New records and observations of macroalgae and associated pathogens from the Falkland Islands, Patagonia and Tierra del Fuego

Subantarctic and Antarctic regions remain little explored with regards to their seaweed diversity. This study is based upon collections in the early 1970s and 2007–2013. It is supported by sequencing COI (mitochondrial cytochrome oxidase I) and reports new records for four species of brown algae Hincksia granulosa, Hincksia sandriana, Myriotrichia clavaeformis, Syringoderma australe), four red algae (Erythrotrichia carnea, Paraglossum salicifolium, Phycodrys antarctica, Plumariopsis eatonii), one green alga (Chaetomorpha aerea) and of the oomycete Anisolpidium ectocarpii. A further four brown algae are reported at genus level and discussed (Cladostephus sp., Colpomenia sp., Dictyota sp., Punctaria sp.). Observations of the biology of three brown algal taxa (Cladothele decaisnei, Geminocarpus geminatus, Halopteris obovata) from the region are also reported here

Seaweed diversity in Vietnam, with an emphasis on the brown algal genus Sargassum

Vietnam, a country in South-East Asia, is characterized by a coastline nearly 3300 km long. The coast; stretching from Gulf of Tonkin in the North to the gulf of Thailand in the South, has a predominant North-South orientation resulting in a rich and varied coastal environment. The people in Vietnam have traditionally relied on the rich coastal resources, first by harvesting natural populations and more recently by implementing aquaculture practices. Next to fish and shellfish, marine seaweeds (macroalgae) have traditionally been harvested among most of the Vietnamese coast. A survey of the uses of Vietnamese seaweeds results in 82 species which are considered economically valuable (Chapter 1). Many of these seaweeds are used for human consumption, while others have a role in traditional medicine or are used for colloid extraction (e.g. agar, carrageenan) or as feed for animals. Contrary however to neighboring countries such as China, the Philippines and Indonesia where seaweed mariculture has been seriously developed over the last decades, culturing seaweeds remains a largely marginal activity in Vietnam. Reasons as to why seaweed mariculture has not taken off as compared to the neighboring countries are at least partly to be found in the absence of a phycolloid industry in Vietnam. Instead Vietnam exports large amounts of raw seaweeds, harvested from natural populations, at a low price, and then imports the purified phycocolloids at a much higher price. A steadily growing demand for seaweed-derived products results in an increasing pressure on coastal ecosystems which risk overharvesting of natural populations. This risk is especially eminent for the brown algal genus Sargassum of which approximately 50.000 wet tons is harvested every year. Sargassum represents an important ecosystem engineering species of subtidal coastal habitats. The plants can grow easily up to 3-4 m in length and form dense vegetations with a major nursery function for countless juvenile vertebrate and invertebrate species. If plants, the uprights at least are annual, are harvested before becoming fertile, this may reduce the rejuvenation of natural populations and eventually lead to habitat degradation. Despite the value of seaweeds for humans as well as their role in coastal ecosystems in Vietnam, relatively little is known about them. Basic information on for example the number of species present and their distributions is not easily available. Most information on seaweeds is scattered in local literatures, written in Vietnamese. Thereto, we compiled a checklist of Vietnamese seaweeds (Chapter 2). A total of 827 species are reported (412 Rhodophyta, 180 Chlorophyta, 147 Phaeophyceae, 88 Cyanobacteria. This species richness is comparable to that of the Philippines and considerably higher than Taiwan, Thailand or Malaysia. A comparison of the species composition with neighbouring countries yielded surprisingly low similarities. Rather than an indication of a biogeographical pattern, we are of the opinion that the low similarity with neighboring countries is primarily an artifact resulting from taxonomic inconsistencies. The checklist could serve as a valuable tool, to reveal the seaweed diversity in Vietnam and to stimulate intraregional comparative research. Sargassum with 70 species and intraspecific taxa is undoubtedly the most species-rich seaweed genus in Vietnam (Chapter 3). The estimate of Sargassum diversity is however entirely based on interpretations of the morphological characters such as the base, secondary axes, the leaves, vesicles and receptacles. Therefore we reassessed Sargassum diversity based on molecular gene sequence data of the internal spaces of the ribosomal cistron (ITS rDNA) (Chapter 4). Although successful at higher taxonomic levels, subgenera and sections, the resolution of the ITS marker was not sufficient to point species boundaries with confidence. Many morphologically distinct ‘species’ were characterized by virtually identical ITS sequences. Conversely, specimens identified on morphological criteria as one ‘species’ were resolved in different clades. Results could be interpreted in two possible ways. First, traditional species concepts in Sargassum have been too broadly defined and the genus contains far less species. Alternatively, species in Sargassum result from a recent radiation and even the highly variable ITS region does not display enough variation to resolve the relationship among them. To address these outstanding questions we explored to use of Restriction site Associated DNA Sequences (RAD-Seq) to generate a set of highly variable nuclear markers. RAD-sequencing is a Next Generation Sequencing-based technique that generates thousands to hundreds of thousands DNA fragments that can be scored for Single Nucleotide Polymorphisms (SNPs) which in turn can be compared between individuals. RAD markers can be used to pinpoint loci under selection, or are used as neutral markers to reconstruct phylogeographical patterns or elucidate phylogenetic relationships among closely related species. During the experiment we generated more than 21 million sequences which after quality control and analyses in Stacks and SiLiX yielded 231 alignments which could potentially be used to address species boundaries in the genus Sargassum. The development of more than 200 markers presents a more than significant increase over markers used in traditional studies which generally combine one or two mitochondrial and/or chloroplast markers with sequences from the ribosomal cistron. It also boosts the number of potential markers by a factor 10 to 20 compared to microsatellite-based studies. Despite these results, there are issues that remain to be solved. For example, the libraries of the individual specimens are highly unequal in size. Some specimens are represented by 1.5 million sequences while others only have barely 800 sequences. We believe the main reason why some specimens are underrepresented is due to insufficient DNA quality. Therefore, future studies should focus on obtaining high quality DNA from Sargassum. A second issue is posed by the presence of multiple alleles in the final alignments. Normally one would expect 2 alleles per marker for a diploid organism. Our final alignments often contain more than 2 alleles per specimen. It is unclear at present if this is a technical issue which could eventually be solved by fine-tuning the parameters of the Stacks analyses or whether the multiple alleles issue has an underlying biological cause (polyploidisation). Despite these issues, RAD Sequencing has a great potential for population based molecular studies in algae. A selection of the current stacks can be used for primer design which can then be used to score markers by PCR followed by traditional Sanger sequencing. This approach can easily increase the number of nuclear markers for phylogeographic or species delimitation studies by a factor ten. Modest as it may be, I hope that by providing a compilation of the seaweed diversity in Vietnam and their economical importance, and by introducing DNA-based methodologies to assess species diversity in the ecologically and economically important genus Sargassum, I have contributed to the foundation for a sustainable exploitation of natural resources and continuous integrity of marine habitats

Liste des algues de l'expedition Santo 2006 (Vanuatu)- list of algae from the Santo 2006 expedition (Vanuatu)

During the month of August 2006, 7 participants of the workshop 'Algae' SANTO 2006 Expedition have prospected exclusively in the South of the island of Santo. Nearly 1,500 samples of calcareous algae and 'soft' algae were collected in 41 stations divided in different habitats from the coast up to 60 m deep. The results of the taxonomic study are 284 species (excluding calcareous red algae) including 8 marine phanerogams, and 4 cyanobacteria. 272 species of algae are divided into 164 Rhodophyta, Chlorophyta 82 and 26 Ochrophyta. Nine taxa would be new to science. This inventory is in addition to those already made to the Solomons (2004) and Fiji (2007) under the CRISP programme and in New Caledonia and French Polynesia for projects funded by communities themselves. South of Santo, appears as a relatively rich site and is part of the diversity gradient that extends from the most species-rich area located in the indo-Malay region the poorest area in the region is the Pacific. This study is the first inventory of marine flora of Vanuatu

Marine algal flora of French Polynesia III. Rhodophyta, with additions to the Phaeophyceae and Chlorophyta

This third paper in a monographic series on the marine macroalgae of French Polynesia gives a detailed coverage of the species of Rhodophyta occurring in these islands. A total of 197 taxa are presented (195 Rhodophyceae, 1 Phaeophyceae and 1 Chlorophyta; of these, 84 (or 43%) represent new records for the flora, while 7 (or 3.6%) are new species. The new combination Jania subulata (J. Ellis et Solander) N’Yeurt et Payri is made for Haliptilon subulatum (J. Ellis et Solander) W. H. Johansen. Padina stipitata Tanaka et Nozawa (Phaeophyceae) and Codium saccatum Okamura (Chlorophyceae) are notable additions to the flora from deepwater habitats in the southern Australs; 56 taxa (or 28.7%) occur only in the Austral archipelago. The flora has most affinities with that of the Hawaiian Islands (Sørensen Index = 0.30), followed by the Cook Islands and Samoa (SI = 0.26 each) and the Solomon Islands (SI = 0.25). There are some disjunct distribution patterns for several subtropical to temperate species, possibly suggesting special oceanic current routes between the southern Australs, Hawaii and the Southern Australian region

Marine Plants of the Black Sea. An Illustrated Field Guide

This Guide has been prepared with the financial assistance of the Commission on the Protection of the Black Sea Against Pollution (BSC). Except for photos, which cannot be used without permission of the author, this book may be reproduced in whole or in part for educational or non-profit purposes without special permission from the copyright holder, provided acknowledgement of the source is made. No use of this publication may be made for resale or for any other commercial purpose without prior permission in writing from the Permanent Secretariat of the BSC. This book is intended for scientists, teachers, students and the general public interested in flora and bottom vegetation and can be used for species identification of the Black Sea marine plants

Ligulate Desmarestia (Desmarestiales, Phaeophyceae) revisited : D. japonica sp. nov. and D. dudresnayi differ from D. ligulata

Funded by Korea Research Foundation UK Natural Environment Research Council Molecular Bioanalytics Facility. Grant Number: MGF-154 Natural Environment Research Council. Grant Number: 2025 NF3 German Academic Merit Foundation European Commission The Marine Alliance for Science and Technology for Scotland Scottish Funding Council. Grant Number: HR09011Peer reviewedPostprintPostprintPostprin

Divergence patterns in Fucus seaweeds (Phaeophyceae) in the northern Baltic Sea and in the Tjongspollen area

To be able to interpret patterns of biodiversity it is important to understand the processes by which new species evolve and how closely related species remain reproductively isolated and ecologically differentiated. Divergence and differentiation can vary during speciation and it can be seen in different stages. Groups of closely related taxa constitute important case studies to understand species and new biodiversity formation. However, it is important to assess the divergence among them at different organismal levels and from an integrative perspective. For this purpose, this study used the brown seaweeds genus Fucus as a model to study speciation, as they constitute a good opportunity to study divergence at different stages. We investigated the divergence patterns in Fucus species from two marginal areas (northern Baltic Sea and the Tjongspollen area), based on phenetic, phylogenetic and biological taxonomical criteria that are respectively characterised by algal morphology, allele frequencies of five microsatellite loci and levels of secondary polyphenolic compounds called phlorotannins. The results from this study showed divergence at morphological and genetic levels to certain extent but complete lack of divergence at biochemical level (i.e. constitutive phlorotannin production) in the Baltic Sea or Norway. Morphological divergence was clearly evident in Tjongspollen (Norway) among putative taxa as they were identified in the field and this divergence corresponds with their neutral genetic divergence. In the Baltic, there are some distinguishable patterns in the morphology of the swedish and finnish individuals according to locality to certain extent but not among putative taxa within localities. Likewise, these morphological patterns have genetic correspondence among localities but not within each locality. At the biochemical level, measured by the phlorotannin contents there were neither evidence of divergence in Norway or the Baltic Sea nor any discernable aggregation pattern among or within localities. Our study have contributed with further understanding of the Baltic Sea Fucus system and its intriguingly rapid and recent divergence as well as of the Tjongspollen area systems where formally undescribed individuals have been observed for the first time; in fact they appear largely differentiated and they may well warrant a new species status. In current times, climate change threatens, peripheral ecosystems, biodiversity, and increased knowledge of processes generating and maintaining biodiversity in those ecosystems seem particularly important and needed

Morphological, genotypic and metabolomic signatures confirm interfamilial hybridization between the ubiquitous kelps Macrocystis (Arthrothamnaceae) and Lessonia (Lessoniaceae)

We thank the support from G. Millne (UoA), M. Rateb (UoA) and D. Zagal (UACh) in the histological preparations, mass spectrometry set-up and the cultivation of the hybrid progeny, respectively. PM and LM developed part of this work with BecasChile (Fondecyt) funding, specifically grants No. 72130422 (PM) and No. 73140389 (LM). We would like to acknowledge the British Council Newton Fund Institutional Links, project No. 261781172 for funding SS a postdoctoral research fellow. We are also grateful to the UK Natural Environment Research Council for their support to FCK (program Oceans 2025–WP 4.5 and grants NE/D521522/1 and NE/ J023094/1). This work also received support from the Marine Alliance for Science and Technology for Scotland pooling initiative. MASTS is funded by the Scottish Funding Council (grant reference HR09011) and contributing institutions. RW thanks financial support from Gobierno Regional de Los Lagos (grants FIC 2012 E7259-2 and FIC 2013 BIP30234872-0) and Fondef, Conicyt (HUAM AQ12I0010), which allows the sampling expeditions at Chiloe Island by PM, LM, DJP.Peer reviewedPublisher PD