Volume 58, Issue 6

Seaweeds represent highly nutritious seafood products with the potential for becoming more central elements in Western human diets than currently realized. Using locally available seaweed species ( Palmaria palmata, Saccharina latissima, Laminaria digitata and Alaria esculenta ), we tested preparation methods, flavour and taste perception in the context of a culinary experience. In collaboration with a local cooking school and a group of chefs, a cooking workshop explored the possibilities for seaweeds to be included in a variety of region-specific menus, testing their individual qualities and characteristics as sea vegetables, flavour enhancers and in condiments. Through developing quality descriptors for both steamed and dried products of the target species, the study laid the foundation for future systematic sensory analyses. Preliminary tests revealed a strong impact of species on sensory perception, with P. palmata having a sensory profile distinct from the kelp species. A consumer test of S. latissima in fish cakes confirmed our hypothesis that seaweeds as food ingredients do not negatively affect the taste experience for seafood dishes.

This study monitored the biomass composition of Saccharina latissima during a potential harvesting season on the West coast of Sweden, in order to find suitable harvest times for biorefinery purposes. Specimens of S. latissima were sampled at three locations in June, August and October and the biomass was analysed for its macromolecular composition, as well as for the content of several specific compounds, e.g. sugars and fatty acids. PERMANOVA analyses showed that there was a significant difference in the biomass composition among time points. The total carbohydrate concentration was lowest in June and peaked at 360 mg g -1 dry weight in August, while the mannitol content was highest, 90 mg g -1 , in June and decreased throughout the sampling period. Total protein and fatty acid concentrations were found to be approximately 80 and 3 mg g -1 , respectively, with relatively little variation over time. Overall, there was little spatial variation in the macromolecular composition, although the concentration of some specific monosaccharides and fatty acids, as well as the total phenolic content, differed among localities. We discuss the implications of the observed variation in biomass composition of S. latissima for future biorefinery purposes.

There is little use of cultivated kelp including Saccharina latissima (syn. Laminaria saccharina ) in the European food industry, in contrast to the extensive use of Pyropia (syn. Porphyra ) as Nori, e.g. in sushi restaurants. A major reason for this discrepancy is possibly the extremely high iodine content in laminarian species, i.e. 3–10 g I kg -1 dry weight, in contrast to the situation in Pyropia with its approximately 10 times lower iodine content. Another serious problem for commercial use of S. latissima from rope culture for food is the presence of epiphytic animals on the blades from May onwards as an unwanted food addition. This investigation presents data on iodine content in commercial samples of S. latissima , with indications of lower iodine values from rope cultivation in the Kattegat (Baltic) at reduced salinities, and in general from tank cultivation, possibly mainly due to rapid iodine depletion of seawater in the tanks. Boiling dried blades for several minutes in fresh water resulted in a reduction of the iodine content to approximately one third of the initial value after 2 min. Results from rope cultures in a Norwegian fjord showed the presence of epiphytic animals from early May onwards in the sea, which ruined the food quality of the blades, but the complete absence of such animals throughout the year in parallel tank-grown S. latissima , probably mainly due to mechanical prevention of larval settlement in tank tumble culture.

This study examined the effect of short-term nitrogen (N) enrichment on Gracilariopsis heteroclada growth and agar quality. Planting materials were soaked in different concentrations of ammonium chloride (NH 4 Cl) for 6 h. Total thallus N content was highest in Gp. heteroclada enriched in 300 mg l -1 NH 4 Cl. Growth experiments showed that this enrichment treatment (300 mg l -1 NH 4 Cl for 6 h) increased the growth of Gp. heteroclada (4.22±0.09% day -1 ) compared with the control (3.68±0.12% day -1 ). Pond culture using enriched Gp. heteroclada resulted in high growth rates (6.14±0.50% day -1 ). No epiphyte growth was observed during either the growth experiment or the pond culture. There were no significant differences between the agar yields of the enriched (3.65±0.36%) or control (3.78±0.18%) Gp. heteroclada . Additionally, no significant differences were detected when the gel strength of the enriched (611±22 g cm -2 ) and control (587±11 g cm -2 ) Gp. heteroclada were compared. The results suggest that the short-term N enrichment method could be an alternative culture strategy to increase Gp. heteroclada production and lower farming costs.

The ribosomal intergenic spacer (IGS) variation was compared for the nine main cultivated varieties of Pyropia yezoensis in China obtained from the Chinese National Pyropia Germplasm Repository. The full length of the IGS is 5984 bp including several sequence repeats and some complex structures. The sequence analysis of four partial IGS amplicons ranged from 3628 bp to 3776 bp; and the G+C content is 52.5%. Through similarity analysis and multiple sequence alignment of these partial IGS amplicons from the nine varieties, we have found 278 variable sites which account for approximately 7.5% of the whole IGS length. Both comparison of partial IGS sequences and phylogenetic analysis indicate high levels of genetic variation among different P. yezoensis cultivars in different areas of China. In comparison to the IGS of P . haitanensis , this study highlights the important function of classification of IGS in P. yezoensis . Therefore, the IGS sequence may be used to identify intraspecific variation in P. yezoensis .

Plants of the red algal genus Parviphycus are typically diminutive and often occur in mixed stands with other turf species, leading to considerable difficulty in locating them in the field. Once sorted, identification to genus and species is challenging because of their lack of conspicuous diagnostic features. Examination of the type specimen and fresh collections of Gelidiella myrioclada from Singapore revealed that this species may be incorrectly classified to Gelidiella . To test the taxonomic position of G . myrioclada , phylogenetic analyses using rbc L and cox 1 data were performed. Parviphycus comprised two clades that corresponded to geographical distributions in the Atlantic and the Indo-Pacific. In all analyses, G. myrioclada was consistently resolved in the Indo-Pacific Parviphycus clade, along with Parviphycus antipae and Parviphycus sp. Based on morphology, G . myrioclada shows subapical growth and tetrasporangial characteristics that are unique to Parviphycus . We therefore, propose the assignment of G. myrioclada as Parviphycus myriocladus (Børgesen) comb. nov.

The genus Hypnea has been known in New Zealand for a long time but identification to species level has been difficult as only fragmentary and sterile material has been available for study and thus the genus has remained poorly known. Recently large amounts of Hypnea were collected in northern New Zealand enabling DNA sequencing and the presence of two species was confirmed: Hypnea flexicaulis which represents a new record for New Zealand, and Hypnea cornuta which was previously known from fragmentary material. Both of these species are regarded as introduced in other regions of the world. The new species described in this paper as Calliblepharis psammophilus was identified in the field as a species of Hypnea but morphological observations and molecular data confirmed it does not belong to this genus. It is characterized by caespitose thalli with irregularly branched terete axes and with tapering or curved tips, the axial cell enclosed by 5–7 pericentral cells, cortical cells packed tightly and not forming “rosettes” in surface view. The gonimoblast filaments originate from a fusion cell and develop outwardly in chains. This species is currently known from a single location in the North Island (south eastern coast), New Zealand.

The occurrence in Morocco of three species of red algae new to the Mediterranean Sea is reported: Polysiphonia havanensis sensu Børgesen (Ceramiales, Rhodomelaceae), Diplothamnion jolyi (Ceramiales, Wrangeliaceae), and Champia compressa (Rhodymeniales, Champiaceae). All were collected in Al-Hoceima National Park, a protected area of the Mediterranean coast of Morocco.

Codium tenue , previously known reliably only from estuarine habitats in South Africa, is recorded from a similar habitat in the Walpole and Nornalup Inlet system, on the south coast of Western Australia. The Australian C. tenue has a repeatedly divaricately dichotomously branched thallus to 11.5 cm in height, with markedly compressed axes up to 1 cm in width at branch dichotomies, but distally attenuating to terete branch apices. Structurally, thalli have cortices with distinctive cuneate utricles up to 1310 μm long and 650 μm in diameter. Both the habit and structural morphology essentially agree with C. tenue as known in South Africa. Sequences generated from the Australian specimens are also wholly comparable with those of South African specimens newly generated in this study. While similarly disjunct South African/Western Australian distributions are known for other algae, that of C. tenue is particularly remarkable in that the species is apparently an estuarine specialist.

Laetinaevia marina is a frequent ascomycetous fungus that is widely distributed on the seashores of Scandinavia and Great Britain. It grows on fronds of Fucales (Phaeophyceae) that are washed ashore and lie decaying at the high tide mark or further up on the beach. It is one of the few described marine discomycetes. In the current generic concept it is regarded as a member of Naevioideae (Dermateaceae or Mollisiaceae), while it has previously been placed in the genus Orbilia (Orbiliaceae). We studied fresh collections, in live and dead state, to provide a morphological update on the species and to elucidate its systematic placement using molecular systematics. The hemiamyloid reaction of the apical ring, the absence of croziers, and the faintly refractive vacuolar bodies of the terminal cells of living paraphyses are reported here for the first time. A thin gel sheath surrounding the ascospores was confirmed to exist. Based on morphological characters, ribosomal RNA and protein coding gene sequences published for this species here for the first time, we show that L. marina is distinct from the genera and families it was previously placed in, and propose the new combination Calycina marina , despite its erumpent, sessile, pulvinate and rather immarginate apothecia. Furthermore, we present additional observations on the ecology, phenology, and distribution of the species.