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Arthur Sands publishes article

Article Old lake versus young taxa: a comparative phylogeographic perspective on the evolution of Caspian Sea gastropods (Neritidae: Theodoxus)

Arthur F. Sands, Thomas A. Neubauer, Saeid Nasibi, Majid Fasihi Harandi, Vitaliy V. Anistratenko, Thomas Wilke and Christian Albrecht

Abstract

The Caspian Sea has been a highly dynamic environment throughout the Quaternary and witnessed major oscillations in lake level, which were associated with changes in salinity and habitat availability. Such environmental pressures are considered to drive strong phylogeographic structures in species by forcing populations into suitable refugia. However, little is actually known on the effect of lake-level fluctuations in the Caspian Sea on its aquatic biota. We compared the phylogeographic patterns of the aquatic Neritidae snail genus Theodoxus across the Pontocaspian region with refugial populations in southern Iran. Three gene fragments were used to determine relationships and divergence times between the sampled populations in both groups. A dated phylogeny and statistical haplotype networks were generated in conjunction with the analyses of molecular variance and calculations of isolation by distance using distance-based redundancy analyses. Extended Bayesian skyline plots were constructed to assess demographic history. Compared with the southern Iranian populations, we found little phylogeographic structure for the Pontocaspian Theodoxus group, with more recent diversification, homogeneity of haplotypes across the Pontocaspian region and a relatively stable demographic history since the Middle Pleistocene. Our results argue against a strong influence of Caspian Sea low stands on the population structure post the early Pleistocene, whereas high stands may have increased the dispersal possibilities and homogenization of haplotypes across the Pontocaspian region during this time. However, during the early Pleistocene, a more dramatic low stand in the Caspian Sea, around a million years ago, may have caused the reduction in Theodoxus diversity to a single lineage in the region. In addition, our results provide new insights into Theodoxus taxonomy and outlooks for regional conservation.

Sri Nandini, PRIDE ESR, publishes paper

Sri Nandini published this paper in 
 
Sri D. Nandini-Weiss, Matthias Prange, Klaus Arpe, Ute Merkel, Michael Schulz, International Journal of Climatology, 14 October 2019.
 
This is the doi for the paper:
 
or here:
 
Abstract
The Caspian Sea Level (CSL) has undergone variations of more than 3 m during the past century with important implications for the life of coastal people, economy and the ecosystem. The origin of these variations as well as future changes in the Caspian water budget are still a matter of debate. Here, the major modes of North Atlantic winter climate variability and atmospheric teleconnections that have a potential effect on the hydroclimate of the Caspian catchment region are examined. The skill of the Community Earth System Model (CESM1.2.2) regarding the simulation of the modern climatology in the Caspian region and the major North Atlantic modes are analysed using different atmospheric grid resolutions and setups of the atmospheric component, the Community Atmosphere Model (CAM4 and CAM5). CESM1.2.2 with CAM5 atmosphere physics and 1° atmospheric grid resolution shows reasonable skill in simulating the regional Caspian basin climatology and the winter North Atlantic Oscillation (NAO). Using this model version, a weakly positive (r=0.2) statistically significant (p<0.05) correlation between the catchment winter water budget (precipitation minus evaporation, P-E, integrated over the catchment area) and the NAO is found for the historical period 1850-2000. Climate projections of the 21st century under the Representative Concentration Pathways RCP4.5 and RCP8.5 show that the NAO remains the leading mode of winter variability with a dominant influence on the climate in the Caspian catchment region. Under the RCP4.5 scenario the correlation between the winter NAO and winter P-E over the Caspian catchment region increases (r=0.5, p<0.05). For RCP8.5, however, this correlation disappears due to a northsouth dipole pattern with a positive P-E anomaly over the northern and a negative anomaly over the southern parts of the Caspian catchment region, cancelling out an effect on the total Caspian water budget. Nevertheless, due to increasing annual evaporation over the Caspian Sea in the warming climate, the model predicts an additional CSL decrease of about 9 m and 18 m between 2020 and 2100 for the RCP4.5 and RCP8.5 scenarios, respectively. Even though the model tends to overestimate the total evaporation due to a too large Caspian Sea surface area, these values are larger than previous projections of CSL decline.
 
 

4 PRIDE ESRs (S. Lazarev, E.L. Jorissen, S. van de Velde, L. Rausch) published a new paper in Quaternary Science Reviews (2019)

This new PRIDE research of ESRs, supervisors and partners on Pontocaspian magneto-biostratigraphic age constraints can be found here:

Magneto-biostratigraphic age constraints on the palaeoenvironmental evolution of the South Caspian basin during the Early-Middle Pleistocene (Kura basin, Azerbaijan)
by Sergei Lazarev, Elisabeth L. Jorissen, Sabrina van de Velde, Lea Rausch, Marius Stoica, Frank  P. Wesselingh, Christiaan G. C. Van Baak, Tamara  A. Yanina, Elmira Aliyeva, Wout Krijgsman
doi: 10.1016/j.quascirev.2019.105895

HIGHLIGHTS
• Akchagylian flooding of the Caspian Basin with mesohaline fauna is dated around 2.7–2.6 Ma.
• Regression in the Caspian Sea from 2.2 to 2.1 Ma is associated with new Apsheronian mollusc groups.
• FO of Apsheronian indicative molluscs is within the Reunion subchron at an age of ∼2.13 Ma.
• Faunal indications of periodical reconnections between the Caspian Sea and the Black Sea in the Apsheronian.
• The Apsheronian – Bakunian boundary is dated at 0.83–0.85 Ma.

The article can be found here

Show more
 
The sedimentary record of the Caspian Basin is an exceptional archive for the palaeoenvironmental, palaeoclimatic and biodiversity changes of continental Eurasia. During the Pliocene-Pleistocene, the Caspian Basin was mostly isolated but experienced large lake level fluctuations and short episodes of connection with the open ocean as well as the Black Sea Basin. A series of turnover events shaped a faunal record that forms the backbone of the Caspian geological time scale. The precise ages of these events are still highly debated, mostly due to the lack of well-dated sections. Here, we provide an integrated magneto-biostratigraphic age model for two sections from the Kura Basin – Goychay and Hajigabul. Our results reveal several major intervals with elevated salinity, associated with mesohaline faunas, and propose the following age constraints: 1) The Productive Series-Akchagylian boundary is marked by a marine transgression from the open ocean that occurred around the Gauss-Matuyama reversal (∼2.7–2.6 Ma); 2) The Akchagylian-Apsheronian transition is characterized by a regression event and introduction of a new, “Pontocaspian” mollusc assemblage, dated within the Reunion subchron (∼2.13 Ma). The ostracod assemblages of the two sections do not show a major faunal turnover here; 3) The early Bakunian transgression occurs after the upper Apsheronian lowstand (0.85–0.83 Ma). We conclude that major transitions in the age-indicative mollusc groups sometimes occur at different time intervals (i.e. diachronic) and are highly depended on the local depositional environments. A high-resolution interdisciplinary approach on sections outside the Kura Basin is required to better understand the potential diachroneity of these turnover events in the entire Caspian Basin.
 
 

Our PRIDE ESR Liesbeth Jorissen has published a new first-author paper (2019)

This new open-access PRIDE research can be found in the journal of Sedimentology:

Amplitude, frequency and drivers of Caspian Sea lake‐level variations during the Early Pleistocene and their impact on a protected wave‐dominated coastline
by Elisabeth L. Jorissen,  Hemmo A. Abels,  Frank P. Wesselingh,  Sergei Lazarev,  Vusala Aghayeva &  Wout Krijgsman
https://doi-org.proxy.library.uu.nl/10.1111/sed.12658

ABSTRACT

The Caspian Sea, the largest isolated lake in the world, witnessed drastic lake‐level variations during the Quaternary. This restricted basin appears very sensitive to lake‐level variations, due to important variations in regional evaporation, precipitation and runoff. The amplitude, frequency and drivers of these lake‐level changes are still poorly documented and understood. Studying geological records of the Caspian Sea might be the key to better comprehend the complexity of these oscillations. The Hajigabul section documents sediment deposited on the northern margin of the Kura Basin, a former embayment of the Caspian Sea. The 2035 m thick, well‐exposed section was previously dated by magneto‐biostratigraphic techniques and provides an excellent record of Early Pleistocene environmental, lake‐level and climate changes. Within this succession, the 1050 m thick Apsheronian regional stage, between ca 2·1 Ma and 0·85 Ma, represents a particular time interval with 20 regressive sequences documented by sedimentary and palaeontological changes. Sequences are regressing from offshore to coastal, lagoonal or terrestrial settings and are bounded by abrupt flooding events. Sediment reveals a low energy, wave‐dominated, reflective beach system. Wave baselines delimiting each facies association appear to be located at shallower bathymetries compared to the open ocean. Water depth estimations of the wave baselines allow reconstruction of a lake‐level curve, recording oscillations of ca 40 m amplitude. Cyclostratigraphic analyses display lake‐level frequency close to 41 kyr, pointing to allogenic forcing, dominated by obliquity cycles and suggesting a direct or indirect link with high‐latitude climates and environments. This study provides a detailed lake‐level curve for the Early Pleistocene Caspian Sea and constitutes a first step towards a better comprehension of the magnitude, occurrence and forcing mechanisms of Caspian Sea lake‐level changes. Facies models developed in this study regarding sedimentary architectures of palaeocoastlines affected by repeated lake‐level fluctuations may form good analogues for other (semi‐)isolated basins worldwide.

The open-access article can be found here

Our ESR Lea Rausch has published new PRIDE research on ostracod fauna from lake deposits of the Homo Erectus-bearing Kocabaş locality (2019)

This new open-access PRIDE research can be found in the journal Acta Palaeontologica Romaniae:

An Early Pleistocene anomalohaline water ostracod fauna from lake deposits of the Homo Erectus-bearing Kocabaş locality (SW Turkey)
by Lea Rausch & Marius Stoica
Acta Palaeontologica Romaniae (2019)

https://doi.org/10.35463/j.apr.2019.02.04 

ABSTRACT

The early Pleistocene travertines from the Denizli Basin in SW Anatolia, from which the only known Homo erectus finding from Turkey was recovered, are unconformably overlain by a 20 m thick succession of alkaline lake deposits that bear a rich ostracod fauna. The ostracod assemblage consists of a mixture of freshwater and mesohaline tolerant taxa. The following sixteen species have been identified: Candona neglecta, C. ex. gr. candida, Cypria sp., Darwinulina stevensovi, Lineocypris sp., Prinocypris zenkeri, Cyrpideis torosa, C. sp., Tyrrhencythere pontica, T. ex. gr. bailovi, T. sp. 1, T. sp. 2, Amnicythere pediformis, A. mutlituberculata, Loxoconchissa (Loxocaspia) aff. reticulata, L. (L.) aff. reticulata var. rugosa. The conditions inside the lake were interpreted from the encountered assemblage, suggesting a restricted anomalohaline shallow water environment with a salinity no greater than lower mesohaline. The age of the studied succession was previously constrained by cosmogenic nuclide concentration, palaeomagnetic measurements and large mammal biostratigraphy which suggest deposition occurred between ~ 1.6 and 1.1 Ma

The open-access article can be found here

Sri Nandini defended her doctoral thesis

We are very happy to announce that Sri Nandini defended her doctoral thesis at the Univ. of Bremen on 10 Sept 2019. The title of the thesis is Hydroclimate variations in the Caspian Sea region in the late Quarternary to the Future. Congratulations, Sri!!!

Here you will find some pictures.

 

 

 

 

 

Our ESR Justine Vandendorpe has published new PRIDE research results (2019)

This new open-access PRIDE research can be found in the journal Ecology and Evolution:

Historical faunal exchange between the Pontocaspian Basin and North America
by Justine Vandendorpe, Christiaan G. C. van Baak, Björn Stelbrink, Diana Delicado, Christian Albrecht and Thomas Wilke
Ecology and Evolution (2019)
https://doi.org/10.1002/ece3.5602

ABSTRACT

Ecrobia is a genus of small brackish‐water mud snails with an amphi‐Atlantic distribution. Interestingly, the species occurring in the northwestern Atlantic, Ecrobia truncata, is more closely related to the Pontocaspian taxa, Ecrobia grimmi and Ecrobia maritima, than to the species occurring in the northeastern Atlantic and Mediterranean Sea. At least three colonization scenarios may account for this peculiar biogeographical pattern: (1) a recent human‐mediated dispersal, (2) a historical transatlantic interchange, and (3) a historical transpolar interchange. To test these three scenarios, we used five operational criteria—time of species divergence, first appearance in the fossil record, dispersal limitation as well as environmental filtering and biotic interactions along the potential migration routes. Specifically, we inferred a time‐calibrated molecular phylogeny for Ecrobia and reconstructed a paleogeographical map of the Arctic Ocean at 2.5 million years ago (Mya). Based on the five operational criteria, scenarios 1 and 2 can likely be rejected. In contrast, all criteria support scenario 3 (historical transpolar interchange). It is therefore suggested that a bird‐mediated and/or ocean current‐mediated faunal interchange via the Arctic Ocean occurred during the Late Pliocene or Early Pleistocene. This dispersal was likely facilitated by reduced distances between the Eurasian and North American/Greenland landmasses, marine introgressions, and/or a stepping‐stone system of brackish‐water habitats in northern Siberia, as well as a lack of competition along the migration route. As for the direction of dispersal, the scientific data presented are not conclusive. However, there is clearly more support for the scenario of dispersal from the Pontocaspian Basin to North America than vice versa. This is the first study providing evidence for a natural faunal exchange between the Pontocaspian Basin and North America via the Arctic Ocean.

The open-access article can be found here

PRIDE ESR Alexandre Gogaladze first author paper

This new open-access PRIDE research on Pontocaspian social networks can be found in the journal of bioRxiv

Social network analysis and the implications for Pontocaspian biodiversity conservation in Romania and Ukraine: A comparative study
by Aleksandre Gogaladze, Niels Raes, Koos Biesmeijer, Camelia Ionescu, Bianca Pavel, Mikhail O. Son, Natalia Gozak, Vitaliy Anistratenko and Frank P. Wesselingh
doi: https://doi.org/10.1101/740084

ABSTRACTRomania and Ukraine share the Black Sea coastline, the Danube Delta and associated habitats, which harbor the unique Pontocaspian biodiversity. Pontocaspian biota represents endemic aquatic taxa adapted to the brackish (anomalohaline) conditions, which evolved in the Caspian and Black Sea basins. Currently, this biota is diminishing both in the numbers of species and their abundance because of human activities. Consequently, its future persistence strongly depends on the adequacy of conservation measures. Romania and Ukraine have a common responsibility to effectively address the conservation of this biota. The socio-political and legal conservation frameworks, however, differ in the two countries - Romania is a member of the European Union (EU), thus complying with the EU environmental policy, whereas Ukraine is an EU-associated country. This may result in differences in the social network structure of stakeholder institutions with different implications for Pontocaspian biodiversity conservation. Here, we study the structure and implications of the social network of stakeholder organizations involved in conservation of Pontocaspian biodiversity in Romania, and compare it to Ukraine. We apply a mix of qualitative and quantitative social network analysis methods to combine the content and context of the interactions with relational measures. We show that the social networks of stakeholder organizations in Romania and Ukraine are very different. Structurally, in Romanian network there is a room for improvement through e.g. more involvement of governmental and non-governmental organizations and increased motivation of central stakeholders to initiate conservation action, whereas Ukrainian network is close to optimal. Regardless, both networks translate into sub-optimal conservation action and the road to optimal conservation is different. We end with sketching implications and recommendations for improved national and cross-border conservation efforts.

The open-access article can be found here

ESRs Elisabeth Jorissen and Sergei Lazarev published new PRIDE research

And again another PRIDE research article has been published! In the journal of Sedimentology you can now find the original manuscript of Elisabeth L. Jorissen, Sergei Lazarev and other PRIDE co-authors:

Amplitude, frequency and drivers of Caspian Sea lake‐level variations during the Early Pleistocene and their impact on a protected wave‐dominated coastline
by Elisabeth Jorissen, Hemmo Abels, Frank Wesselingh, Sergei Lazarev, Vusala Aghayeva and Wout Krijgsman
doi: 10.1111/sed.12658

ABSTRACTThe Caspian Sea, the largest isolated lake in the world, witnessed drastic lake‐level variations during the Quaternary. This restricted basin appears very sensitive to lake‐level variations, due to important variations in regional evaporation, precipitation and runoff. The amplitude, frequency and drivers of these lake‐level changes are still poorly documented and understood. Studying geological records of the Caspian Sea might be the key to better apprehend the complexity of these oscillations. The Hajigabul section documents sediment deposited on the northern margin of the Kura Basin, a former embayment of the Caspian Sea. The 2035 m thick, well‐exposed section was previously dated by magneto‐biostratigraphic techniques and provides an excellent record of Early Pleistocene environmental, lake‐level and climate changes. Within this succession, the 1050 m thick Apsheronian regional stage, between ca 2.1 and 0.85 Ma, represents a particular time interval with 20 regressive sequences documented by sedimentary and palaeontological changes. Sequences are regressing from offshore to coastal, lagoonal or terrestrial settings and are bounded by abrupt flooding events. Sediment reveals a low energy, wave‐dominated, reflective beach system. Wave baselines delimiting each facies association appear to be located at shallower bathymetries compared to the open ocean. Water depth estimations of the wave baselines allow reconstruction of a lake‐level curve, recording oscillations of ca 40 m amplitude. Cyclostratigraphic analyses display lake‐level frequency close to 41 kyr, pointing to allogenic forcing, dominated by obliquity cycles and suggesting a direct or indirect link with high‐latitude climates and environments. This study provides a detailed lake‐level curve for the Early Pleistocene Caspian Sea and constitutes a first step towards a better comprehension of the magnitude, occurrence and forcing mechanisms of Caspian Sea lake‐level changes. Facies models developed in this study regarding sedimentary architectures of palaeocoastlines affected by repeated lake‐level fluctuations may form good analogues for other (semi‐)isolated basins worldwide.

The open-access article can soon be found here

ESRs Sabrina van de Velde and Elisabeth L. Jorissen pusblished a new article in Biogeosciences (2019)

A new PRIDE article has been published! In open-access interactive journal Biogeosciences you can now find the article of Sabrina van de Velde and Elisabeth L. Jorissen and many PRIDE co-authors:

A conservation palaeobiological approach to assess faunal response of threatened biota under natural and anthropogenic environmental change
by Sabrina van de Velde, Elisabeth L. Jorissen, Thomas A. Neubauer, Silviu Radan, Ana Bianca Pavel, Marius Stoica, Christiaan G. C. Van Baak, Alberto Martínez Gándara, Luis Popa, Henko de Stigter, Hemmo A. Abels, Wout Krijgsman, and Frank P. Wesselingh
Biogeosciences, 16, 2423–2442 (2019)
https://doi.org/10.5194/bg-16-2423-2019

ABSTRACT
Palaeoecological records are required to test ecological hypotheses necessary for conservation strategies as short-term observations can insufficiently capture natural variability and identify drivers of biotic change. Here, we demonstrate the importance of an integrated conservation palaeobiology approach when making validated decisions for conservation and mitigating action. Our model system is the Razim–Sinoie lake complex (RSL) in the Danube Delta (Black Sea coast, Romania), a dynamic coastal lake system hosting unique Pontocaspian mollusc species that are now severely under threat. The Pontocaspians refer to an endemic species group that evolved in the Black Sea and Caspian Sea basins under reduced salinity settings over the past few million years. The natural, pre-industrial RSL contained a salinity gradient from fresh to mesohaline (18 ppm) until human intervention reduced the inflow of mesohaline Black Sea water into the lake system. We reconstruct the evolution of the RSL over the past 2000 years from integrated sedimentary facies and faunal analyses based on 11 age-dated sediment cores and investigate the response of mollusc species and communities to those past environmental changes. Three species associations (“marine”, “Pontocaspian” and “freshwater”) exist and their spatio-temporal shifts through the system are documented. Variable salinity gradients developed, with marine settings (and faunas) dominating in the southern part of the system and freshwater conditions (and faunas) in the northern and western parts. Pontocaspian species have mostly occurred in the centre of the RSL within the marine–freshwater salinity gradient. Today, freshwater species dominate the entire system, and only a single Pontocaspian species (Monodacna colorata) is found alive. We show that the human-induced reduced marine influence in the system has been a major driver of the decline of the endemic Pontocaspian biota. It urges improved conservation action by re-establishing a salinity gradient in the lake system to preserve these unique species.

The open-access article can be found here

Article published by ESRs Arthur F. Sands and Sergei Lazarev et al (2019)

We are happy to let you know that a new PRIDE article has been published in the Journal of Biogeography:

Contributions of biogeographical functions to species accumulation may change over time in refugial regions
by Arthur F. Sands, Sergej V. Sereda, Björn Stelbrink, Thomas A. Neubauer, Sergei Lazarev, Thomas Wilke and Christian Albrecht
Journal of Biogeography 46:1274–1286 (2019)
https://doi.org/10.1111/jbi.13590

Aim
Elevated biodiversity is the result of the cradle, museum or sink functions. The contributions of these three functions to species accumulation and their changes through time remain unknown for glacial refugia. Additionally, our understanding of the role these functions played during pre‐glacial periods is limited. We test for changes in contributions of functions through time leading to the current diversity patterns using a model refugium and taxon.

Location
Anatolia, Western Palaearctic.

Taxon
Freshwater neritid snails (genus Theodoxus).

The open-access article can be found here

New publication by ESRs Sabrina van de Velde et al (2019)

We are happy to let you know that a new PRIDE article has been published in the Journal of Great Lakes Research:

The Late Pleistocene mollusk fauna of Selitrennoye (Astrakhan province, Russia): A natural baseline for endemic Caspian Sea faunas
by Sabrina van de Velde, Tamara A.Yanin, Thomas A.Neubauer and Frank P. Wesselingh
 J. Great Lakes Res. 1–13, 2019
https://doi.org/10.1016/j.jglr.2019.04.001

ABSTRACT:

The native Caspian Sea fauna underwent severe changes since the early 20th century, mostly due to anthropogenic activities. However, the nature, magnitude and rate of biodiversity change can only be assessed by comparison with natural baseline settings. A mostly in-situ mollusk fauna retrieved from Late Pleistocene (Hyrcanian, 107 ± 7 ka) deposits at Selitrennoye (Astrakhan province, Russia) provides a snapshot of a natural Caspian assemblage. In total, 24 gastropod and 13 bivalve species were identified. The fauna is predominantly endemic/native (94% in species numbers and 99% in abundance) and is dominated by three families (Cardiidae, Dreissenidae and Hydrobiidae). The Selitrennoye assemblage is a natural baseline of a pre-invasive Caspian Sea fauna living in a shallow (15–25 m), lower mesohaline (5–8 psu) open lake environment. The species-rich Selitrennoye fauna contrasts with the largely depleted and invasive-dominated fauna that currently occupies similar habitats in the Caspian Sea and underlines the magnitude of the current biodiversity crisis.

Keywords
Pontocaspian; Biodiversity; Turnover; Extinction; Quaternary; Mollusca

The open-access article can be found here

New PRIDE research published by ESRs Thomas M. Hoyle & Manuel Sala-Pérez et al (2019)

We are happy to let you know that a new PRIDE article has been published in the Journal of Micropalaeontology:

Where should we draw the lines between dinocyst “species”? Morphological continua in Black Sea dinocysts
by Thomas M. Hoyle, Manuel Sala-Pérez, and Francesca Sangiorgi
J. Micropalaeontol., 38, 55–65, 2019
https://doi.org/10.5194/jm-38-55-2019

ABSTRACT:

The morphology of dinoflagellate cysts (dinocysts) is related not only to the genetics of the motile dinoflagellate from which it derives, but is also dependent on a range of environmental factors including salinity, temperature and nutrient status. Although this knowledge improves our understanding of the drivers behind dinocyst morphological variations, it makes the taxonomy governing their description somewhat complex. In basins such as the Black Sea, where environmental change can be extreme and occurs on relatively short (millennial) timescales, taxonomy becomes particularly challenging. Morphological continua can be observed between described forms, displaying a large range of intermediate phenotypes that do not necessarily correspond to any genetic difference. As these morphological nuances may preserve information about palaeoenvironments, it is important to find a systematic method of characterising morphotypes. Here, we show a dinocyst matrix within which dinocysts are described according to their similarity to (or difference from) described forms based on key descriptive parameters. In the example set out here, cyst shape and degree of process and/or ectophragm development are taken as two key parameters in Pyxidinopsis psilata and Spiniferites cruciformis, and can allow the description of intermediate forms even though the definitions do not overlap.

We review some frequently occurring morphotypes and propose that using matrices to show the gradual variation between endmember forms is the most pragmatic approach until cyst–theca studies and genetic sequencing can be used to demonstrate relationships between genotypes and morphotypes. As prior studies propose salinity to be a primary driver of intraspecific variability, the endmembers presented may represent salinity extremes within an overall brackish environment. Although we cannot assign each morphotype to a value or a range of an environmental parameter (e.g. salinity) as the different morphotypes can occur in the same sample, using this matrix allows preservation of information about morphological variability without creating taxonomic categories that are likely to require alteration if genetic evidence becomes available.

The open-access article can be found here

PRIDE article published by ESR Matteo Lattuada et al (2019)

We are pleased to let you know that a new article about PRIDE research has been published in Marine Pollution Bulletin:

Differential impact of anthropogenic pressures on Caspian Sea ecoregions
by Matteo Lattuada, Christian Albrecht and Thomas Wilke

ABSTRACT:

Over the past decades, overall ecological conditions in the Caspian Sea have deteriorated. However, a comprehensive understanding of lake-wide spatial differences in anthropogenic pressures is lacking and the biological consequences of human impacts are poorly understood. This paper therefore aims at assessing the individual and combined effects of critical anthropogenic pressures on the Caspian Sea ecoregions. First, cumulative pressure scores were calculated with a cumulative environmental assessment (CEA) analysis. Then, the individual contribution of anthropogenic pressures was quantified. Finally, ecoregion-specific differences were assessed. The analyses show that both cumulative and individual pressure scores are unevenly distributed across the Caspian Sea. The most important individual pressures are invasive species, chemical pollution and poaching. This uneven distribution of pressure scores across Caspian Sea ecoregions creates new challenges for future conservation strategies, as different ecoregions usually require different conservation measures.

The open-access article can be found here.

Mollusc species from the Pontocaspian region – an expert opinion list

Mollusc species from the Pontocaspian region – an expert opinion list

 
expand article infoFrank P. Wesselingh, Thomas A. Neubauer, Vitaliy V. Anistratenko, Maxim V. Vinarski, Tamara Yanina, Jan Johan ter Poorten, Pavel Kijashko, Christian Albrecht, Olga Yu. Anistratenko, Anouk D’Hont, Pavel Frolov, Alberto Martínez Gándara, Arjan Gittenberger, Aleksandre Gogaladze, Mikhail Karpinsky, Matteo Lattuada, Luis Popa, Arthur F. Sands, Sabrina van de Velde, Justine Vandendorpe, Thomas Wilke
 
https://doi.org/10.3897/zookeys.827.31365

Abstract

Defining and recording the loss of species diversity is a daunting task, especially if identities of species under threat are not fully resolved. An example is the Pontocaspian biota. The mostly endemic invertebrate faunas that evolved in the Black Sea – Caspian Sea – Aral Sea region and live under variable salinity conditions are undergoing strong change, yet within several groups species boundaries are not well established. Collection efforts in the past decade have failed to produce living material of various species groups whose taxonomic status is unclear. This lack of data precludes an integrated taxonomic assessment to clarify species identities and estimate species richness of Pontocaspian biota combining morphological, ecological, genetic, and distribution data. In this paper, we present an expert-working list of Pontocaspian and invasive mollusc species associated to Pontocaspian habitats. This list is based on published and unpublished data on morphology, ecology, anatomy, and molecular biology. It allows us to (1) document Pontocaspian mollusc species, (2) make species richness estimates, and (3) identify and discuss taxonomic uncertainties. The endemic Pontocaspian mollusc species richness is estimated between 55 and 99 species, but there are several groups that may harbour cryptic species. Even though the conservation status of most of the species is not assessed or data deficient, our observations point to deterioration for many of the Pontocaspian species.

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