Zhiguang Xu

Microcystis aeruginosa is a common cyanobacterium leading to algal blooms. Coupled effects of temperature increase and UV radiation increase will affect its photosynthesis performance, which may in turn will affect its proliferation and distribution, and change the environmental health of the water body. In this study, M. aeruginosa FACHB 469 was i...

In recent years, the periodic outbreak of green tides in the coastal areas of China, caused by the combined effects of environmental changes and human activities, has been attracting extensive attention due to the serious negative impacts on the coastal marine ecosystem. In the study, the samples of Ulva linza, a green tide species, were cultivated...

In recent years, golden tides caused by floating Sargassum have induced severe ecological disasters globally. Eutrophication is a significant factor contributing to the massive spread of Sargassum golden tides. Furthermore, the thalli of Sargassum that float on the ocean surface are subjected to more ultraviolet radiation (UVR). The coupled impact...

Understanding the relationship between plant diversity and invasibility is essential in invasion ecology. Elton proposed that species-rich communities are more resistant to invasions than species-poor communities. While soil microorganisms play a crucial role in regulating this diversity–invasibility relationship, the effects of plant competition m...

Understanding the relationship between plant diversity and invasibility is essential in invasion ecology. Species‐rich communities are hypothesized to be more resistant to invasions than species‐poor communities. However, while soil microorganisms play a crucial role in regulating this diversity–invasibility relationship, the effects of plant compe...

The aim was to determine the response of a bloom-forming Microcystis aeruginosa to climatic changes. Cultures of M. aeruginosa FACHB 905 were grown at two temperatures (25°C, 30°C) and exposed to high photosynthetically active radiation (PAR: 400–700 nm) alone or combined with UVR (PAR + UVR: 295–700 nm) for specified times. It was found that incre...

As an invasive species of macroalgae, Sargassum muticum (Yendo) Fensholt has invaded European shores and the Mediterranean, and even drifting individuals have been observed in sea area near the Canary Islands, becoming a potential species responsible for the "Sargassum golden tide". When drifting on the sea surface, algae receive more ultraviolet r...

Diatoms form a major component of phytoplankton. These eukaryotic organisms are responsible for approximately 40% of primary productivity in the oceans and contribute significantly to the food web. Here, the influences of ultraviolet radiation (UVR) and ocean warming on diatom photosynthesis were investigated in Thalassiosira pseudonana. The organi...

In recent years, golden tides caused by drifting Sargassum horneri (Turner) C. Agardh have caused serious ecological disasters in coastal areas of China. Eutrophication is an important cause of the formation of the golden tide. Additionally, the drifting population on the surface of the ocean is exposed to more ultraviolet radiation (UVR) than the...

4 Diatoms account for a large proportion of marine primary productivity, they tend to be the predominant species in the phytoplankton communities in the surface ocean with frequent and large light fluctuations. To understand the impacts of increased CO2 on diatoms' capacity in exploitation of variable solar radiation, we cultured a model diatom Tha...

Sargassum golden tides (GT) are common in numerous coastal areas all over the world, and it adversely affects local marine life. Eutrophication is critical for Sargassum GT development. However, its physiological and ecological mechanism remains unclear. To investigate the responses of drifting Sargassum horneri, the species causing GT in the weste...

In recent years, massive Sargassum drifting on the sea surface, known as “golden tides,” negatively impacted on the local marine ecology. However, the physiological mechanisms of its formation remain unclear. To investigate the photosynthetic responses of golden tide algae to UVR, one key factor for drifting Sargassum population, we cultivated thal...

To investigate the effect of reduced salinity on diatoms’ capacity to cope with changing ultraviolet radiation (UVR) and photosynthetically active radiation (PAR), Skeletonema costatum was grown in a range of salinity (15, 25, and 35). The photosystem II (PSII) function was analyzed by increasing PAR and UVR to mimic a mixing event in turbulent wat...

Sargassum golden tides have bloomed frequently in many sea areas throughout the world, and negatively impacted on the local marine ecology. Sargassum muticum commonly inhabits rocky shores. It is now distributed worldwide due to its invasiveness, and recently drifting individuals have been observed on the coasts of Canary Islands. However, as a pot...

As oceans warm, the depth of the upper mixed layer is predicted to decrease, resulting in insufficient nutrient supply and higher solar radiation for phytoplankton. In order to understand the photophysiological responses of the key eukaryotic phytoplankton diatoms to high light and nutrient limitation, we grew two diatoms, Thalassiosira weissflogii...

Microcystis aeruginosa, a common bloom-forming cyanobacterium with both non-toxic and toxic strains, experiences a variable light environment due to buoyancy regulation and the variable mixing of the water columns. However, little is known on how non-toxic and toxic strains respond to changing photosynthetically active radiation (PAR) and ultraviol...

The effects of light intensity on the growth and photosynthetic characteristics of Sargassum horneri, a golden tide causing species, were investigated under different nitrate (NO 3⁻ -N) levels to reveal the physiological mechanism underlying the outbreak of golden tide. There were two NO 3⁻ -N levels and three light intensities: i.e. high N (100 μm...

Seaweed in the diet has been widely reported to improve growth and immunity of fish. In China, a large bloom of Sargassum horneri occurred in 2017, which provided biomass for potential development and utilization in the aquaculture industry. The goal of this study was to evaluate the effects of S. horneri meal as a dietary supplement on the growth...

Diatoms usually dominate phytoplankton community in coastal waters and experience rapid changes of underwater light. However, little is known regarding how increased CO2 would affect diatoms’ capacity in dealing with changing photosynthetically active radiation (PAR) and ultraviolet radiation (UVR). Here, we cultured a globally abundant diatom Thal...

Diatoms, as important contributors to aquatic primary production, are critical to the global carbon cycle. They tend to dominate phytoplankton communities experiencing rapid changes of underwater light. However, little is known regarding how climate change impacts diatoms’ capacity in coping with variable light environments. Here we grew a globally...

The development of golden tides is potentially influenced by global change factors, such as ocean acidification and eutrophication, but related studies are very scarce. In this study, we cultured a golden tide alga, Sargasssum muticum, at two levels of pCO2 (400 and 1000 µatm) and phosphate (0.5 and 40 µM) to investigate the interactive effects of...

Cu is considered to be toxic to macroalgae at higher levels. Ocean acidification can also alter the physiological performances of macroalgae. However, little is known regarding the interactive effects of Cu and ocean acidification on macroalgae. In this study, a green tide macroalga, Ulva prolifera, was cultured at the conditions of three levels of...

The evolvement of golden tides would be influenced by global change factors, such as ocean acidification and eutrophication, but the related studies are very scarce. In this study, we cultured a golden tide alga, Sargasssum muticum, at two levels of pCO2 (400, 1000 µatm) and phosphate (0.5 µM, 40 µM) conditions to investigate the interactive effect...

Marine macroalgae are ecologically and economically important primary producers, being adjacent to human living areas and playing key roles in coastal carbon cycles. They are subject to both regional and global environmental changes in coastal waters, where environmental factors fluctuate dramatically due to high biological production and land runo...

To investigate physiological characteristics of Saccharina japonica cultured in enriched media with different nitrogen sources, kelp were cultured for 7 days in three nitrogen conditions, including natural seawater, enrichment of ammonia and nitrate, and then growth rate, photosynthesis at different carbon levels (P-Ci curve) and nitrogen uptake ra...

The aim of this study was to investigate the effects of light intensity and enhanced nitrogen supply on the growth and photosynthesis of the green-tide macroalga, Ulva prolifera. Thalli of U. prolifera were grown in natural or NH (4) (+) -enriched seawater under two different light intensities for 7 days, and then the growth rate, pigmentation, and...

Increasing atmospheric CO 2 is causing global public concern and seabed sequestration is one possible method of carbon reduction. However, studies on the potential risk of CO 2 leakage and its possible effects on the marine environment are still very limited. To investigate such possible effects on sensitive marine organisms, coralline algae, Coral...

Solar ultraviolet radiation (UVR, 280-400 nm) is known to inhibit the photosynthesis of macroalgae, whereas nitrogen availability may alter the sensitivity of the algae to UVR. Here, we show that UV-B (280-315 nm) significantly reduced the net photosynthetic rate of Gracilaria lemaneiformis. This inhibition was alleviated by enrichment with ammonia...

The red alga Gracilaria lemaneiformis was cultured under different CO2 and phosphorus conditions for 16 days, and its growth, photosynthesis and uptake of nitrate and phosphate were examined in order to establish the longer-term impacts of elevated CO2 and phosphorus supplies on this economically important seaweed. Enrichment with either CO2 or pho...

Solar ultraviolet radiation (UVR, 280–400 nm) is known to negatively affect macroalgal growth and photosynthesis, while phosphorus availability may affect their sensitivity to UVR. Here, we show that UV-A enhanced the growth rate of the red macroalga, Gracilaria lemaneiformis Bory de Saint-Vincent under inorganic phosphorus (Pi)-replete but reduced...

To investigate the effects of increased atmospheric CO2 and N supply in seawater on the red alga Gracilaria lemaneiformis, the thalli were incubated in laboratory for 15 days under 4 different conditions of CoNo, C + No, CoN + and C + N + respectively, then the growth, nutrient uptake rates, contents of pigments and soluble proteins in alga were me...

Dark respiration (nonphotorespiratory mitochondrial CO2 release) in the light (R-L) of the intertidal macroalga Ulva lactuca (Chorophyta) during emersion was investigated with respect to its response to variations in temperature and desiccation. R-L was estimated by CO2 gas-exchange analysis using the Kok effect method, whereas dark respiration in...