# Predicting Habitat Suitability and Range Dynamics of Three Ecologically Important Fish in East Asian Waters Under Projected Climate Change

## TL;DR

This study predicts how climate change will affect the habitats of three important fish species in East Asia and suggests the need for updated conservation strategies.

## Contribution

The study provides new projections of habitat shifts for three fish species under climate change and identifies gaps in current marine protected areas.

## Key findings

- C. lucidus is projected to lose suitable habitat, while K. punctatus and C. thrissa are expected to expand their ranges.
- Only a small percentage of the species' habitats are currently protected by marine protected areas.
- Climatically stable regions in the Yellow and East China seas may serve as refuges for C. lucidus.

## Abstract

Climate change poses a significant threat to ecologically important fish species, underscoring the need to predict potential shifts in their distributions. Using ensemble species distribution models based on occurrence data from GBIF and OBIS, we assessed the current and future distributions of Collichthys lucidus, Konosirus punctatus, and Clupanodon thrissa in East Asia under present and future climate scenarios. Key environmental predictors were dissolved oxygen and salinity for C. lucidus and chlorophyll and phosphate for K. punctatus and C. thrissa. Projections indicated a contraction of suitable habitats for C. lucidus, in contrast to range expansions for K. punctatus and C. thrissa. Given the limited protection of these species by existing marine protected areas (MPAs), our findings highlight the urgent need for adaptive conservation strategies, including the expansion and reconfiguration of MPAs to safeguard future habitats.

The vulnerability of ecologically important fish species to climate change underscores the need to predict shifts in their distributions and habitat suitability under future climate scenarios. In this study, we modeled the potential distribution ranges of three ecologically important fish species (Collichthys lucidus, Konosirus punctatus, and Clupanodon thrissa) across East Asia using a species distribution modeling framework under both current and projected future climate scenarios. Occurrence data were obtained from the Global Biodiversity Information Facility (GBIF) and the Ocean Biodiversity Information System (OBIS), while environmental data were retrieved from the Bio-ORACLE database. Our models demonstrated high predictive performance (AUC > 0.88). Results showed that dissolved oxygen and salinity were the strongest bioclimatic predictors for C. lucidus, whereas chlorophyll and phosphate primarily shaped the distributions of K. punctatus and C. thrissa. Model projections indicated a decline in suitable habitats for C. lucidus, particularly under high-emission scenarios, and range expansions for K. punctatus and C. thrissa toward higher latitudes and nutrient-enriched waters. Highly suitable habitats were concentrated along coastlines within exclusive economic zones, exposing these species to significant anthropogenic pressures. Conservation gap analysis revealed that only 7%, 2%, and 6% of the distributional ranges of C. lucidus, C. thrissa, and K. punctatus, respectively, are currently encompassed by marine protected areas (MPAs). Our study further identified climatically stable regions that may act as climate refugia, particularly for C. lucidus in the Yellow and East China seas. Our findings highlight the urgent need for adaptive management, including the expansion and reconfiguration of MPAs, transboundary conservation initiatives, stronger regulation of exploitation, and increased public awareness to ensure the resilience of fisheries under future climate change.