scholarly journals Sea turtle diving and foraging behaviour around the Greek Island of Kefalonia

2000 ◽  
Vol 80 (4) ◽  
pp. 761-762 ◽  
Author(s):  
Jonathan D.R. Houghton ◽  
Andrew Woolmer ◽  
Graeme C. Hays
Keyword(s):  
Foraging Behaviour ◽  
Mytilus Galloprovincialis ◽  
Posidonia Oceanica ◽  
Sea Turtle ◽  
Bivalve Mollusc ◽  
Food Sources ◽  
Neutral Buoyancy ◽  
Sea Grass ◽  
Foraging Site ◽  
Greek Island

The discovery of a shallow water (<2 m) foraging site off the Greek Island of Kefalonia, where diving and foraging behaviour of male loggerhead turtles (Caretta caretta) could be observed simultaneously, was of great interest. The preferred food sources were shown to be the bivalve mollusc Mytilus galloprovincialis, the sea grass Posidonia oceanica, and the entrails of fish discarded by local fishermen. Whilst foraging, the turtles generally rested on the seabed and employed their forelimbs to clear away detritus from their selected prey. Foraging dives were of short duration (mean ±SE = 2.3 ±0.43 min, N=96) compared to deeper dives reported in the literature presumably, because of the small lung volumes required to attain neutral buoyancy at such shallow depths.

scholarly journals Lipid metabolism of sea urchin Paracentrotus lividus in two contrasting natural habitats

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Roberto Anedda ◽  
Silvia Siliani ◽  
Riccardo Melis ◽  
Barbara Loi ◽  
Maura Baroli
Keyword(s):  
Sea Urchins ◽  
Paracentrotus Lividus ◽  
Posidonia Oceanica ◽  
Food Sources ◽  
Gut Contents ◽  
Total Lipids ◽  
Natural Habitats ◽  
Recovery Stage ◽  
Sea Grass ◽  
Halopteris Scoparia

AbstractSea urchins Paracentrotus lividus were harvested monthly from April 2015 to March 2016 from two sites in Sardinia (Italy). The two sites, a Posidonia oceanica meadow and a rocky bottom habitat, were naturally characterized by different food sources and availability, being mainly populated by the sea grass Posidonia oceanica and the brown algae Halopteris scoparia, respectively. Total lipids showed a minimum during winter in mature gonads, and a maximum in the summer (recovery stage). Fatty acid (FA) profiles of gut contents and gonads differed from those of the most available food sources. Levels of C18:3 (n-3) (ALA) discriminated samples from the two sites. Despite the very low amounts of C20:5 (n-3) (EPA) and C20:4 (n-6) (ARA) in P. oceanica, the main FA in gonads and gut contents were EPA and ARA in both sites. Increase in green algae intake prior to gametogenesis, especially C. cylindracea, likely affected EPA and ARA levels in gonads. The results show that P. lividus is able to concentrate lipids in gut contents and also to selectively store EPA, ARA and their precursors ALA and 18:2 (n-6) (LA). Moreover, bioconversion of ALA to EPA and of LA to ARA in P. lividus is suggested.

scholarly journals An ecological study of Electra posidoniae Gautier, 1954 (Cheilostomata, Anasca), a bryozoan epiphyte found solely on the seagrass Posidonia oceanica (L.) Delile, 1813

2020 ◽  
Vol 144 (1) ◽  
Author(s):  
Gilles Lepoint ◽  
Olivier Mouchette ◽  
Corine Pelaprat ◽  
Sylvie Gobert
Keyword(s):  
Water Column ◽  
Posidonia Oceanica ◽  
Early Spring ◽  
Food Sources ◽  
Seagrass Ecosystem ◽  
Life Traits ◽  
Colonization Dynamics ◽  
Marine Angiosperms ◽  
The Relationship ◽  
Quantitative Importance

The bryozoan Electra posidoniae Gautier is found solely on the leaves of the Neptune grass Posidonia oceanica (L.) Delile, dominating the leaf epifauna of this seagrass. Epiphytes of marine angiosperms (or seagrasses) often play an important role in ecosystem functioning, for example as food web suppliers. As dysfunction of the epiphytic component is often implied in human-induced seagrass decline, it is important to understand the dynamics and life traits of this community in pristine areas. This study involved the monthly assessment of colonization dynamics, biomass seasonality, and diet composition through measurements of stable isotopes, in E. posidoniae at a depth of 10 m in the Revellata Bay (Corsica, Mediterranean Sea). Ancestrulae (i.e. colony founders) appeared towards the end of winter and were very selective in their settlement position along the leaves of P. oceanica. A maximum of 100,000 colonies per square meter was recorded. Colonies of E. posidoniae dominated the epiphytic community biomass in early spring, but were overtaken by epiphytic algae in June. Food shortage could be involved in this reduction in dominance. Although stable isotope ratios of C, N and S showed that this suspension feeder mainly relies on the water column for its food, other food sources such as re-suspended epiphytic diatoms could be important in late spring (i.e. after the phytoplanktonic bloom). Additionally, a contribution of seagrass phytodetritus to the diet of this species cannot be excluded. The species was almost absent in winter, raising the question of its recruitment in spring. This study confirms the quantitative importance of this species in the seagrass meadow and explores its role in the relationship between the water column and this seagrass ecosystem.

Feeding habits of the burrowing shrimp Alpheus macellarius

2004 ◽  
Vol 84 (6) ◽  
pp. 1199-1202 ◽  
Author(s):  
N.E. Palomar ◽  
M.A. Juinio-Meñez ◽  
I. Karplus
Keyword(s):  
Organic Matter ◽  
Feeding Habits ◽  
Organic Matter Content ◽  
The Philippines ◽  
Matter Content ◽  
Food Sources ◽  
Feeding Mode ◽  
Field Surveys ◽  
Sea Grass ◽  
Deposit Feeding

The diet and feeding behaviour of the burrowing shrimp Alpheusmacellarius (Decapoda: Alpheidae) in sea grass beds in the Philippines were evaluated in the present study through field and laboratory activities. Sediment organic matter and sea grass appear to be important food sources for the shrimp based on the combined results of field surveys, gut content, stable isotope (δ13C) and sediment C content analyses. There was a significant positive correlation between organic matter content in the sediment and shrimp densities. In terms of behaviour, observations under controlled set-ups detected marked trends in duration and frequency of feeding. Feeding bouts became longer and more recurrent as the days progressed. Periodicity was exhibited with burrowing generally performed in the morning and feeding in the afternoon. A deposit-feeding mode was predominant in tank conditions as demonstrated by the shrimp's behaviour and burrow features.

Lipids that contain arsenic in the Mediterranean mussel, Mytilus galloprovincialis

2020 ◽  
Vol 17 (3) ◽  
pp. 289 ◽  
Author(s):  
Fabiana P. Freitas ◽  
Georg Raber ◽  
Kenneth B. Jensen ◽  
António J. A. Nogueira ◽  
Kevin A. Francesconi
Keyword(s):  
High Performance ◽  
Mytilus Galloprovincialis ◽  
Trophic Levels ◽  
Food Sources ◽  
Tissue Type ◽  
Unicellular Algae ◽  
Molecular Mass Spectrometry ◽  
Mediterranean Mussel ◽  
The Mediterranean ◽  
First Time

Environmental contextAlthough arsenic-containing lipids are widespread in marine environments, their origin remains unknown. We show that the arsenolipids in a filter-feeding bivalve mollusc closely match those found in marine food sources, including unicellular algae and bacteria. The results demonstrate the role of lower trophic levels in determining the forms of arsenic found in higher organisms. AbstractArsenic-containing lipids, arsenolipids, are widely found among marine organisms, but their origin and possible biochemical roles remain unknown This work describes the diversity and abundance of arsenolipids in the digestive gland and mantle of nine specimens of the Mediterranean mussel, Mytilus galloprovincialis. By using high performance liquid chromatography (HPLC) coupled to both elemental and high-resolution molecular mass spectrometry, we identified 36 arsenolipids including arsenic derivatives of fatty acids, hydrocarbons, sugar-phospholipids and sugar-phytol; 21 of these arsenolipids were identified for the first time and included a new group comprising ether-phospholipids. The arsenic compounds in the mussels show distinct profiles depending on the tissue type, which provide insight into the arsenolipid origin. The results suggest that the presence of some arsenolipids in the mussels is from direct uptake of the compounds, presumably from food, rather than biogenesis within the mussels.

scholarly journals Assessing the effects of neonicotinoid insecticide on the bivalve mollusc Mytilus galloprovincialis

2020 ◽  
Vol 700 ◽  
pp. 134914 ◽  
Author(s):  
Alzbeta Stara ◽  
Maria Pagano ◽  
Gioele Capillo ◽  
Jacopo Fabrello ◽  
Marie Sandova ◽  
...  
Keyword(s):  
Mytilus Galloprovincialis ◽  
Bivalve Mollusc ◽  
Neonicotinoid Insecticide

scholarly journals Westland petrel (Procellaria westlandica) foraging behaviour: Patterns and drivers of individual variation

2021 ◽  
Author(s):  
◽  
Douglas Rands
Keyword(s):  
Habitat Selection ◽  
West Coast ◽  
Foraging Behaviour ◽  
Sea Surface ◽  
Foraging Strategies ◽  
Sea Surface Temperatures ◽  
The West ◽  
Surface Temperatures ◽  
Foraging Site ◽  
Incidental Mortality

<p><b>Foraging behaviour can have a major influence on the survival and reproduction of individuals which can ultimately impact the viability of a population. Foraging is particularly challenging for procellariiformes (tube nosed seabirds) who feed on patchily distributed prey in the highly dynamic marine environment. During the breeding season procellariiformes must also increase their foraging effort to raise their chick whilst having a reduced foraging range. As a result, procellariiformes have adopted various foraging strategies, such as dual foraging and sexual foraging dimorphism, to cope with this energy demanding lifestyle. Westland petrels (Procellaria westlandica) are an endangered winter breeding procellariform endemic to the West Coast of New Zealand’s South Island. Unlike other procellariiformes, previous studies have found little evidence of Westland petrels using sexually dimorphic or dual foraging strategies. Furthermore, Westland petrels also display a high level of individual variation in foraging behaviour. To understand why there is so much variation and what factors are driving it, I first examined variation at the population, individual and within individual level to describe and categorise different foraging strategies. I then investigated how factors such as year, sex and foraging site influenced variation. Finally, I examined how oceanic variables influenced habitat selection and foraging characteristics to understand how the environment drives variation in foraging behaviour.</b></p> <p>Considerable variation was found at all levels. Most of the variation was explained by year with individuals taking shorter foraging trips in 2011 and longer trips in 2015. Females foraged further than males suggesting that there is some degree of sexual foraging segregation occurring in Westland petrels. I also found that the highest variation in foraging behaviour was exhibited by individuals within their core foraging site on the West Coast. Sea surface temperatures were highest at the West Coast foraging site and individuals within this site showed differences in habitat selection among years. Habitat selection at the West Coast site also differed between sexes suggesting that males are outcompeting females for prime foraging spots.</p> <p>Overall, my results indicate that foraging conditions on the West Coast are highly variable likely due to rising sea surface temperatures, marine heatwaves, and the effects of the El Nino-Southern Oscillation. As a result, it is likely that prey availability on the West Coast is unpredictable causing high variation in foraging behaviour and sexual foraging segregation. With climate change, foraging conditions on the West Coast are predicted to get more unpredictable as sea surface temperatures continue to rise and extreme weather events become more frequent. These factors will make foraging increasingly difficult for Westland petrels and could see them rely more on fishery discards as a source of food, increasing their risk of incidental mortality. Conservation management should focus on protecting the petrels core foraging area around the Hokitika canyon to help limit the effects of climate change. Fishery management should also focus on limiting or prohibiting offal discards to prevent the incidental mortality of Westland petrels.</p>

scholarly journals Westland petrel (Procellaria westlandica) foraging behaviour: Patterns and drivers of individual variation

2021 ◽  
Author(s):  
◽  
Douglas Rands
Keyword(s):  
Habitat Selection ◽  
West Coast ◽  
Foraging Behaviour ◽  
Sea Surface ◽  
Foraging Strategies ◽  
Sea Surface Temperatures ◽  
The West ◽  
Surface Temperatures ◽  
Foraging Site ◽  
Incidental Mortality

<p><b>Foraging behaviour can have a major influence on the survival and reproduction of individuals which can ultimately impact the viability of a population. Foraging is particularly challenging for procellariiformes (tube nosed seabirds) who feed on patchily distributed prey in the highly dynamic marine environment. During the breeding season procellariiformes must also increase their foraging effort to raise their chick whilst having a reduced foraging range. As a result, procellariiformes have adopted various foraging strategies, such as dual foraging and sexual foraging dimorphism, to cope with this energy demanding lifestyle. Westland petrels (Procellaria westlandica) are an endangered winter breeding procellariform endemic to the West Coast of New Zealand’s South Island. Unlike other procellariiformes, previous studies have found little evidence of Westland petrels using sexually dimorphic or dual foraging strategies. Furthermore, Westland petrels also display a high level of individual variation in foraging behaviour. To understand why there is so much variation and what factors are driving it, I first examined variation at the population, individual and within individual level to describe and categorise different foraging strategies. I then investigated how factors such as year, sex and foraging site influenced variation. Finally, I examined how oceanic variables influenced habitat selection and foraging characteristics to understand how the environment drives variation in foraging behaviour.</b></p> <p>Considerable variation was found at all levels. Most of the variation was explained by year with individuals taking shorter foraging trips in 2011 and longer trips in 2015. Females foraged further than males suggesting that there is some degree of sexual foraging segregation occurring in Westland petrels. I also found that the highest variation in foraging behaviour was exhibited by individuals within their core foraging site on the West Coast. Sea surface temperatures were highest at the West Coast foraging site and individuals within this site showed differences in habitat selection among years. Habitat selection at the West Coast site also differed between sexes suggesting that males are outcompeting females for prime foraging spots.</p> <p>Overall, my results indicate that foraging conditions on the West Coast are highly variable likely due to rising sea surface temperatures, marine heatwaves, and the effects of the El Nino-Southern Oscillation. As a result, it is likely that prey availability on the West Coast is unpredictable causing high variation in foraging behaviour and sexual foraging segregation. With climate change, foraging conditions on the West Coast are predicted to get more unpredictable as sea surface temperatures continue to rise and extreme weather events become more frequent. These factors will make foraging increasingly difficult for Westland petrels and could see them rely more on fishery discards as a source of food, increasing their risk of incidental mortality. Conservation management should focus on protecting the petrels core foraging area around the Hokitika canyon to help limit the effects of climate change. Fishery management should also focus on limiting or prohibiting offal discards to prevent the incidental mortality of Westland petrels.</p>

scholarly journals Metal pollution determined by pollution indices for sea grass P. oceanica and surface sediments

2015 ◽  
Vol 67 (1) ◽  
pp. 91-101 ◽  
Author(s):  
Slavka Stankovic ◽  
Mihajlo Jovic ◽  
Marija Mihajlovic ◽  
Danijela Joksimovic ◽  
Bojan Tanaskovski
Keyword(s):  
Surface Sediment ◽  
Metal Pollution ◽  
Pollution Index ◽  
Posidonia Oceanica ◽  
Pollution Indices ◽  
Metal Enrichment ◽  
Metal Pollution Index ◽  
Sediment Samples ◽  
Sea Grass ◽  
The Impact

Concentrations of Fe, Mn, Cu, Zn, Pb, Ni, Co, As, Co, and Hg in the sea grass Posidonia oceanica and surface sediment samples were determined. Together with P. oceanica, surface sediment samples were collected at eight locations in the major demographic, tourist and port areas along the Montenegrin coast to assess metal pollution. The metal pollution index (MPI) and metal enrichment factor (EF) were calculated and used to evaluate the impact of heavy metals in the surface sediment on P. oceanica. The sediment MPI and EF values were lower than these values in P. oceanica at the same locations. Since the surface sediment contained lower mean concentrations of Zn, Ni, Pb, Cd and Hg, than the sea grass P. oceanic, we concluded that the sea grass absorbed some metals from the seawater column.

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