Volume 46, Issue 3

An annotated checklist of the free-living dinoflagellates (Dinophyceae) of the Mediterranean Sea, based on literature records, is given. The distribution of 673 species in 9 Mediterranean sub-basins is reported. The number of taxa among the sub-basins was as follows: Ligurian (496 species), Balear-Provençal (360), Adriatic (322), Tyrrhenian (284), Ionian (283), Levantine (268), Aegean (182), Alborán (179) and Algerian Seas (151).

Four species of the red algal genus Dasya (Dasyaceae, Ceramiales), including two new species, are reported from Malaysia. Dasya iyengarii Borgesen and D. pilosa (Weber-van Bosse) Millar are reported from Malaysia for the first time, and their morphological features are described along with taxonomic comments. Dasya longifila Masuda et Uwai, sp. nov. is chiefly distinguished by its long, monosiphonous, pseudolateral filaments (often longer than the axis) in which intercalary cell divisions take place, and a small number of tetrasporangial stichidia and spermatangial branches per fertile pseudolateral from several related species that possess small-statured, sparsely corticated axes. Dasya malaccensis Masuda et Uwai, sp.nov.is characterised by its diminutive thallus (up to 10 mm high) with thickly corticated axes, relatively short pseudolaterals, and narrow tetrasporangial stichidia and spermatangial branches. This species has no close relatives among small-sized species of Dasya .

The glacial moraine along the Baltic Sea of the south-eastern coast of Sweden is composed mainly of porous and soft Lower Cambrian sandstone and hard granite together with small amounts of alkaline amphibolite and diabase. Our objective was to determine whether the chemical and structural properties of these bedrock types, in combination with wave exposure, affect germling survival and adult plant density of Fucus vesiculosus L. commonly found growing on stones and boulders in the area. The number of surviving F . vesiculosus germlings was found to be similar on the alkaline amphibolite and diabase (1.0x10 4 ±0.8x10 3 ind.m −2 ). It was significantly higher than on the acidic porphyry, sandstone, granite, and gneiss (0.6x10 4 ±0.5x10 3 ind.m −2 ) after two months of growth. These results indicate that small-scale differences in surface structures such as porosity, holes and fissures may affect the survival of early stages of F . vesiculosus germlings in the Baltic Sea. Also the natural density of F . vesiculosus individuals at the wave-exposed site was shown to differ depending on bedrock type, with the highest number of plants on sandstone (1893±125 ind. m −2 ) followed by granite (405±28 ind.m −2 ) and amphibolite (374±33 ind.m −2 ). Contrary to the wave-exposed site, the density of plants was similar on all three types at the sheltered site. Further, the attachment strength of adult F . vesiculosus specimens was similar, i.e. 57.6±4.1 N and 61.8±6.8 N on granite and sandstone, respectively, and significantly higher than on amphibolite (36.3±4.2 N). Thus we suggest that the distribution and proportion of different bedrock types on a moraine coast may affect both the survival of Fucus germlings on a very small scale and may affect the density of plants due to differences in attachment strength and impact of waves.

Eutrophication-induced macroalgal blooms can impact marine communities, yet little is known about this phenomenon in the northeastern Pacific region. Changes in ulvoid biomass and water quality parameters (nutrients, transparency, temperature, salinity, and oxygen concentrations) were monitored at 6 sites on Blakely Island, Washington State, USA for two years. Observed ulvoid biomass varied from 0 to 441 g dw m −2 . Biomass peaked in summer and autumn and was greatest at sites with the highest water-column nitrogen concentrations. Intertidal ulvoid communities were dominated by Ulva fenestrata Postels et Ruprecht while Ulvaria obscura (Kützing) Gayral dominated the subtidal zone near Blakely Island. In contrast with these observations, prior quantitative studies describe Ulvaria as rare or ephemeral. Fifteen additional sites were examined for species composition patterns. Similar patterns were seen at sites in Puget Sound, while Enteromorpha spp. were more common and U . obscura absent at sites in Hood Canal, Willapa Bay, and Grays Harbor. Green tides and other macroalgal blooms are typically reported to be monospecific, while in the present study two or more species are in close association, albeit at different tidal elevations. Enteromorpha spp. and Ulva spp. are known as important components of green tides, but relatively little is known about the biology of Ulvaria . Substantial variation in biomass on a fine geographic scale indicates the need for fine scale monitoring of the green tide phenomenon in the northeastern Pacific region.

Light and temperature demands for photosynthesis and growth of two benthic diatoms from Potter Cove, a shallow bay in King George Island, South Shetland Islands (Antarctica), were determined in laboratory cultures. The species investigated were Gyrosigma subsalinum var. antarctica and the Antarctic endemic Odontella litigiosa . The algae exhibited different light requirements for growth and photosynthesis. G. subsalinum was adapted to low light conditions, with a high light utilisation coefficient (α) and low saturating photon irradiances for photosynthesis and growth (~25 μmol m −2 s −1 and 11 μmol m −2 s −1 , respectively). Photosynthesis and growth in O. litigiosa were saturated at a photon irradiance of ~100 μmol m −2 s −1 . Both benthic diatoms exhibited extremely low upper survival temperature (UST, 5–7 °C) and growth only occurred over a narrow range from 0 and 7 °C. Optimal temperature for growth (0 °C) was slightly lower than optimum temperature for photosynthesis (5 °C). The results suggest that G. subsalinum is well-adapted to the low light and constant low temperature conditions present in water depths below 10 m where it occurs. In contrast, O. litigiosa requires more light and is able to tolerate the higher temperatures typical of shallow waters and tide pools. The northern distribution limit of G. subsalinum is the 4 °C summer isotherm, i.e. at the northern boundary of the Antarctic region. In contrast, O. litigiosa could potentially also occur in the sub-Antarctic region up to the 7 °C summer isotherm.

Although the number of algicolous fungi is small, they are of particular interest because of their parasitic or symbiotic properties. Only 79 species of filamentous fungi—out of a total of 465 marine species—are associated with marine algae, and 18 with animals; many of them have not been illustrated in detail. The present paper provides illustrations and full descriptions of 8 marine ascomycetes, 6 of them from algae and 2 from animal hosts. The algicolous species belong to the genera Didymella, Haloguignardia, Spathulospora and Turgidosculum ; those from animals are members of Abyssomyces and Laboulbenia . The illustrations are line drawings made with the aid of a camera lucida, and are almost all based on type material.

Wild-grown Gracilaria chilensis subjected to a post-harvest period of light-deprived culture prior to extraction gave native agar with greatly improved gel strength. Two quite different sets of post-harvest seawater nutrient and motion conditions gave the greatest improvements in gel strength. Gel strengths of dialysis/freezethaw purified native agars (711–912 g cm −2 for a 1.5% w/w gel) compared favourably with those of a commercial bacteriological agar (645 g cm −2 for a 1.5% w/w gel). Such a post-harvest light deprivation regime might be a practical, environmentally friendly alternative to the chemical processing (alkali treatment) currently necessary for the production of food grade agar from Gracilaria chilensis .

Eight fucols and two phlorethols were isolated by HPLC from the ethanolic extract of the brown alga Scytothamnus australis, . Because of their instability the substances were peracetylated before isolation. The phlorotannins trifucolnonaacetate, tetrafucol-A-dodecaacetate, tetrafucol-B-dodecaacetate, cis-pentafucol-A-pentadecaacetate, diphlorethol-A-pentaacetate and triphlorethol-A-heptaacetate have been characterized previously. In addition to these substances we found hydroxytetrafucol-B-tridecaacetate, pentafucol-B-pentadecaacetate, cis, trans-pentafucol-A-pentadecaacetate and hexafucol-B-octadecaacetate all of which are described for the first time. The elucidation of their structure was achieved by 1 H NMR, 13 C NMR, 1 H 1 H ROESY NMR and mass spectral data.