CAN WE SAVE LAND THROUGH PRODUCTION INTENSITY IN AQUACULTURE?  A META-ANALYTIC APPROACH WITH SHRIMP FARMS

Our demand for seafood is increasing, and harvests from the world's ocean have plateaued.  This means that any future growth must be accomplished via aquaculture.  Shrimp aquaculture is one of the fastest growing sectors in aquaculture, at approximately 5 million metric tons of production annually, and has a considerable land footprint.  Here, we explored the impact of utilizing different production methods (extensive vs intensive) for expanding aquaculture production on cumulative land footprint of shrimp aquaculture.

A meta-analytic approach was utilized to simultaneously estimate model coefficients to create global models to explore three relationships: production intensity and total land burden (model 1), production intensity and the proportion of the burden at the farm level (model 2), and production intensity and the farm land burden (model 3).  Structured literature searches were conducted in relevant databases and studies included had to meet the following criteria: i) published in English ii) contain multiple farms iii) not include experimental feed trials iv) report total farm area, total pond area, production or production intensity and Food Conversion Ratio (FCR) vi) include intensive farms vii) report on farms producing Whiteleg shrimp  Penaeus vannamei  or Black Tiger Shrimp  Penaeus monodon  viii) were published after 2003.

These models were used to generate projections of land use in shrimp aquaculture under different scenarios.  The most land intensive projections involved using only extensive production to increase production when compared to a business as usual scenario.  The least land intensive scenario involved utilizing intensive production.  The average production intensities needed to meet a zero farm expansion target were explored.  Scenarios where farm land were not expanded used 23% less land and 34% less land to produce 7.5 and 10 million mt of shrimp, respectively, when compared to business as usual scenarios.  These estimates are limited by uncertainty of ingredient composition in shrimp feeds, but demonstrate the effect of different land uses in shrimp aquaculture on the overall land footprint.