scholarly journals Interaction among bacterioplankton and macrophytes in shallow lakes with high macrophyte cover

2020 ◽  
Vol 82 (4) ◽  
Author(s):  
Nóra Szabó-Tugyi ◽  
Viktor R. Tóth
Keyword(s):  
Shallow Lakes ◽  
Bacterial Production ◽  
Heterotrophic Bacteria ◽  
Seasonal Pattern ◽  
Biomass Accumulation ◽  
Emergent Macrophytes ◽  
Macrophyte Growth ◽  
Macrophyte Biomass ◽  
The Relationship ◽  
Bacterioplankton Abundance

Abstract Growth of submerged and emergent macrophytes was studied together with heterotrophic bacterioplankton abundance and production in two Hungarian shallow lakes with dominant macrophyte covers. It was expected that bacterioplankton numbers and activity would have an effect on macrophyte biomass accumulation. Bacterial production and abundance showed a strong seasonal pattern with maximum in the warmest months (July, August). It was found that macrophyte biomass increased with heterotrophic bacterial production and abundance up to 5.6 µg C l− 1 h− 1 and 5.30*106 cells, respectively, while over that value was negatively associated with macrophyte growth. It was also shown that the relationship between heterotrophic bacteria and macrophytes also varied seasonally, showing a multifaceted relationship. It was demonstrated that macrophytes are not only the most significant carbon and energy source for the bacteria in shallow, macrophyte-dominated lakes, but are also competing organisms that could be supressed by excessive bacterial activity. These findings could help better understand the interaction between macrophytes and bacterioplankton, and assist wetland managers in quantifying what may be a primary cause of reed die-back.

scholarly journals Fe and C co-limitation of heterotrophic bacteria in the naturally fertilized region off the Kerguelen Islands

2015 ◽  
Vol 12 (6) ◽  
pp. 1983-1992 ◽  
Author(s):  
I. Obernosterer ◽  
M. Fourquez ◽  
S. Blain
Keyword(s):  
Trace Metal ◽  
Bacterial Production ◽  
Bacterial Abundance ◽  
Heterotrophic Bacteria ◽  
Kerguelen Islands ◽  
High Nutrient ◽  
Limiting Nutrient ◽  
Heterotrophic Metabolism ◽  
Heterotrophic Production

Abstract. It has been univocally shown that iron (Fe) is the primary limiting nutrient for phytoplankton metabolism in high-nutrient, low-chlorophyll (HNLC) waters, yet the question of how this trace metal affects heterotrophic microbial activity is far less understood. We investigated the role of Fe for bacterial heterotrophic production and growth at three contrasting sites in the naturally Fe-fertilized region east of the Kerguelen Islands and at one site in HNLC waters during the KEOPS2 (Kerguelen Ocean and Plateau Compared Study 2) cruise in spring 2011. We performed dark incubations of natural microbial communities amended either with iron (Fe, as FeCl3) or carbon (C, as trace-metal clean glucose), or a combination of both, and followed bacterial abundance and heterotrophic production for up to 7 days. Our results show that single and combined additions of Fe and C stimulated bulk and cell-specific bacterial production at the Fe-fertilized sites, while in HNLC waters only combined additions resulted in significant increases in these parameters. Bacterial abundance was enhanced in two out of the three experiments performed in Fe-fertilized waters but did not respond to Fe or C additions in HNLC waters. Our results provide evidence that both Fe and C are present at limiting concentrations for bacterial heterotrophic activity in the naturally fertilized region off the Kerguelen Islands in spring, while bacteria were co-limited by these elements in HNLC waters. These results shed new light on the role of Fe in bacterial heterotrophic metabolism in regions of the Southern Ocean that receive variable Fe inputs.

Seasonal growth and duration of the parasitic life stage of the landlocked sea lamprey (Petromyzon marinus)

1995 ◽  
Vol 52 (6) ◽  
pp. 1257-1264 ◽  
Author(s):  
Roger A. Bergstedt ◽  
William D. Swink
Keyword(s):  
Seasonal Pattern ◽  
Life Stage ◽  
Petromyzon Marinus ◽  
Biomass Accumulation ◽  
Sea Lamprey ◽  
Gonadal Development ◽  
Adult Size ◽  
Sea Lampreys ◽  
Mean Size ◽  
Host Mortality

We used lengths and weights of 2367 live parasitic-phase sea lampreys (Petromyzon marinus) collected from Lake Huron, 1984–1990, to calculate their mean size at half-month intervals. Growth in weight was linear during June through September; increments averaged 11.1 g per half month. Growth increased sharply in October to several times the summer rate. We speculate that the increase in growth in October is explained partly by water temperature and partly by an increase in appetite related to the onset of gonadal development. The greater compression of biomass accumulation in autumn than has been previously demonstrated better explains the autumn pulse of sea lamprey induced host mortality. Based on the seasonal pattern of growth and on recaptures of marked sea lampreys, we conclude that landlocked individuals grow to adult size and mature in one parasitic growth year. Regressions of weight (grams) on total length (millimetres) differed significantly among months, and the season of collection must be considered in predicting weight from length.

scholarly journals Spatial distribution and seasonal pattern of biogenic sulphur compounds in snow from northern Victoria Land, Antarctica

1998 ◽  
Vol 27 ◽  
pp. 535-542 ◽  
Author(s):  
R. Udisti ◽  
R. Traversi ◽  
S. Becagli ◽  
G. Piccardi
Keyword(s):  
Seasonal Pattern ◽  
Temporal Distribution ◽  
Transport Mechanisms ◽  
Sulphur Compounds ◽  
Secondary Sources ◽  
Victoria Land ◽  
Range Transport ◽  
Transport Effects ◽  
Coherent Information ◽  
The Relationship

A study of the spatial and temporal distribution of methane sulphonic aeid (MSA) and nssSO42-concentrations in snow-pit samples was performed to determine the main and secondary sources, transport effects and seasonal pattern of biogenic sulphur compounds. Four snow pits, about 3 m deep, excavated at the same time at different altitudes (870-2960 m a.s.1.) in northern Victoria Land, Antarctica, gave coherent information about the effect of altitude and seasonality on the snow chemical composition. A progressive, well-defined decreasing concentration trend is shown as altitude increases, with the biggest effect in the first 1000 m a.s.1. At higher altitudes, biogenic sources make the most important contribution to the tola! sulphate balance with respect to sea-mray input. Particular attention was paid to the relationship between MSA and nssSO42-by using MSA as a univoca] biogenic marker. The nssSO42-/MSA ratio was evaluated with respect to altitude and seasonality to determine the effect of transport mechanisms (such as long-range transport and fractionation) or non-dimethyl sulphide sources on nssSO42-snow content.

Balance between primary and bacterial production in North Patagonian shallow lakes

2008 ◽  
Vol 43 (4) ◽  
pp. 867-878 ◽  
Author(s):  
Marcela Bastidas Navarro ◽  
Beatriz Modenutti ◽  
Cristiana Callieri ◽  
Roberto Bertoni ◽  
Esteban Balseiro
Keyword(s):  
Shallow Lakes ◽  
Bacterial Production

scholarly journals Using environmental niche modelling to investigate abiotic predictors of crocodilian attacks on people

Oryx ◽  
2020 ◽  
Vol 54 (5) ◽  
pp. 639-647
Author(s):  
George Powell ◽  
Thomas M. M. Versluys ◽  
Jessica J. Williams ◽  
Sonia Tiedt ◽  
Simon Pooley
Keyword(s):  
Human Life ◽  
Seasonal Pattern ◽  
Alligator Mississippiensis ◽  
Effect Of Temperature ◽  
Environmental Niche ◽  
Niche Modelling ◽  
Human Safety ◽  
Hunting Behaviour ◽  
The Tropics ◽  
The Relationship

AbstractCrocodilians are distributed widely through the tropics and subtropics, and several species pose a substantial threat to human life. This has important implications for human safety and crocodilian conservation. Understanding the drivers of crocodilian attacks on people could help minimize future attacks and inform conflict management. Crocodilian attacks follow a seasonal pattern in many regions, but there has been limited analysis of the relationship between attack occurrence and fine-scale contemporaneous environmental conditions. We use methods from environmental niche modelling to explore the relationships between attacks on people and abiotic predictors at a daily temporal resolution for the Nile crocodile Crocodylus niloticus in South Africa and Eswatini (formerly Swaziland), and the American alligator Alligator mississippiensis in Florida, USA. Our results indicate that ambient daily temperature is the most important abiotic temporal predictor of attack occurrence for both species, with attack likelihood increasing markedly when mean daily temperatures exceed 18 °C and peaking at 28 °C. It is likely that this relationship is explained partially by human propensity to spend time in and around water in warmer weather but also by the effect of temperature on crocodilian hunting behaviour and physiology, especially the ability to digest food. We discuss the potential of our findings to contribute to the management of crocodilians, with benefits for both human safety and conservation, and the application of environmental niche modelling for understanding human–wildlife conflicts involving both ectotherms and endotherms.

The influence of water level on macrophyte growth and trophic interactions in eutrophic Mediterranean shallow lakes: a mesocosm experiment with and without fish

2012 ◽  
Vol 57 (8) ◽  
pp. 1631-1642 ◽  
Author(s):  
TUBA BUCAK ◽  
ECE SARAOĞLU ◽  
ETİ E. LEVİ ◽  
Ü. NİHAN TAVŞANOĞLU ◽  
A. İdİl ÇAKİROĞLU ◽  
...  
Keyword(s):  
Water Level ◽  
Shallow Lakes ◽  
Trophic Interactions ◽  
Mesocosm Experiment ◽  
Influence Of Water ◽  
Macrophyte Growth

scholarly journals SEBARAN BAKTERI HETEROTROF, BAHAN ORGANIK TOTAL, NITRAT DAN KLOROFIL-A AIR MUARA SUNGAI CIPASAURAN, SERANG

2018 ◽  
Vol 6 (3) ◽  
pp. 222-229
Author(s):  
Denita Irma Santi ◽  
Norma Afiati ◽  
Pujiono Wahyu Pujiono Wahyu Purnomo
Keyword(s):  
Water Quality ◽  
Chlorophyll A ◽  
Organic Material ◽  
Heterotrophic Bacteria ◽  
Sampling Technique ◽  
Local Communities ◽  
Nutrient Elements ◽  
Purposive Sampling ◽  
Household Activities ◽  
The Relationship

ABSTRAK Muara Sungai Cipasauran merupakan ekosistem yang dimanfaatkan oleh masyarakat setempat untuk kegiatan rumah tangga. seperti mandi, mencuci pakaian dan kegiatan nelayan. Aktivitas kegiatan tersebut menyebabkan masuknya air limbah ke saluran air sungai lainnya. Hilir Cipasauran Muara, berakhir di Pantai Anyer. Kegiatan penangkapan ikan di sekitar Pantai Anyer menunjukkan kualitas air yang relatif baik. Tujuan dari penelitian ini adalah untuk menentukan sebaran bakteri heterotrofik, bahan organik total, nitrat dan klorofil-a, serta untuk mengetahui hubungan antara variabel. Bahan yang digunakan dalam penelitian ini adalah air sampel dari 4 lokasi di muara Cipasauran ke Pantai Anyer. Penelitian ini menggunakan teknik purposive sampling. Pengambilan sampel dilakukan dengan interval dua minggu, masing-masing dengan dua kali pengulangan. Hasil penelitian menunjukkan bahwa jumlah bakteri heterotrofik  di empat stasiun berkisar antara 250-2500 cfu/ml, kandungan bahan organik jumlah berkisar 27,83-100,64 mg/l, konsentrasi nitrat berkisar antara 4,12-11,8 mg/l, dan klorofil-a pada empat stasiun berkisar 0,01- 6,31 mg/m3. Muara Sungai Cipasauran termasuk dalam kategori perairan yang subur (Eutrofik). Analisis regresi berganda memperlihatkan bakteri heterotrof signifikan pada bahan organik total (0,02< p<0,05). Adapun, ekstrak klorofil-a yang dihasilkan dari fitoplankton lebih tergantung kepada kadar nitrat (0,03<p< 0,05) dibandingkan terhadap kadar bahan organik total (0,11>p>0,05), sehingga unsur hara yang lebih banyak dibutuhkan adalah nitrat. Namun tingginya nitrat dapat memicu terjadinya eutrofikasi.  Kata Kunci : Bakteri Heterotrof; Bahan Organik Total; Nitrat; Klorofil-A; Muara Sungai Cipasauran ABSTRACT Cipasauran estuarine ecosystems utilized by local communities for household activities, such as bathing, washing clothes and fishing activities. These activities led to an influx of wastewater into waterways of the river. Downstream Cipasauran Estuary, ends at Anyer Beach. Fishing activities around Anyer Beach indicates the relatively good water quality. The purpose of this study is to determine the distribution of heterotrophic bacteria, total organic material, nitrate and chlorophyll-a, as well as to study the relationship between those variables. The material used in this study is water sampled from 4 location, at the estuary of Cipasauran down to Anyer Beach. The study used purposive sampling technique. Sampling was conducted at intervals of two weeks, each with two replication. The results showed that number heterotrophic bacteria in four stations ranged between 250-2500 cfu/ml, where as total organic materials ranged from 27.83 to 100,64 mg/l, nitrates ranged from 4.12 to 11.8 mg/l, and  chlorophyll-a at four stations ranged from 0.01 to 6.31 mg/m3. Cipasauran estuarine included in the fertile waters (Eutrofik). Regression analysis showed a significant increase in heterotrophic bacterial organic matter total (0.02<p<0.05). So, extract the chlorophyll-a resulting from more phytoplankton depend on nitrate levels (0.03<p<0.05) compared against the total organic material levels (0.11>p>0.05), so the more nutrient elements needed is nitrate. But high nitrate can trigger the onset of eutrophication.                Keywords: Heterotrophic Bacteria, Total Organic Material, Nitrate, Chlorophyll-a Cipasauran Estuary 

‘La Niña’ phenomenon and the relationship between decapod populations and fishes in temporarily isolated shallow lakes

2017 ◽  
Vol 68 (6) ◽  
pp. 1010 ◽  
Author(s):  
María Victoria Torres ◽  
Federico Giri ◽  
Pablo Agustín Collins
Keyword(s):  
Shallow Lakes ◽  
Paraná River ◽  
La Niña ◽  
Additional Stress ◽  
Complete Disappearance ◽  
Parana River ◽  
La Nina ◽  
Local Species ◽  
Abiotic And Biotic Factors ◽  
The Relationship

The ‘La Niña’ phenomenon causes temporary isolation of shallow lakes in rivers with floodplain. Furthermore, as abiotic conditions become more extreme, and intra–interspecific relationships intensify, the risk of local species extinction increases. The Paraná River in South America is a river with an extensive floodplain with many shallow lakes. In these environments, freshwater prawns and many fish species coexist. The aim of the work was to study the interaction between two species of prawns (Palaemonetes argentinus and Macrobrachium borellii) and fishes during ‘La Niña’ phenomenon. Density variations of prawns and fishes were examined in three shallow lakes at Paraná River. The samples were collected monthly at several points of each aquatic environment with a trawl net. Abiotic and biotic factors were measured. Density and population structure varied in both prawns, and fishes, and the changes have not been simultaneous. These variations might be associated with predation, aggressive behaviour of the prawns and internal micro-migrations. The effect of La Niña creates additional stress on prawn populations when water inflow is delayed. This fact could promote the decrease or the complete disappearance of one or both prawn species in the environments, and modify the trophic web in the next phase of the shallow lakes.

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