Advances in Biology & Earth Sciences

Nutrients in the substrate are environmental parameters that play an important role in the spread of Enhalus acoroides in seagrass ecosystem on small islands. The research methods include the analysis of nutrient content in sediments and the measurement of the vegetative organs of E. acoroides. Nitrate (NO₃^-) and total phosphate (TP) analyses were measured in the laboratory. The results of the study found that the average concentration of NO₃^- was very extreme (456 mg kg^-1) in the Northeast Monsoon compared to the Southeast Monsoon (9 mg kg^-1), while the average concentration of TP was found to be very high (940-1012 mg kg^-1) with a pattern that did not show a significant difference. The combination of NO₃^- and TP has caused severe damage and seagrass mortality on Ternate Island in the Northeast Monsoon. The average size of the vegetative organs of E. acoroides is leaf length 55.85±16.4 cm, leaf width 1.24±0.3 cm, sheath length 12.15±4.1 cm, internode length 0.29±0.1 cm, rhizome diameter 1.18±0.4 cm, root length 9.98±5.0 cm and root diameter 0.34±0.1 cm. The adaptation of E. acoroides in responding to nutrient conditions occurs by a trade-off between organs such as internode length and rhizome diameter. The value of similarity in nutrient distribution and morphometric character of E. acoroides was very high (0.999), but there were differences in variable associations that were specific to each station.