Coral mortality increases wave energy reaching shores protected by reef flats: Examples from the Seychelles

In the granitic Seychelles, many shores and beaches are fringed by coral reef flats which provide protection to shores from erosion by waves. The surfaces of these reef flats support a complex ecology. About 10 years ago their seaward zones were extensively covered by a rich coral growth, which reached approximately to mean low water level, but in 1998 this was largely killed by seawater warming. The resulting large expanses of dead coral skeletons in these locations are now disintegrating, and much of the subsequent modest recovery by new coral recruitment was set back by further mortalities. A mathematical model of wave energy reaching shorelines protected by coral reef flats has been applied to 14 Seychelles reefs. It is derived from equations which predict: (1) the raised water level, or wave set-up, on reef flats resulting from wave breaking, which depends upon offshore wave height and period, depth of still water over the reef flat and the reef crest profile, and (2) the decay of energy from reef edge to shoreline that is affected by width of reef flat, surface roughness, sea level rise and 'pseudo-sea level rise' created by increased depth resulting from disintegration of coral colonies. The model treats each reef as one entity, but because biota and zonation on reef flats are not homogenous, all reefs are divided into four zones. In each, cover by both living and dead biota was estimated for calculation of parameters, and then averaged to obtain input data for the model. All possible biological factors were taken into account, such as the ability of seagrass beds to grow upwards to match expected sea level rise, reduction in height of the reef flat in relation to sea level as zones of dead corals decay, and the observed 'rounding' of reef crests as erosion removes corals from those areas. Estimates were also made of all these factors for a time approximately a decade ago, representing a time before the mass coral mortality, and for approximately a decade in the future when the observed rapid state of dead coral colony disintegration is assumed to have reached an end point. Results of increased energy over the past decade explain observations of erosion in some sites in the Seychelles. Most importantly, it is estimated that the rise in energy reaching shores protected by fringing reefs will now accelerate more rapidly, such that the increase expected over the next decade will be approximately double than that seen over the past decade. (c) 2005 Elsevier Ltd. All rights reserved.

Palynostratigraphy of Ordovician strata, Canning Basin, Western Australia. Part Two: chitinozoans and biostratigraphy

This second and concluding part of a comprehensive palynological study of the Lower to Middle Ordovician succession of the central-northeastern Canning Basin completes the systematic documentation of the palynomorphs, i.e., chitinozoans, and formulates a palynostratigraphic zonation scheme embracing all three constituent formations of this investigation, viz., the Willara, Goldwyer, and Nita formations. A total of 21 species of chitinozoans (five genera), detailed systematically herein, are identified. Although chitinozoan recovery per sample proved variable, the following species occur fairly persistently in the productive samples: Belonechitina micracantha, Conochitina subcylindrica, C. poumoti, C. langei, Calpichitina windjana, and Rhabdochitina magna. Five, stratigraphically successive acritarch/prasinophyte assemblage zones, ranging in age from early Arenig through late Llanvirn, are proposed as follows (ascending order): Athabascaella rossii Assemblage Zone (corresponding to the lower Willara Formation; and dated as early-mid Arenig); Comasphaeridium setaricum Assemblage Zone (upper Willara and lowermost Goldwyer; late Arenig-earliest Llanvirn); Sacculidium aduncum Assemblage Zone (lower Goldwyer; early Llanvirn); Aremorica-nium solaris Assemblage Zone (middle and lower upper Goldwyer; mid Llanvirn); and Dactylofusa striatogranulata Assemblage Zone (upper Goldwyer and lower Nita; late Llanvirn). Four chitinozoan assemblage zones, stratigraphically coinciding (within the limits of sampling) with the acritarch/prasinophyte zones, comprise (in ascending order): Lagenochitina combazi Assemblage Zone (equivalent to the A. rossii and L. heterorhabda Assemblage Zones); Conochitina langei Assemblage Zone; Conocbitina subcylindrica Assemblage Zone; and Belonecbitina micracantha Assemblage Zone. Chronostratigraphic assignments are based principally on associated conodont and graptolite faunas. Whereas the acritarch/prasinophyte zones bear scant similarities to those established globally elsewhere, the chitinozoan zones show significant affiliations with those known from Laurentia.

Studio Integrato Geomorfologico-Geofisico dell'Area Epicentrale del Terremoto del 20 Maggio 2012 (Mw 5.9) in Emilia-Romagna

La Sequenza Sismica Emiliana del 2012 ha colpito la zona compresa tra Mirandola e Ferrara con notevoli manifestazioni cosismiche e post-sismiche secondarie, soprattutto legate al fenomeno della liquefazione delle sabbie e alla formazione di fratturazioni superficiali del terreno. A fronte del fatto che la deformazione principale, osservata tramite tecniche di remote-sensing, ha permesso di individuare la posizione della struttura generatrice, ci si è interrogati sul rapporto tra strutture profonde e manifestazioni secondarie superficiali. In questa tesi è stato svolto un lavoro di integrazione di dati a varia scala, dalla superficie al sottosuolo, fino profondità di alcuni chilometri, per analizzare il legame tra le strutture geologiche che hanno generato il sisma e gli effetti superficiali percepiti dagli osservatori. Questo, non solo in riferimento allo specifico del sisma emiliano del 2012, ma al fine di trarre utili informazioni in una prospettiva storica e geologica sugli effetti di un terremoto “tipico”, in una regione dove le strutture generatrici non affiorano in superficie. Gli elementi analizzati comprendono nuove acquisizioni e rielaborazioni di dati pregressi, e includono cartografie geomorfologiche, telerilevamenti, profili sismici a riflessione superficiale e profonda, stratigrafie e informazioni sulla caratterizzazione dell’area rispetto al rischio sismico. Parte dei dati di nuova acquisizione è il risultato dello sviluppo e la sperimentazione di metodologie innovative di prospezione sismica in corsi e specchi d’acqua continentali, che sono state utilizzate con successo lungo il Cavo Napoleonico, un canale artificiale che taglia ortogonalmente la zona di massima deformazione del sisma del 20 Maggio. Lo sviluppo della nuova metodologia di indagine geofisica, applicata ad un caso concreto, ha permesso di migliorare le tecniche di imaging del sottosuolo, oltre a segnalare nuove evidenze co-sismiche che rimanevano nascoste sotto le acque del canale, e a fornire elementi utili alla stratigrafia del terreno. Il confronto tra dati geofisici e dati geomorfologici ha permesso di cartografare con maggiore dettaglio i corpi e le forme sedimentarie superficiali legati alla divagazione fluviale dall’VIII sec a.C.. I dati geofisici, superficiali e profondi, hanno evidenziato il legame tra le strutture sismogeniche e le manifestazioni superficiali seguite al sisma emiliano. L’integrazione dei dati disponibili, sia nuovi che da letteratura, ha evidenziato il rapporto tra strutture profonde e sedimentazione, e ha permesso di calcolare i tassi geologici di sollevamento della struttura generatrice del sisma del 20 Maggio. I risultati di questo lavoro hanno implicazioni in vari ambiti, tra i quali la valutazione del rischio sismico e la microzonazione sismica, basata su una caratterizzazione geomorfologico-geologico-geofisica dettagliata dei primi 20 metri al di sotto della superficie topografica. Il sisma emiliano del 2012 ha infatti permesso di riconoscere l’importanza del substrato per lo sviluppo di fenomeni co- e post-sismici secondari, in un territorio fortemente eterogeneo come la Pianura Padana.

When do conservation planning methods deliver? Quantifying the consequences of uncertainty

The rapid global loss of biodiversity has led to a proliferation of systematic conservation planning methods. In spite of their utility and mathematical sophistication, these methods only provide approximate solutions to real-world problems where there is uncertainty and temporal change. The consequences of errors in these solutions are seldom characterized or addressed. We propose a conceptual structure for exploring the consequences of input uncertainty and oversimpli?ed approximations to real-world processes for any conservation planning tool or strategy. We then present a computational framework based on this structure to quantitatively model species representation and persistence outcomes across a range of uncertainties. These include factors such as land costs, landscape structure, species composition and distribution, and temporal changes in habitat. We demonstrate the utility of the framework using several reserve selection methods including simple rules of thumb and more sophisticated tools such as Marxan and Zonation. We present new results showing how outcomes can be strongly affected by variation in problem characteristics that are seldom compared across multiple studies. These characteristics include number of species prioritized, distribution of species richness and rarity, and uncertainties in the amount and quality of habitat patches. We also demonstrate how the framework allows comparisons between conservation planning strategies and their response to error under a range of conditions. Using the approach presented here will improve conservation outcomes and resource allocation by making it easier to predict and quantify the consequences of many different uncertainties and assumptions simultaneously. Our results show that without more rigorously generalizable results, it is very dif?cult to predict the amount of error in any conservation plan. These results imply the need for standard practice to include evaluating the effects of multiple real-world complications on the behavior of any conservation planning method.

Late Caledonian magmagenesis in Southern Scotland

The Priestlaw and Cockburn Law intrusions are zoned granitoid plutons intruded into Lower Palaeozoic sediments at the margin of, and prior to closure of, the Iapetus Ocean. They vary from marginal basic rocks to more acid rocks towards their centres. The parental magmas to the plutons were derived from an isotopically depleted mantle modified by melts/fluids during subduction. Zonation in the plutons was caused by combined assimilation and fractional crystallisation (AFC), and rates of assimilation were low relative to rates of fractionation. A series of pyroxene-mica diorites in Priestlaw are however hybrids formed by simple mixing. Porphyrite-acid porphyrite dykes, associated with the plutons, represent chilled portions of the pluton magmas; more evolved quartz porphyry dykes represent crustal melts. Lamprophyre dykes have high LILE and LREE abundances and relative depletions of HFS elements, typical of subduction related ultra-potassic magmas. High Mg numbers, Ni and Cr contents and experimental constraints, imply near primary status for the least evolved lamprophyres. Their enrichments in incompatible elements, high La/Nb, La/Yb, Sr and low Nd indicate derivation from a previously metasomatised mantle source. Granitoid plutons and lavas in the northern Southern Uplands have high Nd and low Sr, whereas the younger plutons of the southern Southern Uplands have higher Sr, La/Yb and lower Nd, consistent with derivation from a more enriched source. No plutons however have remained as closed systems. Three magmatic suites are present in southern Scotland: (1) Midland Valley Suite (2) Northern Southern Uplands Suite and (3) Southern Southern Uplands Suite, consistent with previous models indicating northward underthrusting of English lithosphere below the southern Southern Uplands. Further underthrusting of decoupled lithospheric mantle is indicated by the presence of lamorophyres in the eastern Southern Uplands, and took place between 410 Ma and 400 Ma.

The diagenesis and palaeomagnetism of permian and triassic sediments from central Spain

Detailed diagenetic and palaeomagnetic studies have been made of Permian and Triassic rocks from the Iberian Cordillera, Spain. Five stratigraphical units comprising the Autunian, Saxonian, Buntsandstein, Muschelkalk, and Keuper have been studied in a number of sections which have been well documented sedimentologically. Autuninan rocks have a characteristic remanence which is exclusively reversed and corresponds to the Kiaman Interval. The pole position identified is consistent with previous studies, which indicate the rotation of Iberia in post-Triassic times. The Saxonian facies show complex multicomponent magnetizations; no polarity zonation can be resolved. The Buntsandstein is remarkable in that much of it is remagnetised in a direction similar to the present-day local geomagnetic field direction. The secondary remanence is carried by fine-grained haematite which has been formed as a result of carbonate dissolution associated with structural inversion of the Iberian Cordillera. Dating of diagenetic events associated with this remagnetization is also possible. Fragments of primary remanence are preserved in some fine-grained lithologies of the Buntsandstein. These indicate that normal and reversed zones of magnetization were originally present. The magnetization of the Muschelkalk and Keuper carbonates is also complex; secondary components similar to those of the Buntsandstein are present but there is evidence that primary components were predominantly normal during Karnian times.

Topographic studies of scalp potentials evoked by pattern presentation

The waveform and scalp distribution of the visual evoked potentials elicited by stimuli in the foveal and parafoveal regions have been investigated in a group of normal humans using a 16-channel `brain mapping' system. The waveform and topography of the responses to pattern onset and pattern reversal stimulation were investigated, using 4 x 4o full field and 4 x 2o lateral and altitudinal half-field stimuli. The responses were composed of several successive peaks which are in some respects consistent with those demonstrated by other workers using larger field sizes. The differences in the behaviour of these components with respect to the position of the stimulus in the visual field were suggestive of origins in different areas of the visual cortex and/or different visual mechanism. Of particular interest were the major early positive components `P90' and `P95' of the responses to pattern onset and pattern reversal stimulation respectively. More detailed exploration of the behaviour of these major early positive components was carried out using `M-scaled' stimuli selected to activate one square centimetre patches of striate cortex and associated extrastriate re-projections, positioned at different points in the foveal and parafoveal area of the visual field. The inter- and intra-subject variability in amplitude and localisation of the signals elicited by these targets was considered to be a reflection of the individual variations in relationship of visual field projections with the pattern of gyri and fissures on the proximal surface of the occipital lobe. The behaviour of component P90 of the onset response is consistent with a lateral origin in extrastriate visual cortex; that of P95 of the pattern reversal response is consistent in some respects with a striate cortical origin, but in others with a partial origin in extrastriate cortex.

Modeling the Impacts of Climate Change on Phytogeographical Units. A Case Study of the Moesz Line

Regional climate models (RCMs) provide reliable climatic predictions for the next 90 years with high horizontal and temporal resolution. In the 21st century northward latitudinal and upward altitudinal shift of the distribution of plant species and phytogeographical units is expected. It is discussed how the modeling of phytogeographical unit can be reduced to modeling plant distributions. Predicted shift of the Moesz line is studied as case study (with three different modeling approaches) using 36 parameters of REMO regional climate data-set, ArcGIS geographic information software, and periods of 1961-1990 (reference period), 2011-2040, and 2041-2070. The disadvantages of this relatively simple climate envelope modeling (CEM) approach are then discussed and several ways of model improvement are suggested. Some statistical and artificial intelligence (AI) methods (logistic regression, cluster analysis and other clustering methods, decision tree, evolutionary algorithm, artificial neural network) are able to provide development of the model. Among them artificial neural networks (ANN) seems to be the most suitable algorithm for this purpose, which provides a black box method for distribution modeling.

The effect of climate change on the potential distribution of the European Phlebotomus species and the parasite Leishmania infantum in 2011-2070. A climate envelope modeling approach

Aims: In the Mediterranean areas of Europe, leishmanisasis is one of the most emerging vector-borne diseases. Members of genus Phlebotomus are the primary vectors of the genus Leishmania. To track the human health effect of climate change it is a very important interdisciplinary question to study whether the climatic requirements and geographical distribution of the vectors of human pathogen organisms correlate with each other. Our study intended to explore the potential effects of ongoing climate change, in particular through a potential upward altitudinal and latitudinal shift of the distribution of the parasite Leishmania infantum, its vectors Phlebotomus ariasi, P. neglectus, P. perfiliewi, P. perniciosus, and P. tobbi, and some other sandfly species: P. papatasi, P. sergenti, and P. similis. Methods: By using a climate envelope modelling (CEM) method we modelled the current and future (2011-2070) potential distribution of 8 European sandfly species and L. infantum based on the current distribution using the REMO regional climate model. Results: We found that by the end of the 2060’s most parts of Western Europe can be colonized by sandfly species, mostly by P. ariasi and P. pernicosus. P. ariasi showed the greatest potential northward expansion. For all the studied vectors of L. infantum the entire Mediterranean Basin and South-Eastern Europe seemed to be suitable. L. infantum can affect the Eastern Mediterranean, without notable northward expansion. Our model resulted 1 to 2 months prolongation of the potentially active period of P. neglectus P. papatasi and P. perniciosus for the 2060’s in Southern Hungary. Conclusion: Our findings confirm the concerns that leishmanisais can become a real hazard for the major part of the European population to the end of the 21th century and the Carpathian Basin is a particularly vulnerable area.

The L-31E Surface Water Rediversion Project Final Report: Implementation, Results, and Recommendations

Throughout the Biscayne Bay watershed, existing coastal wetland communities have been cut off from sheet flow for decades. With the expectation that reconnection of these wetlands to upstream water sources would alter existing hydrologic conditions and recreate a more natural sheet flow to Biscayne National Park, a demonstration project on freshwater rediversion was undertaken. The objectives of the project were to document the effects of freshwater diversion on: (a) swamp and nearshore water chemistry and hydrology; (b) soil development processes; (c) macrophyte and benthic algal community composition, structure and production; (d) abundance of epiphytic and epibenthic invertebrates; (e) zonation, production, and phenology of primary producers in the nearshore environment, and (f) exchanges of nutrients and particulates between nearshore and mangrove ecosystems.

Data compilation on the biological response to ocean acidification: environmental and experimental context of data sets and related literature

The exponential growth of studies on the biological response to ocean acidification over the last few decades has generated a large amount of data. To facilitate data comparison, a data compilation hosted at the data publisher PANGAEA was initiated in 2008 and is updated on a regular basis (doi:10.1594/PANGAEA.149999). By January 2015, a total of 581 data sets (over 4 000 000 data points) from 539 papers had been archived. Here we present the developments of this data compilation five years since its first description by Nisumaa et al. (2010). Most of study sites from which data archived are still in the Northern Hemisphere and the number of archived data from studies from the Southern Hemisphere and polar oceans are still relatively low. Data from 60 studies that investigated the response of a mix of organisms or natural communities were all added after 2010, indicating a welcomed shift from the study of individual organisms to communities and ecosystems. The initial imbalance of considerably more data archived on calcification and primary production than on other processes has improved. There is also a clear tendency towards more data archived from multifactorial studies after 2010. For easier and more effective access to ocean acidification data, the ocean acidification community is strongly encouraged to contribute to the data archiving effort, and help develop standard vocabularies describing the variables and define best practices for archiving ocean acidification data.

Caracterização da comunidade bentônica do recife raso de Pirangi/RN, Brasil, e avaliação do seu processo de estruturação sob impacto de pisoteio

Despite being areas of socioeconomic and ecological importance, the reef environments in northeastern Brazil have been suffering with cluttered tourism impacts, such as trampling, activity that leads to decrease in abundance of organisms, especially benthic, and loss of biodiversity. The objectives of this study were 1) to characterize the benthic community in the shallow sandstone reef of Pirangi/RN, identifying patterns of zonation, and 2) evaluate its process of structuring under different degrees of impact of trampling, providing information to the proper use of the area. Data on abundance of organisms, the percentage coverage of the substrate and physic-chemical parameters were collected. The formation of two zones on the reef was observed: one that considers submerged areas and ones with shorter time of exposure, lower roughness and higher heterogeneity in the coverage of the substrate, with a predominance of sand, foliose algae, rodolit, being related to organisms such as gastropods, crabs and sea-urchin; the second zone comprises areas with longer time of exposure, greater roughness and predominance of bedrock uncovered, being associated with organisms such as barnacles, gastropods, bivalves and crabs. It is concluded that the studied reef presents its own zonation pattern, influenced by both the time of immersion and the substrate characteristics, such as roughness and type of coverage. To answer the second objective of this study, four experimental blocks were mounted on each of the three areas of different intensities of trampling, containing the following treatments: control (isolated from trampling), shaved isolated, trampling and shaved trampling, with data collection by 11 months. The data in abundance, diversity indices and living coverage of the substrate were compared between areas and treatments. The results showed that at the trampling areas, at the end of the experiment, differences were observed between the intensities of the impact, where higher values of abundance and richness of mobile fauna and richness of live coverage (ANOVA, p <0.05) were found in the area of higher trampling intensity. For fauna withdrawal of trampled scraped treatments, it was observed in the area of greatest impact that the abundance of small benthic invertebrates is more than three times smaller than that at the area of intermediate trampling (ANOVA, p <0.05). Initial isolated areas and final ones differed only as to the percentage of live coverage, with an increase of 35% at the end of this experiment. As for the areas that were completely scraped and isolated at the end of the experiment was observed an increase in the percentage of live coverage of 11.11% compared to the initial amount in the area of intermediate impact and 37.5% in the area with greater impact, indicating recovery of the area. It is suggested that the current use of the reef of Pirangi be reviewed, with a decentralization of trampling, or a decrease in visits, so that it does not occur at high intensities

Relative abundance of planktonic foraminifera in Pliocene and Pleistocene sediments of DSDP Hole 32-310 from Hess Rise, Central North Pacific (Table II)

Late Neogene planktonic foraminifera have been examined at Site 310 in the Central North Pacific and their stratigraphic ranges and frequencies are presented here. Blow's (1969) zonation developed for tropical regions has been applied where applicable. Where tropical index taxa are rare or absent in this temperate region, Globorotalia crassaformis, and the evolutionary bioseries G. conoidea - G. conomiozea and G. puncticulata - G. inflata have been found useful for zonal subdivisions. A correlation between stratigraphic ranges and frequency distributions of these species at Site 310 in the Central North Pacific, and Site 284 in the Southwest Pacific indicates that these species are relatively consistent biostratigraphic markers in temperate regions of both the North and South Pacific Oceans. An informal zonation for temperate latitudes of the Southwest Pacific has been established by Kennett (1973) and a similar zonal subdivision can be made at Site 310. Paleoclimatic/paleoceanographic interpretations based on coiling ratios, percent abundance, and phenotypic variations of Neogloboquadrina pachyderma indicate four major cold events during early, middle, and late Pliocene, and early Pleistocene. Faunal correlations of these events with similar events elsewhere in the Northeast and Southwest Pacific which have been paleomagnetically dated indicate the following approximate ages for these cold events: 4.7 Ma, 3.0 Ma, 2.6-1.8 Ma, and 1.2 Ma. Faunal assemblages have been divided into three groups representing cool, intermediate, and warmer water assemblages. Cool water assemblages are dominated by ~60% N. pachyderma; intermediate temperature faunas are dominated by species of Globigerina and Globigerinita and contain between 20% and 30% N. pachyderma. Warmer water assemblages are dominated by species of Globorotalia and contain <10% N. pachyderma. Frequency oscillations within these groups, in addition to paleotemperature parameters evident in N. pachyderma, afford refined paleoclimatic/paleoceanographic interpretations.

Distribution of planktonic foraminifera in DSDP Hole 31-296 (Table III)

Late Neogene planktonic foraminiferal biostratigraphy of DSDP Site 296, Leg 31, reveals this site as an ideal reference section for correlation of Blow's low-latitude zonation with the mid-latitude zonation for temperate faunal assemblages developed in this paper and earlier for DSDP Site 310, Leg 31 (Keller). Abundance of temperate species of Globorotalia (G. inflata, G. puncticulata, G. crassaformis, G. conomiozea) permit correlation with the zonal subdivision developed at Site 310 based on these species. Evolutionary changes within the Globorotalia inflata group also appear to be consistent biostratigraphie markers in mid latitudes; a primitive variety of this species first appears at about 3.3-3.1 Ma, G. inflata praeinflata appears at about 2.6 Ma, and the modern form appears at about 2.2-2.1 Ma. Quantitative analyses of planktonic foraminifera at DSDP Site 296 reveal an inversely reciprocal frequency oscillation between species of Globorotalia and the Globigerina-Globigerinita group. Cool climatic periods are characterized by high frequencies in the Globigerina-Globigerinita group and low frequencies in the Globorotalia group, whereas warm intervals are marked by high frequencies in the Globorotalia group and low frequencies in the Globigerina-Globigerinita group. Five cool paleoclimatic events can be recognized between early Pliocene and late Pleistocene: 4.4 Ma, 3.2-3.1 Ma, 2.4-2.2 Ma, 1.2 Ma, and 0.7 Ma. These paleoclimatic/paleoceanographic events have also been recognized in planktonic foraminifera of the Central and Northeast Pacific DSDP Sites 310 and 173 and also correlate to cold events recognized in oxygen isotope measurements of DSDP Site 310 and in equatorial Pacific cores.

Fresh biomass of macroalgae collected at Hansneset, Kongsfjorden, Spitsbergen in 1996/1998

We surveyed macroalgae at Hansneset, Blomstrand in Kongsfjorden, Svalbard, down to 30 m depth between 1996 and 1998. In total, 62 species were identified: 16 Chlorophyta, 25 Phaeophyceae, and 21 Rhodophyta. The majority of species (53.5%) belonged to the Arctic cold-temperate group, followed in frequency by species distributed from the Arctic to the warm-temperate region (25.9%). Four endemic Arctic species (Laminaria solidungula, Acrosiphonia flagellata, A. incurva, and Urospora elongata) were found. Two species (Pogotrichum filiforme and Mikrosyphar polysiphoniae) were new to Svalbard. Chlorophyta, Phaeophyceae, and Rhodophyta extended from the eulittoral zone down to 11, 21, and >30 m depths with maximum biomasses at 1-5 m, 5-10 m, and 5-30 m depths, respectively. Annual and pseudoperennial species had highest biomasses in the upper 5 m, while perennials were distributed deeper. The highest biomass (8600 g/m**2 wet weight) at 5 m depth comprised mainly L. digitata, Saccorhiza dermatodea, Alaria esculenta, and Saccharina latissima. The biogeographic composition of macroalgae at Hansneset was rather similar to that of northeastern Greenland, but different from that of northern Norway, which has a higher proportion of temperate species. Climate warming and ship traffic may extend some of the distribution ranges of macroalgae from mainland Norway to Svalbard.