<![CDATA[Seagrass as a flowering plant can live from muddy substrates to coral fractures. Differences in the characteristics of substrate type, nutrient content and aquatic environmental conditions can affect morphometric seagrass. The purpose of the study was to analyze environmental conditions and nutrient content as well as the morphometric characteristics of T. hemprichii seagrass based on differences in substrate type. This study was conducted in the waters of Tanjung Tiram Coastal, Poka from February-April 2021. Seagrass sampling was using the purposive sampling method. Data analysis was conducted using ANOVA with SPSS. The results of environmental parameters analysis showed that the water conditions of Tanjung Tiram, Poka are still at the tolerance limit intended for seagrass life. The substrate consists of sand substrate, gravel mixed sand substrate and mud substrate. The results of ANOVA showed that there was a significant difference in the content of sedimentary nutrients, especially phosphates in each substrate type and there was a significant difference in morphometric seagrass based on differences in substrate type and nutrient content. ABSTRAK Lamun sebagai tumbuhan berbunga dapat hidup mulai dari substrat berlumpur sampai dengan patahan karang. Perbedaan karakteristik jenis substrat, kandungan nutrien dan kondisi lingkungan perairan dapat mempengaruhi morfometrik lamun. Tujuan dari penelitian ini adalah menganalisis kondisi lingkungan dan kandungan nutrien serta karakteristik morfometrik lamun T. hemprichii berdasarkan perbedaan tipe substrat. Penelitian ini dilaksanakan di Perairan Pantai Tanjung Tiram, Poka pada Bulan Februari-April 2021. Pengambilan sampel lamun menggunakan metode purposive sampling. Analisis data menggunakan ANOVA dengan SPSS. Hasil analisis parameter lingkungan, menunjukan bahwa kondisi perairan Tanjung Tiram, Poka masih berada pada batas toleransi yang diperuntukan untuk kehidupan lamun. Substrat terdiri dari substrat pasir, pasir campur kerikil dan lumpur. Hasil anova menunjukan bahwa terdapat perbedaan kandungan nutrien sedimen khususnya fosfat secara signifikan pada masing masing tipe substrat dan terdapat perbedaan morfometrik lamun secara signifikan berdasarkan perbedaan tipe substrat dan kandungan nutrien. Kata Kunci: morfometrik, nutrien, substrat, Tanjung Tiram, Thalassia hemprichii]]>
