A fish-based assessment tool for the ecological quality of the brackish Schelde estuary in Flanders (Belgium)

This paper presents a new approach which was developed to find an optimal combination of candidate metrics for creating a fish-based estuarine biotic index (EBI) for defining the quality status of an estuarine area. The key idea was that a powerful index should minimise two prediction errors simultaneously: falsely declaring the status of a site as disturbed while it is not (Type I error) and the reverse, falsely declaring a disturbed site as undisturbed (Type II error). The balance between both errors is an inherent characteristic of an index and can be displayed as a curve. The area under this curve (AUC) is a measure of the misclassification rate (smaller = better). This criterion was the basis for a stepwise approach whereby in each step a metric resulting in the highest reduction of AUC was added. Five metrics were selected and the distribution of their average was the basis to derive the thresholds for the classes of the EBI. This paper presents the fish-based index (EBI) for the brackish Schelde estuary in Flanders (Belgium). The index was calibrated against fyke net data from five sites during the period from 1995 to 2004. The sites ranged in quality from moderately impacted to very disturbed, classes 3 to 5 respectively. Despite there being neither of the highest classes 1 (high) and 2 (good), the EBI presented can serve as an evaluation tool in the highly impacted situation in Flanders as it discriminates well between moderate and highly impacted sites. In addition, its definition complies with the biological status classes of the European Water Framework Directive (WFD). Handling Editor: K. Martens     

Influence of changes in salinity and light intensity on growth of phytoplankton communities from the Schelde river and estuary (Belgium/The Netherlands)

In the Schelde continuum, a succession in the phytoplankton community is observed along the transition from the river to the freshwater tidal reaches of the estuary and from the freshwater to brackish reaches of the estuary. The goal of this study was to experimentally evaluate the contribution of changes in salinity and light climate to this succession. In summer 2000 and in spring 2001, phytoplankton communities from the river, the freshwater tidal reaches and the brackish reaches of the estuary were incubated under high or low light intensities and exposed to a change in salinity. HPLC analysis was used to evaluate the response of different algal groups to changes in light intensity and salinity. When incubated at a light intensity corresponding to the mean underwater light intensity of the freshwater tidal reaches, growth of phytoplankton from the river as well as from freshwater tidal reaches was significantly lower than when incubated at a light intensity corresponding to the mean underwater light intensity of the river. The phytoplankton community from the freshwater tidal reaches did not appear to be better adapted to low light intensities than the phytoplankton community from the river. Although diatoms were expected to be less sensitive to a reduction in light intensity than green algae, the opposite response was observed. Freshwater and brackish water phytoplankton were negatively affected by respectively an increase or decrease in salinity. However, the effect of salinity was not strong enough to explain the disappearance of freshwater and brackish water phytoplankton between a salinity of 0.5 and 10 psu, suggesting that other factors also play a role. In the freshwater phytoplankton communities from the river and the freshwater tidal reaches, green algae and diatoms responded in a similar way to an increase in salinity. In the brackish water phytoplankton community, fucoxanthin displayed a different response to salinity than lutein and chlorophyll a.     

The first known chamopsiid lizard (Squamata) from the Upper Cretaceous of Europe (Csehbánya Formation; Hungary,Bakony Mts)

The Upper Cretaceous (Santonian) Iharkút terrestrial vertebrate locality, in Hungary, has yielded several lacertilian taxa since its discovery in 2000. One of these is represented by a left mandible fragment and two dentary fragments. The characters observed on these remains support assignment to the family Chamopsiidae (Scincomorpha). Moreover, the remains belong to a new genus and species, Pelsochamops infrequens n. g. n. sp. Pelsochamops is the first known occurrence of chamopsiids outside North America and adds another scincomorphan lizard to the Iharkút fauna. It represents an additional evidence for dispersal routes between North America and Europe.     

The ecology of The Netherlands wetlands: characteristics,threats, prospects and perspectives for ecological research

Wetlands are among the worlds' most important, but also most threatened, environmental resources. Wetland losses have been in progress particularly from the industrial revolution onwards, because wetland functions could not successfully compete for space with other land uses. Wetlands became recently foci of conservation efforts because of the increased awareness of their importance in water management and wildlife conservation, and because of the diversity of their habitats. The Netherlands are relatively rich in wetlands: 16% of its' territory is regarded as internationally important wetland and 7% has been registered as such. The major Dutch wetland types are: coastal ecosystems, large riverine systems, base-rich freshwater systems, and nutrient-poor freshwater systems. Most threats to the Dutch wetlands are of man-made origin. They comprise: (1) Changes in hydrology leading to changed discharges, currents and desiccation; (2) Acidification; (3) Eutrophication; and (4) Toxification. Long-term threats are largely climate-change related, and concern temperature rise and the UV-B increase in irradiation. General conservation goals also apply to wetlands but Ramsar-registered wetlands have a special status. Conservation of the Dutch wetlands is difficult, because of the high population density of the country and its inherent threats. However, ecological targets and standards are increasingly set in national Policy Plans and international agreements. Rehabilitation and creation of wetlands is presently widely advocated, and sometimes realised. For ecological research, the sustainability of wetlands should get top priority. Such a research programme would focus on understanding the underlying ecological processes in natural and man-dominated wetland systems to prescribe conservation, rehabilitation and management strategies that would enhance the sustainability of these systems. Within this framework special attention should be directed to studies (1) At the ecosystem level of ecosystem parameters, of which natural oscillations and trends in time, and on which the impact of disturbances are quantified. Particularly these studies, in which often simulation models are used as tools for interpretation, can provide the basis for extrapolations in space and time; (2) On adaptation capacity and mechanisms of (groups of) species to extreme environmental conditions; (3) On (mutual) relationships between plants, animals and microorganisms (e.g. competition, grazing and mineralization); (4) On dispersion between small wetlands. For the contemporary quantitative assessment of the long-term effects of climate changes, the effects of temperature rise and increase in UV-B irradiation on individual species, communities and ecosystems should also be studied.     

Sinopaninae and Arfianinae (Hyaenodontida,Mammalia) from the Early Eocene of Europe and Asia; evidence for dispersal in Laurasia around the Paleocene/Eocene boundary and for an unnoticed faunal turnover in Europe

Hyaenodontida are represented in Europe by three subfamilies: Proviverrinae, Arfianinae and Sinopaninae. Here, we review all the specimens of Arfianinae and Sinopaninae known to date in Europe and Asia. A new Galecyon species is erected: Galecyon gallus nov. sp. We discuss the taxonomic position of the two Asian hyaenodontidans Anthracoxyaena palustris and Arfia langebadreae; the genus Anthracoxyaena is synonymized with Arfia. The analysis of the European and Asian arfianines and sinopanines provides new data concerning the dispersals and faunal events that occurred during the Early Eocene in Laurasia. The Arfianinae and Sinopaninae appeared in Europe around the Paleocene/Eocene boundary (reference-level MP7). The sinopanines are widespread in Europe; they are known in Dormaal (Belgium, reference-locality of the level MP7), Rians, Soissons, Pourcy, Try, Le Quesnoy (France), and Abbey Wood (England). The analysis of the paleogeographic distribution of all Oxyaenodonta and Hyaenodontida at and after the MP7 supports the existence of two European provinces: the North Province and Mesogean Province. We show that the Arfianinae and Sinopaninae rapidly disappeared from Europe; they are unknown in Avenay (reference-locality of the level MP8+9) and younger localities. Their disappearance from Europe is synchronous with that of the Oxyaenodonta. These observations support the existence of a faunal turnover, which occurred between the reference-levels MP7 (Dormaal) and MP8+9 (Avenay). The hypothesis of a dispersal from Europe to North America during the Paleocene-Eocene transition for the Arfianinae and Sinopaninae is supported. Moreover, the study of Arfianinae supports a dispersal from Europe to Asia around the P/E boundary, followed by a short period of endemic evolution. However, our study does not support a close relationship between Arfia and the “Arfia-like South Asian Proviverrinae” (Kyawdawia, Indohyaenodon, Paratritemnodon and Yarshea).     

International,interdisciplinary research in ecology: Some problems of organization and execution. The case of the man and the biosphere (MAB) programme

Ecological problems — because they involve interactions and interfaces — require for their solution a flexible, interdisciplinary approach. Ecological research can best be supported in an international, intergovernmental framework, but, at first sight, the requirements of such a framework may seem unwieldy to traditionally trained natural and social scientists. Experience acquired in implementing UNESCO's Man and the Biosphere (MAB) Programme indicates that it is possible to overcome the difficulties of conducting integrated research and to achieve internationally comparable results. The MAB Programme is a good example of both the potential and the limitations of integrated, international ecological research programs. There seem to be three imperatives for success: (1) research must be problem oriented, (2) the. unit selected for study must be sufficiently comprehensive and based on human use systems, and (3) research workers in various natural and social science disciplines and the administrative decision-makers must share responsibility for planning and execution.     

A revision of fossil eagle owls (Aves: Strigiformes: Bubo) from Europe and the description of a new species,Bubo ibericus,from Cal Guardiola (NE Iberian Peninsula)

The European fossil record of eagle owls, genus Bubo Duméril 1806 Duméril AMC. 1806. Zoologie Analytique, ou Méthode Naturelle de Classification des Animaux, rendue plus Facile à l’Aide de Tableaux Synoptiques. Paris: H. L. Perronneau. [Google Scholar], is thought to extend back into the Miocene, but records of Bubo before the Middle Pleistocene are scarce and mainly constituted by non-diagnostic or fragmentary specimens. Apart from a number of fossil species of Bubo of uncertain validity, i.e. Bubo? florianae Kretzoi 1957 Kretzoi M. 1957. Bird remains from the Hipparion-fauna of Csákvár. Aquila. 63:239–248. [Google Scholar], Bubo lignitum Giebel 1860 Giebel CG. 1860. Zur Fauna der Braunkohlen Formation von Rippersroda in Thüringen. Zeitschrift für die Gesammten Naturwissenschaften. 16:147–153. [Google Scholar], and Bubo perpastus (Ballman 1976 Ballmann P. 1976. Fossile Vögel aus dem Neogen der Halbinsel Gargano (Italien). Zweiter Teil Scripta Geol. 38:1–59. [Google Scholar]), most fossil Bubo material is unassigned to species or assigned to the extant Bubo bubo (Linnaeus 1758) on the basis of size, especially for Early Pleistocene records. Given the ambiguity about the validity of the earliest records, here we revise the pre-Middle Pleistocene fossil record of Bubo in Europe. Our results indicate that, in Europe, Bubo is first recorded in the Late Pliocene/Early Pleistocene of Italy. By the Early Pleistocene, three taxa can be distinguished: Bubo ibericus sp. nov. from Cal Guardiola (Spain), Bubo sp. nov. indet. from Soave Cava Sud (Italy) and Bubo sp. from various sites across Europe. By the Middle Pleistocene, Eurasian environments experienced a substantial increase in severity and duration of glacial periods which might have led to the replacement of extinct species of Bubo by the recent B. bubo and Bubo scandiacus.     

Additions and corrections to “The Muscidae of Central Europe” III. A new species of <Emphasis Type="Italic">Coenosia</Emphasis> Meigen, 1826 from Central Europe (Diptera: Muscidae)

Coenosia bohemica sp. n. is described from the Bohemian Forest in the Czech Republic. Its relationships to similar species are discussed and its diagnostic characters are illustrated.     

The holotypes of the upper Pleistocene Crocuta crocuta spelaea (Goldfuss, 1823: Hyaenidae) and Panthera leo spelaea (Goldfuss, 1810: Felidae) of the Zoolithen Cave hyena den (South Germany) and their palaeo‐ecological interpretation

The rediscovered holotype skulls of Late Pleistocene Panthera leo spelaea ( Goldfuss, 1810 ) (Felidae) and Crocuta crocuta spelaea ( Goldfuss, 1823 ) (Hyaenidae) from the Zoolithen Cave at Burggeilenreuth, southern Germany, are discussed. The cave became famous mainly due to its rich cave bear bone remains from the late Saalian (OIS 6–8) to Eemian/Weichselian (OIS 3–6) including additionally a third holotype of Ursus spelaeus Rosenmüller, 1794 (Ursidae). The ‘Felis spelaea’ holotype represents an adult male with a strong bite mark on the saggital crest, which was in an early stage of healing. Compared with other European Late Pleistocene lion skulls and skeletons, and with modern African lions, it provides evidence of intraspecific conflict between male Ice Age lions. The holotype of ‘Hyaena spelaea’ is one of several hundred hyena remains from a well‐frequented hyena den cave. The cave was used intensively by Late Pleistocene hyena clans, for collecting lion carcasses in addition to their accustomed prey, as happened in many caves throughout Europe. Ice Age spotted hyena clans might have killed Ice Age steppe lions for many reasons, such as fights over prey and territory, and the protection of cubs, but they did not always scavenge on their carcasses. © 2008 The Linnean Society of London, Zoological Journal of the Linnean Society, 2008, 154 , 822–831.     

From Asia to Europe: The first record of the blue tiger Tirumala limniace (Cramer, [1775]) (Lepidoptera: Nymphalidae: Danainae) in the European continent

The introduction of species by human action is one of the main causes of rarefaction and extinctions of species. This fact is especially relevant in insular ecosystems. Here, we reported for the first time the arrival of Tirumala limniace (Cramer, [1775]) from the Asian to European continent. A single specimen was recorded in the Balearic Islands, which a large list of introductions around their history. Some reasons could explain the occurrence of this species into the islands, but the most likely are the cargo and nursery trade as well as the release of specimens for weddings and other social events as well as escaped from a private butterfly’s garden. This record highlights the importance of implementing early detection of introduced species in insular ecosystems.     

Ecological zonation of the hyperhaline estuary of the Casamance River (Senegal): Foraminifera,zooplankton and abiotic variables

Due to a long-lasting drought afflicting the Sahel, the Casamance River has been transformed into a hyperhaline estuary, with salinities up to 170% at a distance of 210 km from the sea. Foraminifera and zooplankton populations both show a marked decrease in the number of species in increasingly confined water, the distribution of species being closely related to the evolution of abiotic variables. Our three-prong study allowed us to identify six zones, upwards from the sea. The uppermost ones are characterized by drastic conditions which considerably reduce the number of species. Therefore, the populations of Foraminifera, zooplankton and even fish become oligo or mono specific. The Casamance River appears to fit quite well into the general rules concerning hyperhaline environments. However, it shows some peculiar features which are: the large dimensions of the hyperhaline estuary (over 230 km long and over 5 km wide in the lower course); peak salinities among the highest known for a permanently open estuary (up to 170%); and water remaining trapped inside the river for several years.     

New and little-known grylloblattids of the family Geinitziidae (Insecta: Grylloblattida) from the Triassic and Jurassic of Europe,Asia, and South Africa

The fossil history of the family Geinitziidae is reviewed. New taxa are described in the family: Shurabia hissarica, sp. nov. (Lower Jurassic of Tajikistan), Sh. shartegica, sp. nov. (Upper Jurassic of Mongolia), Sh. serrata, sp. nov. and Ginitzia sagulensis, sp. nov. (both Lower Jurassic of Kyrgyzstan). The subfamily Stegopterinae Sharov, 1961 is synonymized under Geinitziinae Handlirsch, 1906. The genera Minesedes Fujiyama, 1973 and Ominea Fujiyama, 1973 (Upper Triassic of Japan) are synonymized under Shurabia Martynov, 1937 and Geinitzia Handlirsch, 1906, respectively. Geinitzia varia Bode, 1953 (Lower Jurassic of Germany) and Fletchizia picturata Riek, 1976 (Upper Triassic of South Africa) are redescribed from their holotypes. F. kapokraalensis Wappler, 2001 and F. aleda Wappler, 2001 (both Upper Triassic of South Africa) are transferred to the genus Shurabia.     

The Ability of Coptera haywardi (Ogloblin) (Hymenoptera: Diapriidae) to Locate and Attack the Pupae of the Mediterranean Fruit Fly, Ceratitis capitata (Wiedemann) (Diptera: Tephritidae), under Seminatural Conditions

In Latin America, the diapriid Coptera haywardi (Ogloblin) attacks the pupae of tephritid fruit flies. Anastrepha spp. are among its natural hosts, but in the laboratory it also develops in the exotic Mediterranean fruit fly, Ceratitis capitata (Wiedemann). Field cage tests demonstrated that C. haywardi could locate and parasitize Mediterranean fruit fly pupae under seminatural conditions as found in a Guatemalan coffee plantation. A mean of 18.3% of the pupae buried artificially at depths of 5 mm were parasitized by C. haywardi, while those buried at 15 mm suffered 3.2% parasitism. In a laboratory experiment, larvae that buried themselves to pupate were not significantly more likely to be parasitized than artificially buried pupae, although they may have left a physical or chemical trail that betrayed their presence. Thus, the artificial burial of pupae is unlikely to grossly underestimate C. haywardi efficacy in the field. Another field cage test found that mortality levels due to unsuccessful parasitoid attacks were similar to those resulting from successful parasitism. Thus, the actual effect of a mass-release might be considerably greater than that suggested from parasitism data alone. The results are considered sufficiently positive to encourage further testing of C. haywardi as a biological control agent of the Mediterranean fruit fly.     

The Use of Artificial Benthic Collectors for Assessment of Spatial Patterns of Settlement of Megalopae of Carcinus maenas (L.) (Brachyura: Portunidae) in the Lower Mira Estuary, Portugal

Artificial benthic collectors have been widely used for the assessment of settlement rates of decapod crustaceans. However, to date no consistent works have addressed spatial patterns of settlement in different estuarine habitats, and no specific studies targeted the interaction of artificial surfaces with the surrounding natural substrate. It may be expected that the artificial surface may produce a different thigmotactic response when compared to the natural substrate, which may limit the use of this technique for assessment of natural settlement rates. In this study the settlement rates of megalopae of the estuarine crab Carcinus maenas were addressed, specifically deploying artificial benthic collectors in different habitats both intertidal and subtidal in the lower Mira estuary. A number of experiments were performed concerning stratification and temporal fluctuations of settlement. Further, the interaction of collector surface with the surrounding substrate was investigated, by comparing settlement rates in natural and artificial substrates in different habitats. Results have shown significant differences in settlement between different estuarine habitats, both in spatially replicated experiments and in a high-resolution temporal experiment. However, comparison between settlement rates in artificial and natural substrates has shown that there is a strong interference between collectors and surrounding substrate, limiting interpretation of results concerning settlement rates in artificial substrate alone.     

The Early-Middle Pleistocene environmental and climatic change and the human expansion in Western Europe: A case study with small vertebrates (Gran Dolina, Atapuerca, Spain)

The dispersal of hominins may have been favored by the opening of the landscape during the Early-Middle Pleistocene transition (EMP) in Western Europe. The structure of the small-vertebrate assemblages of the archaeo-paleontological karstic site of Gran Dolina in Atapuerca (Burgos, Spain) shows important environmental and climatic changes in the faunal succession, across the Matuyama-Brunhes boundary at 780 ka. These changes are interpreted to indicate impoverishment of the forests, along with an increase in dry meadows, and open lands in general that entailed a tendency towards the loss of diversity in small-vertebrate communities above the EMP. We evaluate variation in diversity of the faunal succession of Gran Dolina using Shannon’s Second Theorem as an index of ecosystem structure. The long cultural-stratigraphic sequence of Gran Dolina during the EMP is somewhat similar in its completeness and continuity to that in the locality of Gesher Benot Ya'aqov in the Upper Jordan Valley. We also evaluate related data including faunal and floral (pollen) succession. Both localities present cold, dry and humid, warm fluctuations at the transition between the Early and the Middle Pleistocene. Comparisons between these sites present opportunities to understand large-scale climatic changes.     

A life history model for the San Francisco Estuary population of the Chinese mitten crab, <Emphasis Type="Italic">Eriocheir sinensis</Emphasis> (Decapoda: Grapsoidea)

First discovered in San Francisco Bay in 1992, the Chinese mitten crab,Eriocheir sinensis, has become established over hundreds of km² of the San Francisco Estuary. Ecological and economic impacts of this invasive species motivated our search for a greater understanding of the crabs life history as an important step in better management and control. Data for this life history model comes from the authors research and scientific literature. Juvenile crabs migrate from the Estuary into fresh water where they develop into adults. Environmental signals may stimulate gonad development that is followed by a downstream migration beginning at the end of summer. Mating occurs after the crabs reach saline water. Embryos are carried until hatching, and the larvae undergo five zoeal stages before settlement. Our model projects rates of development at various temperatures and growth increments, supports a minimum of 2 years in low salinity or freshwater habitat, and predicts that most California mitten crabs are at least 3 years old before becoming sexually mature. Environmental factors strongly influence the timing and duration of the crabs life stages, and are discussed in the context of a gradient of development times for worldwide populations of this important invasive species.