Impact of eutrophication on shallow marine benthic foraminifers over the last 150 years in Osaka Bay, Japan

High-resolution foraminiferal analysis was conducted on a short sediment core from the inner part of Osaka Bay, Japan. Changes in foraminiferal assemblages were associated with eutrophication, bottom water hypoxia, and changes in red tide-causing algae. Before the 1920s, the calcareous species Ammonia beccarii, and the agglutinated species Eggerella advena and Trochammina hadai were rare, but calcareous foraminifers in general were abundant. Between the 1920s and 1940s, calcareous foraminifers decreased abruptly in abundance, while A. beccarii, E. advena and T. hadai increased in abundance. This faunal change corresponded in time to an increase in nutrients flowing in through the Yodo River, and bottom water hypoxia related to eutrophication. In the 1960s and 1970s, A. beccarii, E. advena and T. hadai further increased in abundance to become dominant, and many calcareous foraminifers nearly disappeared, corresponding to increasing bottom water hypoxia related to the rapid increase in discharged nutrients during the high economic growth period from 1953 to 1971. After the 1990s, A. beccarii decreased rapidly in abundance and E. advena and Uvigerinella glabra increased in abundance. The main components of red tide-causing algae changed from dinoflagellates to diatoms in the 1980s through 1990s, thus there was a change in the food supply to the benthos, which may have caused the increase in abundance of E. advena and U. glabra.     

锦州湾浮游植物群落结构特征及其对环境变化的响应

锦州湾是我国北方污染严重的海湾,以水体的富营养化和重金属污染为特征。基于2011年8月(夏季)和2012年5月(春季)在锦州湾进行的航次调查,研究了该湾水采浮游植物的群落结构、时空分布及其对生态环境变化的响应。研究结果表明:锦州湾海域浮游植物群落主要由硅、甲藻组成,其生态类型主要为温带近岸型。春季和夏季共鉴定出浮游植物4门41属62种,硅藻在两个季节的物种数和细胞丰度上均占绝对优势,且底栖硅藻比例较高。夏季浮游植物细胞丰度平均值为41.44×103个/L,主要优势种为海链藻Thalassiosira spp.和叉角藻Cerarium furca;春季浮游植物细胞丰度平均值为13.80×103个/L,主要优势种为新月柱鞘藻Cylindrotheca closterium和中肋骨条藻Skeletonema costatum。锦州湾春季和夏季浮游植物群落组成差异明显,冗余分析(Redundancy analysis,RDA)表明硝酸盐浓度和水温分别是夏季和春季影响浮游植物群落结构的最重要环境因子。与历史资料相比,锦州湾优势种发生了显著变化,适于富营养化环境的微型浮游植物和部分耐污种在群落中占优势,表明人类活动引起的水体富营养化以及其它污染物,可能对浮游植物种类组成及分布产生了一定影响。     

The spatial and vertical distribution of living (stained) benthic foraminifera from a tropical,intertidal environment,north Queensland,Australia

We investigated the distribution of living (stained) benthic foraminifera across a tropical, intertidal shoreline adjacent to Cocoa Creek, Queensland, Australia for the purpose of better understanding the nature of test production and ultimately fossil assemblage development within such environments. Short cores (up to 1 m) were collected during the wet and dry season, along an elevational gradient comprising non-vegetated intertidal mudflat and higher-intertidal mangrove forest environments. The distribution of stained specimens can be broadly delineated into assemblages characterising ‘upper mangrove’ (2.64–2.91 m above Lowest Astronomical Tide (LAT)) and ‘low mangrove-mudflat’ (1.62–2.18 m above LAT) environments. Agglutinated species were generally limited to upper mangrove stations. Calcareous species occurred within all of the intertidal environments examined but differ in their composition between upper and lower intertidal settings. Upper mangrove faunas were characterised by the agglutinated species Arenoparrella mexicana, Haplophragmoides wilberti, Miliammina fusca, Miliammina obliqua and Trochammina inflata and the calcareous species Helenina anderseni. Live (stained) assemblages at lower intertidal elevations were dominated by the calcareous species Ammonia aoteana, as well as Rosalina spp., Elphidium oceanicum, Triloculina oblonga, Ammonia pustulosa and Shackoinella globosa.     

Distribution of recent foraminiferal assemblages near the Ombrone River mouth (Northern Tyrrhenian Sea, Italy)

Benthic foraminiferal assemblages in 127 samples, collected at water depth, ranging between 15 and 184 m on the Southern Tuscany continental shelf off the Ombrone River were analysed. Statistical analyses (Cluster and Principal Component Analysis) performed on the 48 most abundant species (>5%) and sedimentological data led to the identification of three clusters related to the size of grain sediment (sand, silt or clay). Q-mode cluster analysis singled out six groups, corresponding to six distinct foraminiferal assemblages: a typical infralittoral assemblage (15-39 m) on sandy silt, clayey silt or silty clay, dominated by Ammonia and Elphidium species, with Eggerelloides scabrus, Rectuvigerina phlegeri and Valvulineria bradyana; a second assemblage (24-78.5 m) associated with vegetated environments or sandy bottoms (Elphidium crispum, Rosalina bradyi, Asterigerinata mamilla, Neoconorbina terquemi, and Tretomphalus concinnus); a third assemblage recognised between 30 and 90 m water depth and characterised by the dominance of the opportunistic species V. bradyana (related to silty bottoms), with Bulimina marginata, R. phlegeri, Ammonia inflata and Ammonia beccarii as other common taxa; an upper circalittoral assemblage (70-100 m) on silty clays, containing B. marginata, Cassidulina carinata and V. bradyana; a lower circalittoral assemblage (95-177 m) on clayey bottoms, with B. marginata, Textularia bocki and Uvigerina mediterranea; and finally, a second lower circalittoral assemblage (104-184 m) on clayey sediments, dominated by two Uvigerina species (U. mediterranea and Uvigerina peregrina), with Sphaeroidina bulloides and B. marginata. The typical V. bradyana assemblage, characterised by relatively low diversity and high dominance, marks the most eutrophicated area running parallel to the coast. The spatial distribution of assemblages is closely associated with sea-bottom sedimentary environments and bathymetry but it is also probably influenced by the outflow of the Ombrone River. The composition, structure and distribution of V. bradyana assemblage suggest an environmental model, useful for paleogeographic reconstruction in areas characterised by a river mouth and a closed morphological setting typical of a nutrient-trap.     

Benthic foraminifera at a scallop aquaculture site in Minonosok Bay,the sea of Japan

The species composition and distribution of benthic foraminifera at a scallop aquaculture site in shallow Minonosok Bay (southern Primorye) were studied. Ninety-three species of benthic foraminifera were found in Minonosok Bay in 1998 and 83 species in 2000; representatives of the families Elphidiidae, Discorbidae, Trochamminidae, and Ataxophragmiidae dominated. In 1998, the calcareous species Cribroelphidium frigidum was most abundant; in 2000, calcareous Protelphidium asterotuberculatum and arenaceous species Trochammina inflata and Eggerella advena were dominant. The effect of scallop cultivation on the distribution of benthic foraminifera was local. The species composition and population density of foraminifera directly under scallop cages were decreased, compared to areas of the bay where there were no mariculture operations.     

Pennisetum setaceum or Pennisetum advena cultivars,what ornamental do we have in our garden

Pennisetum Rich. or following recent taxonomic insights Cenchrus L. is a genus with some 120 species worldwide, especially in warm areas. The genus includes some crops, some ornamentals but mostly species that are considered weedy. The name of one of the weedy species Pennisetum setaceum (Forssk.) Chiov. is also found on labels of ornamental grasses as P. setaceum “Rubrum.” It has been debated to belong to a species on its own Pennisetum advena Wipff & Veldkamp or Cenchrus advena (Wipff & Veldkamp) Morrone, only known from cultivation, whereas others still adhere to a broader species concept of P. setaceum. The recent inclusion of P. setaceum on the EU List of Union concern has revitalized the discussion on this issue for commercial reasons. Based on a morphological and molecular comparison (ITS, rbcL, and the trnh‐psbA intergenic spacer sequences) of the type specimen of P. advena, five of its “cultivars” in trade and collections of P. setaceum from different regions of the world we conclude that plants currently in trade in Western Europe belong to a separate species P. advena. A drooping inflorescence is consistent as is the difference in width of the leaf blade, the leaf blade being flat or involute, the central vein being swollen or not, and the length of the stipe being 0.3–1.1 mm in P. advena and 1.1–3.1 mm in P. setaceum. On the chloroplast markers rbcL and trnH‐psbA, the species consistently differ in 2 and 4 base pairs, respectively. On the nuclear ITS sequence, there is only 90% overlap between the two species. This justifies these ornamentals to be excluded from the List of Union concern of EU regulation 1143/2014.     

Phytoplankton and zooplankton as indicators of water quality in Discovery Bay,Jamaica

Several investigations exist which use planktonic communities as indicators of water quality in Jamaican and Caribbean Bays, however, few are conducted before there are obvious effects of eutrophication. Therefore, most of our ‘baseline’ data are for bays already severely affected by pollution. This study was conducted to assess water quality in Discovery Bay, Jamaica, before there were severe signs of eutrophication. The bay was monitored over a 12-month period (October 1995–September 1996) using 10 stations. Physicochemical data indicated a well mixed upper 5 m of water column, below which discontinuities in temperature/salinity profiles indicated the influence of colder, more saline waters associated with deep offshore currents. Physicochemical variables were within the range for oligotrophic systems with a tendency towards mesotrophic in localized areas close to the shoreline. Signs of anthropogenic stress were associated with the eastern, southwestern and western sections of the bay. Of the over 120 species of phytoplankton found in the waters of Discovery Bay, most were neritic/oceanic and diatoms dominated while 11 were found to be potentially harmful species. While these harmful species occurred at all stations they occurred most frequently at stations on the eastern side of the bay. About 107 zooplankton species were identified, 52 of which were copepods. The species also represented a mix of neritic and oceanic taxa and mean abundances for the area ranged from 1077 m⁻³ at the mouth of the bay to 3794 m⁻³ close to the south shore (station 6). Generally stations closest to shore had greater zooplankton abundances than centrally located bay stations and stations close to oceanic influence. Acartia tonsa and Lucifer faxoni showed greatest densities at shoreline areas of the bay while Oithona plumifera, Undinula vulgaris and Temora stylifera were important at stations closest to oceanic influences. These species were thus considered as indicators of these different areas within the bay. From physicochemical data and the planktonic assemblage, Discovery Bay cannot be considered polluted, it is still more accurately classified as generally pristine with mesotrophic zones in the eastern and southeastern sections of the bay. These data therefore provide a real baseline of conditions for similar tropical coastal embayments.     

Changes in the planktonic copepod community in a landlocked bay in the subtropical coastal waters of Hong Kong during recovery from eutrophication

Tolo Harbour is a poorly flushed bay in the northeastern corner of Hong Kong. Eutrophication caused by discharge of untreated and secondarily treated sewage into the bay was first detected during the 1970s. Increased nutrient input led to a noticeable increase in algal biomass and algal bloom occurrences. Nutrient reduction measures, including the construction of a pipeline to export all sewage effluents from Tolo Harbour, were introduced during the late 1980s. Decline in nutrient levels and decrease in the number of algal blooms have been recorded since 1998 when all nutrient reduction measures became fully operational. Zooplankton samples collected during 2003–2004 revealed that Tolo Harbour still contained a higher density and lower diversity of planktonic copepods compared to Mirs Bay, a less-polluted sea area outside Tolo Harbour. A comparison between data collected in this study to those collected during 1988–1990, several years before nutrient reduction measures were to be fully implemented, showed a decrease in copepod densities and an increase in copepod diversity. Small copepods, notably species of Paracalanus and Oithona, dominated the copepod communities in both periods, but there was an increase in species evenness during 2003–2004, caused by an increase in the number of dominant species. These observations confirm that eutrophication may lead to increases in copepod densities accompanied by increased dominance of small species.     

Spatial Patterns in the Distribution,Diversity and Abundance of Benthic Foraminifera around Moorea (Society Archipelago,French Polynesia)

Coral reefs are now subject to global threats and influences from numerous anthropogenic sources. Foraminifera, a group of unicellular shelled organisms, are excellent indicators of water quality and reef health. Thus we studied a set of samples taken in 1992 to provide a foraminiferal baseline for future studies of environmental change. Our study provides the first island-wide analysis of shallow benthic foraminifera from around Moorea (Society Archipelago). We analyzed the composition, species richness, patterns of distribution and abundance of unstained foraminiferal assemblages from bays, fringing reefs, nearshore and back- and fore-reef environments. A total of 380 taxa of foraminifera were recorded, a number that almost doubles previous species counts. Spatial patterns of foraminiferal assemblages are characterized by numerical abundances of individual taxa, cluster groups and gradients of species richness, as documented by cluster, Fisher α, ternary plot and Principal Component Analyses (PCA). The inner bay inlets are dominated by stress-tolerant, mostly thin-shelled taxa of Bolivina, Bolivinella, Nonionoides, Elongobula, and Ammonia preferring low-oxygen and/or nutrient-rich habitats influenced by coastal factors such as fresh-water runoff and overhanging mangroves. The larger symbiont-bearing foraminifera (Borelis, Amphistegina, Heterostegina, Peneroplis) generally live in the oligotrophic, well-lit back- and fore-reef environments. Amphisteginids and peneroplids were among the few taxa found in the bay environments, probably due to their preferences for phytal substrates and tolerance to moderate levels of eutrophication. The fringing reef environments along the outer bay are characterized by Borelis schlumbergeri, Heterostegina depressa, Textularia spp. and various miliolids which represent a hotspot of diversity within the complex reef-lagoon system of Moorea. The high foraminiferal Fisher α and species richness diversity in outer bay fringing reefs is consistent with the disturbance-mosaic (microhabitat heterogeneity) hypothesis.Calculations of the FORAM Index (FI), a single metric index to assess reef vitality, indicate that all fore- and most back-reef environments support active carbonate accretion and provide habitat suitability for carbonate producers dependent on algal symbiosis. Lowest suitability values were recorded within the innermost bays, an area where natural and increasing anthropogenic influences continue to impact the reefs. The presence of habitat specific assemblages and numerical abundance values of individual taxa show that benthic foraminifera are excellent recorders of environmental perturbations and good indicators useful in modern and ancient ecological and environmental studies.     

Pelagic larvae of bivalve mollusks of Amursky Bay,Sea of Japan

Larvae of 63 Bivalvia taxa were found in Amursky Bay. Of these, 47 were identified to the species level. Larvae of 55 taxa were found throughout the bay. The highest species diversity was recorded in the northeastern part and in the center of the southern part of the bay, as well as at the exit from it. Larvae of Mactra chinensis, Mytilus coruscus, Crassostrea gigas, Teredo navalis, Mya japonica, and Mysella ventricosa were widely distributed in the bay. The maximum numbers of species were observed in July and September. A comparison of species lists using the set-theory method showed that the species complexes typical of different parts of Amursky Bay are formed under the influence of the Razdolnaya River runoff flow from the north and marine waters coming from the south. The mean density of larvae during the observation period was 1100 specimens/m³ in the northern and 735 specimens/m³ in the southern part of the bay. The highest density of larvae in Amursky Bay was observed at the end of June, the beginning of July, and in September; the minimal larval density occurred in April, May, and August. While the species diversity was similarly high, the density of larvae was significantly higher in Amursky Bay than in the nearby Ussuriisky Bay.     

Foraminiferal distribution on the continental margin off Nova Scotia

Q-mode factor analysis of total foraminiferal abundance data (living plus dead) from 250 grab samples taken from the continental margin off Nova Scotia allows the determination of eight factor assemblages. On the northeastern shelf, an exclusively agglutinated assemblage dominated byAdercotryma glomerata occupies both banks and basins. Central shelf basins contain a predominantly calcareous assemblage dominated byGlobobulimina auriculata andNonionellina labradorica. Transitional between these two factor assemblages is an agglutinated assemblage dominated bySaccammina atlantica. Consistently present along the shelf edge is aTrifarina angulosa assemblage. In northeastern bays and a few samples near Sable Island, an agglutinatedEggerella advena assemblage is found. A relict and transport affected assemblage dominated byElphidium excavatum occurs in the southwestern approaches to Emerald Basin. Sandy/gravelly areas of the inner shelf and outer bank regions are characterized by aCibicides lobatulus assemblage.The statistical relationships of these defined assemblages to various aspects of the marine environment (depth, temperature, salinity, percent gravel, sand and mud) were investigated through multiple regression techniques. Results indicate that the present foraminiferal distribution patterns off Nova Scotia are influenced by the prevailing watermass characters and substrate. TheAdercotryma glomerata assemblage is influenced by the presence of cold, (0–4°C) low salinity waters (32–33‰) of arctic, Labrador Current origin. The central basin assemblage (G. auriculata) is related to warmer (8–12°C) more saline waters (35‰) of slope origin. The transition between these two bottom waters is marked by the opportunisticSaccammina atlantica assemblage. Preferred substrate character possibly determines the occurrence of theCibicides lobatulus, Islandiella islandica andEggerella advena assemblages.Trifarina angulosa shows a significant relationship to salinity and depth.Although the surficial sediments on the Nova Scotian Shelf are largely the product of reworking of glacial deposits during late glacial and early Holocene times, all but theE. excavatum factor assemblage appear to be in equilibrium with the modern oceanographic regime.     

Diatom community succession in the recent history of a eutrophic Yunnan Plateau lake, Lake Dianchi, in subtropical China

Fish introduction, eutrophication and disappearance of aquatic vegetation are important disturbances of aquatic ecosystems, especially in plateau lakes, which are generally considered to be very vulnerable. Fish were introduced to Lake Dianchi, a eutrophic plateau lake in southwest China, in the late 1950s and 1970s. After the introduction, invasive fish became the dominant species, and the total fish yield increased. Meanwhile, the trophic level of Lake Dianchi had a tendency to increase in the past decades because of the increases in human activities in the watershed area. In addition, the area of aquatic vegetation decreased from more than 90 to 1.8% of the lake area from the 1950s to 2000. This study investigated the effects of fish introduction, eutrophication and aquatic vegetation on the diatom community of Lake Dianchi by examining the changes of microfossil diatom assemblage and abundance. Results showed that the absolute abundance and diatom assemblages changed after fish were introduced. The endemic species, Cyclotella rohomboideo-elliptica, disappeared with the introduction of fish and increasing trophic levels after 1958. Fragilaria crotonensis entered into the lake with the introduction of fish and gradually thrived in the lake after 1958. Diatom species numbers also decreased gradually from 21 to 9 from the past to present. Epiphytic diatoms disappeared with the decrease of aquatic vegetation after 1985. Our study indicated that eutrophication was the most important process determining diatom abundance, and fish introduction was a secondary process determining diatom abundance, while aquatic vegetation had a more important role in structuring the diatom community in this eutrophic plateau lake.     

Long term study on the influence of eutrophication, restoration and biomanipulation on the structure and development of phytoplankton communities in Feldberger Haussee (Baltic Lake District, Germany)

Feldberger Haussee provides a classic example of eutrophication history of hardwater lakes in the Baltic Lake District (Germany) and of changes in their algal flora during the 20th century. The lake originally was regarded as slightly eutrophic. A process of drastic eutrophication from the 1950s until the end of the 1970s caused mass developments of blue-green and green algae. A restoration program was started in the 1980s to improve the water quality of the lake using both diversion of sewage outside the catchment area, and biomanipulation by altering the fish community. This restoration program led to positive changes in the lake ecosystem. Direct effects of biomanipulation resulted in an increase of herbivorous zooplankton, a decrease of phytoplankton biomass, and an increase of water transparency. The recovery of Feldberger Haussee also may have been indirectly enhanced by an increase in nutrient sedimentation as a consequence of intensified calcite precipitation, decrease in phosphorus remobilization due to a pH-decrease, increased NIP-ratio, and recolonization of the littoral zone by macrophytes. This paper concentrates on the long term development of the phytoplankton community as a response to changes in the food web structure as well as to alterations in the chemical environment of the algae. Both are reflected in four major stages passed by the algal assemblage between 1980 and 1994: (1) From 1980-summer 1985 dense green algal populations were found indicating similar conditions as in the 1970s during the period of maximum eutrophication. (2) A diverse phytoplankton community during summer 1985–1989 showed the first effects of a recovery. (3) From 1990–1992 the phytoplankton was characterized by ungrazeable filamentous blue-green algae first of all as a response to increased herbivory of zooplankton on edible species and to increasing N/P-ratios. (4) Finally, the algal species diversity increased in 1993 and 1994 whereas the phytoplankton biomass decreased showing the success of the combined restoration measures.     

A new small mammal assemblage from the M013 Terre Rosse fissure filling (Gargano,South-Eastern Italy)

The taxonomic study of the small mammal assemblage from fissure M013, sampled by a team of the University of Torino during the 2005–2009 excavations in the Dell’Erba Quarry (Apricena, Foggia) is presented. The assemblage includes the Echinosoricinae Apulogalerix cf. pusillus and the Crocidosoricinae ?Lartetium cf. dehmi; the Myomiminae species Stertomys simplex and Stertomys lyrifer; a new genus and species of Cricetodontinae and a single specimen of Hattomys cf. nazarii. Muridae include Mikrotia cf. parva, Mikrotia sp. 1 and a new genus and species of Murinae, phylogenetically related to Mikrotia. The occurrence of the new Murinae, the new Cricetodontinae, the two species of glirids and the Crocidosoricinae, as well as the absence of Apodemus and Prolagus, indicates M013 as the oldest Gargano's faunal assemblage known to date, despite the occurrence of Hattomys cf. nazarii, Mikrotia cf. parva and Mikrotia sp. 1, which most probably results from infiltrations from younger fissure fillings. The M013 assemblage is an absolute novelty for the Abruzzo-Apulian Palaeobioprovince, opening new perspectives for the timing and mode of dispersal of the forerunners of the Gargano fauna.     

Benthic foraminiferal assemblages between two major extinction events: the Paleocene El Kef section,Tunisia

The development of benthic foraminiferal assemblages from the Paleocene outcrops of the El Haria Formation near El Kef, Tunisia is discussed qualitatively and quantitatively. The aim of the study is to reconstruct the paleoenvironmental evolution between the K/Pg boundary interval and the late Paleocene event, and to compare this evolution with results from other sites along the southern Tethyan margin. Eighty-four samples, covering virtually the entire Paleocene, provide a dataset that allows detailed qualitative and multivariate analysis. The benthic foraminiferal faunas indicate a complex pattern of environmental changes during the Paleocene, marked by the succession of different benthic associations. Following the K/Pg boundary event, community restoration was characterized by the gradual build-up of faunal diversity. Decreasing dominance and the entry of taxa common to normal marine, outer neritic to upper bathyal environments indicate the completion of the ecosystem restoration in Zone Plb. A highly diverse benthic foraminiferal assemblage persisted throughout the remainder of the early Paleocene into the earliest late Paleocene. At the P3a-P3b zonal transition relative sea-level lowering is evidenced by the sudden disappearance or decreasing abundance of deeper-water taxa (e.g. Anomalinoides affinis, A. susanaensis, Gavelinella beccariiformis). Neritic deposition continued into Zone P4, when trophic levels at the seafloor increased as indicated by the entry and increasing dominance of species such as Anomalinoides cf. aegyptiacus, Bulimina midwayensis, and B. strobila, which we consider to be sensitive to eutrophication. The combined effect of shallowing and the subsequent eutrophication led to the establishment of assemblages similar to late Paleocene benthic foraminiferal assemblages from Egyptian sections, some of which record the latest Paleocene extinction event. These assemblages were interpreted to be indicative of a middle neritic, highly eutrophic environment. Enhanced vertical fluxes of organic matter along the southern Tethyan margin may have resulted from intensified upwelling. This eventually led to oxygen deficiency at the seafloor. It appears that oxygen-deficient, high-productivity shelves were a common feature of the southern Tethyan margin during the latest Paleocene.     

Ecological Meltdown in the Firth of Clyde,Scotland: Two Centuries of Change in a Coastal Marine Ecosystem

Background

The Firth of Clyde is a large inlet of the sea that extends over 100 km into Scotland''s west coast.

Methods

We compiled detailed fisheries landings data for this area and combined them with historical accounts to build a picture of change due to fishing activity over the last 200 years.

Findings

In the early 19^th century, prior to the onset of industrial fishing, the Firth of Clyde supported diverse and productive fisheries for species such as herring (Clupea harengus, Clupeidae), cod (Gadus morhua, Gadidae), haddock (Melanogrammus aeglefinus, Gadidae), turbot (Psetta maxima, Scophthalmidae) and flounder (Platichthys flesus, Pleuronectidae). The 19^th century saw increased demand for fish, which encouraged more indiscriminate methods of fishing such as bottom trawling. During the 1880s, fish landings began to decline, and upon the recommendation of local fishers and scientists, the Firth of Clyde was closed to large trawling vessels in 1889. This closure remained in place until 1962 when bottom trawling for Norway lobster (Nephrops norvegicus, Nephropidae) was approved in areas more than three nautical miles from the coast. During the 1960s and 1970s, landings of bottomfish increased as trawling intensified. The trawl closure within three nautical miles of the coast was repealed in 1984 under pressure from the industry. Thereafter, bottomfish landings went into terminal decline, with all species collapsing to zero or near zero landings by the early 21^st century. Herring fisheries collapsed in the 1970s as more efficient mid-water trawls and fish finders were introduced, while a fishery for mid-water saithe (Pollachius virens, Gadidae) underwent a boom and bust shortly after discovery in the late 1960s. The only commercial fisheries that remain today are for Nephrops and scallops (Pecten maximus, Pectinidae).

Significance

The Firth of Clyde is a marine ecosystem nearing the endpoint of overfishing, a time when no species remain that are capable of sustaining commercial catches. The evidence suggests that trawl closures helped maintain productive fisheries through the mid-20^th century, and their reopening precipitated collapse of bottomfish stocks. We argue that continued intensive bottom trawling for Nephrops with fine mesh nets will prevent the recovery of other species. This once diverse and highly productive environment will only be restored if trawl closures or other protected areas are re-introduced. The Firth of Clyde represents at a small scale a process that is occurring ocean-wide today, and its experience serves as a warning to others.     

Benthic foraminiferal assemblages in the severely polluted coastal environment of Drapetsona-Keratsini,Saronikos Gulf (Greece)

Surface sediments were collected from the coastal zone of Drapetsona–Keratsini (Saronikos Gulf, Greece) in December 2012 for determining the local benthic foraminiferal community, identifying their spatial distribution patterns, and evaluating the response of foraminiferal species to geochemical composition through the hierarchical cluster analysis, principal component analysis and Spearman's rho correlation. Foraminifera can be classified into three distinct assemblages associated with the granulometry, elemental geochemistry, particulate organic carbon content and degree of sediment contamination. A relatively low-diversity assemblage, dominated by stress-tolerant taxa with Ammonia tepida Bolivina spathulata and Bulimina elongata being the prevailing species, is characteristic of the silty seabed of the main part of Drapetsona coastal zone and the Keratsini Port central basin, where organic carbon content, aliphatic and polycyclic aromatic hydrocarbons concentrations and trace metal loads are greatly elevated. On the sandy bottom of the investigated area, relatively high frequencies of miliolids prevail. An epiphytic rotaliid-dominated assemblage is recorded in the slightly-polluted sedimentary bottom of the inner and western part of the Keratsini Port.     

Foraminiferal biofacies eco-succession and Holocene sealevels,Port Pirie,South Australia

At Port Pirie, on the eastern coast of Northern Spencer Gulf, South Australia, 10 cores taken along a 3 km transect recovered a succession of Holocene marine sediments. Facies representing shallow subtidal Posidonia seagrass and intertidal sandflat, mangrove and back-storm ridge coastal lagoon environments are recognized on the basis of lithological characteristics and their preserved foraminifera. An assemblage dominated by Nubecularia lucifuga, Peneroplis planatus and Discorbis dimidiatus signifies sediments of shallow subtidal Posidonia seagrass meadows. Subtle changes in the numerical distribution of these species upcore are used to infer the change from subtidal to intertidal sandflat facies; Elphidium crispum and Elphidium macelliforme become more numerous across this transition. The mangrove facies is characterized by Trochammina inflata. This species is present significantly in only one seaward core where modern mangrove woodland continues to grow today and no equivalent biofacies are recognized in other cores. The lagoonal sediments preserve a rich assemblage of species of euryhaline foraminifera. Together with those of the mangrove woodland, they exhibit an ecological succession which can be related to decreasing intervals of tidal inundation and increasing salinity. Helenina anderseni, with subordinate Ammonia beccarii, and Elphidium cf. articulatum are the pioneer species in the euryhaline setting, giving way to Trichohyalus tropicus and Miliolinella schauinslandi. Late stages of hypersaline sedimentation are characterized by Triloculina inflata+Triloculina oblonga. In the mangroves, H. anderseni, A. beccarii and Elphidium cf. articulatum are replaced by Trochammina inflata as the dominant species. In turn, as further sediment aggradation leads to ever shorter intervals of tidal inundation at the landward side of the mangrove woodland, Trochammina inflata is overtaken by Ammobaculites barwonensis. Quantitative foraminiferal biofacies analysis confirms and refines the sedimentological interpretation of intertidal sediment facies from macro-observations of the core materials. It provides independent estimates of the elevation of key facies boundaries in cores and confirmation of a general relative fall in sealevel in Northern Spencer Gulf over the past 7000 yr.     

Composition and spatio temporal variability of the epiphytic macroalgal assemblage of Fucus vesiculosus Linnaeus at Clare Island, Mayo, western Ireland

The composition and the patterns of spatial and temporal variability of the epiphytic assemblages of Fucus vesiculosus of Clare Island, on the western coast of Ireland, were investigated for an annual cycle. Specimens of Fucus were collected on seven sampling dates from three sites of the island (Portlea, Kinnacorra and Portnakilly). Data of cover of the most common epiphytic species were collected and analysed by multivariate and univariate techniques. Elachista fucicola, Polysiphonia lanosa, Porphyra umbilicalis, Spongonema tomentosum and Ulva compressa were the most common species. Spatial and temporal variation was detected both for the whole assemblage and for the most abundant species. In general, the assemblage was quantitatively more abundant and diverse in spring-summer than in autumn-winter. In spring-summer, there was a clear differentiation among the assemblage of Portnakilly and the assemblages of the other two sites. Individual species were also generally more abundant in spring-summer and their distribution at the three sites was often not consistent in time; P. lanosa was the only epiphyte for which a consistent effect of site was found. Spatial variation on a scale of meters to tens of meters was the most striking pattern of distribution of the epiphytic assemblage; significant effects related to this spatial scale were detected both for the whole assemblage and for individual species. Phenological patterns of the epiphytic species determining availability of propagules and limited dispersal, leading to aggregated patterns of distribution, are considered the main factors responsible of such patchiness. The importance of the incorporation of small spatial scales in sampling designs analysing the distributional patterns of epiphytic assemblages is discussed.