Plant-species richness and extinction on isolated dunes along the rocky coast of northwestern Spain

Abstract. Data on distribution and abundance of rare plant species on isolated coastal dunes along the rocky coast of northwestern Spain were compared with the local floristic literature in order to reconstruct past distribution and local extinction of species. Species extinction was not confined to species with a narrow distribution but also included widely distributed ones. Moreover, there was no evidence of colonization. Species number was related to beach and dune area, but species differed in the minimum area required for occurrence. The largest dune reserve possible would probably be insufficient to avoid further extinctions, so also small areas containing particular species should be preserved. There was no significant relationship between abundance of species in the local dune communities and their total distribution, and there were few satellite species. The former might be attributed to low fertility and habitat diversity.     

Conditioning of self-assembled monolayers at two static immersion test sites along the east coast of Florida and its effect on early fouling development

Among the first events after immersion of surfaces in the ocean is surface ‘conditioning’. Here, the accumulation and composition of the conditioning films formed after immersion in the ocean are analyzed. In order to account for different surface chemistries, five self-assembled monolayers that differ in resistance to microfouling and wettability were used. Water samples from two static immersion test sites along the east coast of Florida were collected at two different times of the year and used for experiments. Spectral ellipsometry revealed that conditioning films were formed within the first 24 h and contact angle goniometry showed that these films changed the wettability and rendered hydrophobic surfaces more hydrophilic and vice versa. Infrared reflection adsorption spectroscopy showed that the composition of the conditioning film depended on both the wettability and immersion site. Laboratory and field assays showed that the presence of a conditioning film did not markedly influence settlement of microorganisms.     

Siphonophore assemblages along the east coast of South Africa; mesoscale distribution and temporal variations

Using multivariate statistics we have examined spatio-temporalpatterns in the distribution of siphonophore assemblages alongthe east coast of South Africa, anticipating constancy in cross-shelfand alongshore structure that would mirror the hydrographicstability. Indeed, while the surface temperature of the AgulhasCurrent does vary on a seasonal basis, the position of its coreis thought to have a stable trajectory year round, and its otherphysical and chemical characteristics are considered to be relativelyaseasonal. Two clear aseasonal assemblages were observed, associatedeither with the nearshore waters in the extreme SW (Port Alfredupwelling cell), or with the Agulhas Current and inshore watersnorth of East London. Assemblages in the current-driven upwellingcell were characterized by low overall diversity and dense populationsof Muggiaea atlantica (up to 28 000 ind. 1000 m^–3). Assemblageselsewhere in the region were dominated by Abylopsis eschscholtzi,A. tetragona, Bassia bassensis, Chelophyes contorta, Diphyesdispar, D. bojani, Eudoxoides spiralis, E. mitra, Lensia subtiloidesand Sulculeolaria chuni. There is some evidence of both an alongshoreand a cross-shelf pattern in the distribution of assemblagesnorth of East London, but this is subordinate to a strongerseasonal signal. The impact of seasonality on regional assemblagesis hypothesized to be reflected in significant changes in theupstream structure of Agulhas Current assemblages.     

Pleuromeia from the lower triassic of the far east of the U.S.S.R.

Pleuromeia obrutschewii Elias from Russian Island (Russkiy Ostrov, near Vladivostok) is hardly distinguishable from the European P. sternbergii (Muenster) Corda. The sporangia are adaxial, filling spoon-like depressions of the megasporophylls which have sterile tips. P. olenekensis sp. nov. from the Olenek River (northeastern Siberia) has larger sporangia and much larger megaspores with three-layered walls. The outer layer (ectexosporium) is reticulate. It is assumed that in other species this layer is lacking due to imperfect preservation. Mature megasporophylls, when shed, have a buoy-like shape and are often deposited together with cephalopod shells. This suggests a special mechanism of propagation by means of megasporophylls dispersed by water currents. The cosmopolitan distribution of Pleuromeia points to weakened climatic zonation in the Early Triassic.     

Life history and habitat use of the speckled worm eel, Myrophis punctatus, along the east coast of the United States

Many species of fishes along the east coast of the United States have complex life histories, especially those that move over hundreds of kilometers across ocean and estuarine habitats. To further unravel the life history of one of these, the speckled worm eel, Myrophis punctatus we examined samples from extensive time series and discrete samples collected in the ocean and estuaries between Florida and Massachusetts. We now surmise spawning occurs between fall and early winter in the ocean south of Cape Hatteras, North Carolina and in the vicinity of the Bahamas. The pelagic leptocephalus larvae (10?C80 mm Total Length [TL]) are transported north in the Gulf Stream and across the continental shelf to arrive at estuarine inlets at ages of 53 ?C 110 days. Their estuarine immigration and abundance varies along the east coast, with higher levels occurring at inlets in South Carolina (North Inlet), and North Carolina (Beaufort Inlet), during the winter and early spring. Much lower abundances occur in New Jersey (Little Egg Inlet) in winter and spring and again in the summer. These ingressing individuals were euryodontic leptocephali and metamorphic stages and were shrinking to lengths of 76?C52 mm TL as these stages progressed. Metamorphic individuals and glass eels subsequently settle and burrow in estuarine sediments, as do all subsequent stages, and thereby become relatively unavailable to many sampling gears. In estuaries they attained sizes up to 440 mm TL. Later, they presumably enter the ocean to spawn because that is where the smallest larvae are found.     

Ecology,evolution and genetics join together on Canada's east coast

The 4th regular meeting of the Canadian Society of Ecology and Evolution was held in conjunction with the 52nd Annual Conference of the Genetics Society of Canada at Dalhousie University, Halifax, from 14 to 17 May 2009.     

Studies on several genetic hematological traits of the Mexican population. XVI. Hemoglobin, S and glucose-6-phosphate dehydrogenase deficiency in the east coast

The distribution of abnormal hemoglobins, glucose-6-phosphate dehydrogenase deficiency, blood group antigens A, B, M, N, C, c, D, E, e, V, Duffy and Diego, serum haptoglobins, transferrins and pseudocholinesterase types, were investigated in five villages of the East Coast of Mexico, where vivax malaria was endemic until recently. Hemoglobin S and G-6-PD deficiency were present in variable degrees in all five locations. All patients with the enzyme deficiency had the A band by electrophoresis, which coupled with the presence of hemoglobin C and haptoglobin 2-1 M in a few individuals strongly suggested Negro admixture. The high frequency of antigen V and the relatively low frequency of Fy (a +) were congruent with the above hypothesis and the conclusion was drawn that the presence of hemoglobin S and G-6-PD deficiency in this area is due to Negro admixture. Unusually high frequencies of the Diego antigen were observed in three of the five villages studied.     

Rift valley fever on the east coast of Madagascar

In March 1990, a Rift Valley fever virus (RVFV) outbreak was suspected in the district of Fenerive on the east coast of Madagascar after an abnormally high incidence of abortions and disease in livestock. Sera from humans and cattle were tested for RVFV antibodies by immunofluorescence assay (IFA) and ELISA-IgM capture. Sera and mosquitoes collected in the same area were tested for virus isolation by tissue culture and suckling mouse intracerebral inoculation, and for antigen detection by an ELISA antigen capture assay. Among cattle from the area, RVFV antibody prevalence was 58.6 % by IFA and 29.6 % by ELISA-IgM. In contrast, human populations in the same area had a lower RVFV antibody prevalence, with 8.01 % IFA and 5.4 % IgM-positive sera. No RVFV antigen was detected and virus isolation was unsuccessful from the sera and mosquito pools tested. Different hypotheses concerning the emergence and diffusion of RVFV in this area and the occurrence of the outbreak are discussed.     

Patterns in species richness,species density,and evenness in groundfish assemblages on the continental slope of the U.S. Pacific coast

For many taxa, diversity, often measured as species richness, decreases with latitude. In this report patterns of diversity (species richness, species diversity, and evenness) in groundfish assemblages were investigated in relation to depth (200–1200 m) and latitude (33–47°N) on the continental slope of the U.S. Pacific coast. The data originated from the 1999–2002 upper continental slope groundfish surveys conducted by the National Marine Fisheries Service. When the data were pooled across depths, species density and evenness were found to decline with latitude. All three diversity measures declined with depth, with the lowest overall diversity in the 600- to 900-m depth range where longspine thornyhead Sebastolobus altivelis constituted close to 70% of the catch. When latitudinal gradients were examined within four depth zones (200–300 m, 400–500 m, 600–900 m, and 1000–1200 m) more complex patterns emerged. At depth species richness and evenness were inversely correlated with latitude as longspine thornyhead dominated catches to the north. However, in shallower areas of the slope, species richness and evenness were positively correlated with latitude. Latitudinal patterns of diversity in the deeper zones and when pooled across depths were positively correlated with temperature and broadly consistent with the Ambient Energy hypothesis discussed by Willig et al. [Annu Rev Ecol System 34:273–309 (2003)].     

Northern range extension of the seagrasses Halophila johnsonii and Halophila decipiens along the east coast of Florida,USA

The northern geographic limit for Halophila johnsonii and Halophila decipiens has been reported as Sebastian Inlet, within the Indian River Lagoon, Florida. Surveys conducted in August 2007 determined the new northern limit to be 21.5 km north of the previously known limit. This new northern limit is a 10% range extension for H. johnsonii, a federally threatened species. We conclude that these range extensions are recent, based on (1) the small size of patches; (2) unusually good water clarity conditions due to a recent drought; (3) recent mild/warmer winters; and (4) a recent mechanism for transporting propagules, the numerous hurricanes of 2004. Although this recent range extension is considered ephemeral, similar range extensions may have occurred in the past and may occur again in the future under favorable conditions given the high capacity of these two species for dispersal to favorable sites. The northern limits of these species should not be viewed as static locations; rather, they must be considered dynamic features.     

Orientation of Phalerisida maculata Kulzer (Coleoptera, Tenebrionidae) in sandy beaches of the Chilean coast. Orientation of Phalerisida maculata in sandy beaches

The orientation stimuli of adult individuals of the beetle Phalerisida maculata Kulzer (Coleoptera, Tenebrionidae) over the beach surface, were studied at two sandy beaches of the chilean coast approximately 1300 km apart, Apolillado (ca. 29 degrees S) and Playa Universitaria de Mehuín (ca. 39 degrees S). Phalerisida maculata did not orient by astronomic cues such as the sun and moon, nor by the terrestrial magnetic field. Both populations showed positive scototaxis, and oriented downward on slopes with dry sediments, and upwards on slopes with wet sediments.     

Interactions between mycorrhizal colonization and plant life forms along the successional gradient of coastal sand dunes in the eastern Mediterranean, Turkey

The mycorrhizal status of dune plant species in relation to their plant life forms was surveyed along a successional gradient of sand dune on the southern Mediterranean coast of Turkey. Roots of 64 dune plant species belonging to 30 families were collected from sand dune communities at four different successional stages: embryonic dunes (ED), mobile dunes (MD), fixed dunes (FD), and remnant dunes (RD). Of the plant species surveyed in all successional stages, 54 (84%) had formed mycorrhizal associations. Nonmycorrhizal plants with cryptophyte life forms predominated in the earlier successional stages (ED and MD), whereas the number and percent coverage of mycorrhizal plant species belonging to hemicryptophytes, phanerophytes, and chamaephytes generally increased with the stabilization of sand dunes. Arbuscular mycorrhizal (AM) colonization was found to be the dominant mycorrhizal type in ED, MD, and RD. But phanerophytes with dual colonization, AM and ectomycorrhizal, became the dominant life form with high plant coverage in the FD stage. Total percentage of mycorrhizal root length colonization showed significant positive correlations relating to soil parameters such as organic matter and nitrogen content, while negatively correlating to high soil reaction (pH).     

Restoration of isolated and small coastal sand dunes on the rocky coast of northern Spain

The coastal dunes of the Basque Country have suffered a significant anthropic process of regional-scale destruction and fragmentation. This has led to the loss of seven, and endangerment of 14, of the 37 species of plants recognized as exclusive to these dunes. In response to this situation, the restoration of one of the lost dune systems, the Laida Dune, began in 2002 with the installation of sand trapping devices and the plantation of two dune-building species of plants. This study shows the results of a program that monitored the process of natural colonization of plant species in the restored dune over a period of seven years, until the loss of the dune by the action of storms in 2008. The results show that the vegetation dynamics in the restored dune followed a process of primary succession, with a progressive increase in species number, coverage and heterogeneity. The establishment of species was driven by the strong environmental gradient present perpendicular to the coastline. The results indicate that natural colonization in this coastal sector is now possible due to the large number of dune species present, and in spite of the isolation of the restored dune system and the loss and fragmentation of the dune habitats in the region. Over the seven years, 42 plant species became established on the dune, of which 18 were dune-exclusive species, representing 62.1% of the total number of species of the same type in the region. Five of these species are considered to be rare or threatened. Comparison with reference data allowed the evaluation of the trajectory of the plant community assembly. The results indicate that the highest similarity to a reference dune system was to the one located closest to the restored dune.     

Interannual variability of PSP outbreaks on the north east UK coast

Paralytic shellfish poisoning (PSP) occurs sporadically on theNB UK coast. The degree of toxicity shows considerable interannualvariability, but particularly severe events occurred in 1968and 1990. The time sequence of PSP toxin production in 1990is described and compared with 1989 when no significant PSPtoxin occurred. In 1990, PSP toxin was widespread in shellfishsamples taken on 300 km of coastline, from Berwick to Whitby,and toxin was present at high concentrations for >1 month.The distribution of Alerandrium tamarense cysts in the sedimentsis described. High concentrations were found in the Firth ofForth and also in a number of regions offshore of the Scottishand English coasts. A water transport model has been used toestimate back trajectories, with the aim of determining thesource of the A.tamarense bloom. The Firth of Forth has previouslybeen suggested as the seed bed for A.tamarense outbreaks inthe area, but the transport model clearly shows that A.tanwrensemoved inshore over a wide area in 1990; there was no singlesource of the bloom. Sea surface temperatures, estimated fromsatellite imagery, show that water temperatures were much higherat the end of April 1990, when the bloom occurred, than in 1989when PSP toxin incidence was very low. These conditions wouldhave resulted in early seasonal stratification and would havefavoured phytoplankton growth in the water column.