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Effects of copper and cadmium on physiology and antifouling defense of the marine macroalga Ulva reticulata

Al-Khaldi Wejdan Ahmed, Al Solami Lafi, Satheesh Sathianeson

Oceanological and Hydrobiological Studies

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2021

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Vol. 50, No. 2

184--197

EN

Heavy metals are major stressors for benthic macroalgal communities in marine ecosystems. In this study, the effects of copper and cadmium on some physiological parameters along with antifouling defense of the marine macroalga Ulva reticulata were assessed under laboratory conditions. Macroalgal samples were treated with three concentrations (1 mg l−1, 3 mg l−1 and 5 mg l−1) of copper and cadmium for 2 and 7 days. After treatment, algal samples were analyzed for chlorophyll-a, carotenoid, total polyphenol and total antioxidant capacity. Also, algal extracts were tested against biofilm-forming bacteria strains to understand differences in antifouling activity. The results indicated that exposure of U. reticulata to copper and cadmium, on the one hand, induced protective mechanisms such as total phenol production and antioxidant capacity against metal stress and, on the other hand, reduced photosynthesis. While the extract obtained from control algal samples showed a strong inhibitory effect on the growth of biofilm-forming bacteria, treatment with heavy metals resulted in reduced antibiofilm activity. In general, the results revealed that exposure of macroalgae to heavy metals can affect antifouling defense traits in addition to changes in photosynthetic pigment content.

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Differentiation of inland Ulva flexuosa Wulfen (Ulvaceae, Chlorophyta) from Western Poland

Rybak A. S., Czerwoniec A.

Oceanological and Hydrobiological Studies

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2015

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Vol. 44, No. 3

393--409

EN

The macroalgae representing the cosmopolitan Ulva flexuosa Wulfen species have been found in inland water ecosystems of Europe since the mid-1800s. The presence of the Ulva genus in waters of inland salt marshes was explained by high salinity of water in such systems. However, Ulva flexuosa thalli were found in lakes and rivers having no supply from strongly mineralized sources, either of natural or anthropogenic origin. The study focused only on populations of Ulva flexuosa subsp. pilifera (Kűtz.) M.J. Wynne and Ulva flexuosa subsp. paradoxa (C. Agardh) M.J. Wynne occurring in inland ecosystems isolated from seawater. The differentiation of inland U. flexuosa subsp. pilifera and subspecies paradoxa was assessed by using classical morphological data and molecular techniques. We found that only two subspecies of Ulva flexuosa Wulfen occur in inland water ecosystems of Poland. On the basis of the analysis combining morphological features with the ITS region and rbcL gene sequences, a small degree of differentiation of the two inland taxa was demonstrated. These two subspecies have high differentiation of the habitat niches. U. flexuosa subsp. paradoxa settled in habitats featuring high salinity levels, and the second subspecies pilifera occurred only in fresh waters.

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The distribution of green algae species from the Ulva genera (syn. Enteromorpha, Chlorophyta) in Polish inland waters

Messyasz B., Rybak A.

Oceanological and Hydrobiological Studies

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2009

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Vol. 38, No.1

121-138

EN

Marine algae in inland waters in Poland have been rarely recorded. The distribution of 5 species and 1 subspecies of the Ulva genus (syn. Enteromorpha, Chlorophyta) observed in different inland aquatic ecosystems is reported. The algal distribution was established on the basis of the available literature, unpublished material, and oral reports. Information about the algal morphology and habitat conditions, from all of the 58 reported locations of ulvas in Poland, were assimilated and are presented here. The most widespread species of Ulva in inland waters in Poland was U. intestinalis (syn. Enteromorpha intestinalis) reported at 34 sites, while the rarest species was U. paradoxa (syn. Enteromorpha paradoxa), recorded at 2 sites. Species of Ulva have been reported at a range of inland aquatic ecosystems, but most commonly in lakes and small water-courses, such as ditches, channels and creeks. Most of the reported sites of penetration of Ulva (Enteromorpha) inland are concentrated in northwestern and central Poland.