Study of suitable habitats for Sepiella maindroni in Zhoushan sea areas based on MaxEnt model

Cuttlefish (Sepiella maindroni) has high economic and nutritional value, but its resources have declined in recent years due to overfishing and habitat destruction. To quantitatively assess the impact of multiple ecological factors on the distribution of S. maindroni, we selected the Zhoushan sea area which is an important spawning ground and habitat for S. maindroni as the research area, and used the MaxEnt (Maximum Entropy) model to analyze the habitat suitability of S. maindroni as well as to explore its restoration potential and spatial distribution of suitable habitats, based on the bottom trawl survey data from the Zhejiang coastal area from 2017−2021, the survey data from autonomous cruises in 2021−2022, and data from the Global Biodiversity Information Facility (GBIF). The research results show that the maximum sea surface temperature (SST), minimum sea surface salinity (SSS) and pH were the main ecological factors affecting the S. maindroni distribution. S. maindroni tended to be active in areas with higher sea surface temperatures and higher salinity, and could tolerate a weakly alkaline environment. In the Zhoushan sea area, S. maindroni was more likely to exist with maximum SST of 25.5−28.5 ℃, minimum SSS of 20‰−30‰, and pH value of 7.8−8.3. The suitable habitat area in the Zhoushan sea area was quite extensive, covering 30 213.40 km², which accounted for 75.11% of the total area of the research area. Among these, the highly suitable habitats were mainly distributed in the sea areas of Zhongjieshan Islands, Shengsi Islands and Ma'an Islands, with an area of 4 600.78 km². The areas of the sub-highly suitable, moderately suitable and lowly suitable habitats were 8 205.52, 9 723.31 and 7 683.78 km², respectively. In terms of restoration potential, S. maindroni has significant recovery potential in the Zhoushan sea area.