Vlasta Ćosović

Impact of fish farming on foraminiferal community, Drvenik Veliki Island, Adriatic Sea, Croatia

This study examined the impact of fish farming on foraminiferal communities in the Adriatic coastal zone. Samples were taken directly beneath the farm, near the edge of the farm, and at a reference station away from the farm. The foraminiferal community near the farm is characterized by Epistominella exigua, Globocassidulina subglobosa, Haynesina germanica and the genera Elphidium, Bulimina and Brizalina. These foraminiferal species are less abundant seaward. Asterigerinata mamilla, Neoconorbina terquemi and genus Cibicides are almost absent below the cages. Total phosphorus (TP) and total nitrogen (TN) in the sediments decrease with distance from the cages. The abundances of E. exigua, G. subglobosa, H. germanica and the genera Elphidium, Bulimina and Brizalina are correlated with TP and TN, indicating their dependence on nutrient input. The absence of A. mamilla, N. terquemi and the genus Cibicides below the cages is a due to a degraded Posidonia community. According to our study, foraminiferal community composition can be used as indicator of organic enrichment caused by fish farm activities.

Integrated biostratigraphy across the Ypresian/Lutetian boundary at Agost, Spain

Abstract The integrated biostratigraphy of a 112 m thick exposed section near Agost (Southern Spain) was studied to assess its suitability as a Global Stratotype Section and Point (GSSP) for the Early/Middle Eocene (Ypresian/Lutetian) Boundary. This section consists of marls interbedded with calcarenites and detrital turbidite layers deposited in a hemipelagic environment. Planktic foraminifera provided good biozonation from P8 through P11 Zones. The calcareous nannofossil Zones NP13 through NP16, respectively CP11 through CP14a, could be distinguished. The larger foraminiferal Zones SBZ12 to SBZ14 could tentatively be distinguished. The base of the H. nuttalli (P. 10) Zone, which is often used to set the boundary between the Lower and the Middle Eocene (Ypresian/Lutetian) falls at a facies change. The Agost Section can be used as a GSSP only if no better section is found.

Benthic Foraminiferal Assemblages in a Restricted Environment - An Example from the Mljet Lakes (Adriatic Sea, Croatia)

Benthic foraminiferal assemblages from a peculiar restricted marine environment, the Mljet Lakes (Mljet Island, Adriatic Sea, Croatia) have been studied. These lakes are drowned karst dolines, which are connected with the Adriatic Sea through a narrow, shallow channel. Occasional stagnant conditions in the marine lakes cause hypoxic and anoxic conditions in the bottom waters. Such stressed conditions are reflected in oligospecific benthic foraminiferal assemblages with a Shannon-Wiener species diversity index (H) ranging from 0.8 to 1.0 and equitability index (E) ranging from 0.18 to 0.26, identified in samples from each marine lake. In the more dysoxic Malo Jezero, Haynesina depressula dominates an assemblage of 12 benthic foraminiferal species. In the less (and less frequently) hypoxic Veliko Jezero, we found an Asterigerinata mamilla a s s e m b l a g e with 18 foraminiferal species. A more diverse assemblage containing 55 different benthic foraminiferal species occupies an adjacent opensea station. Long-term salinity measurements indicate that H. depressula tolerates higher salinity than formerly presumed (up to 38 ‰), and is well adapted to stressed hypoxic conditions.

Impact evaluation of the industrial activities in the Bay of Bakar (Adriatic Sea, Croatia): Recent benthic foraminifera and heavy metals

The Bay of Bakar is one of the most heavily polluted bays at the Eastern Adriatic. Three major industrial companies potentially endanger the bay. The concentration of major, minor and trace elements in surface sediments from thirteen stations was discussed in relation to the sediment type and foraminiferal assemblages. The distribution of major elements in the bay is influenced by geological nature of surroundings. Heavy metal distribution depends on pollution sources and on amount of mud fraction: fine-grained sediments are enriched by them in comparison with coarse-grained ones. Different sediment quality criteria complicate the pollution assessment in the bay. Heavy metal concentrations generally fall into allowed depositional values for marine environments; only area in front of the coke plant and the City of Bakar harbor is heavily polluted. Stress-tolerant foraminiferal species dominate at stations with higher concentrations of heavy metals and coarse-grained sediments consist of larger number of epifaunal taxa.

Palaeoecological significance of morphology of orthophragminids from the Istrian Peninsula (Croatia and Slovenia)

Abstract Orthophragminids collected on several sections in Istria, ranging in age from the “Upper Cuisian” to the Early-MiddleLutetian, were studied. Morphostructural characteristics of foraminiferal tests and content of glaucony grains in sediments allowed the differentiation of three fossil associations with palaeoenvironmental significance. The foraminiferal association rich in glaucony is characterized by abundant small (dwarf) orthophragminid individuals (about 50% of all orthophragminas studied were these forms). Decrease in content of glaucony is accompanied by higher diversity of species and their shapes, and predominance of larger individuals in fossil associations. Diversity of species and forms was highest in glaucony-poor sediments, thus the inverse relationship is found for foraminiferal diversity and content of glaucony. Stable and favourable environmental condition have produced orthophragmina community of high diversity, in specific and morphological sense. Contemporaneous community formed in unstable condition (in lower euphotic zone, up to 130 m depth; lower oxygen content), shows low specific, but higher interspecific variability, and predominance of dwarf individuals.

NEW CRETACEOUS AND EOCENE DECAPODA (ASTACIDEA, THALASSINIDEA, BRACHYURA) FROM BRITISH COLUMBIA, CANADA

Abstract A collection of Cretaceous and Eocene specimens of decapod crustaceans from southern Vancouver Island, British Columbia, Canada, has yielded the following new taxa: Cowichianassa meckerti, new genus, new species (Callianassidae); Comoxianassa haggarti, new genus, new species (Callianassidae); Preclarocarcinus parvus, new genus, new species (Homolodromiidae); and Nitotacarcinus canadensis, new species (Tumidocarcinidae). Two of the new taxa are callianassid ghost shrimp, each of which displays sexual dimorphism and is well documented from major and minor claws as well as abdomina, unusual in the fossil record and especially unusual for Cretaceous forms. Nitotacarcinus was known previously only from the Eocene of Denmark; thus, the new species extends its paleobiogeographic range dramatically. The layers in which the decapods were collected from the Paleogene Via Appia Beds were deposited in generally high-energy conditions favoring the formation of glauconite. Cuticular structures of Eucorystes platys Schweitzer and Feldmann, 2001, are described.

Decastronema barattoloi (DE CASTRO), characteristic fossil of the Palaeocene and the Eocene peritidal sediments from the Adriatic carbonate platform

The renewed deposition in the Palaeogene and the oldest part of the non-interrupted Palaeocene succession is characterized by the presence of Decastronema barattoloi (DE CASTRO), cyanobacterial tubes originally described in the Apennines. The reinterpretation of limestones from several sections located in the Kras region (NW part of the AdCP: Basovizza, Dolenja vas, Sopada, ?ebulovica) confi rmed the presence of these microfossils in peritidal sediments of Danian age (SBZ 1). The Cuisian (Late Lower Eocene) sediments, from eastern Istria (Brnjci section), Cres Island (Koroma?na Cove section) and Ravni kotari (Benkovac–Korlat section) contain individuals of this species in great numbers. The cyanobacterial tubes are scattered in laminated, fi ne grained mudstones and wackestones, immediately above the Cretaceous sediments (occasionally above bauxites or breccias). The Decastronema-bearing sediments pass upward into the Foraminiferal limestones of Cuisian age (SBZ 11, based on conical agglutinated foraminifera and alveolinids), allowing the age determination of the cyanobacterial remnants. The Palaeocene specimens are minute (up to about 180 ?m long), thick walled tubes that occur with the index fossil Bangiana hanseni DROBNE. The Eocene forms accompanied by ostracods, pelecypods, and miliolid and rotaliid foraminifera are segmented tubes, up to 400 mm long and usually thin walled.

TOWARDS A CALIBRATED LARGER FORAMINIFERA BIOSTRATIGRAPHIC ZONATION: CELEBRATING 18 YEARS OF THE APPLICATION OF SHALLOW BENTHIC ZONES

Abstract: The Shallow Benthic Zonation is one of the most important achievements of biostratigraphy in the last twenty years. Here we summarize the state of the art in the field of Larger Benthic Foraminifera (LBF) and sketch the main lines of research that are improving the precision and usefulness of this scale. The goal of updating the zonation requires a wealth of data coming not only from biostratigraphic investigations but also from paleoenvironmental analyses, biological knowledge, rigorous taxonomic determination, and understanding of paleobiogeography. The papers collected for this special issue are contributions to this broad research program.

HARPACTOCARCINUS FROM THE EOCENE OF ISTRIA, CROATIA, AND THE PALEOECOLOGY OF THE ZANTHOPSIDAE VIA, 1959 (CRUSTACEA: DECAPODA: BRACHYURA)

Abstract Harpactocarcinus punctulatus istriensis Bachmayer and Nosan, 1959 is elevated to species level. Analysis of the larger foraminiferans associated with specimens of H. istriensis suggests a habitat preference for off-shore, clear, shelf environments below fair-weather wave base and an age of early to middle Lutetian (Eocene). A review of the paleoenvironmental indicators for nearly all species within the genera referred to the Zanthopsidae Via, 1959 suggests that all exhibit similar habitat preferences. Description of the paleoenvironmental preference for an entire extinct decapod family has not before been possible.

Identification of the Palaeocene–Eocene Boundary Based on Larger Foraminifers in Deposits of the Palaeogene Adriatic Carbonate Platform, Southwestern Slovenia

Two sections located in the northwestern part of the Palaeogene Adriatic carbonate platform (PgAdCP) were measured and sampled to document the complexity of changes at the Palaeocene–Eocene boundary. Carbon and oxygen isotope records in combination with a detailed study of larger benthic foraminifera (LBF) are used to describe the turnover of foraminifera and to refine the shallow benthic zonation scheme.