Assessment of land and water ecosystems capability to support aquaculture expansion in climate-vulnerable regions using analytical hierarchy process based geospatial analysis

Abstract

The fast-unregulated expansion of shrimp aquaculture led to increasing ecological concerns and conflicts among the coastal resource users worldwide, thus calling for techniques to identify the suitable aquaculture zones to ensure sustainability. The multi-criteria decision-support approach was used to assess the ecosystem's ability to support the shrimp farming expansion using a hierarchical analytical process based on multiple criteria decision analysis, and the assessment of the carrying capacity of the source water bodies. Eighteen thematic layers were grouped into four major groups, namely land type, source water quality, soil characteristics, and infrastructure availability. The pairwise comparison matrix was used to assign the weights to each criterion based on its relative importance. Spatial restriction rules were framed based on the guidelines of the Coastal Aquaculture Authority of India. The favorable conditions exist in 85-100% area for expanding aquaculture in terms of water, soil, and resource availability, but the land was a major controlling factor. The extent of the appropriate area for shrimp aquaculture was found to be 7426 ha. The carrying capacity of twelve source water bodies in the study region indicates that 83.3% of water bodies can accommodate the total identified area associated with it, but the rest 17.7% water bodies can withstand the development up to70 to 72% of the available space. This approach illustrates the suitability of geospatial planning in combination with carrying capacity assessment of source water bodies for sustainable resource use in the shrimp growing nations of the world.