Baltic Fucus Vesiculosus Research Articles

Baltic Fucus vesiculosus as potential bio-sorbent for Zn removal: Mechanism insight

This research aimed to find the best phenotype of the brown algae Fucus vesiculosus (kelp) which has the greater potential to become a sorption byproduct for Zn removal from contaminated waters. Thus, the Zn uptake capacity and sorption mechanisms of the kelp collected from the Baltic Sea shore was, for the first time, investigated under various conditions, and compared to the phenotype habiting on the Irish Sea shore. Sorption studies were performed investigating the effect of algal dosage, Zn sources as well as algal harvesting time of the year on Zn uptake capacity. The results suggested that the Baltic algae is a better bio-sorbent for Zn uptake. Sorption mechanisms were studied by employing various indirect and direct approaches, more importantly, including high resolution synchrotron X-Ray Fluorescence and X-Ray Absorption Spectroscopy (XAS) and molecular modelling (MM). The results revealed that alginate and cellulose are among the main polysaccharide bonding Zn at algal surface, via coordination with O atoms from carboxyl and hydroxyl groups. XAS results giving direct measurements of Zn bonding environment on algal surface are supported by MM outputs and suggested that Zn is surrounded by ca. 5 O atoms at interatomic distances varying from 1.94 to 2.02 Å. The results contribute to understanding sorption mechanisms which can further lead to finding the best eluent for Zn desorption from the used biomass, bio sorbent reconditioning and reuse in multiple sorption desorption cycles as well as process optimization before industrial scaling up.

Recent evolution in Baltic Fucus vesiculosus: reduced tolerance to emersion stresses compared to intertidal (North Sea) populations

The Baltic is a young, brackish and non-tidal sea, supporting an impoverished marine flora compared with adjacent open coastal areas. Populations of the normally intertidal brown alga Fucus vesiculosus L. are permanently submerged in the Baltic. We tested the hypothesis that these populations have evolved a reduced ability to withstand water-stresses caused by aerial exposure (desiccation and freezing), relative to adjacent intertidal populations in the North Sea. Desiccation and freezing tolerance were compared using chlorophyll fluorescence to monitor photosynthetic sta- tus during stress and recovery. To control for the influence of growth salinity on stress tolerance, the experimental material consisted of either adult algae cross-acclimated at Baltic and North Sea salin- ities (6.5 and 20 to 24 practical salinity units (psu), respectively), or juveniles from both populations grown in the Baltic from embryos (submersed, 6.5 psu). Baltic algae were less able to recover maxi- mum photochemical yield (Fv/Fm) after freezing at -15°C than North Sea algae, and neither acclima- tion (adults) or growth salinity (juveniles) accounted for between-population differences. During des- iccation at 5°C, differences in the response of variable fluorescence (Fv), as well as in initial fluorescence (F0) and Fv during recovery, indicated that impaired photoprotective processes may con- tribute to the inability of Baltic algae to fully recover Fv/Fm after stress, in contrast to North Sea algae which displayed dynamic and rapidly recoverable reductions of Fv/Fm. Subsequent desiccation experiments during the summer (at 25°C) showed that, relative to North Sea algae, the effective pho- tochemical yield (ΔF/Fm') of Baltic algae started to decline at lower tissue-water content (TWC) and recovered less completely after a return to seawater. A critical TWC of ca 10% for Baltic populations was identified, below which ΔF/Fm' did not fully recover. In addition, Baltic algae were less able to regain initial TWC during recovery. These results indicate that, in ca 7500 yr since the recruitment of the present marine flora to the Baltic, F. vesiculosus has evolved reduced tolerance to emersion stresses compared to adjacent intertidal populations.

Morphological variation of northern BalticSea Fucus vesiculosusL

Abstract The variation of northern Baltic Fucus vesiculosus morphology along the salinity gradient is described. Samples of 15–30 mature receptacle-bearing plants were collected by SCUBA diving from 19 sampling points on moderately exposed and exposed shores along the salinity gradient in the Gulf of Finland and in the Bothnian Sea. Eight morphological characteristics were measured and then analyzed using linear regression analysis and stepwise discriminant analysis. The analyses indicate considerable morphological divergence according to decreasing salinity. In both the Gulf of Finland and in the Bothnian Sea the width and length of thallus as well as distance of dichotomies and stipe dimensions decreased along the gradient. Along the exposed shores, plants are shorter and have narrower fronds. The change in morphology towards the low salinity areas is a clinal one and different morphological types can be distinguished to a certain extent. Discriminant analysis revealed that a combination of four morphol...

Effects of salinity on growth of Baltic and AtlanticFucus vesiculosus

Vegetative apices of intertidal Atlantic and permanently sublittoral, brackish water, Baltic Fucus vesiculosus were cultured in a salinity range (1·5–45 ppt) in the laboratory. Tank experiments with running Baltic sea-water were also conducted under summer (10–20°C) and autumn (7–10°C) temperature ranges. Both populations were able to grow in a wide range of salinity in laboratory culture. The Atlantic population showed better growth in higher salinities and virtually no growth in 1·5 ppt, in which it died after 7 weeks. In contrast the Baltic plants grew better in the lower range of salinity. Baltic material took nearly 4 weeks to recover from upshock in salinities 34 and 45 ppt, and showed 10–15% loss of tissue weight during the first two weeks. Growth then started, but in the highest salinity (45 ppt) growth was negligible. When cultured in a semi-natural Baltic environment, in a tank experiment, Atlantic plants could not survive whereas Baltic plants showed vigorous growth. The combination of continuo...

Aspects of the reproductive biology ofFucus vesiculosusfrom the coast of SW Finland

Abstract The reproductive biology of permanently submerged Baltic Fucus vesiculosus L. (Phaeophyceae) has been investigated at two sites (exposed and sheltered) in S. W. Finland. Phenological observations included the time of receptacle initiation, the periods of receptacle growth, oogonial maturation and receptacle abscission. The earliest stages of receptacle initiation were detected in the second week of October, when plants had been exposed to short-day ( < 12 h) stimulus for only 1-2 weeks. These receptacle initials were only a few mm in length and sexually immature. They remained dormant over winter until the April ice melt, when rapid increase in length occurred at water temperatures below 5°C. By early June, receptacles had reached maximum length but dry weight increased as gametangia (oogo-nia) matured. Spent receptacles were shed at the end of July. The effect of photoperiod on receptacle initiation was studied and initiation was found to occur under short-day conditions. The populations did not...