scholarly journals Forever young... Colonization pattern of epibionts on Posidonia oceanica artificial leaves in relation to ocean acidification

2015 ◽  
Author(s):  
Maria Cristina Gambi ◽  
Emanuela Di Meglio ◽  
Luigia Donnarumma
Keyword(s):  
Ocean Acidification ◽  
Posidonia Oceanica ◽  
Progressive Increase ◽  
Low Ph ◽  
Coralline Algae ◽  
Short Exposure ◽  
Marine Biota ◽  
Short Exposure Time ◽  
Colonization Pattern ◽  
Ph Conditions

Ocean acidification (OA) is today considered one of the most pervasive stressors for marine biota at the level of species, communities and ecosystems. Naturally acidified systems, such as the CO2 vents, represent suitable laboratories to study the effects of OA on benthic organisms. An analysis of the colonization pattern of epibionts settled on artificial leaves (mimics) of Posidonia oceanica in relation to ocean acidification at the shallow CO2 vents off the island of Ischia, is here presented. Mimics of Posidonia oceanica artificial leaves (dark green flexible PVC stripes 1 cm wide x 36 cm long) were placed from September 2009 to September 2010 along a gradient of OA of the Ischia vent’s system at six stations (3 on the south and 3 on the north side of the study area), located at extreme low pH (mean pH 7.5), low pH (7.8), and control, normal pH conditions (8.12). Six artificial leaves per station were collected every three months and analysed for taxa identification and estimates of coverage (algae and sessile clonal invertebrates) and number of individuals (not clonal taxa). Patterns of colonization in control stations showed a progressive increase in time in coverage values of many organisms, mainly calcifying forms as coralline algae, which represent the dominant taxon, spirorbids and bryozoans. Colonization of artificial leaves located in low pH stations followed a similar temporal pattern as control conditions, but with lower coverage and higher patchiness of calcareous forms at 12 months of colonization. Epibionts in extreme low pH conditions were dominated by filamentous green/brown algae, with the occurrence of a few coralline algae, spirorbids and bryozoans, especially in the early months of colonization (3 and 6 months). Colonization at 9 and 12 months showed the disappearance of even these rare calcareous organisms and occurrence only of filamentous turf and fleshy algae, with a very simplified epibiont assemblage, remaining at an early, young colonization stage. These results indicate a strong selection of calcareous forms and the lack of successional stages in extreme low pH conditions, while the few calcifiers settled at short exposure time (3-6 months) do not seem to survive at longer exposure to critical values of OA.

scholarly journals Forever young... Colonization pattern of epibionts on Posidonia oceanica artificial leaves in relation to ocean acidification

2015 ◽  
Author(s):  
Maria Cristina Gambi ◽  
Emanuela Di Meglio ◽  
Luigia Donnarumma
Keyword(s):  
Ocean Acidification ◽  
Posidonia Oceanica ◽  
Progressive Increase ◽  
Low Ph ◽  
Coralline Algae ◽  
Short Exposure ◽  
Marine Biota ◽  
Short Exposure Time ◽  
Colonization Pattern ◽  
Ph Conditions

Ocean acidification (OA) is today considered one of the most pervasive stressors for marine biota at the level of species, communities and ecosystems. Naturally acidified systems, such as the CO2 vents, represent suitable laboratories to study the effects of OA on benthic organisms. An analysis of the colonization pattern of epibionts settled on artificial leaves (mimics) of Posidonia oceanica in relation to ocean acidification at the shallow CO2 vents off the island of Ischia, is here presented. Mimics of Posidonia oceanica artificial leaves (dark green flexible PVC stripes 1 cm wide x 36 cm long) were placed from September 2009 to September 2010 along a gradient of OA of the Ischia vent’s system at six stations (3 on the south and 3 on the north side of the study area), located at extreme low pH (mean pH 7.5), low pH (7.8), and control, normal pH conditions (8.12). Six artificial leaves per station were collected every three months and analysed for taxa identification and estimates of coverage (algae and sessile clonal invertebrates) and number of individuals (not clonal taxa). Patterns of colonization in control stations showed a progressive increase in time in coverage values of many organisms, mainly calcifying forms as coralline algae, which represent the dominant taxon, spirorbids and bryozoans. Colonization of artificial leaves located in low pH stations followed a similar temporal pattern as control conditions, but with lower coverage and higher patchiness of calcareous forms at 12 months of colonization. Epibionts in extreme low pH conditions were dominated by filamentous green/brown algae, with the occurrence of a few coralline algae, spirorbids and bryozoans, especially in the early months of colonization (3 and 6 months). Colonization at 9 and 12 months showed the disappearance of even these rare calcareous organisms and occurrence only of filamentous turf and fleshy algae, with a very simplified epibiont assemblage, remaining at an early, young colonization stage. These results indicate a strong selection of calcareous forms and the lack of successional stages in extreme low pH conditions, while the few calcifiers settled at short exposure time (3-6 months) do not seem to survive at longer exposure to critical values of OA.

scholarly journals Polychaetes associated with Posidonia oceanica meadows along a gradient of ocean acidification at a CO2 vent system (Ischia, Italy)

2015 ◽  
Author(s):  
Maria Cristina Gambi ◽  
Erica Keppel ◽  
Rosanna Guglielmo ◽  
Adriana Giangrande ◽  
Samantha L. Garrard
Keyword(s):  
Ocean Acidification ◽  
Feeding Habits ◽  
Posidonia Oceanica ◽  
Shoot Density ◽  
Low Ph ◽  
Marine Biota ◽  
The South ◽  
South Side ◽  
Seagrass Meadows ◽  
Ph Conditions

Polychaetes represent one of the most diversified and abundant taxa associated with seagrass meadows. These organisms show various feeding habits at different levels of the complex seagrass food web, representing suitable bioindicators of meadow structure and environmental status and disturbances. Ocean acidification (OA) is today considered one of the most pervasive stressors for marine biota at the level of species, communities and ecosystems. Naturally acidified systems, such as CO2 vents, represent suitable natural laboratories to study the effects of OA on benthic organisms. An analysis of polychaetes associated with Posidonia oceanica meadows located around shallow CO2 vents off the island of Ischia, is presented here. Polychaetes were collected in November 2011 with an air-lift sampler (40x40 cm; 4 replicates per station) along a gradient of OA at the Castello’s vent system at six stations (3 on the south and 3 on the north side), ranging from extreme low pH conditions (mean pH 7.5 occurring only on the south side) to control, normal pH conditions (8.12); a further control station was considered, 600 m from the Castello in similar environmental conditions and ambient pH (S. Anna meadow). A total of 99 taxa and about 4200 individual polychaetes were collected. Taxa richness showed higher values in the acidified stations, especially on the south side; similarly abundances were from two- to four-fold higher under low and extreme low pH conditions, in respect to control ones, due to relatively few dominant taxa. These are represented by Amphiglena mediterranea, Syllis gerlachi, S. prolifera, Exogone dispar, Sphaerosyllis pirifera, Polyophthalmus pictus and Kefersteinia cirrata. Multivariate analysis showed a separation between control and low pH assemblages and a separation between low pH and the extreme low pH site on the south side. Control stations showed higher variability among replicates, while acidified stations, especially those under extreme low pH conditions, showed a more homogeneous assemblage structure. These results demonstrate that many species of polychaetes are robust to OA, however, the high seagrass shoot density, occurring at acidified stations, may buffer the negative effect of this stressor on the biota, and explain both the high diversity and abundance observed there.

scholarly journals Settlement pattern of Posidonia oceanica epibionts along a gradient of ocean acidification: an approach with mimics

2014 ◽  
Vol 15 (3) ◽  
pp. 498 ◽  
Author(s):  
L. DONNARUMMA ◽  
C. LOMBARDI ◽  
S. COCITO ◽  
M.C. GAMBI
Keyword(s):  
Ocean Acidification ◽  
Posidonia Oceanica ◽  
Settlement Pattern ◽  
Low Ph ◽  
Ph Gradient ◽  
Artificial Substrates ◽  
Coralline Algae ◽  
Cascading Effects ◽  
Epiphyte Communities ◽  
Ph Conditions

Effects of ocean acidification (OA on the colonization/settlement pattern of the epibiont community of the leaves and rhizomesof the Mediterranean seagrass,Posidoniaoceanica, have been studied at volcanic CO2vents off Ischia (Italy), using “mimics”as artificial substrates. The experiments were conducted in shallowPosidoniastands (2-3 m depth), in three stations on the northand three on the south sides of the study area, distributed along a pH gradient. At each station, 4 rhizome mimics and 6 artificialleaves were collected every three months (Sept 2009-Sept 2010). The epibionts on both leaf and rhizome mimics showed clearchanges along the pH gradient; coralline algae and calcareous invertebrates (bryozoans, serpulid polychaetes and barnacles) weredominant at control stations but progressively disappeared at the most acidified stations. In these extremely low pH sites theassemblage was dominated by filamentous algae and non calcareous taxa such as hydroids and tunicates. Settlement pattern onthe artificial leaves and rhizome mimics over time showed a consistent distribution pattern along the pH gradient and highlightedthe peak of recruitment of the various organisms in different periods according to their life history.Posidoniamimics at theacidified station showed a poor and very simplified assemblage where calcifying epibionts seemed less competitive for space. Thisprofound difference in epiphyte communities in low pH conditions suggests cascading effects on the food web of the meadow and,consequently, on the functioning of the system

scholarly journals Polychaetes associated with Posidonia oceanica meadows along a gradient of ocean acidification at a CO2 vent system (Ischia, Italy)

2015 ◽  
Author(s):  
Maria Cristina Gambi ◽  
Erica Keppel ◽  
Rosanna Guglielmo ◽  
Adriana Giangrande ◽  
Samantha L. Garrard
Keyword(s):  
Ocean Acidification ◽  
Feeding Habits ◽  
Posidonia Oceanica ◽  
Shoot Density ◽  
Low Ph ◽  
Marine Biota ◽  
The South ◽  
South Side ◽  
Seagrass Meadows ◽  
Ph Conditions

Polychaetes represent one of the most diversified and abundant taxa associated with seagrass meadows. These organisms show various feeding habits at different levels of the complex seagrass food web, representing suitable bioindicators of meadow structure and environmental status and disturbances. Ocean acidification (OA) is today considered one of the most pervasive stressors for marine biota at the level of species, communities and ecosystems. Naturally acidified systems, such as CO2 vents, represent suitable natural laboratories to study the effects of OA on benthic organisms. An analysis of polychaetes associated with Posidonia oceanica meadows located around shallow CO2 vents off the island of Ischia, is presented here. Polychaetes were collected in November 2011 with an air-lift sampler (40x40 cm; 4 replicates per station) along a gradient of OA at the Castello’s vent system at six stations (3 on the south and 3 on the north side), ranging from extreme low pH conditions (mean pH 7.5 occurring only on the south side) to control, normal pH conditions (8.12); a further control station was considered, 600 m from the Castello in similar environmental conditions and ambient pH (S. Anna meadow). A total of 99 taxa and about 4200 individual polychaetes were collected. Taxa richness showed higher values in the acidified stations, especially on the south side; similarly abundances were from two- to four-fold higher under low and extreme low pH conditions, in respect to control ones, due to relatively few dominant taxa. These are represented by Amphiglena mediterranea, Syllis gerlachi, S. prolifera, Exogone dispar, Sphaerosyllis pirifera, Polyophthalmus pictus and Kefersteinia cirrata. Multivariate analysis showed a separation between control and low pH assemblages and a separation between low pH and the extreme low pH site on the south side. Control stations showed higher variability among replicates, while acidified stations, especially those under extreme low pH conditions, showed a more homogeneous assemblage structure. These results demonstrate that many species of polychaetes are robust to OA, however, the high seagrass shoot density, occurring at acidified stations, may buffer the negative effect of this stressor on the biota, and explain both the high diversity and abundance observed there.

scholarly journals Ocean Acidification and Mollusc Settlement in Posidonia oceanica Meadows: Does the Seagrass Buffer Lower pH Effects at CO2 Vents?

Diversity ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 311
Author(s):  
Alessandra Barruffo ◽  
Laura Ciaralli ◽  
Giandomenico Ardizzone ◽  
Maria Cristina Gambi ◽  
Edoardo Casoli
Keyword(s):  
Ocean Acidification ◽  
Benthic Communities ◽  
Plant Cover ◽  
Posidonia Oceanica ◽  
Low Ph ◽  
High Pco2 ◽  
Future Climate Change ◽  
Ph Effects ◽  
Ph Conditions ◽  
Mollusc Assemblages

Ocean acidification has been broadly recognised to have effects on the structure and functioning of marine benthic communities. The selection of tolerant or vulnerable species can also occur during settlement phases, especially for calcifying organisms which are more vulnerable to low pH–high pCO2 conditions. Here, we use three natural CO2 vents (Castello Aragonese north and south sides, and Vullatura, Ischia, Italy) to assess the effect of a decrease of seawater pH on the settlement of Mollusca in Posidonia oceanica meadows, and to test the possible buffering effect provided by the seagrass. Artificial collectors were installed and collected after 33 days, during April–May 2019, in three different microhabitats within the meadow (canopy, bottom/rhizome level, and dead matte without plant cover), following a pH decreasing gradient from an extremely low pH zone (pH < 7.4), to ambient pH conditions (pH = 8.10). A total of 4659 specimens of Mollusca, belonging to 57 different taxa, were collected. The number of taxa was lower in low and extremely low pH conditions. Reduced mollusc assemblages were reported at the acidified stations, where few taxa accounted for a high number of individuals. Multivariate analyses revealed significant differences in mollusc assemblages among pH conditions, microhabitat, and the interaction of these two factors. Acanthocardia echinata, Alvania lineata, Alvania sp. juv, Eatonina fulgida, Hiatella arctica, Mytilys galloprovincialis, Musculus subpictus, Phorcus sp. juv, and Rissoa variabilis were the species mostly found in low and extremely low pH stations, and were all relatively robust to acidified conditions. Samples placed on the dead matte under acidified conditions at the Vullatura vent showed lower diversity and abundances if compared to canopy and bottom/rhizome samples, suggesting a possible buffering role of the Posidonia on mollusc settlement. Our study provides new evidence of shifts in marine benthic communities due to ocean acidification and evidence of how P. oceanica meadows could mitigate its effects on associated biota in light of future climate change.

scholarly journals Effects of ocean acidification on phenology and epiphytes of the seagrass Posidonia oceanica at two CO2 vent systems of Ischia (Italy)

2020 ◽  
Vol 21 (1) ◽  
pp. 70
Author(s):  
SILVIA MECCA ◽  
EDOARDO CASOLI ◽  
GIANDOMENICO ARDIZZONE ◽  
MARIA CRISTINA GAMBI
Keyword(s):  
Ocean Acidification ◽  
Posidonia Oceanica ◽  
Shoot Density ◽  
Control Area ◽  
Leaf Length ◽  
Coralline Algae ◽  
Cascading Effects ◽  
Ph Conditions ◽  
The Mean ◽  
Epiphyte Community

Morphological features of the seagrass Posidonia oceanica (L.) Delile and its epiphyte community were studied in three acidified stations located in two CO2 vents systems and one control station under normal pH conditions off the island of Ischia (Italy) to highlight the possible effects of ocean acidification. Plant phenology was analyzed every two months for a year cycle (June 2016–April 2017), while epiphytes were studied in the period of highest development of both the leaf canopy and the epiphytic community (June, August, and October 2016). The shoot density of Posidonia beds in the acidified stations of the studied sites was significantly higher than that in the control area. Significant differences in the mean leaf length according to the pH condition, month, and the interaction of these two factors were observed (PERMANOVA); the mean leaf width differed also among pH conditions and months. We recorded lower leaf lengths and widths in the acidified stations in all the considered months, compared to those in the control station. These differences are consistent with the higher impact of grazing by the herbivorous fish Sarpa salpa observed on the leaves in the acidified stations. However, the overall leaf surface available for epiphytes was similar among stations because of the higher shoot density under ocean acidification conditions. Overall, the composition and structure of the epiphytic community on the Posidonia leaves showed significant differences in relation to acidification: in both acidified sites, all the calcareous forms, both encrusting red algae (Corallinales) and animals (bryozoans, foraminiferans, and spirorbids), disappeared or were strongly reduced, in favor of encrusting or erect fleshy algae, and non-calcifying invertebrates (hydrozoans, tunicates) which dominated the assemblage. Coralline algae are early species in the epiphytic colonization of P. oceanica and therefore their absence can further modify the pattern of leaf colonization by other species. Therefore, the changes found in the epiphyte community in low pH areas could have potential cascading effects on the seagrass trophic network and the functioning of the system.

scholarly journals Dynamic response in the larval geoduck clam proteome to elevated pCO2

2019 ◽  
Author(s):  
Emma Timmins-Schiffman ◽  
José M. Guzmán ◽  
Rhonda Elliott ◽  
Brent Vadopalas ◽  
Steven B. Roberts
Keyword(s):  
Ocean Acidification ◽  
Pacific Coast ◽  
Low Ph ◽  
Molecular Physiology ◽  
Proteomics Analysis ◽  
Bivalve Larvae ◽  
Energetic Stress ◽  
The Pacific ◽  
Aquaculture Industry ◽  
Ph Conditions

AbstractPacific geoduck clams (Panopea generosa) are found along the Northeast Pacific coast where they are significant components of coastal and estuarine ecosystems and the basis of a growing and highly profitable aquaculture industry. The Pacific coastline, however, is also the sight of rapidly changing ocean habitat, including significant reductions in pH. The impacts of ocean acidification on invertebrate bivalve larvae have been widely documented and it is well established that many species experience growth and developmental deficiencies when exposed to low pH. As a native of environments that have historically lower pH than the open ocean, it is possible that geoduck larvae are less impacted by these effects than other species. Over two weeks in larval development (days 6-19 post-fertilization) geoduck larvae were reared at pH 7.5 or 7.1 in a commercial shellfish hatchery. Larvae were sampled at six time points throughout the period for a in-depth proteomics analysis of developmental molecular physiology. Larvae reared at low pH were smaller than those reared at ambient pH, especially in the prodissoconch II phase of development. Competency for settlement was also delayed in larvae from the low pH conditions. A comparison of proteomic profiles over the course of development reveal that these differing phenotypic outcomes are likely due to environmental disruptions to the timing of molecular physiological events as suites of proteins showed differing profiles of abundance between the two pH environments. Ocean acidification likely caused an energetic stress on the larvae at pH 7.1, causing a shift in physiological prioritization with resulting loss of fitness.

scholarly journals Variation in brachiopod microstructure and isotope geochemistry under low pH–ocean acidification–conditions

2018 ◽  
Author(s):  
Facheng Ye ◽  
Hana Jurikova ◽  
Lucia Angiolini ◽  
Uwe Brand ◽  
Gaia Crippa ◽  
...  
Keyword(s):  
Stable Isotope ◽  
Ocean Acidification ◽  
Isotope Geochemistry ◽  
Shell Growth ◽  
Low Ph ◽  
Secondary Layer ◽  
Ph Conditions ◽  
One Year ◽  
The Impact ◽  
Δ13c And Δ18o

Abstract. Throughout the last few decades and in the near future CO2–induced ocean acidification is potentially a big threat to marine calcite-shelled animals (e.g., brachiopods, bivalves, corals and gastropods). Despite the great number of studies focusing on the effects of acidification on shell growth, metabolism, shell dissolution and shell repair, the consequences on biomineral formation remain poorly understood, and only few studies addressed contemporarily the impact of acidification on shell microstructure and geochemistry. In this study, a detailed microstructure and stable isotope geochemistry investigation was performed on nine adult brachiopod specimens of Magellania venosa (Dixon, 1789), grown in the natural environment as well as in controlled culturing experiments at different pH conditions (ranging 7.35 to 8.15 ± 0.05) over different time intervals (214 to 335 days). Details of shell microstructural features, such as thickness of the primary layer, density and size of endopunctae and morphology of the basic structural unit of the secondary layer were analysed using scanning electron microscopy (SEM). Stable isotope compositions (δ13C and δ18O) were tested from the secondary shell layer along shell ontogenetic increments in both dorsal and ventral valves. Based on our comprehensive dataset, we observed that, under low pH conditions, M. venosa produced a more organic-rich shell with higher density of and larger endopunctae, and smaller secondary layer fibres, when subjected to about one year of culturing. Also, increasingly negative δ13C and δ18O values are recorded by the shell produced during culturing and are related to the CO2–source in the culture setup. Both the microstructural changes and the stable isotope results are similar to observations on brachiopods from the fossil record and strongly support the value of brachiopods as robust archives of proxies for studying ocean acidification events in the geologic past.

scholarly journals Ocean acidification could cost the UK's shellfish industry £6 billion

2018 ◽  
Author(s):  
OCTO
Keyword(s):  
United Kingdom ◽  
Ocean Acidification ◽  
Low Ph ◽  
Shellfish Aquaculture ◽  
The United Kingdom ◽  
Ph Conditions ◽  
The Uk ◽  
Crustacean Fisheries

Shellfish harvesting accounts for over ⅓ of total fisheries landings by value in the United Kingdom. Contributing over £400 million each year, shellfish aquaculture and the wild-capture shellfish, mollusk, and crustacean fisheries are important economic drivers in the UK. Ocean acidification could affect some of these species, affecting their survival as some of their shells could be affected by low pH conditions. To understand the monetary effects of ocean acidification, the authors calculated the costs of lost shellfish harvesting on the UK economy.

scholarly journals Variation in brachiopod microstructure and isotope geochemistry under low-pH–ocean acidification conditions

2019 ◽  
Vol 16 (2) ◽  
pp. 617-642 ◽  
Author(s):  
Facheng Ye ◽  
Hana Jurikova ◽  
Lucia Angiolini ◽  
Uwe Brand ◽  
Gaia Crippa ◽  
...  
Keyword(s):  
Stable Isotope ◽  
Ocean Acidification ◽  
Isotope Geochemistry ◽  
Shell Growth ◽  
Low Ph ◽  
Secondary Layer ◽  
Ph Conditions ◽  
Set Up ◽  
The Impact ◽  
Δ13c And Δ18o

Abstract. In the last few decades and in the near future CO2-induced ocean acidification is potentially a big threat to marine calcite-shelled animals (e.g. brachiopods, bivalves, corals and gastropods). Despite the great number of studies focusing on the effects of acidification on shell growth, metabolism, shell dissolution and shell repair, the consequences for biomineral formation remain poorly understood. Only a few studies have addressed the impact of ocean acidification on shell microstructure and geochemistry. In this study, a detailed microstructure and stable isotope geochemistry investigation was performed on nine adult brachiopod specimens of Magellania venosa (Dixon, 1789). These were grown in the natural environment as well as in controlled culturing experiments under different pH conditions (ranging from 7.35 to 8.15±0.05) over different time intervals (214 to 335 days). Details of shell microstructural features, such as thickness of the primary layer, density and size of endopunctae and morphology of the basic structural unit of the secondary layer were analysed using scanning electron microscopy. Stable isotope compositions (δ13C and δ18O) were tested from the secondary shell layer along shell ontogenetic increments in both dorsal and ventral valves. Based on our comprehensive dataset, we observed that, under low-pH conditions, M. venosa produced a more organic-rich shell with higher density of and larger endopunctae, and smaller secondary layer fibres. Also, increasingly negative δ13C and δ18O values are recorded by the shell produced during culturing and are related to the CO2 source in the culture set-up. Both the microstructural changes and the stable isotope results are similar to observations on brachiopods from the fossil record and strongly support the value of brachiopods as robust archives of proxies for studying ocean acidification events in the geologic past.

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