Biophysical characteristics that affect the distribution of sandfish in the sea ranch were investigated to determine indicators for a suitable habitat for sandfish sea ranching. These include sediment grain size, organic matter (OM), chlorophyll a, pheophytin, penetrability, depth and seagrass cover. A total of 5864 hatchery-produced sandfish juveniles were released in seven batches in a 5-ha ranching site in Maliwaliw Island over a period of three years. The 5-ha ranch was divided into three zones, with Zone A (50 × 50 m) being the juvenile release site. Survey of the released sandfish was done quarterly from February 2016 until May 2017 and sediment collection done twice. A total of 750 sandfish weighing 10–600 g were recorded; 23% were <150 g, 59% were 151–350 g, 17% were 351–550 g, and 2% were >550 g. Distribution of substrate parameters between the different sea ranch zones showed no significant differences (p > 0.05). Visualized sediment grain-size data showed multiple cohorts of sandfish with varying sizes in different zones with predominantly medium and fine grains with relatively higher total OM and labile OM. Sandfish >351 g were found in deeper waters (>70 cm at low tide) with lower concentrations of labile OM and chlorophyll a, and higher pheophytin. Sandfish <350 g were found in areas with higher labile OM, higher chlorophyll a and lower pheophytin. Results of this study indicate the need for a sandfish sea ranch site with water depth >30 cm at low tide, and varying sediment particle size and composition to support the different stages of growth and development of sandfish.

中文翻译：

---

菲律宾马里瓦利夫岛海域放养沙鱼幼鱼空间分布格局

调查了影响沙鱼在海洋牧场中分布的生物物理特征，以确定适合沙鱼海洋牧场栖息地的指标。这些包括沉积物粒度、有机质 (OM)、叶绿素 a、脱镁叶绿素、渗透性、深度和海草覆盖率。在三年的时间里，共有 5864 只孵化场生产的沙鱼幼鱼被分七批投放到 Maliwaliw 岛一个 5 公顷的牧场。5 公顷的牧场分为三个区域，A 区（50 × 50 m）是幼鱼放生地。从 2016 年 2 月至 2017 年 5 月，每季度对释放的沙鱼进行调查，并进行两次沉积物收集。总共记录了 750 条重 10-600 克的沙鱼；23% < 150 g，59% 151-350 g，17% 351-550 g，2% > 550 g。p  > 0.05）。可视化沉积物粒度数据显示，不同区域的多群沙鱼大小不一，以中等和细粒为主，总有机质和不稳定有机质相对较高。在较深的水域（退潮时> 70 cm）发现了> 351 g的沙鱼，其不稳定的OM和叶绿素a的浓度较低，脱镁叶绿素含量较高。在具有较高不稳定有机质、较高叶绿素 a 和较低脱镁叶绿素的区域发现了 <350 g 的沙鱼。这项研究的结果表明，需要一个在退潮时水深 >30 厘米的沙鱼海洋牧场场地，以及不同的沉积物颗粒大小和成分，以支持沙鱼生长和发育的不同阶段。