Mass occurrence of green algae of the genus Ulva in the form of algal blooms (known as “green tides”) is often associated with high concentrations of biogens in the water. Therefore, Ulva species are most often used in monitoring seawater trophy and far less frequently freshwater trophy. In Europe, the biomonitoring of river ecosystems is based on aquatic plants. According to the River Macrophyte Index (RMI), river populations of Ulva macroalgae (only tubular Enteromorpha-like Ulva) are considered good indicators for eutrophic waters. This paper analyses the legitimacy of using U. pilifera as a trophy indicator in the case of ponds. It has been noted that freshwater populations of U. pilifera are much more common in lakes, dammed reservoirs, or ponds than in rivers. In this study, analysed populations of U. pilifera originated from 14 ponds located in central Poland. Data analysis relied on the Carlson Trophic State Index (CTSI), which was compared with other known trophic indices. According to CTSI values, U. pilifera was most common in eutrophic ponds, where the mean concentrations of ammonium nitrogen, nitrates, total phosphorus, and chlorophyll a reached 581, 241, 212, and 20 µg·L⁻¹, respectively. The results indicate that U. pilifera can be considered a bioindicator for eutrophic waters (50–70 of CTSI). It would therefore be appropriate to introduce U. pilifera as part of biomonitoring conducted in small bodies of water. Major arguments in favour of practical application of U. pilifera are: (i) it is a large macroalga, the thalli of which can reach a length of > 1.0 m, (ii) it is an easy-to-identify species; even by non-experts (it is characterized by a distinctive tubular shape of the thallus), and (iii) it occurs in bulk in conditions of eutrophy, creating an easily observable bloom.

Ulva属的绿藻以藻华形式（称为“绿潮”）大量出现通常与水中高浓度的生物原有关。因此，Ulva物种最常用于监测海水奖杯，而很少用于淡水奖杯。在欧洲，河流生态系统的生物监测基于水生植物。根据河流大型植物指数（RMI），Ulva大型藻类（仅管状的Enteromorpha类Ulva）的河流种群被认为是富营养化水域的良好指标。本文分析了使用U. pilifera作为池塘奖杯指标的合法性。有人指出，pilifera在湖泊，筑坝的水库或池塘中比在河流中更为常见。在这项研究中，分析的U. pilifera种群来自位于波兰中部的14个池塘。数据分析依赖于卡尔森营养状态指数（CTSI），该指数与其他已知的营养指数进行了比较。根据CTSI值，在富营养化池塘中，U。pilifera最常见，那里的铵态氮，硝酸盐，总磷和叶绿素a的平均浓度分别达到581、241、212和20 µg·L ^-1。结果表明，U。pilifera可以被视为富营养化水域的生物指示剂（CTSI的50-70）。因此，引入pilifera是在小水域进行的生物监测的一部分。支持实用的U. pilifera的主要论点是：（i）它是大型大型藻类，其藻类的长度可以达到> 1.0 m，（ii）它是一种易于识别的物种；即使是非专业人士（其特点是丘疹的管状特征），以及（iii）在富营养条件下大量发生，形成了易于观察到的水华。