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Estuaries - Science topic

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Aquatic ecosystems such as freshwater, estuaries, and ocean waters have all been shown to contain microplastics. The consumption of food sourced from these habitats by humans is also put at risk by the presence of microplastic in aquatic systems, which also endangers aquatic creatures. There are several methods/strategies for removing microplastic from water sources across the world, including microbial degradation, thermal treatment, and physical approaches including adsorption and filtration. Which procedures/strategies are most efficient for removing microplastic from aquatic environments?
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Hi
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I would like to calculate the salinity from CTD profiles conductivity (µS/cm) readings in an estuary costal water? The water temperature range is between 1.86 and 5.93 °C.
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Dear Souad Annane
The value of Electrical Conductivity converted to salinity by the following formula
Salinity (‰) = 𝐄𝐂 (μ𝐒/𝐜𝐦) × 𝟎.𝟎𝟎𝟎𝟔𝟒
* Typically expressed in ppt (part per thousand)
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I am working on fish ecology in an Indian estuary. However, proper identification of species belonging to Mugilidae is very difficult particularly of the genus Mugil and Liza. Most of the references available (FAO identification sheets and some Indian keys) differentiate the species based on the premaxillae shape which is difficult to ascertain in juveniles of the family. Also the family is highly dynamic with many new or updated genus and species. So, are there any recent comprehensive taxonomic keys available for the family from the Eastern or Western Indian Ocean regions?
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Hope for u always success
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location: Cochin estuary, Kerala,India
Month and year: May, 2018
Salinity: 30ppt
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May be Calanus sp.
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In previous literature, WTP values have been estimated using Discrete Choice Experiments (DCE) capturing spatial heterogeneity mostly relating to direction, location (e.g. water quality across upper vs lower river basins), rural vs urban areas, agriculture vs forest areas, different disimilar alternatives (e.g. mud flates, beaches & estuaries of a river delta), etc. However, Time-scale validity has never been checked to assess whether preferences and WTP values remain similar over time, say few years. Knowing that population structure and trends change over time, checking Time-scale valudity is very important, if not; the reliability of benefit-transfer will be then questioable when the related development project is complete after some time period, say few years.
® Copy-rights holds.
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Dear Cordula
If you have carefully read my discussion, I rather suggested about doing research in the future which can assess Temporal Validity of two Spatial Heterogeneity studies, say over 3-4 years ! I did not ask any question, but started this discussion as it has a great future scope.
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Rapid industrialization, unplanned urbanization, deforestation for aquaculture and tourism in coastal areas and change in land use pattern have raised carbon dioxide level in the atmosphere, which on mixing with the coastal and estuarine waters shift the pH value left to the normal value of the aquatic phase. It is now well established that the average pH of the world ocean surface waters has already fallen by about 0.1 units from an average value of about 8.21 to 8.10 since the beginning of the industrial revolution. Many Indian estuaries today exhibit an aquatic pH of 7.9–8.0 compared to the value around 8.3 in early eighties. This has altered the biodiversity spectrum of the estuarine ecosystem particularly the shelled organisms in terms of their community structure, morphology and behavior
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Dear Abhijit,
Hereby I send you the pdf of an interesting paper talking about dramatic adverse and threatening impact of heavy metal accumulation in the international wetland of Port Anzali in Northern Iran. This wetland is located in the southern coast of Caspian sea and is a precious habitat for a rich variety of aquatic fauna and flora, but unfortunately is under threat of different kinds of pollution like heavy metal accumulation. So, conserving such kinds of habitats in a healthy status help to preserve its associated biodiversity to reduce the amount of carbon emissions and enhance the carbon sequestration to halt it in Soil not to be released in atmosphere in an unwanted volume. This is a good discussion in this moment, as we recently came out of an important UN climate conference COP26.
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I need to do an environmental quality study to determine the effect of shrimp farms in estuaries with mangroves ( 4 sectors with different proportions betwen shrimp farms and mangroves) . Which criteria or protocole I must to use for to diseminate sampling sites for to collect water, sediments and bentos in every sector.
Thanks for your cooperation.
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Salinity and soil texture along with tides are the main criteria
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why and when surirella diatom abundance increases in estuary and marine water and whar is reason of high abundance of surirella sp.? and
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N:P ratio is the key factor
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I have data on two estuaries and I am trying to determine how changes to freshwater discharge impact the fish communities of these estuaries on an annual basis.
the data I'm working with includes average discharge levels and CPUE for fish species.
I planned to use PRIMER V7 for the community analysis, utilizing PERMANOVA and MDS to start.
My first thoughts were to break my discharge data into categories of high, medium, and low and use this as a factor for PEROMANOVA and MDS. However, I am not sure of the best approach for breaking this up. Can anyone recommend a method for this? Or is there a way to avoid categories and just use the continuous data for discharge?
Can any suggest another method for analysis to test for effects of river discharge?
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Using the average flow to categorize years into high/medium/low would certainly be a good start. You could then use this as a factor for your ANOSIM or PERMANOVA tests. An alternative might be to calculate Euclidean distance between years using the flow rate data, cluster those distances, and look at the dendrogram to see if this will group the years in some sensible fashion.
To look at the flow data more continuously you could overlay bubbles on your MDS scaled to flow rates as an easy first step.
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I am currently trying to understand the mixing behavior of major elements by observing the deviation from mixing line as done in several studies (few references are mentioned below). Dilution line should vary for different seasons as concentration in seawater and river water will change.
References:
Patra, S., Liu, C.Q., Wang, F.S., Li, S.L. and Wang, B.L., 2012. Behavior of major and minor elements in a temperate river estuary to the coastal sea. International journal of Environmental Science and Technology, 9(4), pp.647-654.
Ramanathan, A.L., Vaithiyanathan, P., Subramanian, V. and Das, B.K., 1993. Geochemistry of the Cauvery estuary, east coast of India. Estuaries, 16(3), pp.459-474.
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The end-member model is a mass-balance model, the mixing line basically reflect the ideal mixing process of end-members. However, beyond the ideal mixing process, there are some additional processes influence the mixing processes, like dissolution-precipitation, ion exchange, oxidation-reduction, et. al. For the different season (like dry season and wet season), the concentration of major elements in groundwater (always shallow groundwater) and river can be influenced by rainfall, there are surely some different. However, the concentration of major elements in seawater is far more than groundwater or seawater, and the season different is not very obvious. Using logarithmic coordinate system, the positions of seawater samples in different seasons are similar (There may be some differences if the seawater is sampled from different places). In the study of groundwater, if there are different season, I will choose samples from same monitoring well for the end-members. I do not know if it is same in the surface water research, but I hope this way can give you some ideas.
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Hello,
I am trying to decide on the best approach for statistical analyses of my data. I have never done this before and was wanting a second opinion.
I am studying the impacts of nitrogen pollution on the near-shore nekton communities. There are three different estuaries each divided in to three stations: an upper (impacted region), middle (less impacted region), and lower (less impacted region). The upper impacted regions tend to be dominated by macroalgae are are subjected to frequent anoxic events. The two lower sites generally are dominated by seagrass.
The the estuaries' station are going to be sampled twice: in 2020 (July and August, already completed) and again in 2021 (June, July, August) to account for temporal variation. Five seine net samples will be done at each station. Environmental data will be collected as well: temperature, salinity, dissolved oxygen, vegetation cover.
My main question is if the upper station's community differs from the lower two stations' communities. I am also interested in determining if the communities between estuaries differ, but this is not the main question. The response variable is the proportional abundances of species in the estuary. The ultimate goal would be to identify what species appear to drive this change.
If I look at each estuary individually I will have two factors: Station (Levels: 3 (upper, middle, lower); Factor effect: I think is fixed) and Month (Levels: 2 in 2020 (July, August), 3 in 2021 (June, July, August); Factor effect: fixed). I am wondering If I would consider the stations fixed, as I revisited the same spots? I think Month would be considered ordered, as July comes before august. Would I consider stations to be ordered? as they are in an order from upper to lower.
I am using PRIMER_e as the stats program. I looked over the data I have so far and I decided to standardize the data first so it proportional abundance per seine, then it seems that either 4th root or log transformation shows rare taxa the same so I went with Log transformed. I want rare taxa to be represented. I think a Bray -Curtis similarity matrix will suit my purposes, but several of the species are schooling fish, so we caught thousands in on seine but nothing in the next. I was wondering how best to deal with that?
I thought a two-factor crossed ANOSIM would be the best way of analyzing each estuary. But as I understand it ANOSIM can only tell you if a difference exists, nothing more, and PERMANOVA can tell you the magnitude of difference. I was wondering what anyone thinks which would be the better option for answer my question, or will it not matter that much?
I would really appreciate any feedback, I am just learning about multivariate statistics and I have so much to learn.
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Suggestions:
1- Ordination analysis (nMDS or Cluster) + PERMANOVA + SIMPER for a multivariate assessment. PERMANOVA could be designed with three factors (estuary + station + year). As your main objective seems to assess the impact of pollution, station is clearly a fixed factor, but the other two (estuary and year) could be considered random factors. But this depends on your objectives. SIMPER analysis would show you which are the species responsible for dissimilarities among stations, for instance.
2- ANOVA or PERMANOVA or other non-parametric analysis of variance to compare richness and total abundance (and perhaps dominance or diversity indexes) among stations in each estuary and year. I would include three factors too, like the multivariate PERMANOVA. Don't forget to inspect homoscedasticity, normality and linearity!
3- Multiple regression analysis including temperature, salinity, dissolved oxygen and vegetation cover as predictive variables and total abundance, richness and perhaps a diversity/dominance index as response variables is a good option. Don't forget to assess colinearity and to perform a strong model selection. In this case I think that each station could be your sampling unit.
4- If you are planning to select indicator species, I suggest to perform separate analysis for each one of the most important species. You can use species that were responsible for dissimilarities showed by SIMPER analysis.
5- I think you will have enough data to testing some species as "umbrellas" for conservation inittiatives. Please, look at Gilby et al 2017 (https://doi.org/10.1016/j.ecss.2017.10.003) or Costa & Zalmon 2021 (
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While comparing several biogeochemical parameters measured in different stations of the same estuary, or two different aquaculture ponds within the same wetland, reviewers have asked for carrying out repeated measures ANOVA instead of students t-test. I would like to know more about the applicability of repeated measures ANOVA, like when can it be applied? why is it better than students t-test (independent samples)? and most essentially when can we not consider this test?
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Now that was such a lucid explanation and so easy to understand. You cleared many of my doubts, Sir. I really appreciate it.
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On a tidal freshwater mudflat in Belgium, we often encounter this small flatworm. It could possibly be Phaenocora. Does anyone have experience with this species?
The video can also be seen on youtube:
Jan
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Dear Arash, your reply was not coming through...
Jan
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Good Morning everyone,
We have conducted studies with microplastic (MP) contamination in different food web levels in an estuary. Now we would like to analyse which heavy metal and POPs which were adsorbed by
MP. In addition, we would like also to analyse the MP in relation to their chemical components. In this way, I ask you, if you know a laboratory which has an interest in realising these analyses.
Thank you very much for your attention,
With my very best regards,
Mario Barletta
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Obrigado Marcelo!
Abraços
Mario
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Hi, everyone, here I have some question for you, in order to clarify the N2O production problem, I have done some work in four estuaries of China, focused on the abundance (DNA),activity (cDNA) and divesity of N2O releated groups using quantitive PCR and sequencing method, combined with biomarkers such as amoA(AOA/AOB),nirS/K and nosZ(I/II). however, when it comes to the explaination of the result , I found that biochemical physiology knowlege is important for understanding the reault and drawing a seasonable conclusion. so now I want to seek advice about how do you think about the relationship between oxygen and denitrification? how dose oxygen influence denitrification? on the distribution of gene or through transcriptional and metabolic regulation?
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Denitrification is reduction process in which nitrate form of nitrogen can be converted into nitrous oxide, nitric oxide and elemental nitrogen. From these both nitrous oxide and elemental nitrogen can escape into atmosphere as gases. This denitrification occur in waterlogged condition thats is why we should apply nitrate containing fertilizers at oxidized zone to prevent denitrification process. In similar way nitrification is oxidation process which needs oxygen for conversion of ammonical ion into nitrate ion. That's why we should apply ammonical fertilizers at oxidized zone. (Denitrification and Nitrification depends on redox potential too. If the redox potential is less than + 250 mV then denitrification takes place and in similar way if the redox potential is > + 250 mV nitrification will occur)
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Can anyone identify this species? It's from a temperate lagoon located in the southern part of the Po River delta (Italy).
Many thanks,
Monia
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It is an Anthuroidea species for sure. The estuarine character of your sampling location indicated the possibiloty of Cyathura carinata, but it can also be another species.
Please check Wägele (1981) Study of the Anthuridae (Crustacea: Isopoda: Anthuridae) from the Mediterranean and the Red Sea. Israel Journal of Zoology 30: 113-159
Cheers
Michael
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I have been looking for information on water column DO, pH, SST , Chl-a, POC for areas in the peninsula near the glaciers vs the Southern Shetland Inland with no luck. Any information available to look for the main differences? Mostly influence of freshwater inputs to the fjords at the peninsula.
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Hey Jorge Arigony-Neto ! Thank you very much!
Best,
G
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I want to use the red mangrove roots foulers or epibionts (invertebrates and anemones principally) for to measure impacts of shrimp farming effluents in estuaries of the northern ecuadorian coast.
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Tanks a lot, Mr J.C. Tarafdar and Abhijit Mitra. The colombian case is so good for me.
My study are focused to the impacts of the shrimp farming to the northern ecuadorian mangroves, close to the colombian border. I want to integrate water quality data, quality of sediments and some ecological descriptions and indexes in a predictive model (are going to be my doctoral thesis..). The soft bottom benthic community have a lot of indexes related to the ecological status and marine quality but I have interest in the mangroves root foulers or epibionts (if could be named there..) the macroinvertebrates that growth in the red mangroves roots, there are a lot of anemone in the "clean zones" and I suppose that could be a good candidate like to bioindicator of quality of mangroves.
Newly, thanks for your interest
Eduardo Rebolledo
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Anyone has field experience on eficiency of using this type of casting traps (image attached) versus more "traditional" pots ? If applied to the blue crab, would be optimal.
The idea would be to use these casting traps to cover a wider geographical area (also more replicates) on a much shorter time period. And avoid the trouble of going once to deploy the pots and having to go back one or two days later to retrieve them.
Any thoughts or knowledge on any study carryed-out with such casting traps would be well appreciated.
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Hi João ,
The crab rings are widely used in brackish waters of India, especially from south-west coast for mud crab. Since this fishery is sustenance level, reports is very limited. Currently, we working on traps and pots of India, a review article on this underway. I'll share you once its published.
Best wishes,
Chinna
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Greetings and Good day to all,
I am working through a project and was seeking information from anyone that has had experience using the South Florida Water Management DBHYDRO data platform.
Also if anyone has any information on comparison or analysis of salinities between wet_dry season and then how to graphically show the influence on natural salinity fluctuation/changes and then pinpoint where Freshwater inflow effect those level due to artificial actions like opening_closing levees.
My Gratitude and Thanks
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Abhijit Mitra Thank you I appreciate the information.
Michael Waldon I know some folks on that team, i just spent a summer in the Everglade on an internship will definitely reach out.
I will keep you all posted as I will be working on this analysis in the coming month during the academic break.
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My study is on diversity and abundance of brachyuran crabs in the inter-tidal region of tropical estuary.
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Hi Mithila
Please try PRIMER software for simplified statistics. You could browse Youtube regarding "how to use PRIMER software"
All the best
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I want to develop a ecological risk model for the measure and if were possible to predict the shrimp farming assessment in estuaries with mangroves in the north of Ecuador.
I have some ideas but I don´t about a basic protocole for ecological risk modelling.
Thanks in advanced
Eduardo Rebolledo Monsalve
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Even while calculation you need to take all aspects constantly
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For some time now I've been thinking about diadromous fish - that move between freshwater and estuarine habitats to complete critical lifecycle stages. I was snorkeling recently in freshwater (tropical river) and notice juvenile fish of a species I know are diadromous - but we've not yet had rainfall flow connection........ is it possible that diadromous fish can become adapt to reduced connect with downstream estuaries. Has anyone some data or comments?
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In Lke Kinneret the situation is more complicated:marine species are removed from the Mediterranean and stocked in freshwater lake
Ptesently results are great success: beneficial for both: water quality and fishery income improvement
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The terrestrial organic matter injected into the sea through estuaries may be the important hydrocarbon generating parent material of natural gas in sea areas.
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Hi,
Their are some forward stratigraphic models (e.g. DORS) which can simulate the transport, degradation and burial of preserved organic matter in sediments. You can have a look at IFPEN work on this topic (https://www.researchgate.net/project/DORS-Dionisos-Organic-Rich-Sediments).
Cheers,
Mathieu
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I am doing my thesis research on "Water quality parameters of a mangrove estuary". Spectrophotometry of nutrient parameters (Nitrite, Nitrate, Phosphate) showed negative concentration from few sampling stations.
What can be the reason behind these? How can I explain these findings?
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Hi Shoaibe;
The matrix in your sample is likely somewhat different than in your blank/standards causing some of the samples with low concentrations of nutrients to read as negative numbers. This may affect all of your values to some degree. Perhaps see if you can find a laboratory with an ion chromatograph to run the samples and measure concentratins via conductiviry (look up "EPA Method 300 "for anion analysis). If that is not an option, perhaps you can run matrix spikes where you add known concentraitns of your nutrients (i.e., nitrate, nitrite, etc) to actual samples and measure the spectrophotometric values. At a minimum, this will provide a means to assess the accuracy of your instrument and determine minimum detection limits in the matrix you are measuring (estuary water) compared to the solution you are using to make blanks and standards. This may ehelp to xplain your issue more clearly.
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I am a student studying phytoplankton pigment analysis by HPLC. We analyzed phytoplankton pigment of estuary. Of these, only the results of two seasons are difficult to understand.
1. Can fucoxanthin concentrations be 1.5-3 times higher than chlorophyll a in estuaries dominated by diatoms (Cheatoceros, Auracoseira spp. Etc. under microscope)?
 
2. If other pigments are too high, can chlorophyll a be over-measured on a fluorophotometer (10-au)?
3. Assuming a problem of analysis; Is it possible to reduce only chlorophyll-a without affecting other pigments during sample storage, extraction and analysis?
Thank you.
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Yes I too got same
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Studies from Indian coastal and estuarine waters show that heterotrophic dinoflagellates are negatively correlated with oxygen/ dominant in hypoxic water.
Ref 1
Ref 2
Wenlu Lana., Bangqin Huang., Minhan Dai., Xiuren Ning., Lingfeng Huang., Huasheng Hong. (2009). Dynamics of hetrotrophic dinoflagellates of the Pearl River Estuary. Northern South China Sea. Estuarine, Coastal and Shelf Science 85, 422–430.
Please answer this question.
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Low dissolved oxygen is more often the result of autotrophic algal bloom in response to eutrophication. Aerobic degradation of cellulose/lignin and other biomolecules strip off oxygen. Many or most heterotrophic dinoflagellates or picoeukaryotes feed on the diverse array of bacterial blooms which are associated with algal degradation and decomposition as well as hypoxic conditions, hence it could simply be a cue for the dinoflagellates to know that their is bacterial feed present and so they congregate at such specific locations. The question might simply be the case of inverted observation and the hypoxic condition may not be conducive to the heterotrophic dinoflagellates but their presence could mean ongoing decomposition of the autotrophic species biomass that had started to sponge up the dissolved oxygen.
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Sampled from a mangrove estuary in South Africa
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like pramesium ....
good capture
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CDOM is the colored dissolved organic matter. What makes the fresh water higher in CDOM concentrations than the ocean?
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Most of the coloured dissolved organic matter (CDOM) occurring in freshwater and estuarine waters has been leached from organic rich soils. Humic substances, which result from the incomplete decomposition of terrestrial plant material, make up the bulk of this CDOM. As CDOM is carried by rivers from land to ocean, a sequence of processes act on these substances. First, flocculation affects a large portion as it crosses the salinity gradient between freshwater and seawater, so that portion is effectively removed as it settles out of the water. Secondly, sunlight is, by definition, absorbed by CDOM and the absorption of certain radiations may lead to photo-degradation into components which are no longer optically active, i.e. no longer coloured. Thirdly, marine microbes may also contribute to CDOM degradation, releasing enzymes that break down the photodegraded components into a form they can absorb. All in all, these processes explain why CDOM is much more abundant in freshwater than in seawater, even though there are also sources of CDOM in the ocean such as biological production.
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what is the appropriate sampling design for the caracterisation and the study of the spatial and temporal variability of coastal phytoplankton in a bay in response to hydroclimatic conditions? knowing that this is going to be the first study of this kind in this region In the absence of preliminary studies on the study area, I decided to opt for a systematic plan. what would you say? is it possible to work with a purposive sampling method, knowing that the bay has an estuary and is subject to an ocean current?
Best wishes
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You can go through this book
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MSc Dissertation on the Feasibility of Power Generation from Pressure Retarded Osmosis.
Bi product/discharge is diluted seawater. I am trying to understand the environmental impact of salinity variations as a result of discharging high volumes of diluted seawater back into the sea either directly or via an estuary.
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Thanks Bayan
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Climate change continues to drive up water temperature and the risk is that aquatic species will need to deal with this in some way (either move away, adapt to regulate the new conditions, or die). Has anyone published data on how coastal aquatic species (flora or fauna) will deal with climate change and higher water temperatures ?
Thanks
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Found in the marginal areas of estuaries. Transparent cases of about 10cm size.
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Probably its a sea cucumber.
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Glass eels collected from estuaries are usually composed of a mixture of A.pacifica bicolor and A. marmorata. Though the method of segregating these species by microscopy and by DNA analyses exist. However these methods lack applicability in segregating large amount of elvers for nursery or grow-out purposes. Microscopy and DNA analyses are no longer applicable when separating 10-100 Kg of glass eels (around 10,000 pcs /kg).
I would like to ask if a practical method exists to separate the species of glass eels (visually, or other ways)??? Or pigmented elvers 3-6 cm in size???
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There will be dimensional and counts (meristic and morphometric) differences between most species and life stages, including sexes. This would be a valuable project for a careful student, starting with older eels and identifying the most probable differences, then moving back to younger forms.
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Is it possible to have access to other estuary restoration projects and strategies, restoration guidelines, intervention guideline, etc.
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I coauthored a paper in my researchgate list on wetland mitigation banking on the national forests. Much of the information has not changed. The Corps of Engineers manages the program which evaluates and approves compensatory mitigation projects proposed to offset unnecessary or unavoidable wetland losses due to development. This link may also help, and you may get added assistance from NRCS if the COE is still busy with hurricane recovery, assuming you might be referring to an estuary in Puerto Rico: https://www.epa.gov/cwa-404/compensatory-mitigation
Compensatory mitigation is typically paid for by the developer, and sometimes partnerships are encouraged. The mitigation has to be effective for a decade approximately to receive credit, and may require easements to ensure long term management. Development in big cities and ports that require dredging may also be periodically in need of compensatory mitigation credits. If a University project, I would suggest review and certification by licensed civil engineer to help limit liability exposure.
Restoration of a damaged USA including Commonwealth of PR estuary would most likely have a high priority within the compensatory mitigation program. They normally like to stay within the same watershed, but my researchgate report in 2013 has an exception project for a federal agency that might be of interest where work was outside of watershed. I am relatively certain COE, NRCS and EPA may have examples of estuarine recovery or restoration projects to share. Since Florida is so close, you might search for examples there first. Restoring hydrology is often a critical element In wetland restoration.
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Hi everyone,
I have an amphipod that is evading identification. I think it belongs to the family Oedicerotidae, particularly in the genera Synchelidium or Pontocrates.
I have come to this conclusion as it has a subchelate gnathopod (G)1, a chelate G2 and a distinct rostrum. Photographs of the specimen are attached.
However, the crux is that neither genus is recorded in Australian waters. I have Lincoln's British Marine Amphipoda: Gammaridea and it does appear to match the description of these genera but it exhibits a mix of the feature that separates between them, i.e. the palm of G1 is half toothed and half smooth.
I have attached scans of the genera descriptions for your interest(extracted from Lincoln's book).
Anyone have any ideas? Could we have a new amphipod in Australia?
Samples collected from the Peel Harvey Estuary, Western Australia (temperate waters).
All the best,
Sorcha
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Hi Jose. Thanks very much for commenting. I did look to see if it belonged to either genera you have mentioned but it has a half-toothed, half-smooth palm placing it somewhere in between the two. This may be a characteristic of an Australian genus but I have not had much luck locating it. The hunt continues!
Also thank you Ton. I have purchased a hard copy of the book - couldn't resist, so I am all set for now. I appreciate the thought though.
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Water of estuaries
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Thank you very much for all the clarification and cooperation
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Since estuaries are dynamic are environmental conditions vary on spatial and temporal scale, how we study climate change effects?
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Hi;
I guess dose-response function type of estimation might help. The impact might have reflected on some other human activities like recreation, etc. which can to captured using some non-market valuation method as well.
Resham
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I have an estuary having 5 rivers as its inlet and 3 outlet connected to sea. I wanted to water balance of estuary and how it is changing with drastic change in surrounding landuse/land cover change. Is there any model that computes water balance of estuary?
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For Vemband estuary cwrdm is already carried out water balance in collaboration with koyoto university japan
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Am looking for time and resource efficient method to quantify nitrogen (ammonium and nitrate OR total) and/ available N.
Getting a method using spectrophotometer would be nice. Many thanks!
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Nitrogen measurement in estuaries is complicated by salinity effects on the normal spectrophometric methods used for the determination of nitrate, ammonia, urea etc. The wide range of concentrations found in estuaries due to freshwater inputs and tidal effects is also problematic. Newer in situ instrumentation is improving but the contribution from ammonia and nitrate to total N is variable, So I am not sure that a neasy "one size fits all method exists but certainly robust salinity measurement s essential.
Systematic salt effects in the automated determination of nutrients in seawater B.M.Stewart and P.A.W.Elliott Water Research Volume 30, Issue 4, April 1996, Pages 869-874
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I am Prof. N. Rajeshwara Rao from the Department of Applied Geology, University of Madras. I have been working on Foraminifera from diverse ecosystems such as the littoral zone, inner shelf, continental slope, deep-sea, mangroves, coral reefs, backwaters and estuaries for the last 30 years. Currently, my team is working on forams from a seamount in the Arabian Sea (water depth of ~520 m). I'm interested in working on forams from the core you have documented. Please let me know if you are willing to have a collaboration with me.
Best regards.
RAO
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Dear RAO,
All information on cores from this - and similar - expeditions can be found on the web (www.pangaea.de - search GeoB...". Here you can also see what kind of investigations already exist. In general, all cores recoverd by Bremen scientist during cruises are available for additional cooperations. They are stored in our repository at 4C. For specific interests, you have to fill out and send a specific request formular, which can be downloaded from the MARUM page.
Cheers,
Matthias
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I would like to know the best option for coupled catchment-ocean hydrological model to apply under climate change at the Sydney estuary to assess estuarine dynamics.
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Australia to ensure connection with total coast remains productive and rewarding the outlook is at once positive and challenging remain vigilant in all efforts to reduce the impact of land-based activities on the coastal and marine environment and look for new ways to involve all spheres of government, local communities and industry and is a challenge for all Australians.
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In laboratory incubation experiments, how to set the ratio of overlying water and sediment (6:1 in some lakes, but estuary )? And the size of incubation Plexiglass column?
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Four years ago, I had conducted some laboratory incubation experiments to explore the indicator of sediment oxygen demand (SOD). At that time, I had read some publication about incubation of sediment cores. And a scientist named George.T think the volume to surface ratios (V/S) of the sediment core was the most important index in incubation experiments. And it should be carefully taken in to concideration before the incubation was conducted. Also, a suitable range of 100 ~ 200 L/m2 were recommended by him. Unfortunately, I have forgotten the exact reference (it was published about 1990s). I hope these answers are helpful to you Good luck!
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I am a bit confused about the terminology used for Sunderban (in West Bengal, India). Is it a delta or estuarine settings.
Or I would say, Sunderban is a complex system of the delta which consists of tidal rivers, estuaries, mangrove forests and creeks.
Thank you
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Yes, as you have rightly understood, it a complex delta system criss-crossed by mighty estuarine rivers; innumerable creeks; tributaries and mangrove forests. Thanks Dr. Bayan for the map, which serves as a ready reference to the RG readers.
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It was collected with a plankton net in an estuary. It is about 10 mm length.
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Clara;
Your specimen is a dipteran larva. It looks very much like Ephydra, a genus of shoreflies/brine flies (Ephydridae). If you have access to the old (and somewhat out of date) "Aquatic Insects of California", check out the illustraion on p, 472. There are other families of aquatic larvae that somewhat resemble your photo- Empididae & Syrphidae. However, from what I can see, shoreflies are your best match.
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Hello,
I took hydrological measurements (pH, salinity, dissolved oxygen, temperature) in an estuary, a coastal lagoon, and the salinity increased in winter season. On the other hand, higher temperatures were registered during rainy season but the salinity were lesser than the winter period. What, in your experience and knowledge, do you think this is due to? given that higher temperatures has a direct correlation to high salinity values.
Thank you
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I just recollected another impact of meteoric water into an esturay, namely that of pH-influence. Whereas the seawater in the estuary is expected to have a normal pH-value somewhere between 7.9 and 8.2, the addition of rainwater will impede this value. The pH of distilled water, e.g., rainwater (meteoric water) has a considerably less pH-value, perhaps even as low as 5.6 (at least here in Norway, where I live).
This means that during torrential rain, from a cyclone (low pressure) system, or even from a very large cumulunimbus cloud (thunder-cloud/super-cell/ anvil cloud), which is located and precipiting over your relatively small esturay (less than 10 sq km?), you can expect large (extreme) temporal deviations in pH-values in the upper meters of the estuary water column. The animals you observe, will most probably dive to deeper layers to prevent exposure to this temporal parameter deviation.
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On the littoral of an estuary area of the Murman coast (the Barents Sea) we have revealed the increase in salinity within intertidal pools during the low tide for 2003 -2015. Bottom fauna and algae are affected by this salinity increase.
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Hi Aleksandr
Yes, very interesting and not much discussed in the literature. In Maine (NE USA) I certainly have seen large increases in salinity in tide pools because of freezing during winter - upto 2-3 x normal salinity - (Pearson et al. 1996. Reproductive ecology of Fucus distichus (Phaeophyceae):an intertidal alga with successful external fertilization. MEPS, 43: 211-223).
Not sure of the extent of salinity changes that occur with summer warming, but I suspect freezing may cause even more dramatic changes... What is causing the changes you observe, also freezing?
best
Gareth
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I was wondering if anyone knew of early Cretaceous crocodillian taxa that have teeth that are typically conical in shape but the carina bares very fine serrations.
Some teeth are large, the largest is 35 mm tall, 15 mm labiolingually, 10 mm mesiodistally. The crown is typically long, narrow, and with a slight curvature directed lingually.
There are faint longitudinal labiolingual striations that barely make it to the tip and are evenly spaced.
The geologic location is the Maryland Arundel Clay, Early Cretaceous (Aptian-Albian), considered freshwater channel to oxbox lake deposition, though not far from a estuary.
Thank you for your time and I hope to hear from the community.
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Dear Mr. Hodnett,
In continuation to my earlier answer which was somewhat inclined towards the Late Cretaceous or even the Paleocene, I think Wannchampsus or Paluxysuchus of Lower Cretaceous (Texas) might be a suitable species to which you are looking for. It had conical teeth which gradually lost the conical shape towards the jaw point.
I am an avid paleontology enthusiast and would eagerly wait for more answers.
Thanking you,
Regards,
Dr. Abhishek Mukherjee
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I want to measure the DIC(Dissolve inorganic carbon) DOC(Dissolved organic carbon) in estuaries. what is procedure? suggest any reference book.
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Dear colleagues,
I am exhaustively looking for a reference that explains how to identify dry and rainy months through precipitation values. What is the threshold?
Thanks in advance.
Regards,
Gabriel Barros
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Thanks, Luiz!
This index seems to be helpful.
I found the following paper interesting.
Regards,
Gabriel
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Today 25-01-2018 we documented more than a lakhs no of Faunus ater (Linnaeus, 1758) were seen in small estuary. Watch this link https://www.youtube.com/watch?v=p7BA1OvrN-k&feature=share .
This species are any indicator of usual.
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Similar documentation was done by our team at Aadbandhar in Maharashtra a couple of years ago.
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The marine water inter the river body in the high tide this is making the salinity problem.
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It is a complicated problem solving. To manage the salinity problem near the river mouth (estuary), the possible solutions are:
Proper Reservoir Operation Plan
Controlled groundwater withdrawal in the coastal areas
Salinity extrusion structures to control intrusion of salinity towards inland
Groundwater recharge in the coastal areas to dilute the salinity effect in groundwater
However availability of rainfall and fresh surface water flow in the up-stream is very important.
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I am interested in published papers examining trends in relation to environmental variables, or just datasets that have not been published. Of particular interest is Hypomesus nipponensis, but information on any species would be great. Thanks in advance.
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I have fisheries data for both- migratory and lake smelt Osmerus eperlanus since ~1946- 1947.
Janis
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I have a geochemical data from the estuarine sediments. I would like to calculate the pollution and accumulation index of the samples. But I am a bit confused about which background value (UCC or PAAS) should I use.
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Ideally, you should be using the source rock/background composition if you know it. In most of the cases, people however use a shale or UCC data for convenience. If someone has used PAAS, and if you want to compare with them, you may use PAAS.
If you are dealing with a sediment core chemistry, the sediments which are presumably not contaminated may be there deep down. If you have sediment core of say 200 years old, you may use the elemental data of older sediments as a background value.
Please keep in mind that these are only indicative values. Certain elements may vary geographically because of changes in source rock lithology. The index/contamination values can only be compared after accounting for these changes in source rock composition. The excess values you may see after using PAAS/UCC may not necessarily mean "contamination" always.
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Hi everyone
I am studying rate of sedimentation in ports and seawater body. I need information about chemical and nano methods for decreasing sedimentation rate or avoid of suspended sediments sinking in sea water body such as ports. pleas help
thanks a lot.
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hello abbas einali
I recommend you send email to M.r NIBPOUR, I think he has been Phd student in tarbiat modares university yet, having good experience in laboratory study's suspended sediments sinking in sea water body or M.R. MOHAJERI (mohajeri@srbiau.ac.ir).
I hope you could get good advice.
sincerely you.
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The watershed management practice is trapping the water along with the sediments, which used to be transferred to the estuary region. These sediments in turn transported to the coasts, the food for that landscape !
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Thank you.
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we wish to observe small (<10 cm) waves as well as large (2.5 m).
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Jeff, Ken Riley at the NOAA lab in Beaufort showed me a neat little velocity meter/wave meter you would attach to a vertical line; you could put a number of them vertically. They were cheap but I cannot find the information.
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Sample was taken at the Guadalquivir estuary and fixed with formaldehyde.
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Great! Thank you very much.
Do yo know if this species form colonies instead chains?
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I think this is a holothurian - have not come across this before. Found in a saltmarsh site in the Alde and Ore, Suffolk, UK. 
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Hello Daniel,
Due to segmentation of this creature definitively not a sea cucumber ... I agree with others, a member of Annelida ...
Best wishes,
Mike
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I got this species from dolnet catch at bhayander estuary,Maharashtra.this species doesn't had dorsal fin,looking more like scatophagus argus.
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I think it is just Scatophagus argus with anomaly in dorsal fin.
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Best sediment quality for tropical estuaries
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You can also have a look at Pamela Hallock's FoRAM index. It is not a sediment but water quality index, but could be useful too.
See link and references cited in.
Cheers
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I am trying to model salinity dispersion in coastal and riverine system. Is there a way to estimate spatially varying diffusivity over a specified area in estuarine condition?
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Mr.Nazir Hussain, Thanks for you reply. Actually we are trying to model salinity variation in a coastal region of 200km2 domain which includes many rivers flowing inside the domain. We have hydrodynamic model setup and got good correlation between measured and model. Now I like to model the salinity variation near shore and at bay area. so to model this, we use a spatially varying diffusivity map which was obtained based on the spatial velocity over the domain. 
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I am looking for real cases of esturies where sediment material from beaches in their vicinity is trapped. As a result, coastal structures like groynes or ports near such estuaries may possibly suffer from erosion problems as well.   
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Dear Antonios, you're welcome, would be great if some cooperation might be possible
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I am searching references and papers about the negative relationship of TOC and DIC in coastal ecosystems (estuaries, lagoons, etc). In general, I just found positive relations. Can anyone indicate please something about this thematic? 
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Dear Alaistair McDonald. The system is a tropical hypertrophic coastal embayment, dominated by saline waters and marine phytoplankton. I have seasonal, diurnal and spatial measurements. As I said in the question, I have a negative relationship, i. e., when DIC decreases, DOC and POC increases. The bay is a  strong CO2 sink. For more details of the study area, I am sending one reference. 
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We wish to perform a large-scale screening assessment of a large number of  sites, to build a semi-quantitative 'map' of sediment condition throughout a large (130 km2) estuary.
Ideally this will be very rapid and low cost, involving little to no laboratory analysis.
This broad-scale assessment would allow us to identify a range of sites from 'best available' to 'worst' sediment condition, for subsequent targeted field sampling of sediment parameters and benthic macroinvertebrate fauna.
Many thanks for any suggestions you may be able to provide.
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Thanks for the precision Chris. In that case if you want to choose your sites by more than smell and color your should define specific criteria as grain size because grain size is often well correlated with organic matter content and several micro pollutant concentration. I would then suggest to sieve (four mesh size should be enough starting with 2 mm and ending with 60 micrometer) directly on board and estimate the volume occupied by each fraction using a graduated cylinder or something equivalent. You should get semi-quantitative-qualitative results that should help you in selecting your sampling sites. Sieving is time consuming but if you take only small volume it should be acceptable. We've done that in the Garonne river some years ago where we have more or less the same environmental problems that you described . We were processing around 20 samples per day including the time to travel from a site to another.
Good luck
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I'm trying to run a mixed model of nested permanova with adonis function in R. I'm not sure how to write the factors so R understand which are fixed factors and which are nested factors.
I want to test diferences between: estuaries (fixed, 2 levels), points (random, 4 levels, nested in estuaries), depht (random, 2 levels, nested in points), season (fixed, 4 levels and orthogonal to estuaries), and month (18 levels, random, nested in season)
Some one can help me?
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Hi Ileana,
I am not sure if a PERMANOVA was designed for a mixed model with a nested term. You can try modifying the block term using strata= in vegan to accommodate the nested term or try the nested.npmanova function in BiodiversityR as suggested in the link below, but I don´t know if this will work for a mixed model:
I am curious to see other responses.
good luck!
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I am going to use WEAP to simulate model of river basin system in estuaries area regarding water supply and demand. 
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Again. Thanky you very much, Mr William and Mr. Mahdi
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Hi. I am working on avifaunal assemblage of an estuary and I have 3 seasons data across 5 different habitat types. I used nmds ordination to look for any gradient in the assemblage across the habitats but in both 2-D and 3-D ordinations my stress values were high, almost equal to 0.3.
In such a case, reducing the number of species (using the most abundant species) would lead to a better ordination of the habitats or do I need to transform the abundances of all species before computing the dissimilarity matrix? I tried the second option using fourth root transformation, still the stress was higher than the non-transformed data. Or do I need to use a different ordination technique or a different dissimilarity matrix (I used Bray-Curtis)? If so please give some suggestions. (I use PAST and R for my analysis). 
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Hi, You need first to pretransform your data if there is strong dominance if suit to your hypotheses. Ordination, like nMDS are not test for difference. Use ANOSIM or PERMANOVA to test if there is difference among your factors with an appropriate design. Whatever the results, you can interpret it. You can illustrate the results with an nMDS only if it make sens stress below 0.25, otherwise do not present it. In your results you can describe differences in the main text without figures. Remember that only the tests for differences among factors count, and do not use the ordination to describe where are they. 
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I am using the SWAN wave model to hindcast waves in an estuary. I have an offshore boundary condition containing some swell energy. I output the energy spectrum in my fine resolution domain but the swell energy does not show up anywhere in the time series. The energy spectrum seems to be shifted toward higher resolution when comparing to field measurements.
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Hi Thomas,
What is the directional resolution you use in your SWAN discretization for swell?
If you scroll down to the last three paragraphs on directional space:
You will see that for swell, a directional resolution of 2 degrees or less may be required, for swell with a directional spreading of less than 10 degrees.
Heng
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We are trying to estimate the biomass of adult snook in Brazilian estuaries where underwater visual census methods cannot be used. A method using gillnets perhaps? Thank you.
We have found methods mostly for juvenile fish, such as those listed in Rozas and Minello 1997 (Estimating Densities of Small Fishes and Decapod Crustaceans in Shallow Estuarine Habitats: A Review of Sampling Design With Focus on Gear Selection. Estuaries Vol. 20, No. 1, p. 199-213 March 1997). However any method for young adults or adults in mangrove estuaries will be most welcomed. Thank you. 
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You'd probably need a long seine. Florida's Fisheries-Independent Monitoring Program uses a 183-meter seine set from the back of a shallow-draft boat ("mullet skiff") in a rectangle shape (one edge of the rectangle being the shore). Then 4 people haul it in. Great exercise! See Winner et al, for example (http://www.tandfonline.com/doi/abs/10.1577/T08-215.1). You could use a net like this in conjunction with mark and recapture to get a biomass estimate, or perhaps just do some gear efficiency studies and extrapolate. The appropriate measure of extrapolation may be length of shoreline rather than area, given the species tends to be along the shore. Hope this helps.
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The animal was collected from Shatt Al-Arab Estuary in Iraq .  
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Thank you very much for the great information
Best regards 
Huda
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Is the Moynapara tidal creek (as Das, Gautam K, has mentioned in the article called "Holocene tidal flat sedimentation in the Sunderban Biosphere Reserve, NE India" published in Coastal Zone Management journal, spl. publication, vol.2 in 2000) same as the Kalnagini Khal (as mentioned in the topographical sheet published in 1972 by SOI)?
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Try MNDWI water index with Landsat 5-8 / SPOT 5 imagery.