分布北限に近い奄美大島産海草ウミジグサの光合成における光と温度の影響を明らかにした。15℃と24℃における光合成光曲線は，最大純光合成速度が15℃で顕著に抑制された。総光合成速度と最大量子収率による光合成温度曲線（8–40℃）は，それぞれ30.5℃と23.9℃で最大となった。15℃と24℃，光量300と1000 µmol photons m－2 s－1の組み合わせによる光と温度の複合応答では，低温・強光条件で量子収率が顕著に低下し，その後の暗馴致でも回復しなかったことから，低温光阻害が示唆された。

Seagrass condition, resilience and ecosystem services are affected by the below-ground tissues (BGr) but these rarely monitored. In this study we compiled historical data across northern Australia to investigate biomass allocation strategies in 13 tropical seagrass species. There was sufficient undertake statistical analysis for five species: Cymodocea serrulata, Halophila ovalis, Halodule unin...

Seagrasses around the world are threatened by human activities that degrade water quality and reduce light availability. In this study, light requirements were determined for four common and abundant seagrasses along the Gulf coast of peninsular Florida using a threshold detecting algorithm. Light requirements ranged from 8% to 10% of surface irradiance for Halophila engelmannii to 25-27% of su...

A survey of leaf soluble amino acids was conducted for four subtropical seagrasses grown at several salinities. Proline functioned as an organic osmoticum in Halodule wrightii Aschers., Thallasia testudinum Banks ex Koenig, and Ruppia maritima L., while alanine functioned in an osmoregulatory capacity in Halophila engelmanni Aschers. When light-and salinity-induced variations in leaf NH(4) and ...

Perairan Kepulauan Riau yang terdiri dari pulau-pulau kecil umumnya memiliki ekosistem pesisir tersusun mangrove, lamun dan terumbu karang. Ekosistem merupakan bagian peran tidak kalah penting seperti habitat biota, area pengasuhan, regulasi karbon lain sebagainya. Monitoring terkait kondisi untuk dilakukan dalam rangka mengetahui status sehingga kedepan dapat menentukan langkah pengelolaan bai...

Inhibition of photosynthesis by ultraviolet-A radiation (UV-A, 315-380 nanometers) was examined in three marine angiosperms: Halophila engelmannii Aschers, Halodule wrightii Aschers, and Syringodium filiforme Kütz. Sensitivity to UV-A and photosensitization to UV-A by photosynthetically active radiation (PAR, 380-700 nanometers) were characterized.Net photosynthesis by Halodule and Syringodium ...

Nitrogen fixation (acetylene reduction) associated with roots of the seagrass Halodule wrightii was measured offshore near Beaufort and Moorhead City, N.C. Rates of acetylene reduction were higher in aerobic than in anaerobic assays and were linear for up to 5 days. The temperature range for acetylene reduction was 15 to 35 degrees C with a maximum activity at 35 degrees C. Nitrogenase activity...

Abstract. This paper assesses the reflectance difference values between respective spectral bands in visible and near-infrared (VNIR) of Sentinel 2A/2B Multi-Spectral Instrument (MSI) Landsat 8/9 Operational Land Imager (OLI) sensors for seagrass, algae, mixed species discrimination monitoring a shallow marine environment southeast Bahrain Island Arabian Gulf. To achieve these, field survey was...

Multiple stress mechanisms have caused a worldwide decrease in seagrasses, which are vulnerable to environmental and/or anthropogenic pressure. The loss of seagrass meadows of Halodule wrightii is reported for the littoral of Itamaracá Island (Northeastern Brazil). The present study identified the main anthropogenic factors that negatively influenced over the abundance and distribution of seagr...