in fertiliser.”

In a paper published in the journal Nature Communications, The University of Tasmania research team examined global patterns of where seafood is sourced from ocean ecosystems and where it is consumed, what portion of finite global marine production is required, and whether through aquaculture to supplement wild sources we can hope to meet future demands.

“Our results illustrate how incrementally each year, marine foods have been sourced farther from where they were consumed and, moreover, require an increasing proportion of the total ocean primary productivity that underpins all marine life,” Prof Watson said.

He said considerable evidence indicates that agricultural food supply systems are struggling to meet expanding demand, with production challenged by climate change, loss of top soil and critical shortages of phosphates and water. A similar situation exists in the marine environment with ocean warming and acidification leading to a range of concerns.

 “While aquaculture has allowed our consumption of seafood to increase, it continues to require feeds based on fully or near fully exploited wild stocks,” Prof Watson said.

“Our examination of the global ocean’s ability to meet future demands to 2100 indicates that even with aquaculture supplementing near-static wild catches, growing demand is unlikely to be met without significant changes,” Prof Watson said.