Search results for "Reefs"

A New Niche for Anoxygenic Phototrophs as Endoliths

2018

ABSTRACT Anoxygenic phototrophic bacteria (APBs) occur in a wide range of aquatic habitats, from hot springs to freshwater lakes and intertidal microbial mats. Here, we report the discovery of a novel niche for APBs: endoliths within marine littoral carbonates. In a study of 40 locations around Isla de Mona, Puerto Rico, and Menorca, Spain, 16S rRNA high-throughput sequencing of endolithic community DNA revealed the presence of abundant phylotypes potentially belonging to well-known APB clades. An ad hoc phylogenetic classification of these sequences enabled us to refine the assignments more stringently. Even then, all locations contained such putative APBs, often reaching a significant pro…

Artificial Reefs in the Gulf of Castellammare (North-West Sicily): A Case Study

2000

Most of the plans for fish stock replenishment recently undertaken in Sicily have focused on the Gulf of Castellammare. Reasons for choosing this biotope for a restocking plan include the size of the Gulf (300 km2), the importance and traditional role of its fisheries and the existence of information describing the local marine environment. The Gulf of Castellammare is the widest bay in Sicily and fishing has always played a major role in the local economy. Today income from fishing complements that from tourism.

Crostacei Anfipodi associati ai reef di Sabellaria alveolata (Annelida: Sabellariidae) del Canale di Sicilia (Mar Mediterraneo)

2015

We describe diversity and patterns of spatial distribution of the amphipod fauna associated with reefs of the polychaete Sabellaria alveolata (L.) in the Sicily Strait. Samples were collected in June 2013, at three localities. Amphipod assemblages appeared homogeneous in the study area with variability increasing with decreasing spatial scale of observation. Jassa ocia (Bate) and Gammaropsis ulrici Krapp-Schickel & Myers characterized the studied assemblages.

Temporal dynamic of biofilms enhances the settlement of the central-1 Mediterranean reef2 builder Dendropoma cristatum (Biondi, 1859)

2021

Research on marine invertebrate settlement provides baseline knowledge for restoration technique implementation, especially for biogenic engineers with limited dispersion ability. Previously, we determined that the maturity of a biofilm strongly enhances the settlement of the vermetid reef-builder Dendropoma cristatum . In order to elucidate which biofilm features support a higher settlement of this species, we analyse the structure and composition of a marine biofilm over time, through microscopic observations, eukaryotic and prokaryotic fingerprinting analyses and 16S rDNA Illumina sequencing. The vermetid settlement temporal increase matched with the higher biofilm extent on the substrat…

The "Tracked Roaming Transect" and distance sampling methods increase the efficiency of underwater visual censuses.

2018

Underwater visual census (UVC) is the most common approach for estimating diversity, abundance and size of reef fishes in shallow and clear waters. Abundance estimation through UVC is particularly problematic in species occurring at low densities and/or highly aggregated because of their high variability at both spatial and temporal scales. The statistical power of experiments involving UVC techniques may be increased by augmenting the number of replicates or the area surveyed. In this work we present and test the efficiency of an UVC method based on diver towed GPS, the Tracked Roaming Transect (TRT), designed to maximize transect length (and thus the surveyed area) with respect to diving …

METODOLOGIE DI ANALISI DEL PAESAGGIO NELLA VALUTAZIONE DELL’ETEROGENEITÁ STRUTTURALE NEI REEF A VERMETI

2012

Landscape ecology is a discipline that uses many indices to describe environmental dynamics as a function of structural patch organization. Application of landscape ecology methods can be a way to evaluate heterogeneity and fragmentation of a habitat. Landscape indices were applied to evaluate if the algal heterogeneity of a vermetid reef can be related to the reef structure. Results show that heterogeneity is independent from reef width, but algal patches are wider and less abundant in a large cuvette and less wide but in higher number in small cuvette.

Ocean acidification and elevated temperature negatively affect recruitment, oxygen consumption and calcification of the reef-building Dendropoma cris…

2019

Expected temperature rise and seawater pH decrease may affect marine organism fitness. By a transplant experiment involving air-temperature manipulation along a natural CO2 gradient, we investigated the effects of high pCO(2) (similar to 1100 mu atm) and elevated temperature (up to +2 degrees C than ambient conditions) on the reproductive success, recruitment, growth, shell chemical composition and oxygen consumption of the early life stages of the intertidal reef-building vermetid Dendropoma cristatum. Reproductive success was predominantly affected by temperature increase, with encapsulated embryos exhibiting higher survival in control than elevated temperature conditions, which were in t…

Spatial variations in habitat use and food habits of juvenile and adult fishes in a mangal ecosystem (Gazi Bay, Kenya)

2009

Rekomendācijas aizsargājamās jūras teritorijas "Rīgas līča rietumu piekraste" monitoringa metožu uzlabošanai

2021

Akmeņu sēkļi ir svarīgi jūras vides bioloģiskās daudzveidības un kvalitātes nodrošināšanai – tie ir mājvieta gan daudzām sēdošām un peldošām bentisko jūras dzīvnieku un aļģu sugām, gan nozīmīga nārsta vieta zivju sugām. Dažādu abiotisko faktoru ietekmē akmeņu sēkļos nereti veidojas mikrobiotopi vai atšķirīgi biotopu kompleksi, kas savas mozaīkveida struktūras, kā arī mainīgā dziļuma dēļ apgrūtina šo aizsargājamo jūras biotopu monitoringu. Šo apgrūtinājumu dēļ nepieciešams uzlabot monitoringa metožu efektivitāti un rekomendēt tādas monitoringa metodes, kas pietiekami atspoguļotu teritorijas bioloģisko daudzveidību. Galvenās rekomendācijas monitoringa uzlabošanai, būtu veikt monitoringu staci…

Mediterranean bioconstructions along the Italian coast

2018

Marine bioconstructions are biodiversity-rich, three-dimensional biogenic structures, regulating key ecological functions of benthic ecosystems worldwide. Tropical coral reefs are outstanding for their beauty, diversity and complexity, but analogous types of bioconstructions are also present in temperate seas. The main bioconstructions in the Mediterranean Sea are represented by coralligenous formations, vermetid reefs, deep-sea cold-water corals, Lithophyllum byssoides trottoirs, coral banks formed by the shallow-water corals Cladocora caespitosa or Astroides calycularis, and sabellariid or serpulid worm reefs. Bioconstructions change the morphological and chemicophysical features of prima…