Influence of hydrographic features on larval fish distribution during the south‐westerly monsoon in the waters of Taiwan,western North Pacific Ocean

The spatial distribution patterns of fish larvae and the relationships with hydrographic conditions in the waters surrounding Taiwan were studied in August 2004 when the south‐westerly monsoon prevailed. A total of 6566 fish larvae were identified, belonging to 80 families, 129 genera and 230 species. Cluster analysis revealed two station groups, one associated with the South China Sea Surface Current (SCSSC) and the other with the Kuroshio Current (KC). The SCSSC group was characterized by mostly coastal and neritic species, and the KC group was predominated by oceanic species. Larger fish larvae were generally more abundant in the neritic waters west of Taiwan where the SCSSC prevails than in the waters east of Taiwan where the KC prevails. The combination of chlorophyll a, zooplankton and nitrite best explained the relationship of larval fish distribution and environmental variables, implying that the distribution of fish larvae in summer was closely linked to the food source. The changing of monsoons potentially affects the succession of water masses and the transport and assemblage of fish larvae in this study area.     

Ocean acidification responses in paralarval squid swimming behavior using a novel 3D tracking system

The study presents the biomass and spatial distribution of Sardinella aurita in the Libyan, Maltese and southern Sicily waters, estimated during four acoustic surveys in summer 2008 and 2010. Strong differences in terms of both spatial distribution and total biomass between years and areas were found, with higher total biomass in 2010 than in 2008 in both southern and northern areas of the central Mediterranean. Habitat suitability and changes in the spatial dynamics of round sardinella among areas and years are then explored in relation to total biomass variation and environmental factors. The area of presence of S. aurita increased in the Maltese and Sicilian waters in 2010 with respect to 2008, while most of the total biomass observed in the two years occupied the same proportion of the continental shelf in Libyan waters. The link between environmental conditions and S. aurita area of presence and aggregation was investigated by means of generalized additive models (GAM). The application of GAM singled out the key role of depth and temperature in driving higher round sardinella aggregations, as they were able to explain in both years about the 48% of total deviance in the case of strictly positive values. Favourable habitat for round sardinella was found in waters shallower than 60 m depths, with a clear peak around 40 m depth. Favourable temperature values were above 22°C for presence/absence case and above 24°C when GAM was applied on strictly positive values. Overall S. aurita biomass and distribution were discussed in the light of the classical models proposed to describe the fish spatial dynamics in relation to an increase in total biomass.     

Climate-driven changes in abundance and distribution of larvae of oceanic fishes in the southern California region

We examined climatic effects on the geographic distribution and abundance of 34 dominant oceanic fishes in the southern California region using larval fish data collected from the 50‐year long California Cooperative Oceanic Fisheries Investigations (CalCOFI) surveys. The oceanic species responses to environmental changes in their geographic distributions were not very pronounced, perhaps because they lived in the deep layer where temperature change was relatively small or because the environmental variation of the CalCOFI region is not strong enough (with an average temperature gradient of the upper 100 m around 91 km °C^?1). Among the 34 taxa, 16 showed a significant distributional shift (median latitude or boundaries) in relation to environmental variables, and eight species significantly shifted their geographic distribution from the 1951–1976 cold period to the 1977–1998 warm period. Interestingly, the vertically migrating taxa more often showed a significant response to environmental variables than the nonmigrating mesopelagic taxa, reflecting the more significant increase in heat content of the upper ocean (<200 m), compared with the deeper zone (300–500 m) where the mesopelagic fishes typically remain. Climate change has significant effects on the abundances of oceanic fishes. Twenty‐four taxa exhibited a significant change in abundance in relation to environmental variables, and 25 taxa, including both warm and cold‐water taxa, showed a significant increase in abundance from the cold to warm period. Analysis of physical data indicated that the surface‐layer (20–200 m) warmed significantly and the isotherms approached shoreward from the cold to the warm period. We further show that the spatial distribution of coastal–neritic fish retreated shoreward and oceanic fish extended shoreward from the cold to warm period. Our results suggest intensified stratification of the southern California region during the warm period may create a suitable habitat for the oceanic species. Moreover, such an unfavorable condition (e.g. changes in food habitat) for coastal–neritic species might result in competitive release for the oceanic fishes to flourish.     

Helminth communities of loggerhead turtles (Caretta caretta) from Central and Western Mediterranean Sea: The importance of host's ontogeny

We investigated the factors providing structure to the helminth communities of 182 loggerhead sea turtles, Caretta caretta, collected in 6 localities from Central and Western Mediterranean. Fifteen helminth taxa (10 digeneans, 4 nematodes and 1 acanthocephalan) were identified, of which 12 were specialist to marine turtles; very low numbers of immature individuals of 3 species typical from fish or cetaceans were also found. These observations confirm the hypothesis that phylogenetic factors restrict community composition to helminth species specific to marine turtles. There were significant community dissimilarities between turtles from different localities, the overall pattern being compatible with the hypothesis that parasite communities reflect the ontogenetic shift that juvenile loggerheads undergo from oceanic to neritic habitats. The smallest turtles at the putative oceanic, pelagic-feeding stage harboured only the 2 digenean species that were regionally the most frequent, i.e. Enodiotrema megachondrus and Calycodes anthos; the largest turtles at the putative neritic, bottom-feeding stage harboured 11 helminth taxa, including 3 nematode species that were rare or absent in turtles that fed partially on pelagic prey. Mean species richness per host was low (range: 1.60–1.89) and did not differ between localities. Variance ratio tests indicated independent colonization of each helminth species. Both features are expected in ectothermic and vagrant hosts living in the marine environment.     

Complexity and variation in loggerhead sea turtle life history

Juvenile loggerhead sea turtles spend more than a decade in the open ocean before returning to neritic waters to mature and reproduce. It has been assumed that this transition from an oceanic to neritic existence is a discrete ontogenetic niche shift. We tested this hypothesis by tracking the movements of large juveniles collected in a neritic foraging ground in North Carolina, USA. Our work shows that the shift from the oceanic to neritic waters is both complex and reversible; some individuals move back into coastal waters and then return to the open ocean for reasons that are still unclear, sometimes for multiple years. These findings have important consequences for efforts to protect these threatened marine reptiles from mortality in both coastal and open-ocean fisheries.     

Late Aptian to early Cenomanian dinoflagellate cysts from Agadir Basin,southwestern Morocco: Biostratigraphy and palaeoenvironment

The Agadir Basin (Moroccan Atlantic margin) is characterized by its fossil richness, including organic-walled microfossils. The palynological analysis of the middle Cretaceous succession from the Tamzargout section and EGA.1 well reveals the presence of well-preserved and diverse assemblage, rich in dinoflagellate cysts. The assemblages contain stratigraphic marker taxa and show significant chronostratigraphic events. Based on these bioevents and on the comparison with different palaeogeographic domains, a determination of age was proposed. The biogeographic characteristics of most cosmopolitan taxa in this study confirm the establishment of new oceanic communication related to the opening of the equatorial Atlantic. The Albian-Cenomanian transition has been recognized only in EGA.1 well, whereas the Aptian-Albian transition, the early-mid Albian and the mid-late Albian have been defined in both the section and the well. The recorded associations are comparable to those of neighboring deposits and those of the Tethyian and Atlantic domains. The vertical distribution of the organic matter in the sediments of the Agadir Basin and the compilation of all palaeoenvironmental proxies allowed identifying an Albian transgression with specific palaeoenvironments in each interval. Neritic marine environments alternated with short phases of continental and oceanic influence is deduced for the late Aptian-early Cenomanian in this basin. The late Aptian-early to mid Albian recorded an outer neritic palaeoenvironment under oceanic influence; the mid to late Albian showed littoral conditions during a regressive phase fluctuating to middle to outer neritic environment; finally the late Albian-early Cenomanian transition was characterized by a middle neritic palaeoenvironment under coastal influence.     

STOMACH CONTENTS OF FALSE KILLER WHALES (PSEUDORCA CRASSIDENS) STRANDED ON THE COASTS OF THE STRAIT OF MAGELLAN,TIERRA DEL FUEGO

We examined the stomachs of 25 false killer whales collected from a mass stranding of 181 animals along both coasts of the Strait of Magellan, Chile, in March 1989. The 21 stomachs (nine males and 12 females), with food remains contained 11 prey species (nine cephalopods and two fishes) with a total of 442 individuals. Except for one case, food remains were meager, indicating that the animals had not eaten for some time or through stress had vomited on the beach. Eleven of the 21 animals had mud (often with squid beaks) in the esophagus and first stomach. The prey were identified employing squid beaks, fish otoliths and bones, and their wet weights were estimated using regressions between hard parts and known weights of species. The most important prey were the oceanic and neritic-oceanic squids, Martialia byadesi and Illex argentinus, followed by the neritic fish, Macruronus magellanicus. Of less importance were the oceanic squid, Todaroes fillipovae, the oceanic and epipelagic octopus, Ocytboe sp., and the oceanic squid, Moroteuthis ingens. The rest of the prey were poorly represented and included four oceanic squids and one neritic fish. The prey species of these animals were subantarctic, with two antarctic species, abundant over the Patagonian shelf and adjacent oceanic waters around Tierra del Fuego.     

Anchovy (<Emphasis Type="Italic">Engraulis encrasicolus</Emphasis>) early life stages in the Central Mediterranean Sea: connectivity issues emerging among adjacent sub-areas across the Strait of Sicily

The combined use of field data on anchovy (Engraulis encrasicolus, Linnaeus, 1758) egg distribution in the Central Mediterranean Sea on both sides of the Strait of Sicily (Sicilian–Maltese and Tunisian waters) and Lagrangian simulations were used to assess the pattern of connectivity between these two sub-areas as a result of spawning activity. The field data were collected during ichthyoplankton surveys carried out in summer 2008 and 2010. The simulation runs showed considerable (up to 20%) rates of particle exchange in both directions (from Tunisian to Sicilian–Maltese waters and vice versa). However, considering the typical high mortality rates of anchovy early stages, the actual larval exchange rates across the Sicily Strait are supposed to be significantly lower (<1%), supporting the hypothesis that the anchovy population sub-units in the Strait of Sicily can be considered as separate fish stocks for the evaluation of their optimum exploitation rates.     

Dinoflagellate cysts as indicators of water quality and productivity in British Columbia estuarine environments

Palynological analyses of 60 surface sediment samples from estuarine environments near Vancouver Island, including the Georgia Strait (GS), the Effingham (EFF) and the Seymour–Belize (SB) Inlets were performed in order to document the distribution of dinoflagellate cyst assemblages and their relationship to hydrographic conditions, productivity and nutrient concentrations. We tested transfer functions using the analogue method, and suggest that dinoflagellate cyst assemblages can be used to reconstruct primary productivity, temperature and salinity. The EFF and SB Inlets are characterized by a dominance of autotrophic taxa, particularly Operculodinium centrocarpum, whereas the Protoperidinioid and gymnodinial heterotrophic taxa such as Quinquecuspis concreta and Brigantedinium spp. dominate the assemblages of the GS. Multivariate analysis shows that this distribution is closely linked to primary productivity, sea-surface temperature (SST) and spring silica concentration. The abundance of autotrophic taxa in the EFF and SB Inlets is associated with high primary productivity and low summer SST, indicating summer upwelling of coastal British Columbia, whereas the heterotrophic taxa that characterizes the GS assemblages are related to low productivity, high summer SST and high silica concentration during spring. Multivariate analysis shows that the most important environmental parameters related to dinocyst distribution in the restricted embayment of the GS, are distance to the shore, distance to Vancouver Harbor, spring sea surface salinity (SSS), spring phosphate concentration and spring productivity. The autotrophic taxa are generally more common in coastal and shallow waters, but Spiniferites ramosus and Pentapharsodinium dalei show an opposite correlation to spring productivity and salinity. P. dalei is particularly abundant around Vancouver Harbor, near highly urbanized shores and within the Fraser River plume, where salinity is low and spring productivity and continental runoff are high. S. ramosus shows its highest abundance on the western coast of GS. Protoperidinioid and gymnodinial cysts characterize distal zones within the central and southern GS that are associated with a mixture of brackish waters coming from the Fraser River and deep upwelling waters entering the GS via Juan de Fuca Strait. The relationship between dinoflagellate cyst assemblages and primary productivity in these estuarine systems differs from that in oceanic and outer neritic zones, where the abundance of heterotrophic taxa is commonly associated with upwelling and high productivity.     

Higher contribution of globally rare bacterial taxa reflects environmental transitions across the surface ocean

Microbial taxa range from being ubiquitous and abundant across space to extremely rare and endemic, depending on their ecophysiology and on different processes acting locally or regionally. However, little is known about how cosmopolitan or rare taxa combine to constitute communities and whether environmental variations promote changes in their relative abundances. Here we identified the Spatial Abundance Distribution (SpAD) of individual prokaryotic taxa (16S rDNA‐defined Operational Taxonomic Units, OTUs) across 108 globally‐distributed surface ocean stations. We grouped taxa based on their SpAD shape (“normal‐like”‐ abundant and ubiquitous; “logistic”‐ globally rare, present in few sites; and “bimodal”‐ abundant only in certain oceanic regions), and investigated how the abundance of these three categories relates to environmental gradients. Most surface assemblages were numerically dominated by a few cosmopolitan “normal‐like” OTUs, yet there was a gradual shift towards assemblages dominated by “logistic” taxa in specific areas with productivity and temperature differing the most from the average conditions in the sampled stations. When we performed the SpAD categorization including additional habitats (deeper layers and particles of varying sizes), the SpAD of many OTUs changed towards fewer “normal‐like” shapes, and OTUs categorized as globally rare in the surface ocean became abundant. This suggests that understanding the mechanisms behind microbial rarity and dominance requires expanding the context of study beyond local communities and single habitats. We show that marine bacterial communities comprise taxa displaying a continuum of SpADs, and that variations in their abundances can be linked to habitat transitions or barriers that delimit the distribution of community members.     

Calcareous dinoflagellate cysts in surface sediments from the Mediterranean Sea: distribution patterns and influence of main environmental gradients

The distribution of calcareous dinoflagellate cysts in surface sediments from the Mediterranean Sea was quantitatively analysed. The samples contain 11 cyst species and the vegetative coccoid Thoracosphaera heimii. Cyst abundance increases towards the deeper parts of the basins and is generally higher in the eastern Mediterranean Sea. Three major distribution characteristics exist: (1) different assemblages in oceanic and neritic regions, (2) little agreement with the associations of areas studied so far like the Atlantic Ocean, and (3) a unique oceanic assemblage in the eastern Mediterranean Sea. A gradual change in cyst assemblages from the western to the eastern Mediterranean Sea was observed and statistically compared with the main environmental gradients in the upper water column. Temperature, nitrate concentration and possibly salinity appear to be the most important factors controlling cyst production. Three groups containing cysts with similar environmental preferences can be distinguished: (1) an eastern Mediterranean group related to relatively high temperature and salinity but low nitrate concentration, (2) a group of more or less consistently abundant cosmopolitan species tolerating or even preferring relatively low temperature and salinity but high nitrate concentration, and (3) a group containing species that are possibly adapted to neritic environments and have probably been transported from coastal areas into the studied regions. In contrast to other calcareous plankton, calcareous dinoflagellate cysts correlate strongly with the main environmental gradients in the Mediterranean Sea, bearing a high potential for palaeoenvironmental reconstructions.     

Modelling the niche for a marine vertebrate: a case study incorporating behavioural plasticity,proximate threats and climate change

The integration of satellite telemetry, remotely sensed environmental data, and habitat/environmental modelling has provided for a growing understanding of spatial and temporal ecology of species of conservation concern. The Republic of Cape Verde comprises the only substantial rookery for the loggerhead turtle Caretta caretta in the eastern Atlantic. A size related dichotomy in adult foraging patterns has previously been revealed for adult sea turtles from this population with a proportion of adults foraging neritically, whilst the majority forage oceanically. Here we describe observed habitat use and employ ecological niche modelling to identify suitable foraging habitats for animals utilising these two distinct behavioural strategies. We also investigate how these predicted habitat niches may alter under the influence of climate change induced oceanic temperature rises. We further contextualise our niche models with fisheries catch data and knowledge of fisheries ‘hotspots’ to infer threat from fisheries interaction to this population, for animals employing both strategies. Our analysis revealed repeated use of coincident oceanic habitat, over multiple seasons, by all smaller loggerhead turtles, whilst larger neritic foraging turtles occupied continental shelf waters. Modelled habitat niches were spatially distinct, and under the influence of predicted sea surface temperature rises, there was further spatial divergence of suitable habitats. Analysis of fisheries catch data highlighted that the observed and modelled habitats for oceanic and neritic loggerhead turtles could extensively interact with intensive fisheries activity within oceanic and continental shelf waters of northwest Africa. We suggest that the development and enforcement of sustainable management strategies, specifically multi‐national fisheries policy, may begin to address some of these issues; however, these must be flexible and adaptive to accommodate potential range shift for this species.     

Did the Mediterranean marine reflooding precede the Mio–Pliocene boundary? Paleontological and geochemical evidence from upper Messinian sequences of Tuscany,Italy

The events related to the Messinian salinity crisis are among the most deeply investigated of Earth's history. According to the current hypothesis of Neogene paleogeographic evolution, approximately 5.5 Ma ago, after evaporitic sedimentation and before the Mio–Pliocene boundary, the Mediterranean was characterized by the widespread development of non-marine environments inhabited by molluscs and ostracods of brackish affinity. The Messinian post-evaporitic deposits that testify such a dramatic environmental change are commonly referred to as ‘Lago-mare’ and have been reported from several outcrops and boreholes throughout the entire Mediterranean basin. The origin of ‘Lago-mare’ conditions is commonly interpreted as the result of the synergistic effect of both the humid climatic conditions and change of the drainage patterns at the Mediterranean scale, with the capture of Paratethyan brackish waters. A few recent studies, however, suggest that such a scenario probably represents an oversimplification of the original context, from both a paleogeographical and paleoenvironmental point of view. Unfortunately, the results of these studies have never been commonly accepted and the proposed evidences have been considered questionable. In this paper we describe the fish assemblages from the ‘Lago-mare’ deposits of two localities, Cava Serredi and Podere Torricella, located in the Neogene hinterland basins of Tuscany, central Italy. These assemblages consists of a mixture of marine euryhaline and stenohaline taxa suggesting that the depositional environments were characterized by permanently open connections with a marine basin filled with normal marine waters. In order to better define the paleontological significance of these upper Messinian fish assemblages, the oxygen, carbon and strontium isotopic composition of fish otoliths and other fossils has been measured. These isotopic compositions are strongly indicative of the presence of normal marine conditions close to the depositional environments testified by the sedimentary sequences, thereby implying that the interpretation of the geochemical results are consistent with those derived from the paleoecological analyses of the fish assemblages. Based on the integrated paleoichthyological–geochemical approach discussed in this paper it is possible to unambiguously demonstrate that normal marine rather than fresh- or brackish waters were present in the Mediterranean at least during the upper part of the ‘Lago-mare’ event, providing an unquestionable evidence that the marine refilling of the basin preceded the Mio–Pliocene boundary.     

Paleocene-Early Eocene ostracodes from the Southern Galala Plateau (Eastern Desert, Egypt): Taxonomy, impact of paleobathymetric changes

Ostracode faunas obtained from nine sections spanning the Paleocene-Early Eocene interval from a platform-basin transect in the Southern Galala Plateau area (Eastern Desert, Egypt) have been investigated. The study focuses on taxonomy and biostratigraphy of the ostracode assemblages across the P/E boundary, with supporting comments on paleoecology and paleobiogeography. The studied nine sections yielded 60 taxa belonging to 39 genera. Five species are new. The P/E transition is characterized by the appearance of new taxa rather than extinctions. During the Early and early Late Paleocene, the ostracode assemblages throughout the study area are largely similar, being dominated by middle-outer neritic taxa. In the late Late Paleocene and Early Eocene, changes in the paleobathymetry from deeper marine environments in the distal area in the south to shallower marine environments in the proximal area in the north become pronounced. Many of the recorded taxa have a wide geographic distribution throughout the Middle East and North Africa. Similarities with basins of West Africa are also found, reflecting faunal exchanges between this area and southern Tethys during the Paleocene and Early Eocene.     

Comparison of inshore and offshore fish larval assemblages within the wider Yangtze River estuary (China)

It is hypothesized that fish larvae undertake vertical movements in estuarine waters. To test this hypothesis, a sampling period was selected during times when many spring‐spawning fish reach maximum abundance in coastal waters so that spring and summer variations in larval fish assemblages could be determined in the Yangtze River estuary. Six oceanographic surveys were conducted across the salinity gradient of an inshore (freshwater) and offshore area (brackish intersection) during spring (May) and summer (August) between 2010 and 2012. The fish larval community was dominated by species of Engraulidae, Gobiidae, Champsodontidae and Mugilidae. The pre‐flexion and flexion larval stages of euryhaline marine species, which are dependent on estuaries as nursery areas, were common. The brackish and marine larval assemblage was the most abundant with taxa such as Coilia mystus and Engraulis japonicus accounting for more than 57.3% of the total catch. Spatial differences in the taxonomic composition of larval fish assemblages were evident between the inshore and offshore areas. Additionally, the Yangtze River runoff regulatory functions as affected by the Three Gorges Reservoir operational mode (hydrological alternating operations) showed weak influences on fish and habitat environments. Low salinities from high freshwater inflow limited bay anchovy production in the inshore area.     

Paleoenvironmental change at the Danian–Selandian transition in Tunisia: Foraminifera, organic-walled dinoflagellate cyst and calcareous nannofossil records

In the present study, we document paleoenvironmental change across the Danian–Selandian transition (planktic foraminiferal interval P2–P3b; calcareous nannofossil Zone NP4, Subzones NTp6–NTp8A; 61–59 Ma) in NW Tunisia. Diversifications of Paleogene planktic foraminifera with the evolution of the muricate and photosymbiotic lineages Morozovella, Acarinina and Igorina and of the biostratigraphically important nannofossils genus Fasciculithus are recorded within this interval. The present study aims to understand early Paleogene environmental changes in the southern Tethys, by analyzing the evolution of surface-water and–to a lesser extent–seafloor conditions. Three localities were investigated: Ain Settara, Elles and El Kef, all representing outer neritic deposition in the same basin, the Tunisian Trough. Paleoenvironmental changes are explored by combining planktic foraminiferal, organic dinocyst and calcareous nannofossils assemblages and several proxy parameters (planktic/benthic ratio, numbers of planktic foraminifera per gram, peridinioid/gonyaulacoid ratio; terrestrial/marine palynomorph ratio). In addition, also some geochemical parameters (calcite content and stable isotopes) are examined. Our records indicate that the environment evolved from an initially oligotrophic, open marine, deep outer neritic setting in P2–P3a towards a shallower and nutrient-rich setting from the base of Subzone P3b. This change is seen in the foraminiferal assemblages, with the substitution of Praemurica by Morozovella among the planktic foraminifera and an upward decrease in deeper benthic taxa. Also the organic-dinocyst assemblages show a peak of peridinioid cysts (Cerodinium and Lejeunecysta). Associated to these dinocyst assemblages, the lowest occurrence of Apectodinium is recorded, which seem to have evolved in this region, possibly in response to enhanced nutrient levels on the shelf. Additionally, a distinct change in calcareous nannofossil assemblages is also described, marked by the lowest appearance of Chiasmolithus edentulus, the lowest consistent occurrence of Fasciculithus and a slight increase in near-shore taxa (essentially Pontosphaera).This project provides an accurate understanding of paleoenvironmental change across the Danian–Selandian transition in Tunisia. Especially, integrating different proxies demonstrates a paleobathymetric shallowing from the Danian to the Selandian, associated to increase surface paleoproductivity. Furthermore, the results are compared with those from other localities along the Southern Tethyan margin (Egypt and Jordan) and a more regional paleoclimatic/paleoceanographic perturbation in the Southern Tethys is suggested.     

A comprehensive isotopic investigation of habitat preferences in nonbreeding albatrosses from the Southern Ocean

Albatrosses are among the world's most endangered seabirds. Threats during the nonbreeding period have major impacts on their population dynamics, but for most species, detailed information on distribution and ecology remains essentially unknown. We used stable isotope values (δ¹³C and δ¹⁵N) in feathers to infer and compare the moulting (nonbreeding) habitats of 35 populations that include all the 20 species and subspecies (444 individuals) of albatrosses breeding within the Southern Ocean and in fringing subtropical waters. Isotopic values together with a review of available information show that the 20 albatrosses can be categorized into three groups depending on their favoured moulting grounds: 12 (60%) taxa forage primarily in warm neritic waters, six (30%) in northern oceanic waters and two (10%) in oceanic waters of the Southern Ocean. Stable isotopes indicate that habitat preferences during the nonbreeding period vary much less among different breeding populations in some species (wandering, Salvin's, grey‐headed and light‐mantled sooty albatrosses), than others (black‐browed, Indian yellow‐nosed and sooty albatrosses). The major finding of our isotopic investigation is that the great majority of albatrosses spend the nonbreeding period outside the Southern Ocean, with only three species (and in the sooty albatross, just one of the breeding populations) favouring oceanic subantarctic waters at that time. Hence, the study highlights the overwhelming importance of subtropical waters for albatrosses, where the birds are known to interact with human activities and are more likely to be negatively affected by the diverse range of fisheries operating in both neritic and oceanic waters.     

Fish Assemblages Survey Technique (Fast) in Tunisian marine waters (Central Mediterranean)

Following the heightened damage of marine ecosystems, Marine Protected Areas (MPAs) have been created for the protection and the conservation of species and habitats. However, their implementation requires accurate data availability used by decision makers to enable their boundaries and zoning. Thus, for this purpose of management, a new method of fish assemblages monitoring (FAST—Fish Assemblages Survey Technique) has been tested in Tunisian marine waters. FAST survey was applied between 2011 and 2012 in three areas with various degrees of geomorphological features and human pressures; the future Marine Protected Area of Cap Serrat–Cap Negro and two coastal areas of Hammamet and Bizerte. The depths of the surveyed 11 stations are between 0 and 20 m. The FAST index is calculated seasonally for targeted species according to their presence / absence, and depending on two size classes. In terms of diversity and species richness, differences between sites were observed and results show that FAST method appears to be relevant, easy to implement and accurately reflects the environmental status of the study site. The advantages and shortcomings of this method were discussed.     

Fish otoliths from the pre-evaporitic (Early Messinian) sediments of northern Italy: their stratigraphic and palaeobiogeographic significance

The study of otolith assemblages from the pre-evaporitic Messinian deposits allows the reconstruction of a fauna of 79 taxa of which 35 could be identified at the specific level. Three of these are new: Diaphus rubus, Myctophum coppa, and Uranoscopus ciabatta. The assemblages reflect mainly a neritic environment influenced by the oceanic realm. Analysis of the global present-day geographic distribution of 42 of the recognised Messinian genera indicates that 88% of these are still living in the Mediterranean, 98% in the Atlantic and 78% in the Indo-Pacific realm. These results are in good agreement with the evolutionary trends documented for the Oligocene and Miocene teleost fauna, specifically an increase in percentage of genera inhabiting the modern Mediterranean, a very high percentage of Atlantic and Indo-Pacific genera, and a slight fall of the importance of present-day Indo-Pacific genera from the Rupelian up to the Late Miocene. Analysing the composition of the Early Messinian fauna at the level of nominal species indicates that about 53% of the species represented in the assemblages are still living in the Recent Mediterranean, and that a significant number of these were already present in the Tortonian. It is interesting that these species are mainly neritic. This seems to confirm that the close affinity of the fossil assemblage with the present-day Mediterranean neritic fauna, which was already recorded at the genus level for the Rupelian fauna, persists during the Neogene and continues until the Pleistocene.     

Life cycles and challenges for fish species that breed in South African estuaries

The literature currently recognizes four guilds of estuarine resident fish species, namely solely estuarine, estuarine and marine, estuarine and freshwater, and estuarine migrant. In this review the life cycles of actual representatives from these four guilds are assessed to determine whether the current definitions, which have never been formally tested, are appropriate to fish species resident in South African estuaries. Detailed information and diagrammatic life cycles are provided for the selected species covered by this review. A potential new estuarine resident guild category is also identified, namely, those taxa that are primarily estuarine but also have subpopulations recorded in both adjacent marine and freshwater habitats. The full range of reproductive characteristics employed by estuary resident species is examined, ranging from live bearers, pouch and nest brooders, to a suite of oviparous taxa that attach their ova to estuarine rocks, shells, and submerged vegetation, all of which assists with larval retention within the estuarine environment. The small size and early reproductive maturity of most estuarine resident species is highlighted, with reduced vulnerability to predation in shallow, sheltered, often turbid estuary waters offering considerable protection during spawning events when compared to the open ocean. In addition, these small fish would not have to move considerable distances at any stage of their life cycle, since egg, larval, juvenile, and adult stages all occur in the same place. The existence of contingent subpopulations within many estuarine resident species is noted, physico-chemical stresses on these species are highlighted, and the eurytopic nature of these small fish taxa emphasized.