Questions related to Aquatic Ecology
What Causes the green color change? Because Diatoms are produce brown color tint in the tank. Does It lead high mortality rate in shrimp post larvae in larval rearing tank
I need indices essentially based on different physico-chemical parameters to assess fair state of aquatic ecosystem
Metal nanoparticles are showing promise in tackling different problems in different domains of environment. How they can be used in aquatic ecosystems? What are different likely interactions? What may the possible toxic effects on different ecosystem components (planktons, bacteria, macrophytes and fish)? How can we track the ecotoxicological linkages? How could we manage metal nanoparticles for positive (beneficial) uses and avert the adverse/untoward consequences?
RG friends and researchers you all are welcome to participate and help to promote a sustained brainstorming on pros and cons of apllyting metal nanoparticles in aquatic systems like, ponds, lakes, rivers, etc.
I have not dealt with heavy metals data in an advanced way before, except for calculating some indicators, but I think, according to my opinion, this is what is referred to as detection limits (negative values) If this is the case then I have already seen several methodologies about substitution for negative or zero values
Could you please explain what it means when you get a negative value from Atomic Absorption Analysis?
I'm currently studying the length-weight relationship of freshwater fishes in Taiwan, which is an all new topic for me to work on. However, I've came across problems in calculating the 95% confidence interval and confidence limit for my parameters a and b in the LWR formula W=aL^b that I do not understand how. Publications I've viewed gives little info and couldn't actually help me out, so is anyone here able to help me to understand and calculate these parameters?
The problem for me is that I do not understand how I can gain the CI and CL from a single data since all publications mentioned "95% CI of b".
I was wondering if any of you have recently (2021/2022) submitted a manuscript to Environmental Microbiology or Functional Ecology and what are your thoughts?
I recently submitted my manuscript to a journal that provided only one reviewer (unprofessional for such an established journal!), and I am considering withdrawing the manuscript and submitting to one of the Wiley journals.
Have you had any experience, what is the quality of peer review in these two journals and how long it took for the paper to be rejected or accepted? Thank you in advance!
Does anyone have comprehensive references (review articles, books, data set/bank) on Vitamin B12 (cobalamin) levels or concentrations in aquatic ecosystems (lakes, ocean, coastal and marine, sea, etc.)? I collected papers and articles for a complete study, however, they only published data from their lab investigations.
Thank you in advance.
Please give an example of a scientific hypothesis about Antarctica that has not yet been confirmed. I am also interested in the gaps in scientific knowledge about Antarctica. As a member of Russian Antarctic program I am familiar with general enigmas (ice sheet stability, life in subglacial lakes, paleoclimatic records, influence of subglacial heat flows etc.). So here I would like you to share with me not so common things about Antarctica
I thought there would be more work done on the topic; there doesn't seem to be very many papers.
My experiment requires to extract Tissue DNA from zebrafish intestine , this is my first time to learn Tissue DNA extraction. Recently I have learned about extracting DNA using magnetic beads, but i need more recommendations and and what is your experience about magnetic DNA extraction technique and how many samples can be extracted from single kit. Beside this , please can you suggest me any other methods that follow more simple steps.
I have separate algal and zooplankton samples that I want to have stable isotope analysis of C and N performed on.
The samples were filtered onto 0.4 µm glass fibre filters (GF/F) that were then freeze-dried and stored at - 80 degrees. In error, the glass fibre filters were not pre-combusted or pre-weighed prior to having the zooplankton and algal samples filtered onto them.
Is there a way to still use these samples for stable isotope analysis of C and N? I have read that you can scape the material of the filter paper and then place in a tin foil boat for analysis but don't feel confident in the reliability of this approach.
I am trying to predict/discriminate macrophyte groups in rivers (https://snwikaij.shinyapps.io/RF_macrophyte_models). I have run out of viable options to predict groups with an "acceptable" model performance. Does anyone has some suggestions/experience on groups of macrophytes that can be clearly predicted/discriminated?
These groups do not have to be linked to the dataset I use, but it has to be linked to literature and logic(?). I have provided the included species in the added Excel file, in which suggestion can be added. The the predictors in the models are substrate type (fine and coarse, categorical), depth, flow velocity, alkalinity, total phosphorus and conductivity. Based on trial-and-error and literature, I find an accuracy of >50% and Cohen's kappa of > 0.3 acceptable. This amounts to maximum 3-5 groups. Currently the models predict each species individually, growth forms, river types, bryophyte and vascular plants, and HCO3 and CO2-only-users.
Hello everyone, I am interested to know what is your "go-to" microscope for live plankton organisms (Zooplankton, Phyto, bacteria,...) observation, identification, and pictures. What microscope would you recommend buying if money wasn't a problem... I am looking at all possibilities here. But I am surely interested to know what is needed in research. Thank you
I have a large dataset of fish abundance as well as some environmental variables covering around 795 sampling sites. I have tried to find the relationship of my environmental variables with the biological data with the RELATE function in PRIMER-E. The results indicate that using Spearman rank correlation, the sample statistic (Rho) is 0.11. Now the significance level of sample statistic is 0.1% (much less than 5%), so according to the manual, this is significant result! I used 999 permutations to get this result. I am unable to interpret this result as I would usually expect that if the p value is significant, the corresponding degree of association should be high also. So, I would expect the sample statistic to be much higher than 0.11! (above 0.7 or so). Smilar situation with the distLM procedure, here the p value suggests that each of the variable has significant effect on the model but again the overall R^2 of fit is only 0.13! How is this possible that with such a poor R^2, individual variables are all significant.
I have used the square root transformation and Bray-Curtis similarity on the biological data and have normalized the environmental variable and Euclidean measure. I haven't transformed the environmental variables.
I would really appreciate it if someone can help me to interpret these results.
I will be working on stream amphibians in Sichuan in 2020, and part of the work will focus on the diet of some aquatic species and prey availability. I thought I'd identify macroinvertebrates with a key to North American or European aquatic macroinvertebrates, but I would like to use the closest key possible to avoid possible mistakes.
I don't know precisely to which taxonomic level I can identify available preys and prey items, certainly to Order, and hopefully to Family with intact invertebrates from the streams. I trained with North American Plecoptera and Odonata from France under a microscope, and it seems reasonnable that I could go as far as Family level with an adequate key.
Another way of putting the question can be : do you think I can identify these prey items and intact insects to order or family level with a key to macroinvertebrates from North America or Europe ?
Thanks in advance !
I have noted dramatically change in color on the body of some marine fishes. For example, I saw a dramatically change from a "intense-yellow" color to "brown" color (normal color), just in one second. Is not a gradual change of color, is very quickly, similar like an octopuses. How could be explained this color change?
Photo number 1 is a fish that came out in the stomach contents of a Coryphaena hippurus collected in the Southeast Pacific.
Photo number 2 (Fish) and 3 (Otolith of the fish) is a fish that came out in the stomach contents of a Xiphias gladius collected in the Southeast Pacific.
Photo number 4 is a fish that came out in the stomach contents of a Xiphias gladius collected in the Southeast Pacific.
Some people argue that it is completely acceptable to trade non-endangered sharks species, such as bull shark and blue shark by-caught by fisheries. They hold that even if these sharks are still alive and stand high chance of surviving by-catch if released, it is still okay to kill them and trade their fins, meat and jaw.
What do you think of this problem?
I study fish assemblage structures, which observed unimodal response to environmental gradient and relationships between environmental factors.
I would like to use constrained ordination methods (like RDA or CCA), which allow to use bray-curtis dissimilarity matrix.
(If I choose using RDA or CCA , I will choose CCA.)
I think CAP or db-RDA is useful for my study.
When assemblages response unimodal to environmental factors, which should I choose CAP or db-RDA?
When you let concrete channels "go" and do not maintain them, vegetation seems to take over and the concrete can crack or collapse over time. I am sure there are effects to biota when you let the channels naturalize, but I am not sure what those effects are. Is there any uplift or benefit to letting concrete channels naturalize? I am looking for articles (preferably free/available) that would help answer this question. Are there any specific cases where someone did a study on this? Studies can be from any time frame and any location in the world.
My name is Hairul from Selangor, Malaysia, 36 years old, 175cm, 66kg. I am looking for an opportunity to further study in PhD level. Any body here looking for a PhD student in research field such as wildlife management, conservation biology or life sciences. So far my expertise on breeding assessment, exitu management, terrapins/turtles, ecology and conservation.
Hello! I am looking for info (published literature, grey literature, or also any personal observation that you may have had) about the current -- or at least most up-to-date -- geographical distribution of the planorbid snail Planorbarius corneus L. in Europe. This species seems on the decline in many areas, though where still found it occurs in high numbers. Myself, I haven't seen a single individual (not even as an empty shell) anywhere in central Italy in the past ten years at least, though it was a common sight just 20-25 years ago. Info about any change in the past 20-30 years (or less) would be greatly welcome to try to understand the reasons behind the apparent decline of this otherwise very sturdy species. Published work would be especially welcome, as I'm trying to get my experimental results on Planorbarius published. Thanks a lot!!
The seriousness of the ecological crisis creates major new philosophical and scientific global challenges. What can you suggest? What is your response?
I'm looking for the proper way to analyze some of my data.
I studied predation in fish, by looking at survival rates of different groups of larval fishes when facing predators.
In the first trial of the experiment, I put 10 larval fishes of the group A, 10 larval fishes of the group B, and 10 larval fishes of the group C, all together in a predation arena.
After 2 hours:
Group A had 10 survivors
Group B had 8 survivors
Group C had 6 survivors
In the second trial, same procedure.
Group A had 5 survivors
Group B had 4 survivors
Group C had 3 survivors
etc, multiple times.
The issue here is that predators are sometimes very hungry (see the second trial) and sometimes not that much (see thr first trial) so calculating a "survival mean" for each group, among all the trials, makes no sense to me (lot of variability).
So what I did is calculating the "overall survival rate" in each trial.
Overall survival in trial 1 : 0.8
Overall survival in trial 2 : 0.4
Then I substracted this "overall survival" to each group survival, in order to create some sort of an index that "normalizes" each survival rate according to the "overall predation" in each trial.
So this gives me the following:
In the 1st trial
Group A survival index = 1 - 0.8 = 0.2
Group B survival index = 0.8 - 0.8 = 0
Group C survival index = 0.6 - 0.8 = -0.2
In the second trial
Group A survival index = 0.5 - 0.4 = 0.1
Group B survival index = 0.4 - 0.4 = 0
Group C survival index = 0.3 - 0.4 = -0.1
So when I calculate the mean of these indexes for each fish groups among all the trials, I end up with something nice : group A survival index is always positive, group B around 0, and group C always negative, so low variability and nice means that suggest that group A survived more than group B, and group B survived more than group C.
But now I would like to test this statistically, and I can't find out how to compare multiple paired data of that type. I usually do my stats in R.
If anyone has suggestions I'll be more than happy.
Thank you very much for those who read me up to here, and thanks in advance for those who'll be able to help :)
UPD: This week we have a great news! The deparment will function as separate one as it was during last 90 year and continue marine and fresh water investigations! We are realy happy and thankful to everyone who wrote letters and signed the petition!
- 100.46 KBThe Appeal of graduates of the Department of Ichthyology and Hydrobiology.pdf
- 54.62 KBA letter from the head of the Ichthyology and hydrobiology department Dr. Prof. Nicolay Maximovich to the dean of the Biology faculty.pdf
- 88.05 KBThe petition Save the Department of Ichthyology and Hydrobiology in the St. Petersburg State University.pdf
I was looking for some decent company which supplies field material as kick nets, litter bags or emergence traps (aquatic biology bias, here). Does any one can recommend me some supplier within Europe?
Thanks for the help,
Im working with a community matrix (abundance data), and i would like to check if there is a taxa indicative of different trophic state of lakes. I would to that with Indval command in R.
The problem is that my data has zeros and some taxa abundance goes up to 10000 individuals per sample.
In this scenario, would it be advisable to transform my data prior to the analisys? Should i use a Hellinger transformation?
I ask about a hellinger transformation because im thinking of doing after a CCA in this same community matrix, with some environmental data.
Thank you for your time!
I have a long term dataset which includes a variety of chemical and physical water variables sampled from an inland river. These variables include: metal loads (Al, Ca, Cd, Cu, Fe, Hg, Mg, Mn, Na, K, Pb, Ni, Zn); in Situ measurements (Electrical conductivity [EC], water temperature, air temperature, dissolved oxygen, pH); water nutrients (Ammonium, Chloride, Nitrate, Phosphate, Sulphate, Total Organic Carbon [TOC], Dissolved Organic Carbon [DOC]); and others (Acid capacity, base capacity). Some of these variables (e.g. chloride, EC, ammonium, nitrate, dissolved oxygen, phosphate, pH, sulphate, TOC and water temperature) were sampled consistently and therefore have a good resolution, whereas others (e.g. metal loads [Al, Cu, Fe, Hg, Pb, Ni, Zn], acid capacity and base capacity) were sampled less frequently and therefore do not have the same data resolution.
With that said, the focus of my research is not exactly the chemical interactions of DOC and other chemical constituents per se, but rather the interaction and effect of DOC on freshwater macroinvertebrate taxa. I do, however, understand that the interaction of DOC with other water chemical properties is of vital importance and ones needs to consider these interactions.
Therefore, I would like to know what variables (from the lists mentioned above) are the most likely to interact with DOC within the freshwater environment. This will aid in my selection of the relevant variables that I will carry into further statistical analyses.
Any help in this regard would be greatly appreciated.
There is a directive in Ghana by the Ministry of Fisheries and Aquaculture Department to ban all imports on ornamental fishes and Tilapia species including gametes-eggs and milts from now to the close of the year as an immediate response to halt the spread of the virus which is said to be prevalent in Africa, South America and Asia, especially in farmed Tilapia. This is a blow against the global Tilapia industry.
Kindly share your views on the new virus, ways of preventing it and other references. Thanks in advance. Best regards
Is nitrogease enzyme (nifH) are stable in extreme environments??
Very interesting project!
Will it take place in freshwaters?
What techniques will you use for sampling fish larvae / juveniles at the microhabitat scale?
How are you going to describe the vegetated beds?
A Malagasy PhD student is presently trying address identical questions in Toliara Bay, SW Madagascar (so, tropical marine species, a lot of them unknown at larval & juvenile stage...).
We are looking into building an antenna system for a project. Anyone done this and have an idea of price, etc. or have some general advice? I'd also love to talk to someone who used solar for energy. Wondering if its more price effective to do this. We will be doing this in a pretty shallow narrow-width aquatic system but heat will be a factor.
I am currently analysing temporal and spatial zooplankton groups and in many samples from the same time period there appears to be a very high proportion (~90%) of the same group (Cladocera). I have been unable to find literature related to whether zooplankton (specifically cladocera) can develop in blooms under optimum conditions, similar to those of phytoplankton.
If anyone could point me in the direction of any literature related to this topic, it would be greatly appreciated!
do you know if:
1 - can I run an RDA with negative (taxa) values (as delta Control - Treatment)?
2 - Do I have to use the function decostand function on these delta values before performing the RDA?
3 - Shall I use Bray-Curtis distance (dist='bray") in the RDA function?
I have maybe for the "time series" experts a silly question:
-I have a dataset of European rivers =80
-In 50% of the rivers I have more than 1 project; in the other 50% is 1 river = 1 project
-In 50 % of the projects I have data collected only for 1 year; in the other 50% of the projects data were collected over years (from 2 untill 20 years, depending on the project)
->I want to assess the Fish diversity depending on the altitude, latitude, catchment size.
After exploring data for the model assumption of normality, variance heterogeneity etc..I though to run this model:
mod<-lme(Fish Diversity~log(altitude)+log(latitude)+log(catchment size), random~1|Rivers/Projects, method="ML", data=dati)
When I look at the residuals of model mod and at the acf (residuals(mod) and pacf(residuals(mod), they are pretty good but in acf there is autocorrelation in lag1
and in pacf the line goes slightly over in lag 3. I think I would give it a try with CorAR1 (p=1) correction in lme.
My questions are:
1- Is the model developed in your opinion correct?
2- Can I fit a correlation CorrAR1 in the lme by just looking at the acf and pacf plots from the model mod? As u see I have different project over time that means potentially multiple time series (for each project). Can I just fit a unique AR1 structure looking at the residuals of the model (without CorrAR1) and not at the raw data and assume that the same temporal trend is present in all the projects analysed? How can the acf and pacf know what is the temporal repetion (i.e.
how the acf and pacf biuld the lags in the plots)?
3- if the question number 2 is yes, do I have to organise in the dataframe chronologically in the dataset for each project? (e.g. Project1 from 2000 untill 2008; Project 2 from 1998 untill 2015, and so on?) as dati[order(dati$Project_names, dati$Year_evaluation), ]
and give to the corrAR1 the form structure form=1|Rivers/Project_names
Would this model be ok?
modAR<-lme(Abu~log(altitude)+log(latitude)+log(catchment size), random~1|Rivers/Project_names, method="ML",
correlation=corARMA(form = ~1|Rivers/Project_names, p=1)
Thank you for your time
I'm trying to collect wild animals for ecological and aquaculture research and there seems to be very few of these in Sarasota Florida where we have subtropical weather. The only place we have found any is in a specific shallow Thalassia seagrass habitat near deeper pass water during Summer and Fall. I suspect the population is low and might be recruitment limited but maybe there are more animals in deeper water. Any insight on this would be greatly appreciated.
In aquatic ecology research, the relationships between different trophic level are important. Stable carbon and nitrogen isotopes analysis(SIA) are widely used to ravel the interactions between linkages in food web.
The biomass and quantity of top level organisms in food web are always low, and the collection metod requires dead individuals, and which could collect tissue samples easily.
Currently, a large proportion of top predators are rare or threatened. Few articles use the non-lethal methodologies which collect the blood or fins.
Why the non-lethal method is not widely used?
I am investigating the functionality of a lotic river and would like to calculate the exergy to compare with the values of other biotic and abiotic parameters to obtain a quality scale of ecosystem functionality. So I need the values of the βi coefficients in accordance with the Functional Feeding Groups (FFGs) of the macroinvertebrate community of a lotic river.
Loss of species of Heleopera, Hyalosphenia, and Nebela and increase of species and numbers of Trinema, Corythion,and small Euglena should parallel physico-chemical changes in dessication.
Hello there, i'd like to plot some environmental variables (Cond, Clo-a, pH, etc..) with some biotic diversity index (Shannon, Simpson, Pielou), to check the effects of these parameters on macroinvertebrate diversity.
And i'd like to know if are there any drawbacks or if its statistically wrong the use of PCA to do this analisys.
-My PCA is based on correlation matrix and rotated by Varimax technique (SPSS).
Thank you very much!
I am trying to understand what drives bioerosion by grazing organisms. I understand that algae are a major food source, but there are often problems in the literature distinguishing between basic herbivory grazing and BIOEROSIONAL grazing. My question is specifically related to what controls bioerosional grazing in reefs with depth, especially related to food sources. Please let me know if you can help.
One of my student is going to start her work on eutrophication modelling and sag curve modelling for a local pond extensively used for drinking purpose. Could anyone help me to find out the software's and manuals to proceed the work in a good way.
What could be the reason of a massive single-night macroinvertebrate drifting event occurred in an sub-alpine stream after 2 days of a 4 week experiment performed in Mai 2014? Drifting rate of the night before and of the night after was 100 times lower then the one observed during the night of "the event". Moon-light intensitites? Ice melting? Thanks in advance
Or other important methods (outside of standard Molecular Biology techniques) that would be appropriate to have a grasp of if wanting enter the field.
How deep into a structure - an artificial or a natural reef - is utilized as habitat by settling organisms? e.g - how far inside a gap between boulders of a breakwater, we can expect to find encrusting organisms?
Any papers on the subject will be appreciated.
I'm referring to the spread of freshwater species that are attractive aquarium/angling fishes such as the sunfishes, catfishes and snakeheads in European waters (aliens!!!). Europeans will continue to keep them in captivity and will use them as angling attractions or to stock their big mouth bass fishing areas. Please, any innovative ideas would be very much appreciated!
Our group in the Office of Research and Development at the U.S. Environmental Protection Agency would like your help. We are conducting a systematic review of stream algae and macroinvertebrate responses to nutrients and ask for any relevant studies or reports to consider.
The focus of our review is ONLY on total nitrogen and total phosphorus and its effects on chlorophyll-a, diatoms, and benthic macroinvertebrates in flowing waters. We have completed searches of standard publication databases based on these parameters, but want to ensure that we have not missed any relevant publications that include primary data on these relationships (i.e., not reviews or meta-analyses).
If you know of any relevant studies, particularly difficult-to-find reports or older publications, please send a citation (for easily obtainable works) or a PDF to: bennett.micah 'at symbol' epa.gov or post a response here. PLEASE LIMIT THE NUMBER OF STUDIES TO 10. If you have more than 10 studies for consideration, we can speak directly to better assess the relevance of the studies.
Please send any relevant materials by 31 August 2017.
Thank you in advance for your help!
Micah Bennett, Ph.D.
i want to know that does there exist any change in the feeding behaviour pattern of an organism in lakes and streams
Does anyone know of research indicating that large-polyp stony corals (e.g. Tubastraea coccinea) prey on ichthyoplankton? I am aware that there are several studies that indicate that they can prey on copepods and crustacean nauplius. Generally, I am considering if reefs dominated by predatory corals are more hazardous to settling fish larva than reefs dominated by primary consumer bivalves. I have evidence indicating the bivalves in question are generally primary consumers and the corals are secondary consumers.
I'm looking for an example of a country that possesses both the source and the recipient habitat of an invasive species, except Israel and Egypt..
It may be marine, terrestrial, faunal or floral organism.
I'm mainly interested about the conservation management-actions taken by the country.
In other words, how to protect a species in one place, and cull it from the other.
Thanks in advance,
Israel Oceanographic and Limnological Research Institute
Most fish have a range of wavelengths which they respond to (e.g. see electroretinography studies by researchers at the Virginia Institute of Marine Science):
Some fish have two regions (bimaxwellian) of peak response within the range of wavelengths that they respond to, while most seem to only have one (a Maxwellian distribution). I suppose this has to do with evolution and how they have adapted to their habitat (e.g. standing/flowing fresh vs salt water, depth of preferred temperature), predators and prey, etc. I am a physicist, but interested in both physical and biological explanations, preferably with references, not just speculation.
Best regards and thank you for your contributions in advance!