Search results for " Reef"

The influence of thermal extremes on coral reef fish behaviour in the Persian Gulf

2019

AbstractDespite increasing environmental variability within marine ecosystems, little is known about how coral reef fish species will cope with future climate scenarios. The Arabian/Persian Gulf is an extreme environment, providing an opportunity to study fish behaviour on reefs with seasonal temperature ranges which include both values above the mortality threshold of Indo-Pacific reef fish, and values below the optimum temperature for growth. Summer temperatures in the Gulf are comparable to those predicted for the tropical ocean by 2090-2099. Using field observations in winter, spring and summer, and laboratory experiments, we examined the foraging activity, distance from refugia and res…

Persentase Tutupan Terumbu Karang di Perairan Pasir Putih Kabupaten Manokwari

2017

Penelitian ini dilakukan pada bulan Oktober sampai November 2014 di perairan Pasir Putih Kabupaten Manokwari, berlokasi di Pantai Air Salobar. Tujuan penelitian adalah untuk mengetahui persentase tutupan terumbu karang, kualitas fisik-kimia air dan korelasi kualitas fisik-kimia air terhadap persentase tutupan terumbu karang di bagian barat daya perairan Pasir Putih, Manokwari. Metode yang digunakan untuk memperoleh data persentase tutupan karang adalah Point Intercept Transect (PIT) pada kedalaman 3 m (Transek I), 7 m (Transek II) dan 10 m (Transek III). Hasil pengamatan diperoleh persentase tutupan karang pada Transek I adalah 91%, Transek II adalah 78% dan Transek III adalah 54%. Kondisi …

Freshwater discharge and sediment dispersal — Control on growth, ecological structure and geometry of Late Miocene shallow-water coral ecosystems (ea…

2007

Abstract Insolation-driven oceanographic changes are well documented in the Mediterranean deep-sea record and reflect episodes of high precipitation and/or freshwater discharge. In the shallow-water record, however, changes in relative sea-level and sea surface temperature are usually regarded as prime controls on Miocene coral reefs, whereas pulses of freshwater influx represent a hitherto unrecognized factor influencing their growth, ecological structure and geometry. On the island of Crete (NW Messara Basin, Greece) early Tortonian coral biostromes occur associated with deltas along the basin margin and rimming islands formed by large uplifted tectonic blocks. In turbid delta environment…

Interspecific-Competition Strongly Constrains Species-Richness and Species-Abundance Evenness in a Tropical Marine Molluscan Community Inhabiting Cau…

2021

Increasing species-richness at the local scale (within species communities) is accommodated, first, by the diversification of the niches respectively associated to species. Yet, in case of excessive supply in colonizing species issued from the regional pool, the corresponding increase in the number of solicited niches may lead to some “niche-overcrowding” resulting in significant niche-overlaps. Then, second, strong interspecific competition for shared resource can arise, triggered by the density in individuals among those species co-occurring at niche-overlaps. Accordingly, the accommodation of species-richness within a local community involves a balance between (i) the positive contributi…

One Rational Strategy for Restoration of Coral Reefs: Application of Molecular Biological Tools to Select Sites for Rehabilitation by Asexual Recruits

2000

Experiments for reef rehabilitation were performed at two selected sites near Hurghada (Red Sea, Egypt) the reef close to the Marine Biological Station (with a high sedimentation rate from landfilling) and El-Fanadir Reef (a clear water site). Since only little is known about the influence of the physical environmental conditions, novel molecular biological approaches have been introduced to assess the metabolic status of corals. In order to avoid possible interference with symbionts the molecular studies have been performed with the octocoral Dendronephthya klunzingeri; this species does not contain zooxanthellae. The metabolic enzymes fructose-1,6-bisphosphatase and the succinat-dehydroge…

Lowstand carbonates, highstand sandstones?

2003

The sedimentary facies, sediment dynamics and sequence architecture of modern high-energy shelves in the mid and high latitudes are largely governed by wave abrasion processes. Cool-water carbonates may form there, if the influx and/or net accretion of siliciclastics is kept at a minimum. Little dilution of the carbonate produced in situ is generally promoted by a wide "epicontinental" shelf, subdued topography of the adjacent mainland, the predominance of limestone outcrops, and an arid climate. The aforementioned requirements are rarely met, and thus will automatically lead to the formation of mixed siliciclastic-cool-water carbonates. Such an example is found in the Early to Mid-Miocene …

Trophic cascades in benthic marine ecosystems: lessons for fisheries and protected-area management

2000

An important principle of environmental science is that changes in single components of systems are likely to have consequences elsewhere in the same systems. In the sea, food web data are one of the few foundations for predicting such indirect effects, whether of fishery exploitation or following recovery in marine protected areas (MPAs). We review the available literature on one type of indirect interaction in benthic marine ecosystems, namely trophic cascades, which involve three or more trophic levels connected by predation. Because many indirect effects have been revealed through fishery exploitation, in some cases we include humans as trophic levels. Our purpose is to establish how wi…

REMOTELY PILOTED AIRCRAFT SYSTEMS (RPAS) APPLICATION FOR STRUCTURE DESCRIPTION OF MEDITERRANEAN VERMETID REEFS

2016

Vermetid gastropods are coastal habitat engineers which build biogenic platforms typical of intertidal rocky shores of central and south -east of the Mediterranean. These bioconstructions create a secondary habitat which increases resource availability and space for organisms, locally transforming the environment and modifying coastal geomorphology. Biological characteristics and physical structure of these bioconstructions are commonly studied by field-based sampling. Nevertheless, a lot of time is required to collect data over large areas of reef, field conditions can impair data collection and direct reef image interpretation may be a challenge due to their intertidal position. In this s…

Selezione dell’habitat in quattro specie ittiche criptobentoniche nell’infralitorale superiore di coste rocciose in Mediterraneo

2010

Invasive mussels directly threat intertidal vermetid reef: some evidences from a Sicilian MPA

2009

Biological invasions pose a great threat to natural communities. Brachidontes pharaonis is an Eritrean mussel that has accessed in the Mediterranean sea shortly after the opening of the Suez Canal. At the beginning it had a restrained distribution with small local populations along the Israeli intertidal coast. More than a hundred years later it spread westward as far as NW Sicily, colonizing some hyperaline and natural habitats. Previous studies along the Israeli coast have proved that anthropogenic habitat modi#- cations occurring on vermetid reefs may promote the colonization of this invasive mussel causing a reduction of the indigenous mussel Mytilaster minimus. This study focuses on a …