What Counts as Integrated Mangrove-Shrimp Aquaculture? Standardised Criteria as a Precondition for Assessing Environmental and Animal Welfare Outcomes

Abstract

IMSA has been promoted to address environmental concerns associated with shrimp aquaculture. IMSA may also alter conditions in which shrimps are held, but these have only been studied from a yield and survival perspective, which provides limited information about the welfare animals experience across their lives. We found that investigating the impact of IMSA on the environment and animal welfare is not possible until the system has been clearly defined. IMSA is a loosely characterised concept – its edges are contested in the literature, and there are no agreed thresholds that a shrimp farm must meet to count as IMSA. Mangrove cover requirements range from 30% to 70% across different bodies, meaning a farm may qualify as IMSA under one set of guidelines but not another. Field observations in West Bengal, India, showed that IMSA farms vary in the mangrove position relative to the water, the level of cover present, and mangrove species and density. This lack of standardisation makes IMSA difficult to assess, certify, or establish as a credible alternative to current practices. We propose categories that an IMSA definition must span, questions that certifiers should address, the stakeholders who must co-design the system, and a research agenda.