Shellfish culture: a complex driver of planktonic communities

2018 ◽  
Vol 12 (1) ◽  
pp. 33-46 ◽  
Author(s):  
Vivien Hulot ◽  
Denis Saulnier ◽  
Céline Lafabrie ◽  
Nabila Gaertner‐Mazouni
Keyword(s):  
Shellfish Culture ◽  
Planktonic Communities

Zooplankton Biogeochemical Cycles

2017 ◽  
Author(s):  
Deborah Steinberg
Keyword(s):  
North Atlantic ◽  
North Atlantic Ocean ◽  
Significant Proportion ◽  
Biogeochemical Cycles ◽  
Biological Pump ◽  
The North ◽  
Particle Export ◽  
Chemical Cycling ◽  
Cycling Of Nutrients ◽  
Planktonic Communities

The structure of planktonic communities profoundly affects particle export and sequestration of organic material (the biological pump) and the chemical cycling of nutrients. This chapter describes the integral and multifaceted role zooplankton (both protozoan and metazoan) play in the export and cycling of elements in the ocean, with an emphasis on the North Atlantic Ocean and adjacent seas. Zooplankton consume a significant proportion of primary production across the world's oceans, and their metabolism plays a key role in recycling carbon, nitrogen, and other elements. The chapter also addresses how human or climate-influenced changes in North Atlantic zooplankton populations may in turn drive changes in zooplankton-mediated biogeochemical cycling.

scholarly journals Suspended shellfish culture impacts on the benthic layer: a case study in Brazilian subtropical waters

2012 ◽  
Vol 60 (2) ◽  
pp. 219-232 ◽  
Author(s):  
Natália de Moraes Rudorff ◽  
Carla Van Der Haagen Custodio Bonetti ◽  
Jarbas Bonetti Filho
Keyword(s):  
Total Population ◽  
Organic Content ◽  
Multivariate Techniques ◽  
Data Sets ◽  
Productive Activity ◽  
Local Conditions ◽  
Benthic Environment ◽  
Shellfish Culture ◽  
Population Ratio

This study aimed to assess benthic impacts of suspended shellfish cultures in two marine farms located in South Bay, Florianópolis (SC, Brazil). The goal was to detect changes in the benthic layer and evaluate the influence of local conditions, such as hydrodynamics and geomorphology, on the degree of impact at each site. The method included analysis of three groups of oceanographic descriptors: hydrodynamic; morpho-sedimentological (bathymetry, grain size and organic content), and ecological (foraminiferal fauna). Data sets were analyzed using geostatistical and multivariate techniques. Ecological descriptors seemed to be more effective under different environmental conditions than sedimentological variables. Those that best identified culture-related biodeposits, were: dominance of Ammonia tepida; test size; and living: total population ratio. Only slight differences were observed within and outside the culture structures. However, a greater alteration was observed at the site with weaker hydrodynamics and located in shallower depths. The conclusion is that biodeposition at studied still causes little alteration in the local benthic environment. However, local factors such as hydrodynamics and geomorphology were shown to be important in minimizing these impacts. These are criteria that should be considered in site selection programs for the development of this productive activity.

The Influence of Current Speed, Body Size and Water Temperature On the Filtration Rate of Five Species of Bivalves

1972 ◽  
Vol 52 (2) ◽  
pp. 345-374 ◽  
Author(s):  
P. R. Walne
Keyword(s):  
Body Size ◽  
Water Temperature ◽  
Filtration Rate ◽  
Current Speed ◽  
Suitable Method ◽  
Water Filtration ◽  
Water Current ◽  
Water Requirements ◽  
Important Species ◽  
Shellfish Culture

The rate of water filtration by bivalves has long excited interest, but it has in practice proved difficult to measure in conditions where the animal is relatively free from constraint. Its estimation is important from a number of aspects: feeding studies; as an indicator of the animal's reaction to its environment; and for predicting the flow of water required for the culture of economically important species. The work reported in this paper started as part of the general programme on shellfish culture in progress at this laboratory. During the development of a suitable method for studying the water requirements it became clear that one factor, water current, had a more important influence than has been generally recognized.

The role of aerobic metabolism and intragel oxygen in hypoxia tolerance of three ctenophores: Pleurobrachia bachei, Bolinopsis infundibulum and Mnemiopsis leidyi

2005 ◽  
Vol 85 (3) ◽  
pp. 627-633 ◽  
Author(s):  
Erik V. Thuesen ◽  
Ladd D. Rutherford ◽  
Patricia L. Brommer
Keyword(s):  
Aerobic Metabolism ◽  
Hypoxia Tolerance ◽  
Mnemiopsis Leidyi ◽  
Survival Times ◽  
Partial Pressures ◽  
Pleurobrachia Bachei ◽  
Oxygen Measurements ◽  
Surrounding Seawater ◽  
Planktonic Communities

Ctenophores are important members of planktonic communities that are often abundant in dysaerobic environments. Previous studies have shown that ctenophores are not adversely affected by extended periods of hypoxia. The three species used in this study, Pleurobrachia bachei, Bolinopsis infundibulum, and Mnemiopsis leidyi, were all able to oxyregulate to very low partial pressures of oxygen (PO2s). These species were found to have mean critical oxygen tensions of 7.7, 10.6, and 7.2 hPa respectively. In general, ctenophores are better oxyregulators than medusae and many species of shrimps, fish and squid. Intragel oxygen was measured using a fibre optic oxygen optode. All these ctenophores have intragel subsurface [O2]s of 5–10% below that of the surrounding seawater. Intragel oxygen measurements of P. bachei showed a gradient of decreasing PO2 from surface tissues to the gut. Specimens of P. bachei over 14 mm in diameter had anaerobic guts. Survival times in anoxia ranged from 0 h for M. leidyi to up to 6 h for P. bachei. Ctenophores rely on aerobic metabolism to tolerate hypoxia.

scholarly journals Demography and feeding behavior of Stenostomum leucops (Dugés, 1828)

2016 ◽  
Vol 75 (s1) ◽  
Author(s):  
Alma R. Núñez-Ortiz ◽  
Sarma Nandini ◽  
S.S.S. Nandini
Keyword(s):  
Functional Response ◽  
Food Preference ◽  
Type Ii ◽  
Final Density ◽  
Two Temperatures ◽  
The Difference ◽  
Growth Experiments ◽  
Pelagic Communities ◽  
Type Ii Functional Response ◽  
Planktonic Communities

<p>Freshwater turbellarians, despite their mainly benthic habits, interact with pelagic communities of rotifers and cladocerans. However, very little is known about their demographic characteristics, food preference and functional response. To fill that gap we studied one of the most widely spread species, <em>Stenostomum leucops</em>.  We conducted population growth experiments using abundant food (several rotifer and cladocerans species). To evaluate possible impact of <em>S. leucops</em> on planktonic communities, we conducted prey preference experiments at two temperatures: 18 and 23°C. The number of rotifers and cladocerans consumed was calculated by the difference between the initial and final density. We found that diets supplemented with fresh algae achieved higher <em>S. leucops</em> densities than those with detritus supplements in their diets. In the case of animal diets, <em>Euchlanis dilatata</em> allowed <em>S. leucops</em> reach higher densities than the other zooplankton species; <em>E. dilatata</em> was positively selected for in the selectivity study at both 18 and 23°C.  <em>Stenostomum leucops</em> showed a type II functional response on rotifers and the cladoceran <em>Alona glabra</em>. Our results suggest that <em>S. leucops</em> select their prey according to their vulnerability using different mechanisms, which optimize their food intake.</p>

scholarly journals HYDROBIOLOGICAL STUDIES OF PLANKTON COMMUNITIES OF MAKHACHKALA SEAPORT

2019 ◽  
pp. 12-18
Author(s):  
Magomed Magomedovich OSMANOV ◽  
Frangiz Shamilievna AMAEVA ◽  
Ayshat Abdulmajidovna ABDURAKHMANOVA
Keyword(s):  
Aquatic Organisms ◽  
Water Area ◽  
Acartia Tonsa ◽  
Anthropogenic Influence ◽  
The Caspian Sea ◽  
Spring Period ◽  
Brackish Water Species ◽  
Water Species ◽  
Plankton Communities ◽  
Planktonic Communities

The article presents data from spring hydrobiological studies in the Makhachkala l Seaport during the period of dredging. It is noted that plankton of the studied water area of the Caspian Sea is a typical community of the spring period, formed mainly by marine and brackish-water species of phytoplankton and zooplankton. Diatoms mainly dominate in phytoplankton, and Copepods in zooplankton, where the main dominant is the Azov-Black sea invader Acartia tonsa Dana,1843. The analysis of planktonic communities indicates a rather developed quantitative and qualitative community of aquatic organisms with a characteristic abundance of species inhabiting it in the spring, despite a significant anthropogenic influence. It is established that the ongoing dredging operations do not have a tangible effect on the productivity of planktonic organisms.

scholarly journals Rates and drivers of Red Sea plankton community metabolism

2018 ◽  
Author(s):  
Daffne C. López-Sandoval ◽  
Katherine Rowe ◽  
Paloma Carillo-de-Albonoz ◽  
Carlos M. Duarte ◽  
Susana Agusti
Keyword(s):  
Red Sea ◽  
Gross Primary Production ◽  
Environmental Drivers ◽  
Community Respiration ◽  
Net Community Production ◽  
Chl A ◽  
Warm Environment ◽  
Increasing Temperature ◽  
Community Production ◽  
Planktonic Communities

Abstract. Resolving the environmental drivers shaping planktonic communities is fundamental to understanding their variability, present and future, across the ocean. More specifically, resolving the temperature-dependence of planktonic communities in low productive waters is essential to predict the response of marine ecosystems to warming scenarios, as ocean warming leads to oligotrophication of the subtropical ocean. Here we quantified plankton metabolic rates along the Red Sea, a unique oligotrophic and warm environment, and analysed the drivers that regulate gross primary production (GPP), community respiration (CR) and the net community production (NCP). The study was conducted on six oceanographic surveys following a north-south transect along Saudi Arabian coasts. Our findings revealed that Chl-a specific GPP and CR rates increased with increasing temperature (R2 = 0.41 and 0.19, respectively, P 

Microbial and classic food web components under ice cover in eutrophic lakes of different morphometry and fisheries management

2017 ◽  
Vol 46 (3) ◽  
Author(s):  
Krystyna Kalinowska ◽  
Agnieszka Napiórkowska-Krzebietke ◽  
Elżbieta Bogacka-Kapusta ◽  
Joanna Hutorowicz ◽  
Jakub Pyka ◽  
...  
Keyword(s):  
Global Warming ◽  
Fisheries Management ◽  
Ice Cover ◽  
Taxonomic Composition ◽  
High Variability ◽  
Lake District ◽  
Nitrogen And Phosphorus ◽  
Eutrophic Lakes ◽  
Short Time ◽  
Planktonic Communities

AbstractThe thickness and duration of ice cover are strongly influenced by global warming. The aim of this study was to determine chemical (organic carbon, total nitrogen and phosphorus concentrations) and biological (nanoflagellates, ciliates, phytoplankton, rotifers, crustaceans) parameters under the ice cover in three eutrophic lakes (Masurian Lake District, Poland), differing in their morphometry and fisheries management. All the studied groups of organisms showed high variability over a short time. Taxonomic composition of planktonic communities, except for rotifers and phytoplankton, was similar in all lakes. Nanoflagellates were dominated by autotrophic forms, while ciliates were primarily composed of small oligotrichs and prostomatids. Nano-sized diatoms and mixotrophic cryptophytes were the most important components of phytoplankton and they formed an under-ice bloom in one lake only. Rotifers were mainly represented by

Seasonal dynamics of trophic relationships among co-occurring suspension-feeders in two shellfish culture dominated ecosystems

2009 ◽  
Vol 82 (3) ◽  
pp. 415-425 ◽  
Author(s):  
Sébastien Lefebvre ◽  
Julio César Marín Leal ◽  
Stanislas Dubois ◽  
Francis Orvain ◽  
Jean-Louis Blin ◽  
...  
Keyword(s):  
Seasonal Dynamics ◽  
Trophic Relationships ◽  
Suspension Feeders ◽  
Shellfish Culture
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