Morphological and molecular characterization and phylogenetic relationships of a new species of trypanosome in Tapirus terrestris (lowland tapir), Trypanosoma terrestris sp nov., from Atlantic Rainforest of southeastern Brazil

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Height-diameter relationships of tropical Atlantic moist forest trees in southeastern Brazil

Site-specific height-diameter models may be used to improve biomass estimates for forest inventories where only diameter at breast height (DBH) measurements are available. In this study, we fit height-diameter models for vegetation types of a tropical Atlantic forest using field measurements of height across plots along an altitudinal gradient. To fit height-diameter models, we sampled trees by DBH class and measured tree height within 13 one-hectare permanent plots established at four altitude classes. To select the best model we tested the performance of 11 height-diameter models using the Akaike Information Criterion (AIC). The Weibull and Chapman-Richards height-diameter models performed better than other models, and regional site-specific models performed better than the general model. In addition, there is a slight variation of height-diameter relationships across the altitudinal gradient and an extensive difference in the stature between the Atlantic and Amazon forests. The results showed the effect of altitude on tree height estimates and emphasize the need for altitude-specific models that produce more accurate results than a general model that encompasses all altitudes. To improve biomass estimation, the development of regional height-diameter models that estimate tree height using a subset of randomly sampled trees presents an approach to supplement surveys where only diameter has been measured.

Evolution and historical biogeography of the Eastern Atlantic skates

In my thesis, I tested the hypothesis that the diversification of the Eastern Atlantic skate faunas arose through vicariance rather than dispersal, using combined approach of molecular phylogeny reconstruction and zoogeography (namely historical biogeography). This analyses have been carried out independently on four Rajidae genera belonging to two different tribes: Rajini (Raja and Dipturus) and Amblyrajini (Rajella and Leucoraja). These taxa were selected because they displayed high species diversity and richness of endemic species in the Eastern Atlantic and Mediterranean. The verification of this hypothesis was carried out by reconstructing the best phylogenetic relationships among four genera and 26 species (including several endemism) based on mtDNA and nuDNA gene variation and several statistical approaches. Divergence times of taxa have been estimated based on molecular clock and fossil calibration to explain evolutionary patterns in the context of geological framework. Main issues are (i) the evidence that Eastern Atlantic skate evolution and displacement of species diversity occurred from pulsed geographical speciation (i.e. repeated series of parallel and independent speciation events) started in the Late Eocene-Early Miocene and they have occurred prevalently during Miocene; (ii) such relatively ancient origin of diversification has been allowed the sympatric displacement and evolution of several congeneric taxa likely because they have accumulated huge differences in the genomic and physiological/behavioural phenotypic traits; (iii) recently diverged sister species and taxa showed allopatric or parapatric evolution by the presence of oceanographic or hydrogeographical barriers which likely prevent large mixing between parapatric sister species.

Genetic characterisation and global comparison of ancient Mediterranean Great White Sharks population (Carcharodon carcharias, L.1758)

This study poses as its objective the genetic characterization of the ancient population of the Great White shark, Carcharodon carcharias, L.1758, present in the Mediterranean Sea. Using historical evidence, for the most part buccal arches but also whole, stuffed examples from various national museums, research institutes and private collections, a dataset of 18 examples coming from the Mediterranean Sea has been created, in order to increase the informations regarding this species in the Mediterranean. The importance of the Mediterranean provenance derives from the fact that a genetic characterization of this species' population does not exist, and this creates gaps in the knowledge of this species in the Mediterranean. The genetic characterization of the individuals will initially take place by the extraction of the ancient DNA and the analysis of the variations in the sequence markers of the mitochondrial DNA. This approach has allowed the genetic comparison between ancient populations of the Mediterranean and contemporary populations of the same geographical area. In addition, the genetic characterization of the population of white sharks of the Mediterranean, has allowed a genetic comparison with populations from global "hot spots", using published sequences in online databases (NCBI, GenBank). Analyzing the variability of the dataset, both in terms space and time, I assessed the evolutionary relationships of the Mediterranean population of Great Whites with the global populations (Australia/New Zealand, South Africa, Pacific USA, West Atlantic), and the temporal trend of the Mediterranean population variability. This method based on the sequencing of two portions of mitochondrial DNA genes, markers showed us how the population of Great White Sharks in the Mediterranean, is genetically more similar to the populations of the Australia Pacific ocean, American Pacific Ocean, rather than the population of South Africa, and showing also how the population of South Africa is abnormally distant from all other clusters. Interestingly, these results are inconsistent with the results from tagging of this species. In addition, there is evidence of differences between the ancient population of the Mediterranean with the modern one. This differentiation between the ancient and modern population of white shark can be the result of events impacting on this species occurred over the last two centuries.

First assessment on genetic structure and phylogeography of Mediterranean blue shark (prionace glauca, L. 1758) population using mitochondrial gene variation: a comparison with the Atlantic.

The blue shark, Prionace glauca, is one of the most vagile shark species worldwide distributed. The particular body shape allows blue sharks make transoceanic movements, leading to a circumglobal distribution. Due to its reproductive cycle, an extraordinarily high number of specimens is globally registered but, even if it is still a major bycatch of longline fishery rather than a commercial target, it is characterized by a high vulnerability. In this perspective it is important to increase the amount of informations regarding its population extent in the different worldwide areas, evaluating the possible phylogeographic patterns between different locations. This study, included in the "MedBlueSGen" European project, aims exactly at filling a gap in knowledges regarding the genetic population structure of the Mediterranean blue sharks, which has never been investigated before, with a comparison with the North-Eastern Atlantic blue shark population. To reach this objective, we used a dataset of samples from different Mediterranean areas implementing it with some samples from North-Eastern Atlantic. Analyzing the variability of the two mitochondrial markers control region and cytochrome b, with the design of new species-specific primer pairs, we assessed the mitochondrial genetic structure of Mediterranean and North-Eastern Atlantic samples, focusing on the analysis of their possible connectivity, and we tried to reconstruct their demographic history and population size. Data analyses highlighted the absence of a genetic structuring within the Mediterranean and among it and North-Eastern Atlantic, suggesting that the Strait of Gibraltar doesn't represent a phylogeographic barrier. These results are coherent to what has been found in similar investigations on other worldwide blue shark populations. Analysis of the historical demographic trend revealed a general stable pattern for the cytochrome-b and a slightly population expansion for the control region marker.

The importance of ship log data: reconstructing North Atlantic, European and Mediterranean sea level pressure fields back to 1750

Local to regional climate anomalies are to a large extent determined by the state of the atmospheric circulation. The knowledge of large-scale sea level pressure (SLP) variations in former times is therefore crucial when addressing past climate changes across Europe and the Mediterranean. However, currently available SLP reconstructions lack data from the ocean, particularly in the pre-1850 period. Here we present a new statistically-derived 5° × 5° resolved gridded seasonal SLP dataset covering the eastern North Atlantic, Europe and the Mediterranean area (40°W–50°E; 20°N–70°N) back to 1750 using terrestrial instrumental pressure series and marine wind information from ship logbooks. For the period 1750–1850, the new SLP reconstruction provides a more accurate representation of the strength of the winter westerlies as well as the location and variability of the Azores High than currently available multiproxy pressure field reconstructions. These findings strongly support the potential of ship logbooks as an important source to determine past circulation variations especially for the pre-1850 period. This new dataset can be further used for dynamical studies relating large-scale atmospheric circulation to temperature and precipitation variability over the Mediterranean and Eurasia, for the comparison with outputs from GCMs as well as for detection and attribution studies.

(Table 2) Observations of anticyclonic lenses of Mediterranean water in the Central North Atlantic

Analyses of spatial structure of hydrophysical fields and its vertical evolution in the Northeast Atlantic in a layer from the surface down to 2-2.5 km are carried out based on results of measurements in a testing area (31°-36°N, 20°-26°W) southeast of the Azores in autumn 1993. A description of an anti-cyclonic lens (ACL) of Mediterranean water (MW), which was found in the eastern part of the testing area from data of sets of sequential surveys, is presented. Analysis of CTD and XBT measurements in an area west of the lens allows to conclude that despite some contraction of width of the Azores Current directed eastward (from 60-80 km to 50-60 km) its total eastward volume transport for a period of time from October to November does not vary much. It is shown that intermediate salinity maxima in the northern part of the testing area formed by advection of MW and meddy destruction weakens while intersecting the Azores frontal zone (AFZ) from north to south, displacing itself to larger depth, and increases in thickness. Analysis of data shows that the number of lenses observed within the selected area north of the AFZ is two times more than that observed south of it. North of the AFZ observed salinity maximum and local temperature maxima may be associated with accumulation of heat and salt because of the fact that the AFZ is not only a southern boundary of penetration of MW into the North Atlantic, but also is a "semitransparent" boundary for Mediterranean lenses.

(Table 3) Observations of Mediterranean water lenses in the Eastern North Atlantic

Spreading pattern and mesoscale structure of Mediterranean water outflow in the eastern North Atlantic are studied on the basis of historical hydrographical records. Effect of bottom topography on Mediterranean water distribution is revealed. It is shown that the Mediterranean water outflow is divided into two streams after leaving the Gulf of Cadiz. These are northwestern and southwestern ones; the former is more intensive and spreads in more regular and continuous way. West of the Tejo (Tagus) Plateau it splits into three branches; the most intense of them keeps continuity up to 14°W. The less intensive southwestern stream passes south of the Gettysburg Bank and splits into two branches immediately after the Gulf of Cadiz. From 11°W, this stream has lenticular, intermittent character. West of 14°-15°W all Mediterranean water branches are represented mainly by isolated salty patches. As a result of historical data analysis in the 32°-44°N, 8°-22°W area, 30 Mediterranean water lenses have been found; 12 of them had not been previously mentioned in publications. A table of main parameters of Mediterranean water lenses is presented. It includes data of 108 observations from 1911 to 1993.

Abundance of microzooplankton in surface waters of the East Atlantic and Mediterranean in August-September 1970

Abundance of microzooplankton was studied from August to October 1970 in a ship laboratory using the method of concentration of water samples by filtration and then counting living organisms under a microscope. The main groups (in order of decreasing abundance) were as follows: infusorians, nauplii, copepodids, radiolarians, appendicularians, and some others (rotifers, worm and mollusk larvae). Concentration of infusorians rarely exceeded 100 #/l, possibly an underestimate. Nauplii often numbered 20 to 30 #/l. Study of vertical distribution of microzooplankton showed that peak concentrations in the Mediterranean Sea were at depth of 20-30 m regardless of day time. There were 2 peaks in the Atlantic Ocean, one in the 10- to 20-m layer, the other in the 50- to 75-m layer.

Oxygen and hydrogen isotopes measured in the Northeast Atlantic

Only a few studies have examined the variation of oxygen and hydrogen isotopes of seawater in NE Atlantic water masses, and data are especially sparse for intermediate and deep-water masses. The current study greatly expands this record with 527 d18O values from 47 stations located throughout the mid- to low-latitude NE Atlantic. In addition, dD was analyzed in the 192 samples collected along the GEOTRACES North Atlantic Transect GA03 (GA03_e=KN199-4) and the 115 Iberia-Forams cruise samples from the western and southern Iberian margin. An intercomparison study between the two stable isotope measurement techniques (cavity ring-down laser spectroscopy and magnetic-sector isotope ratio mass spectrometry) used to analyze GA03_e samples reveals relatively good agreement for both hydrogen and oxygen isotope ratios. The surface (0-100 m) and central (100-500 m) water isotope data show the typical, evaporation related trend of increasing values equatorward with the exception for the zonal transect off Cape Blanc, NW Africa. Off Cape Blanc, surface water isotope signatures are modified by the upwelling of fresher Antarctic Intermediate Water (AAIW) that generally has isotopic values of 0.0 to 0.5 per mil for d18O and 0 to 2 per mil for dD. Along the Iberian margin the Mediterranean Outflow Water (MOW) is clearly distinguished by its high d18O (0.5-1.1 per mil) and dD (3-6 per mil) values that can be traced into the open Atlantic. Isotopic values in the NE Atlantic Deep Water (NEADW) are relatively low (d18O: -0.1 to 0.5 per mil; dD: -1 to 4 per mil) and show a broader range than observed previously in the northern and southern convection areas. The NEADW is best observed at GA03_e Stations 5 and 7 in the central NE Atlantic basin. Antarctic Bottom Water isotope values are relatively high indicating modification of the original Antarctic source water along the flow path. The reconstructed d18O-salinity relationship for the complete data set has a slope of 0.51, i.e., slightly steeper than the 0.46 described previously by Pierre et al. (1994, J. Mar. Syst. 5 (2), 159-170.) for the tropical to subtropical Northeast Atlantic. This slope decreases to 0.46 for the subtropical North Atlantic Central Water (NACW) and the MOW and to 0.32 for the surface waters of the upper 50 m. The dD-salinity mixing lines have estimated slopes of 3.01 for the complete data, 1.26 for the MOW, 3.47 for the NACW, and 2.63 for the surface waters. The slopes of the d18O-dD relationship are significantly lower than the one for the Global Meteoric Water Line with 5.6 for the complete data set, 2.30 for the MOW, 4.79 for the NACW, and 3.99 for the surface waters. The lower slopes in all the relationships clearly reflect the impact of the evaporation surplus in the subtropics.

Mercury concentrations in waters of the Atlantic Ocean and Mediterranean Sea

Total mercury concentration in waters of the Atlantic Ocean and Mediterranean Sea measured in January-April 1982 varied from 0.007 to 0.192 µg/l. Particulate form was 1.6-16% of dissolved form. Inorganic mercury accounted for 16-67% of dissolved mercury. Total mercury concentration in the surface film was 0.74-1.85 µg/l, 10-40 times higher than in seawater. Concentration of particulate form in the film was from 100 to 400 times higher than in seawater.