Ulva lactuca and Ulvaria obscura are seaweeds that form green tides on Salish Sea shores. They have similar macroscopic morphologies but differ in their biochemistries and physiological responses. To understand how they are affected by changes in environmental conditions, a factorial experiment was conducted in which algae were grown in artificial seawater with either low (10 μM) or high (160 μM) nitrate (NO₃⁻) concentrations at high (29 mol photons·m^−2.day⁻¹) and low (4 mol photons·m^−2.day⁻¹) light levels. Light and NO₃⁻ affected algal responses, but always independently. After two weeks, U. lactuca grown in high light were larger, had lower maximum quantum yields (MQYs), and lower nitrogen (N), carbon (C), pigment, and dimethylsulfoniopropionate (DMSP) concentrations, respectively, relative to algae in low light. In contrast, U. obscura growth was unaffected by light. Like U. lactuca, U. obscura grown in high light had lower MQYs, and N, pigment, and DMSP concentrations. In high light, U. obscura also had 89% higher dopamine concentrations and a tendency to fragment. Both U. lactuca and U. obscura grown in 160 μM NO₃⁻ were larger, had higher MQYs, and higher N, pigment, and DMSP concentrations, respectively, than algae in 10 μM NO₃⁻. Also, when U. obscura was grown in the 160 μM NO₃⁻ medium, it significantly increased its surface area/mass ratio. Although both species grew faster in high NO₃⁻, high light only promoted the growth of Ulva, which may explain the dominance of Ulva in summer months. High light was physiologically stressful to both species and caused increases in photoprotective mechanisms, such as the production of dopamine, a melanin precursor, in Ulvaria, and DMSP lysis in Ulva to generate antioxidants. Growing in 10 μM NO₃- produced responses that were consistent with nitrogen limitation and had greater impacts on Ulvaria than Ulva, suggesting that Ulvaria responds more strongly to eutrophication.

Ulva lactuca和Ulvaria obscura是在Salish海岸形成绿色潮汐的海藻。它们具有相似的宏观形态，但在生物化学和生理反应方面有所不同。为了理解它们是如何通过在环境条件的变化的影响，阶乘实验，其中藻类是进行在人工海水中生长或者低（10μM）或高（160μM）硝酸盐（NO ₃ ^- ）的浓度在高温（29摩尔光子·^米-2。天^-1）和低（4个摩尔光子·^米-2。天^-1）的光的水平。光与NO ₃ ^-影响藻类的反应，但总是独立。两周后，U。lactuca相对于弱光藻类，在强光条件下生长的藻类更大，最大量子产率（MQYs）更低，氮（N），碳（C），色素和二甲基磺酰丙酸酯（DMSP）的浓度更低。相反，隐球藻的生长不受光的影响。与U. lactuca一样，在高光下生长的U. obscura具有较低的MQYs，N，色素和DMSP浓度。在强光下，暗黑伞菌的多巴胺浓度也高89％，并且容易碎裂。既U.莼和U.暗箱在160μMNO生长₃ ^-均较大，具有较高的MQYs，和更高的N，颜料，和DMSP浓度，分别比藻类在10μMNO₃ ^- 。此外，当U.暗箱在160μMNO生长₃ ^-介质，它显著增加了其表面积/质量比。虽然这两个品种在高NO增速快₃ ^{- ，}高光不仅促进生长石莼，这也许可以解释的主导地位，石莼在夏季。高光对这两种物种都具有生理压力，并导致光保护机制的增加，例如在乌尔瓦里亚产生多巴胺，黑色素前体，在乌尔瓦产生DMSP裂解以产生抗氧化剂。在10μMNO _3中生长-产生的响应与氮限制相符，并且对Ulvaria的影响大于Ulva，这表明Ulvaria对富营养化的响应更强烈。