Search results for "benthic foraminifera"

“Hidden invaders” conquer the Sicily Channel and knock on the door of the Western Mediterranean sea

2019

Abstract This study updates the current distribution, range expansion and establishment status of the non-indigenous species Amphistegina lobifera Larsen, 1976 and other foraminifera that are cryptogenic in the Sicily Channel. Prior to this study, amphisteginids were reported from the Levantine Basin, the Central Mediterranean (Tunisia, Malta, Pelagian islands) and the southern Adriatic Sea. Here, we provide new records documenting a north-western expansion in the Central Mediterranean. In summer-autumn 2017 and spring-summer 2018, we collected algae and sediment samples from shallow coastal habitats along the shores of the Maltese archipelago, southern and north-western Sicily, Pantelleria…

Seaweed fails to prevent ocean acidification impact on foraminifera along a shallow-water CO2 gradient

2014

Ocean acidification causes biodiversity loss, alters ecosystems, and may impact food security, as shells of small organisms dissolve easily in corrosive waters. There is a suggestion that photosynthetic organisms could mitigate ocean acidification on a local scale, through seagrass protection or seaweed cultivation, as net ecosystem organic production raises the saturation state of calcium carbonate making seawater less corrosive. Here, we used a natural gradient in calcium carbonate saturation, caused by shallow-water CO2 seeps in the Mediterranean Sea, to assess whether seaweed that is resistant to acidification (Padina pavonica) could prevent adverse effects of acidification on epiphytic…

Assessing the effect of mercury pollution on cultured benthic foraminifera community using morphological and eDNA metabarcoding approaches

2018

Mercury (Hg) is a highly toxic element for living organisms and is known to bioaccumulate and biomagnify. Here, we analyze the response of benthic foraminifera communities cultured in mesocosm and exposed to different concentrations of Hg. Standard morphological analyses and environmental DNA metabarcoding show evidence that Hg pollution has detrimental effects on benthic foraminifera. The molecular analysis provides a more complete view of foraminiferal communities including the soft-walled single-chambered monothalamiids and small-sized hard-shelled rotaliids and textulariids than the morphological one. Among these taxa that are typically overlooked in morphological studies we found poten…

A SMALL INVADER CONQUERS SICILY: AMPHISTEGINA LOBIFERA (FORAMINIFERA: AMPHISTEGINIDAE)

2018

The highly invasive Amphistegina lobifera (Larsen, 1976), a benthic foraminiferal species native to the Red Sea, has colonized the Eastern Mediterranean through the Suez Canal and altered the native community structure. More recently, it has been reported from Malta and the Pelagian Islands within the Sicily channel. Here, we report new records from the southern coasts of Sicily, where we found it abundant both in the soft-bottom sediment and as epiphyt on algae. The occurrence of A. lobifera in Pantelleria and Favignana islands represents the Mediterranean westernmost record of this non-indigenous species.

Assessing the effect of mercury pollution on cultured benthic foraminifera using DNA metabarcoding and morphological approaches

2016

Heavy metals such as mercury (Hg) occur in ecosystems from both natural sources and human activities, with large variations in concentrations and pose a significant health hazard through bioaccumulation and biomagnification. The aim of this experimental study is to assess the impact of different concentrations of Hg through time on the diversity of cultured benthic foraminifera. Tanks with concentrations of Hg up to 100 ppm were considered. Mesocosms containing 1-cm-thick sediment from each tank were subsampled at pre-established time intervals for geochemical (Hg content), morphological and molecular analyses. Morphological analyses were based on both Rose Bengal and the CellTracker Green …

High-frequency modification of the central Mediterranean seafloor environment over the last 74 ka

2022

Here we present a high-resolution record of benthic foraminiferal assemblages for the last 74 kyr from the Sicily Channel Ocean Drilling Program Leg 160 Site 963. Benthic foraminiferal results are compared with geochemical (benthic and planktic δ18O and δ13C) and calcareous plankton data, previously acquired on the same marine core sediments. Within the succession, three benthic foraminifera compositional zones were defined. Temporal changes in the assemblages are interpreted in the context of the modification of subtropical and temperate climate systems that affected the Mediterranean thermohaline circulation. A close connection between bottom conditions in the Sicily Channel and eastern M…

Influence of waste water in marine ecosystem: preliminary data on benthic foraminifera assemblages and metal concentration in marine sediments

2007

Preliminary data on correlations between aberrant benthic foraminifera and metal concentrations in sediments from Palermo and Termini gulfs (Sicily)

2005

Organic matter quantity and quality, metals availability and foraminiferal assemblages as environmental proxy applied to the Bizerte Lagoon (Tunisia)

2016

International audience; This study analyzes the benthic trophic state of Bizerte Lagoon (Tunisia) based on the total organic matter and the bioavailability of biopolymeric carbon including proteins (PTN), carbohydrates (CHO), lipids (LIP), chlorophyll a, as well as bacteria counts. The overall simultaneously extracted metals (SEM), and acid volatile sulfides (AVS) as well as the SEM/AVS ratio indicative of the toxicity of the sediments also were analyzed aiming to study their impact in the dimension, composition and structure of both dead and living benthic foraminiferal assemblages.In the studied sites TOC content is relatively high and the PTN/CHO values indicate that they can be consider…

Response of benthic foraminifera to heavy metal contamination in marine sediments (Sicilian coasts, Mediterranean sea)

2011

To examine the suitability of benthic foraminifera and their test deformations as bioindicators of pollution in coastal marine environments, we studied foraminifera and metal concentrations in 72 marine sediment samples, collected from the inner shelf along the Sicilian coast (Gulfs of Palermo and Termini) and on the south-eastern coast of Lampedusa Island. These areas are characterised by different environmental conditions. On the basis of pollution sources and foraminiferal assemblages, we recognised different zones in the Gulf of Palermo. The most polluted zones showed high metal concentrations, and low diversity of benthic foraminifera with species typical of stressed environments. By c…