Résultats d'une étude d'homogénéité de peuplements algaux photophiles sur substrat rocheux à Port-Cros et à Banyuls (France)

The homogeneity of photophilous algal vegetations at Port-Cros and Banyuls (France) have been calculated by different methods. The results are compared. They are very high: 75-80%

Résultats d'une étude d'aire minima de peuplements algaux photophiles sur substrat rocheux à Port-Cros et à Banyuls (France)

The minimal area of photophilous algal vegetations at Port Cros and Banyuls (France) has been determined by different methods. A comparison is made between the results. The minimal area of the studied vegetation-type is very small : 100-250 cm²

Putting geography into phycology: recent advances

In the last decade, ecological and biogeographical studies (mainly terrestrial) have greatly benefited from recent developments in geographical techniques, and numerous test cases have been published. However, very few phycological studies emphasizing ecology and biogeography have incorporated these techniques, using traditional, nonspatially explicit descriptive and multivariate statistics instead. Here, we show a satellitebased seasonal mapping study of macroalgal communities in the Arabian Sea, and a global species’ distribution modelling effort of a cryptic green algal complex forming worldwide blooms on physically damaged coral reefs. We demonstrate how spatially explicit information contributes to more efficient work and new insights in marine ecology and biogeography, and comment on why previous studies did not include geographical techniques. Lastly, we briefly discuss future perspectives of spatially explicit phycological studies

Note on <i>Stoechospermum</i> Kütz. (Dictyotales, Phaeophyta)

Stoechospermum polypodioides (J.V.Lamour.) J.Agardh is found to be conspecific with S. marginatum (C.Agardh) Kutz. after examination of the type specimen. The anteriority of Dictyota polypodioides J.V.Lamour. on Zonaria marginata C.Agardh, results in S. marginatum to be a synonym of S. polypodioides. Additionally all taxa attributed to the genus Stoechospermum are typified

Taxonomy and biogeography of macroalgal communities in the upwelling region off the coast of Dhofar, Oman

This study investigates the floristic composition and the ecological and biogeographical characteristics of macroalgal communities in three bays along the coastline of the southern province of Dhofar in the Sultanate of Oman. Dhofar is located in the north-western Arabian upwelling province. From June through September the south-west monsoon winds cause Ekman transport of surface waters away from the Arabian coastline. This brings cold nutrient-rich waters from deeper layers into the eufotic zone.At each study site nine 0.25 m2 quadrants were sampled, three in the intertidal zone, three at a depth of 5m and three at a depth of 10m. In the intertidal zone Ulva fasciata and Melanothamnus somalensis are the dominant species. At two of the study sites Nizamuddinia zanardinii and Sargassum oligocystum are the dominant species in the subtidal zone, at the third site Jania sp. and Codium duthieae are the most abundant.Multivariate analysis was carried out on the data collected in the present study and data from previous studies on the macroalgal assemblages of the Socotra Archipelago and Masirah Island (Schils & Coppejans, 2003). DCA at species level showed a strong gradient in floristic composition from upwelling sheltered sites (Gulf of Oman, west coast of Masirah, north coast of Socotra and seagrass beds of both Masirah Island and the Socotra Archipelago) to upwelling exposed sites (east coast of Masirah Island, south coast of Socotra and Dhofar). The bays of Dhofar clearly have high affinities with the other upwelling exposed sites, but nonetheless cluster analysis showed that they are very well separated from all the other study areas. This uniqueness is also illustrated by the large number of indicator species pointed out by the indicator species analysis, among which are many endemics and species with a disjunct distribution.Affinities with remote areas were assessed based on the data collected in this study and species inventories of 11 countries in the Indian Ocean. For all Arabian Sea locations the similarity with the tropical coasts of east Africa and Indonesia is much lower than the similarity with South Africa and Australia, where besides subtropical conditions also temperate conditions occur. The rbcL gene of a number of specimens of Codium and Portieria was sequenced in order to assess whether these specimens are related to morphologically similar Japanese specimens. This analysis has shown that the Japanese and Omani specimens of the supposedly disjunctly distributed species are not related

Annotated list of new records of marine macroalgae for Kenya and Tanzania, since Isaac's and Jaasund's publications

48 species of Rhodophyta, 10 species of Phaeophyta and 38 species of Chlorophyta, newly reported since Isaac's publications on seaweeds from Kenya and Jaasund's papers on macroalgae fiom Tanzania, are listed with bibliograpbic, taxonomic and biogeographic comments. Some of these species were previously published in more detailed taxonomic studies by this paper's authors