The small yellow croaker (Larimichthy polyactis) is a fish with significant economic value, but it has been depleted by long-term fishing activities. Ecological corridors, as an important means of protecting ecological connectivity, play a crucial role in resource conservation and sustainable use. Therefore, this study aimed to investigate seasonal changes in the habitat of the small yellow croaker in the East Yellow Sea of China, to identify ecological corridors of the small yellow croaker in winter and spring seasons, and to evaluate the effectiveness of corridor protection. First, we modelled habitat distribution using random forest (RF) to produce a resource distribution map of small yellow croaker for 12 months, we found that there are significant seasonal variations in the habitat distribution of small yellow croaker by comparison. The core habitats in winter and spring were then extracted based on the results of the random forest model. The results showed that the core habitats in winter were distributed between 26°N-35°N in winter and between 27°N-33°N and 36°N-38°N in spring. Subsequently, a resistance surface constructed based on three important environmental factors that influence the distribution and migration of small yellow croaker: sea surface temperature, dissolved oxygen, and chlorophyll concentration. Finally, the spatial distribution of the small yellow croaker ecological corridor was simulated using Least-cost pathways in ArcGIS v10.2. There is a corridor connecting the winter habitat at 125°E-126°E, 30°N-33°N with the northern spring habitat at 123°E, 37°N and the spring habitat at 123°E, 28°N.By overlaying existing protected areas with the identified corridors, it was found that existing protected areas do not adequately protect the corridors. Our work not only provides a new case for the identification of marine ecological corridors, but also identifies cross-seasonal ecological corridors for the first time and establishes a method for identifying ecological corridors for marine fishes.
 

Marine ecological corridors; Sciaenidae; Least-cost pathways; Resource protection