Limnological variations of a deep reservoir in periods with distinct rainfall patterns

AIM: This study intends to provide information on how precipitation variation may impact environmental parameters (total phosphorus, water temperature, pH, conductivity, dissolved oxygen, Secchi depth, chlorophyll a and Anabaena abundance) and crustacean zooplankton composition and abundance. METHODS: Samples were collected monthly from October 2000 to September 2002 and from October 2007 to September 2009 at one single sampling station located at the deepest point of the reservoir. All data were obtained in the euphotic zone. RESULTS: The highest values of total phosphorous concentrations were reported together with the maximal values of precipitation. Conversely, conductivity decreased during the wet periods. Anabaena presence was only detected between September and December 2001. Daphnia longispina total abundance showed large inter-annual differences. A clear seasonal pattern was inferred for Diaphanosoma brachyurum and Ceriodaphnia pulchella. Both species are thermophilic and begin to be detected in early summer when the water temperature is around 15 ºC. Copidodiaptomus numidicus abundance did not present a clear seasonal pattern. CONCLUSIONS: Some of the observed shifts in environmental parameters (Conductivity, total phosphorus concentrations and Anabaena abundance) resulting in changes in zooplankton abundance are induced by rainfall variation. The most affected species were those with a lack of seasonality (C. numidicus) or species occurring mainly in winter/early summer (Daphnia longispina). However, a wide range of physical, chemical and biotic interactions is likely to influence zooplankton abundance. Therefore, caution is advised when relating the observed variation exclusively with rainfall intensity. In fact, some of the observed shifts were induced by other factors varying subtly in a seasonal or inter-annual pattern, independently of rainfall intensity.

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Reproductive Cycle of Nassarius Reticulatus in the Ria De Aveiro, Portugal: Implications for Imposex Studies

Journal of the Marine Biological Association of the United Kingdom ◽

10.1017/s0025315400044453 ◽

1998 ◽

Vol 78 (4) ◽

pp. 1233-1246 ◽

Cited By ~ 30

Author(s):

C.M. Barroso ◽

M.H. Moreira

Keyword(s):

Water Temperature ◽

Reproductive Cycle ◽

Seasonal Pattern ◽

Shell Height ◽

Ria De Aveiro ◽

North West ◽

The North ◽

Nassarius Reticulatus ◽

Clear Seasonal Pattern ◽

Penis Length

The reproductive cycle of Nassarius (Hinia) reticulatus was investigated in the Ria de Aveiro on the north-west Portuguese coast during 1992 and 1993. A clear seasonal pattern was observed with the beginning of gametogenesis in August followed by ripening of the gonads in January and February and spawning from February to July. The increase of water temperature above 11°C in February 1993 was associated presumably with the release of gametes. Recruitment inside the Ria of juveniles with 6·5 mm mean shell height was detected in February 1993 and these individuals were spawned in the previous year. Males of N. reticulatus exhibited a considerable variation in length of the penis throughout the reproductive cycle. The accuracy of the use of relative penis length (RPL) index for intersite comparisons of imposex is discussed and the magnitude of the error that might be involved when comparisons are made using populations in different phases of the reproductive cycle is evaluated.

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A study on bioecology of macroalgae, genus Caulerpa in northern Minahasa Waters, North Sulawesi Province

AQUATIC SCIENCE & MANAGEMENT ◽

10.35800/jasm.1.1.2013.1965 ◽

2013 ◽

Vol 1 (1) ◽

pp. 26

Author(s):

Irma Pulukadan ◽

Rene Ch Keppel ◽

Grevo S Gerung

Keyword(s):

Dissolved Oxygen ◽

Water Temperature ◽

Raw Materials ◽

Economic Value ◽

Algal Growth ◽

Environmental Parameters ◽

Caulerpa Racemosa ◽

Bottom Substrate ◽

North Sulawesi ◽

Ecological Aspects

Alga is a marine resource of potential to fisheries and marine sector. It has an important economic value to promote the economy in Indonesia. Nowdays, algae have been used as a relatively high value fisheries commodity since it has been used for food, industrial, pharmaceutical and cosmetic raw materials. This important potential needs to be supported with understanding of its biology and ecology, so that its utilization could increase the livelihood of the coastal villagers. This study was aimed at inventorying and identifying the members of genus Caulerpa found in North Minahasa Regency waters and studying some biological and ecological aspects of the algae in the area. Resuls showed that there were 7 species recorded, Caulerpa racemosa, C. racemosa var. macrophysa, C. sertularioides, C. taxifolia, C. serrulata,C. lentillifera and C. peltata. Ecologically, the environmental parameters, such as water temperature, salinity, pH, dissolved oxygen, turbidity, were in tolerable ranges for algal growth. Bottom substrate supported the growth of genus Caulerpa as well© Saat ini alga dijadikan sebagai komoditas hasil perikanan dengan nilai ekonomis yang relatif tinggi karena manfaatnya sebagai bahan makanan serta bahan baku industri, farmasi, dan kosmetik. Potensi yang cukup penting ini harus ditunjang dengan ilmu pengetahuan tentang biologi dan ekologi dari alga laut, sehingga pemanfaatannya dapat meningkatkan taraf hidup masyarakat pesisir. Penelitian tentang kajian bioekologi alga makro genus Caulerpa di perairan Minahasa Utara ini dilaksanakan dan diharapkan dapat memberikan informasi ilmiah tentang bioekologi alga makro genus Caulerpa, sehingga dapat dimanfaatkan untuk pengembangan pemanfaatan bagi kepentingan masyarakat pesisir khususnya dan industri alga makro umumnya. Penelitian ini bertujuan untuk menginventarisasi dan mengidentifikasi alga makro genus Caulerpa di perairan Kabupaten Minahasa Utara, dan mengkaji aspek bioekologinya. Hasil penelitian menunjukkan bahwa ditemukan 7 spesies, yaitu Caulerpa racemosa, C. racemosa var. macrophysa, C. sertularioides, C. taxifolia, C. serrulata, C. lentillifera dan C. peltata. Parameter lingkungan seperti suhu, salinitas, pH, oksigen terlarut, tingkat kecerahan air berada pada kisaran yang dapat ditolerir untuk pertumbuhan alga makro, sedangkan substrat juga mendukung pertumbuhan alga makro ini©

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Extreme Meteorological Events in a Coastal Lagoon Ecosystem: The Ria de Aveiro Lagoon (Portugal) Case Study

Journal of Marine Science and Engineering ◽

10.3390/jmse9070727 ◽

2021 ◽

Vol 9 (7) ◽

pp. 727

Author(s):

José Fortes Lopes ◽

Carina Lurdes Lopes ◽

João Miguel Dias

Keyword(s):

Water Temperature ◽

Coastal Lagoon ◽

Early Summer ◽

Extreme Weather Events ◽

Climate Change Scenarios ◽

State Variables ◽

Ria De Aveiro ◽

Physical Conditions ◽

Weather Events ◽

The Impact

Extreme weather events (EWEs) represent meteorological hazards for coastal lagoon hydrodynamics, of which intensity and frequency are increasing over the last decades as a consequence of climate changes. The imbalances they generated should affect primarily vulnerable low-lying areas while potentially disturbing the physical balances (salt and water temperature) and, therefore, the ecosystem equilibrium. This study arises from the need to assess the impact of EWEs on the Ria de Aveiro, a lagoon situated in the Portuguese coastal area. Furthermore, it was considered that those events occur under the frame of a future sea-level rise, as predicted by several climate change scenarios. Two EWEs scenarios, a dry and an extremely wet early summer reflecting past situations and likely to occur in the future, were considered to assess the departure from the system baseline functioning. It was used as a biogeochemistry model that simulates the hydrodynamics, as well as the baseline physical and biogeochemistry state variables. The dry summer scenario, corresponding to a significant reduction in the river’s inflow, evidences a shift of the system to a situation under oceanic dominance characterized by colder and saltier water (~18 °C; 34 PSU) than the baseline while lowering the concentration of the nutrients and reducing the phytoplankton population to a low-level limit. Under a wet summer scenario, the lagoon shifted to a brackish and warmer situation (~21 °C, <15 PSU) in a time scale of some tidal periods, driven by the combining effect of the tidal transport and the river’s inflow. Phytoplankton patterns respond to variability on local and short-term scales that reflect physical conditions within the lagoon, inducing nutrient-supported growth. Overall, the results indicate that EWEs generate local and transient changes in physical conditions (namely salinity and water temperature) in response to the characteristic variability of the lagoon’s hydrodynamics associated with a tidal-dominated system. Therefore, in addition to the potential impact of changing physical conditions on the ecosystem, saline intrusion along the lagoon or the transfer of brackish water to the mouth of the system are the main consequences of EWEs, while the main biogeochemistry changes tend to remain moderate.

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Scyphomedusae and Ctenophora of the Eastern Adriatic: Historical Overview and New Data

Diversity ◽

10.3390/d13050186 ◽

2021 ◽

Vol 13 (5) ◽

pp. 186

Author(s):

Branka Pestorić ◽

Davor Lučić ◽

Natalia Bojanić ◽

Martin Vodopivec ◽

Tjaša Kogovšek ◽

...

Keyword(s):

Adriatic Sea ◽

Seasonal Pattern ◽

Geographical Location ◽

Distribution Patterns ◽

Mnemiopsis Leidyi ◽

Future Studies ◽

Phenological Data ◽

Pelagia Noctiluca ◽

Regional Trends ◽

Clear Seasonal Pattern

One of the obstacles to detecting regional trends in jellyfish populations is the lack of a defined baseline. In the Adriatic Sea, the jellyfish fauna (Scyphozoa and Ctenophora) is poorly studied compared to other taxa. Therefore, our goal was to collect and systematize all available data and provide a baseline for future studies. Here we present phenological data and relative abundances of jellyfish based on 2010–2019 scientific surveys and a “citizen science” sighting program along the eastern Adriatic. Inter-annual variability, seasonality and spatial distribution patterns of Scyphomedusae and Ctenophore species were described and compared with existing historical literature. Mass occurrences with a clear seasonal pattern and related to the geographical location were observed for meroplanktonic Scyphomedusae Aurelia solida, Rhizostoma pulmo, and to a lesser extent Chrysaora hysoscella, Cotylorhiza tuberculata and Discomedusa lobata. Holoplanktonic Pelagia noctiluca also formed large aggregations, which were seasonally less predictable and restricted to the central and southern Adriatic. Four species of Ctenophora produced blooms limited to a few areas: Bolinopsis vitrea, Leucothea multicornis, Cestum veneris and the non-native Mnemiopsis leidyi. However, differences between Adriatic subregions have become less pronounced since 2014. Our results suggest that gelatinous organisms are assuming an increasingly important role in the Adriatic ecosystem, which may alter the balance of the food web and lead to harmful and undesirable effects.

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Life histories and distribution of ostracods with depth in western Lake Geneva (Petit-Lac), Switzerland: a reconnaissance study

Crustaceana ◽

10.1163/15685403-00003344 ◽

2014 ◽

Vol 87 (8-9) ◽

pp. 1095-1123 ◽

Cited By ~ 1

Author(s):

Laurent Decrouy ◽

Torsten W. Vennemann

Keyword(s):

Life History ◽

Water Temperature ◽

Water Depth ◽

Organic Matter Content ◽

Environmental Parameters ◽

Late Winter ◽

Lake Geneva ◽

Monthly Basis ◽

Sampling Campaign ◽

Western Lake

Because environmental conditions within a given basin are different for each season and at different water depth, knowledge of the life history and depth distribution of target species is important for environmental and palaeoenvironmental interpretations based on ostracod species assemblages and/or the geochemical compositions of their valves. In order to determine the distribution of species with depth as well as the life history of species from Lake Geneva, a one-year sampling campaign of living ostracods was conducted at five sites (2, 5, 13, 33 and 70 m water depth) on a monthly basis in the Petit-Lac (western basin of Lake Geneva, Switzerland). Based on the results, the different species can be classified into three groups. Littoral taxa are found at 2 and 5 m water depth and include, in decreasing numbers of individuals,Cypridopsis vidua(O. F. Müller, 1776),Pseudocandona compressa(Koch, 1838),Limnocythere inopinata(Baird, 1843),Herpetocypris reptans(Baird, 1835),Potamocypris smaragdina(Vávra, 1891),Potamocypris similis(G. W. Müller, 1912),Plesiocypridopsis newtoni(Brady & Robertson, 1870),Prionocypris zenkeri(Chyzer & Toth, 1858) andIlyocyprissp. Brady & Norman, 1889. Sublittoral species are found in a majority at 13 m water depth and to a lesser extend at 33 m water depth and include, in decreasing numbers of individuals,Fabaeformiscandona caudata(Kaufmann, 1900),Limnocytherina sanctipatricii,Candona candida(O. F. Müller, 1776) andIsocypris beauchampi(Paris, 1920). Profundal species are found equally at 13, 33 and 70 m water depth and includes, in decreasing numbers of individuals,Cytherissa lacustris(Sars, 1863),Candona neglectaSars, 1887 andCypria lacustrisLilljeborg, 1890. The occurrence ofLimnocytherina sanctipatricii(Brady & Robertson, 1869) is restricted from late winter to late spring when temperatures are low, whileC. vidua,L. inopinata,P. smaragdina,P. similis,P. newtoniandIlyocyprissp. occur predominantly from spring to early autumn when temperatures are high. Individuals ofC. neglecta,C. candida,F. caudata,P. compressa,C. lacustris,H. reptansandCp. lacustrisoccur throughout the year with juveniles and adults occurring during the same period (C. neglectaat 70 m,C. lacustrisat 13, 33 and 70 m, andH. reptansat 2, 5 and 13 m water depth) or with juveniles occurring during a different period of the year than adults (C. neglectaat 13 and 33 m andC. candida,F. caudataandP. compressaat their respective depth of occurrence). Among the environmental parameters investigated, an estimate of the relationship between ostracod autoecology and environmental parameters suggests that in the Petit-Lac: (i) water temperature and substrate characteristics are important factors controlling the distribution of species with depth, (ii) water temperature is also important for determining the timing of species development and, hence, its specific life history, and (iii) water oxygen and sedimentary organic matter content is less important compared to the other environmental parameter monitored.

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Forest harvest impacts on water quality and aquatic biota on the Boreal Plain: introduction to the TROLS lake program

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/f00-259 ◽

2001 ◽

Vol 58 (2) ◽

pp. 421-436 ◽

Cited By ~ 44

Author(s):

E E Prepas ◽

B Pinel-Alloul ◽

D Planas ◽

G Méthot ◽

S Paquet ◽

...

Keyword(s):

Total Phosphorus ◽

Drainage Basin ◽

Zooplankton Biomass ◽

Phosphorus Concentration ◽

Zooplankton Abundance ◽

Total Phosphorus Concentration ◽

Buffer Strip ◽

Stratified Lakes ◽

Lake Volume ◽

Order Of Magnitude

Eleven headwater lakes in Alberta's Boreal Plain were monitored for nutrients and plankton 2 years before and 2 years after variable watershed harvesting (harvesting mean 15%, range 0-35%). After harvesting, variations in annual precipitation resulted in lake water residence times that differed by an order of magnitude from one year to the next. During the first posttreatment year, total phosphorus concentrations increased (overall 40%) in most lakes; however, response was most consistent in lakes that were shallow and the water column mixed or weakly thermally stratified. Chlorophyll a, cyanobacteria (Aphanizomenon-Anabaena), and cyanotoxins (microcystin-LR) increased after harvesting, primarily in shallow lakes. Zooplankton abundance and biomass decreased after harvesting, particularly in stratified lakes where edible phytoplankton biomass declined. In the weakly or nonstratified lakes, declines in zooplankton biomass were associated with higher cyanobacterial biomass and cyanotoxins. Posttreatment change in total phosphorus concentration was strongly related to weather (greatest response in a wet year) and relative drainage basin size (drainage basin area to lake volume, r2 = 0,78, P << 0,01). There was no evidence that buffer strip width (20, 100, and 200 m) influenced lake response. These results suggest that activities within the entire watershed should be the focus of catchment-lake interactions.

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Interaction among Controlling Factors on Riverine DIN Export in Small Mountainous Rivers of Taiwan: Inseparable Human-Landscape System

Water ◽

10.3390/w12112981 ◽

2020 ◽

Vol 12 (11) ◽

pp. 2981

Author(s):

Wen-Shiuan Lee ◽

Jr-Chuan Huang ◽

Chung-Te Chang ◽

Shih-Chien Chan ◽

Ying-San Liou ◽

...

Keyword(s):

Inorganic Nitrogen ◽

Seasonal Pattern ◽

Water Quality Management ◽

Negative Relationship ◽

Dry Season ◽

Mitigation Strategies ◽

Minor Effect ◽

Dominant Form ◽

Wide Range ◽

Human Landscape

Increasing anthropogenic nitrogen (N) emission via different pathways has shown prominent impact on aquatic ecosystems for decades, but the effects of interaction among climate-, landscape- and human-associated variables on riverine DIN (dissolved inorganic nitrogen, mainly NO3− and NH4+) export are unclear. In this study, the data of 43 watersheds with a wide range of climate-, landscape- and human-associated gradients across Taiwan were evaluated with partial redundancy analysis (pRDA) to examine their interactive controls on riverine DIN export. Results show that the annual riverine DIN export in Taiwan is approximately 3100 kg-N km−2 yr−1, spanning from 230 kg-N km−2 yr−1 in less disturbed watersheds (eastern and central Taiwan) to 10,000 kg-N km−2 yr−1 in watersheds with intensive human intervention (southwestern and northern Taiwan). NO3− is generally the single dominant form of DIN, while NH4+ renders significance in disturbed watersheds. Nearly all environmental variables display a positive correlation with DIN export, except for landscape setting variables (e.g., slope, area, channel length), which show a negative relationship. In terms of seasonal pattern, climate and human-landscape variables are related to NO3− export independently in the wet season, yet in the dry season climate-human variables jointly dominate NO3− export. Meanwhile, human-landscape (LH) variables (λ1 of LH > 0.60) control NH4+ exports in both seasons, and human-associated (H) variables (λ1 of H = 0.13) have a minor effect on NH4+ exports in dry season. Precisely, the contribution of controlling variables on DIN export vary with species and seasons, indicating water quality management could be time-dependent, which should be taken into consideration for designing mitigation strategies.

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Optimization of nitrogen and phosphorus removal from pig slaughterhouse and packing plant wastewater through electrocoagulation in a batch reactor

Ambiente e Agua - An Interdisciplinary Journal of Applied Science ◽

10.4136/ambi-agua.2233 ◽

2018 ◽

Vol 13 (5) ◽

pp. 1

Author(s):

Fábio Orssatto ◽

Maria Hermínia Ferreira Tavares ◽

Flávia Manente da Silva ◽

Eduardo Eyng ◽

Leandro Fleck

Keyword(s):

Total Phosphorus ◽

Retention Time ◽

Batch Reactor ◽

Maximum Efficiency ◽

Nitrogen And Phosphorus ◽

Nitrogen And Phosphorus Removal ◽

Treatment Conditions ◽

Surface Graph ◽

Wide Range ◽

Kjeldahl Nitrogen

This work evaluated the removal of total Kjeldahl nitrogen (TKN) and total phosphorus (P) through electrocoagulation and used aluminum electrodes to optimize the potential differential (pd) and hydraulic retention time (HRT) variables in a batch reactor. The experimental design used was Rotatable Central Composite Design (RCCD). The application of the electrocoagulation in the treatment of effluents from pig slaughterhouses and packing plants proved to be efficient in relation to the removal of TKN and total phosphorus, obtaining maximum efficiency equal to 67.15% and 99%, respectively. The maximum TKN removal value was found in Test 12, where treatment conditions were 30 minutes for HRT and 20 volts for pd, which corresponds to 0.86 A of electric current and a current density of 17.2 mA cm-2. For P, the only test that removed below 99% was the first. Through statistical analyses, it was only possible to obtain a mathematical model for TKN removal. While the response surface graph did not present a defined range of the best conditions for the independent variables, it was possible to observe the tendency for better removal, a wide range of pd and values over 30 minutes for retention time.

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Modelling Effects of Rainfall Patterns on Runoff Generation and Soil Erosion Processes on Slopes

Water ◽

10.3390/w11112221 ◽

2019 ◽

Vol 11 (11) ◽

pp. 2221

Author(s):

Qihua Ran ◽

Feng Wang ◽

Jihui Gao

Keyword(s):

Soil Erosion ◽

Rainfall Intensity ◽

Temporal Patterns ◽

Runoff Generation ◽

Slope Length ◽

Erosion Processes ◽

Total Runoff ◽

Wide Range ◽

Critical Slope ◽

Rainfall Patterns

Rainfall patterns and landform characteristics are controlling factors in runoff and soil erosion processes. At a hillslope scale, there is still a lack of understanding of how rainfall temporal patterns affect these processes, especially on slopes with a wide range of gradients and length scales. Using a physically-based distributed hydrological model (InHM), these processes under different rainfall temporal patterns were simulated to illustrate this issue. Five rainfall patterns (constant, increasing, decreasing, rising-falling and falling-rising) were applied to slopes, whose gradients range from 5° to 40° and projective slope lengths range from 25 m to 200 m. The rising-falling rainfall generally had the largest total runoff and soil erosion amount; while the constant rainfall had the lowest ones when the projective slope length was less than 100 m. The critical slope of total runoff was 15°, which was independent of rainfall pattern and slope length. However, the critical slope of soil erosion amount decreased from 35° to 25° with increasing projective slope length. The increasing rainfall had the highest peak discharge and erosion rate just at the end of the peak rainfall intensity. The peak value discharges and erosion rates of decreasing and rising-falling rainfalls were several minutes later than the peak rainfall intensity.

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Longitudinal Study of Total and Pathogenic Vibrio parahaemolyticus (tdh+ and/or trh+) in Two Natural Extraction Areas of Mytilus chilensis in Southern Chile

Frontiers in Microbiology ◽

10.3389/fmicb.2021.621737 ◽

2021 ◽

Vol 12 ◽

Author(s):

Cristina Bacian ◽

Cristobal Verdugo ◽

Katherine García ◽

Josu Perez-Larruscain ◽

Ignacio de Blas ◽

...

Keyword(s):

Water Temperature ◽

Vibrio Parahaemolyticus ◽

River Estuary ◽

Environmental Parameters ◽

Economic Losses ◽

Pcr Analysis ◽

Potential Hazard ◽

Detection Rates ◽

Pathogenic Vibrio ◽

Interaction Factor

Vibrio parahaemolyticus is the leading cause of seafood-associated bacterial gastroenteritis worldwide. Although different studies have focused on its pattern of variation over time, knowledge about the environmental factors driving the dynamics of this pathogen, within the Chilean territory, is still lacking. This study determined the prevalence of total and pathogenic V. parahaemolyticus strains (tdh and/or trh genes) in mussels (Mytilus chilensis) collected from two natural growing areas between 2017 and 2018, using selective agar and PCR analysis. V. parahaemolyticus was detected in 45.6% (93/204) of pooled samples from the Valdivia River Estuary. The pathogenic strains carrying the tdh and/or trh gene were detected in 11.8% (24/204): tdh in 9.8% (20/204), trh in 0.5% (1/204), and 1.5% (3/204) presented both genes. In Reloncaví Fjord, V. parahaemolyticus was detected in 14.4% (30/209) of the samples, pathogenic V. parahaemolyticus carrying the trh gene was detected in 0.5% (1/209) of the samples, while the tdh gene was not detected in the samples from this area. The total count of mauve-purple colonies typical of V. parahaemolyticus on CHROMagar was positively associated by multivariate analysis with area, water temperature, and salinity. Similarly, V. parahaemolyticus detection rates by PCR had a positive correlation with the area and water temperature. The chances of detecting total V. parahaemolyticus in the Valdivia River Estuary are significantly higher than in the Reloncaví Fjord, but inversely, during spring-summer months, the interaction factor between the area and temperature indicated that the chances of detecting V. parahaemolyticus are higher in the Reloncaví Fjord. Interestingly, this period coincides with the season when commercial and natural-growing shellfish are harvested. On the other hand, pathogenic V. parahaemolyticus tdh+ was significantly correlated with an increase of water temperature. These environmental parameters could be used to trigger a warning on potential hazard, which would influence human health and economic losses in aquaculture systems.

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