Estuaries - Science topic

Hola que tal, el primero definitivamente no es Petruca es Leptuca, el segundo tampoco es Petruca, creo que también puede ser Leptuca, pero falta ver otros detalles por que es un ejemplar interesante, saludos desde Guayaquil.

Dear Doctor

Go To

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HI Abhijit,

Coral bleaching (i.e., loss of zooxanthellae) may be caused by a number of environmental stressors, but the primary trigger for this response is an increase in seawater temperature. For basic reviews of this phenomenon have a look at:

I hope this helps.

Tom

I am not certain, if the answer to your query is there.

I would recommend that please consult the 24th edition of "Standard Methods for the Examination of Water and Wastewater" published by the American Water Works Association. The methods have been updated in this edition published 13 January 2023. This edition contains 82 updated methods, as well as 4 new sections.

Since simulation is not my expertise, I did not help in updating, or writing that part as a new section. You can Search for the electronic edition on the web site of AWWA, or simply searching for the 2 the edition of the book.

Happy searching.

Hi there, did you finally found an explanation ?

I got same results for benthic diatoms and I was thinking that it might be link with the vertical migration in sediments under light stress ... For the phytoplankton in estuaries, maybe the water turbidity could affect seasonaly the pigment production through the light disponibility ?

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)

Hope for u always success

May be Calanus sp.

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.

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.

Salinity and soil texture along with tides are the main criteria

N:P ratio is the key factor

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.

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.

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 (

Now that was such a lucid explanation and so easy to understand. You cleared many of my doubts, Sir. I really appreciate it.

Dear Arash, your reply was not coming through...

Jan

Obrigado Marcelo!

Abraços

Mario

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)

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

Hey Jorge Arigony-Neto ! Thank you very much!

Best,

G

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

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

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.

Hi Mithila

Please try PRIMER software for simplified statistics. You could browse Youtube regarding "how to use PRIMER software"

All the best

Even while calculation you need to take all aspects constantly

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

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

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.

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.

like pramesium ....

good capture

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.

You can go through this book

Probably its a sea cucumber.

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.

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.

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.

Thank you very much for all the clarification and cooperation

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

For Vemband estuary cwrdm is already carried out water balance in collaboration with koyoto university japan

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

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

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.

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!

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.

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.

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.

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

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.

My sources of information on Wannchampsus and Paluxysuchus are <https://www.cambridge.org/core/journals/journal-of-paleontology/article/small-crocodyliform-from-the-lower-cretaceous-late-aptian-of-central-texas-and-its-systematic-relationship-to-the-evolution-of-eusuchia/CA0E8150EF2B92FA0AE2DC5D4B3A6B19> and <https://www.jstor.org/stable/pdf/23361074.pdf?refreqid=excelsior%3A0d8ff530727e297d1179f652f9866b26> respectively.

Thanking you,

Regards,

Dr. Abhishek Mukherjee

For DIC check out:

Thanks, Luiz!

This index seems to be helpful.

I found the following paper interesting.

Regards,

Gabriel

Similar documentation was done by our team at Aadbandhar in Maharashtra a couple of years ago.

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.

I have fisheries data for both- migratory and lake smelt Osmerus eperlanus since ~1946- 1947.

Janis

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.

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.

Thank you.

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.

Great! Thank you very much.

Do yo know if this species form colonies instead chains?

Hello Daniel,

Due to segmentation of this creature definitively not a sea cucumber ... I agree with others, a member of Annelida ...

Best wishes,

Mike

I think it is just Scatophagus argus with anomaly in dorsal fin.

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

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. 

Dear Antonios, you're welcome, would be great if some cooperation might be possible

If the topic is DIC and TOC in soil, things are complicated. On one hand, Higher DIC means higher salinity, which is harmful to plant growth and thus has negative effect on TOC. On the other hand, hgher salinity means slow decomposition of oganic matter in soil, which should have positive effect on TOC.  

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

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!

Again. Thanky you very much, Mr William and Mr. Mahdi

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. 

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

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.

Try MNDWI water index with Landsat 5-8 / SPOT 5 imagery. 

Ana,

The SET, marker horizon, and plates all measure different portions of the sediment profile, and therefore isolate different process influences on elevation.  But they all measure wetland elevation change with millimeter accuracy.  The SET measures elevation over the depth of the rod base and therefore incorporates both surface accretion-erosion and subsurface subsidence or expansion.  The marker horizon primarily measures surface accretion or erosion.  Thus if you subtract the two, you can calculate shallow subsidence or expansion with mm/y accuracy.  If you go to my site on Research Gate, you can download the SET - MH methods papers.  I attached our recent protocol manual.  Contact me if you have any questions.  Don Cahoon