Changing Isotopic Food Webs of Two Economically Important Fish in Mediterranean Coastal Lakes with Different Trophic Status

Simona Sporta Caputi; Giulio Careddu; Edoardo Calizza; Federico Fiorentino; Deborah Maccapan; Loreto Rossi; Maria Letizia Costantini

doi:10.3390/app10082756

Changing Isotopic Food Webs of Two Economically Important Fish in Mediterranean Coastal Lakes with Different Trophic Status

Applied Sciences ◽

10.3390/app10082756 ◽

2020 ◽

Vol 10 (8) ◽

pp. 2756 ◽

Cited By ~ 2

Author(s):

Simona Sporta Caputi ◽

Giulio Careddu ◽

Edoardo Calizza ◽

Federico Fiorentino ◽

Deborah Maccapan ◽

...

Keyword(s):

External Disturbance ◽

Anguilla Anguilla ◽

Eutrophic Lake ◽

Trophic Relationships ◽

Anthropogenic Pressure ◽

Trophic Conditions ◽

Fish Stocks ◽

Omnivorous Fish ◽

Goods And Services ◽

Feeding Choices

Transitional waters are highly productive ecosystems, providing essential goods and services to the biosphere and human population. Human influence in coastal areas exposes these ecosystems to continuous internal and external disturbance. Nitrogen-loads can affect the composition of the resident community and the trophic relationships between and within species, including fish. Based on carbon (δ13C) and nitrogen (δ15N) stable isotope analyses of individuals, we explored the feeding behaviour of two ecologically and economically important omnivorous fish, the eel Anguilla anguilla and the seabream Diplodus annularis, in three neighbouring lakes characterised by different trophic conditions. We found that A. anguilla showed greater generalism in the eutrophic lake due to the increased contribution of basal resources and invertebrates to its diet. By contrast, the diet of D. annularis, which was mainly based on invertebrate species, became more specialised, focusing especially on polychaetes. Our results suggest that changes in macroinvertebrate and fish community composition, coupled with anthropogenic pressure, affect the trophic strategies of high trophic level consumers such as A. anguilla and D. annularis. Detailed food web descriptions based on the feeding choices of isotopic trophospecies (here Isotopic Trophic Units, ITUs) enable identification of the prey taxa crucial for the persistence of omnivorous fish stocks, thus providing useful information for their management and habitat conservation.

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Carbon concentrating mechanisms maintain bloom biomass and CO<sub>2</sub> depletion in eutrophic lake ecosystems

10.5194/bg-2016-350 ◽

2016 ◽

Author(s):

Ana M. Morales-Williams ◽

Alan D. Wanamaker Jr. ◽

John A. Downing

Keyword(s):

Inorganic Carbon ◽

Phytoplankton Bloom ◽

Dissolved Inorganic Carbon ◽

Negative Relationship ◽

Eutrophic Lake ◽

Anthropogenic Pressure ◽

Phytoplankton Blooms ◽

Eutrophic Lakes ◽

Lake Ecosystems ◽

Carbon Concentrating Mechanisms

Abstract. Harmful phytoplankton blooms are increasing in frequency, intensity, and duration in aquatic ecosystems worldwide. In many eutrophic lakes, these high levels of primary productivity correspond to periods of CO2 depletion in surface waters. Cyanobacteria and other groups of phytoplankton have the ability to actively transport bicarbonate (HCO3−) across their cell membrane when CO2 concentrations are limiting, possibly giving them a competitive advantage over algae not using carbon concentrating mechanisms (CCMs). To investigate whether CCMs can maintain phytoplankton bloom biomass under CO2 depletion, we measured δ13C signatures of dissolved inorganic carbon (δ13CDIC) and phytoplankton particulate organic carbon (δ13Cphyto) in sixteen mesotrophic to hypereutrophic lakes during the ice-free season of 2012. We used mass balance relationships to determine the dominant inorganic carbon species used by phytoplankton under CO2 stress. We found a significant positive relationship between phytoplankton biomass and phytoplankton δ13C signatures, as well as a significant non-linear negative relationship between water column ρCO2 and isotopic composition of phytoplankton, indicating a shift from diffusive uptake to active uptake by phytoplankton of CO2 or HCO3− during blooms. Calculated photosynthetic fractionation factors indicated that this shift occurs specifically when surface water CO2 drops below atmospheric equilibrium. Our results indicate active HCO3− uptake via CCMs may be an important mechanism maintaining phytoplankton blooms when CO2 is depleted. Further increases in anthropogenic pressure, eutrophication, and harmful cyanobacteria blooms are therefore expected to contribute to increased bicarbonate uptake to sustain primary production.

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Drivers of Ecosystem Metabolism in Two Managed Shallow Lakes with Different Salinity and Trophic Conditions: The Sauce Grande and La Salada Lakes (Argentina)

Water ◽

10.3390/w10091136 ◽

2018 ◽

Vol 10 (9) ◽

pp. 1136 ◽

Cited By ~ 2

Author(s):

María Alfonso ◽

Andrea Brendel ◽

Alejandro Vitale ◽

Carina Seitz ◽

María Piccolo ◽

...

Keyword(s):

Water Management ◽

Shallow Lakes ◽

Ecosystem Respiration ◽

Gross Primary Production ◽

Eutrophic Lake ◽

Ecosystem Metabolism ◽

Management Policy ◽

Effective Management ◽

Trophic Conditions ◽

Lake Volume

Understanding the drivers and how they affect ecosystem metabolism is essential for developing effective management policy and plans. In this study, net ecosystem production (NEP), ecosystem respiration (R), and gross primary production (GPP) rates were estimated in relation to physicochemical, hydrological, and meteorological variables in La Salada (LS) and Sauce Grande (SG), two shallow lakes located in an important agricultural region with water management. LS is a mesosaline, mesotrophic-eutrophic lake, whereas SG is a hyposaline and eutrophic lake. GPP and R showed daily and seasonal variations, with R exceeding GPP during most of the study period in both lakes. Net heterotrophic conditions prevailed during the study period (NEP LS: −1.1 mmol O2 m−2 day−1 and NEP SG: −1.25 mmol O2 m−2 day−1). From data analysis, the temperature, wind speed, and lake volume are the main drivers of ecosystem metabolism for both lakes. Despite the significant differences between the two lakes, the NEP values were similar. The different hydrological characteristics (endorheic vs. flushing lake) were crucial in explaining why the two different systems presented similar ecosystem metabolic rates, emphasizing the importance of water management.

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Herbivory of Omnivorous Fish Shapes the Food Web Structure of a Chinese Tropical Eutrophic Lake: Evidence from Stable Isotope and Fish Gut Content Analyses

Water ◽

10.3390/w9010069 ◽

2017 ◽

Vol 9 (1) ◽

pp. 69 ◽

Cited By ~ 10

Author(s):

Jian Gao ◽

Ping Zhong ◽

Jiajia Ning ◽

Zhengwen Liu ◽

Erik Jeppesen

Keyword(s):

Stable Isotope ◽

Food Web ◽

Eutrophic Lake ◽

Gut Content ◽

Food Web Structure ◽

Omnivorous Fish ◽

Web Structure ◽

Content Analyses ◽

Fish Gut

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Zooplankton and environmental factors of a recovering eutrophic lake (Lysimachia Lake, Western Greece)

Biologia ◽

10.2478/s11756-013-0171-9 ◽

2013 ◽

Vol 68 (3) ◽

Cited By ~ 5

Author(s):

Ekaterini Chalkia ◽

George Kehayias

Keyword(s):

Community Dynamics ◽

Zooplankton Community ◽

Eutrophic Lake ◽

Nutrient Concentrations ◽

Eutrophic Lakes ◽

Trophic Conditions ◽

Urban Sewage ◽

The Past ◽

Unique Species ◽

Western Greece

AbstractThe present study investigates the zooplankton community dynamics and the abiotic environment in the eutrophic Lake Lysimachia (western Greece). The lake is considered to be recovering from eutrophication after the termination of an urban sewage inflow in 2000, and its waters are replenished constantly from the nearby oligotrophic Lake Trichonis. The results show that, although a decrease in nutrient concentrations was observed compared to the past, the lake still has eutrophic characteristics. This was reflected in the zooplankton community which is typical of those found in eutrophic lakes where rotifers prevail. Similarities among this lake and other nearby lakes were found considering the zooplankton community composition and seasonal variation. However, Lake Lysimachia is inhabited also by a number of different and even unique species (e.g., Moina micrura), suggesting that this ecosystem may be an important biodiversity refuge. Most of the zooplankton species were correlated with water temperature and, to a lesser extent, eutrophication key-water quality variables. Although there are few available data on the zooplankton of the lake, the abundance and composition of the community presenting characteristics indicative of intermediate trophic conditions and suggesting that the lake is probably under a kind of “biological” recovery.

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The structure of psammic rotifer communities in two boreal lakes with different trophic conditions: Lake Võrtsjärv and Lake Saadjärv (Estonia)

Oceanological and Hydrobiological Studies ◽

10.2478/s13545-014-0116-0 ◽

2014 ◽

Vol 43 (1) ◽

Cited By ~ 3

Author(s):

Külli Lokko ◽

Taavi Virro

Keyword(s):

Plant Density ◽

Eutrophic Lake ◽

Boreal Lakes ◽

Trophic Conditions ◽

Rotifer Species ◽

Quantitative Parameters ◽

Mesotrophic Lake ◽

Rotifer Community ◽

Lake Võrtsjärv ◽

Rotifer Communities

AbstractPsammon communities are still poorly studied worldwide. The aim of the present study was to establish the structure of psammic rotifer communities including their diversity and quantitative parameters. A total of 41 rotifer taxa were found in hydro-, hygro-, and euarenal zones of eutrophic Lake Võrtsjärv and mesotrophic Lake Saadjärv during the study carried out in Estonia in 2008, including 11 rotifer species new to Estonia. In L. Võrtsjärv, the predominant rotifer taxa were Bdelloidea and Lecane psammophila. L. psammophila dominated in July and August and bdelloids prevailed in the rest of the year. In L. Saadjärv, the most abundant taxa were Lepadella ovalis, Keratella hiemalis, and Cephalodella megalocephala. The psammic rotifer community of L. Saadjärv proved to be more diverse than that of L. Võrtsjärv. Microphagous rotifers were dominant in L. Võrtsjärv. Raptorial feeders dominated in L. Saadjärv in summer and autumn and were more abundant at sites with coarser sand and low plant density.

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Zooplankton communities of two lake outlets in relation to abiotic factors

Open Life Sciences ◽

10.2478/s11535-009-0062-9 ◽

2010 ◽

Vol 5 (2) ◽

pp. 240-255 ◽

Cited By ~ 9

Author(s):

Robert Czerniawski ◽

Józef Domagała

Keyword(s):

Abiotic Factors ◽

Zooplankton Community ◽

Eutrophic Lake ◽

Small Rivers ◽

Physical Parameters ◽

Trophic Conditions ◽

Zooplankton Community Structure ◽

Mesotrophic Lake ◽

Significant Difference ◽

Zooplankton Communities

AbstractWe examined the quantitative and qualitative zooplankton community structure in two small rivers flowing out from lakes differing in trophic conditions. Within each river, three sites were chosen for the collection of drifted zooplankton: one at the outflow, and two at distances of 0.2 km and 1 km from the outflow. The most significant difference in zooplankton community between the outflow and the lower course of the river occurred in the first section directly after the outflow. These differences in the zooplankton community were driven largely by crustaceans, which declined faster in the river flowing out from the mesotrophic lake. Physical parameters mainly impacted the zooplankton community found in the river flowing from the mesotrophic lake; however, chemical parameters also had an impact in the river discharging from the strongly eutrophic lake.

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