Water Properties of Ashmore Reef, North-west Shelf, Australia

Ashmore Reef is a tropical marine reserve positioned at the confluence of Indian Ocean waters and the Indonesian Through Flow, has three vegetated cays all with fresh water lenses and two lagoons, separated by a calcareous algal rise. Both lagoons have two entrances on the northern side of the reef. The reef is subject to a 4.75 m semi-diurnal tide and on a spring tide ~7.5 km3 of water washes over the reef. The regional, lagoonal and well water qualities in and around Ashmore Reef have been observed from 1991 with a more intensive program since 1999 to ascertain it's chemistry and possible relationships with biodiversity. Sea surface temperatures of the surrounding oceanic water seasonally range from 25.48°C to 30.2°C and salinity from 34.51 to 34.75. Satellite derived lagoonal temperatures range from 25.4°C - 34.5 °C with an average of 29.4 °C, salinity ranges from 39.6 to 31.2.

The fresh water lens on West Island has up to 150 000 ltr/yr pumped from the well. Well water temperature varies between 28°C and 29°C, and salinity has ranged from 0.03 to 3.94 with a pH of 7.64 dissolved oxygen percentage ranged from 27% to 51 %.

This reef is within the tropical monsoonal belt, with thunderstorms occurring on ~85 days/yr and where evaporation potential is ~1820 mm, almost twice that of annual rainfall of ~950 mm.

This article can be found in The Beagle, pp. 9-12. The Beagle is a print only journal.

阿什莫尔礁（Ashmore Reef）是一处热带海洋保护区，地处印度洋水域与印度尼西亚贯穿流（Indonesian Through Flow）的交汇区域，拥有三座覆有植被的沙岛，各均带有淡水透镜体（fresh water lenses），以及两座被钙藻隆起分隔的泻湖。两座泻湖均在礁体北侧设有两处通口。该礁体受4.75米半日潮的影响，大潮期间约7.5立方千米的海水会流经该礁体。自1991年起，研究人员便对阿什莫尔礁及其周边区域的区域水体、泻湖水及井内水质展开观测，并于1999年起启动更为强化的监测计划，以探明其化学特征及其与生物多样性的潜在关联。周边洋域的海表温度季节变化范围为25.48℃至30.2℃，盐度介于34.51至34.75之间。卫星反演得到的泻湖水温范围为25.4℃至34.5℃，平均温度为29.4℃，盐度区间为39.6至31.2。

西岛（West Island）的淡水透镜体年抽水量可达15万升。井内水温介于28℃至29℃之间，盐度范围为0.03至3.94，pH值为7.64，溶解氧百分比区间为27%至51%。

该礁体位于热带季风带内，年平均雷暴日数约85天，潜在蒸发量约1820毫米，几乎是年均降雨量（约950毫米）的两倍。

本文刊载于《The Beagle》期刊第9-12页，该期刊仅发行印刷版。