Assessment of the Biodiversity Value of Benthic Macroinvertebrates in the Tuojiang River Basin, Chengdu

Benthic macroinvertebrates are crucial to the health of river ecosystems. However, their conservation status is often overlooked. Due to their limited mobility and sensitivity to habitat changes, their survival is threatened. Given the current lack of research on their value composition and evaluation, this study refers to the total economic value (TEV) framework to preliminarily construct a systematic evaluation framework for freshwater benthic macroinvertebrates. Through field surveys, questionnaires, and market survey data, the value composition of benthic macroinvertebrates in the Tuojiang River Basin of Chengdu was systematically clarified. The total value was monetized using methods such as the market price method, substitute market method, and simulated market method. The main conclusions are as follows: (1) The biodiversity value of benthic macroinvertebrates in the study area ranges from 6.36 × 108 to 12.76 × 108 CNY/a, accounting for 0.17–0.34% of the region’s 2019 GDP. The various values in order of proportion are as follows: non-use value > direct service value > Direct Material value > indirect use value. This indicates that this biological group has enormous potential value and significant conservation importance. (2) The proportions of the value amounts of various species in the total value differ. The proportions of Viviparidae, Odonata, Ephemeroptera, and Palaemonidae are relatively high, reaching 9.8–23.8%. The proportions of Atyidae, Semisulcospiridae, and Bithyniidae are about 5%. The proportions of Unionidae, Corbiculidae, and Aillpullaridae are less than 3%. These differences are mainly influenced by factors such as species population numbers in the region, public value perception, aesthetic preferences, and dietary habits. This evaluation framework scientifically and comprehensively assesses the biodiversity value of regional benthic macroinvertebrates, providing a reference for the value assessment of other biological groups within the region and offering a scientific basis for the conservation and sustainable utilization of the target biological groups.