Aquatic Ecosystems

Aquatic Ecosystems

  • Julian D. Reynolds added an answer:
    Is there (scientific) proof that water fowl can transport fish eggs from one water body to an other?
    I am interested in the dispersal of freshwater fishes in artificial water bodies like pit gravels. There is some anecdotic rumor but I could not find proof for the transport of fish eggs by water fowl.
    Julian D. Reynolds

    Hello Harald

    while salmonid eggs are smooth, many other fish eggs are sticky, using this property to adhere to water-weeds. T\I believe they could therefore adhere to birds, or to weeds being transported by birds.

    Best wishes, Julian

  • Alexander Kostenko added an answer:
    Is the species Dalyellia viridis a good bioindicator?

    Respected, before several days I have taken the samples from one artificial hidro ecosystem. I did not analyze the samples, just left the glasses because I was so tired. Yesterday I have seen something strange. Into the water, I saw several individuals that look like Turbellaria, but they were green. I never seen that species before. In the key for determination of Invertebrates I found that the species can be matched with Dalyellia viridis, Turbellaria species that lives in simbiosys with Plant species from the genus Chlorella. Now I wonder what can indicate Dalyellia viridis, maybe some kind of pollution, or could be indicatore of clean environment?

    Alexander Kostenko

    On my knowledge and experience the record of Dalyellia viridis wouldn't indicate the condition of a water reservoir. This species prefer temporary reservoirs located in the floodplain. However sometime I've found it in permanent lakes and ponds. So if this species appears in a sample it indicates that the temperature of water, pH, level of oxygen, salinity, dissolved organic compounds and a food base are suitable for this species (as long as it is within the area of distribution of the species) and doesn't directly indicate how clear the water reservoir is. By the way "Planaria alpina" (as a matter of fact - Crenobia alpina) doesn't indicate the environmental condition as well. Crenobia just lives in relatively cold mountain water springs that usually are away from big cities and therefor much cleaner than water pools on urban territory. It wouldn't live in plain springs and rivers because of higher temperature of water plus some other chemical factors that doesn't belong directly to human influence.

  • Aboulghasem Roohi added an answer:
    How can I culture and set up continuous rearing of copepod Acartia tonsa in lab? I mean the equipment and methodology?

    I found some articles but were not so useful for details in copepod culturing?

    Aboulghasem Roohi

    Thanks Leonid

  • Adam Barcikowski added an answer:
    How can I determine (calculate) the bifurcation point in the dynamics of a series empirical data?

    Bifurcation point is the point of the phase transition of the system from one state to another. How from empirical data of any magnitude characterizing the state of the aquatic ecosystem to calculate the bifurcation point in the dynamics of this magnitude? I can provide the real empirical data on primary production and destruction of organic matter if someone is interested. 

    Adam Barcikowski

    Maybe this paper will be useful for you: Thresholds in ecosystems, in Ch. 5 "Biodiversity and Ecosystem Functioning: Basic Principles", pp. 275-325, H.A. Mooney, J. Lubchenco, R. Dirzo, and J.O.E. Sala

  • Stefano Piraino added an answer:
    Can anyone help me to identify this "jelly thing"?

    This "jelly ball" has been saw twice floating in shallow marine waters in Sicily (Mediterranean Sea). Someone suggested that it might be a damaged jelly umbrella but the evident bilateral symmetry suggests that it should not be a jellyfish. Hence the "damaged jellyfish umbrella" seems improbable. It might possibly be part of an organism or even an ooteca (mollusk ooteca?). What's your idea about?

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    Stefano Piraino

    Hi Antoine,

    sure it will be great to obtain Chrysaora samples from different Atlantic spots. please mail ma a, and I will send you the protocol we use for subsampling and preservation. Thanks in advance, best


  • Robert Walker added an answer:
    What is the extent of ecosystem loss in Florida, since pre-consquet times?

    Does anyone know where I can find information/data documenting the loss of native Floridian ecosystems, including mangrove islands, wetlands (marshes and swamps), pine flatwoods (both long leaf pine with wire grass and slash pine with palmetto), temperate hardwood forest and mesic hammocks.  thanks!  

    Robert Walker

    many, many thanks for all the input/help on this.

  • Romanus Edy Prabowo added an answer:
    Can anyone identify this erosive barnacle?
    This is a family of pyrgomatidae
  • Gana Gecheva added an answer:
    Any suggestion on Macrophyte-based assessment of ecological potential?

    The developed methodologies for macrophyte-based assessment have values for ecological status classes. The WFD also requires assessment of 'heavily modified water bodies' in terms of ecological potential. I am thinking if the given methodology reflects general degradation (i.e. including physical alterations), is there a need of separate scale with values for ecological potential? Thank you for your comments in advance!

    Gana Gecheva

    Dear Andre,

    Thanks a lot!

    Kind regards,


  • Remi Sonier added an answer:
    How can I create an annual trend for chlorophyll a concentration for a coastal location, if availability of data is as stated below?

    1. Chlorophyll a concentration at three sampling points of a study coastal location. (The distance between sampling locations from coast varies between 10 - 25 km).

    2. Chlorophyll a concentration taken on one day of different months in a year but one season.

    (For instance, for year 2002 taken on 12-3-2002 and for year 2003 taken on 14-2-2003)

    3. Chlorophyll a measured at 3 depth levels.

    If data availability is in above mentioned manner, can we prepare annual time series for the study location? how?

    Remi Sonier

    Hi Nitish,

    Chlorophyll a in coastal waters is verry variable in time (and often from day to day , or tide to tide). Your sampling interval is, in my own opinion, rather limited. For instance, in my case for a small estuary for one year sampling during ice-free months, the minimum sampling protocol was 7 sampling stations, sampled bi-weekly, in triplicatas, for 7 months and we size fractionned as well.

    Basically I think one season each year is probably not sufficiant to have good statistical confidence in the data.



  • Erra Sunitha Babu added an answer:
    What are these plankton (Rhizosolenia alata or R. setigera)?

    I found these plankton in Arabian sea. Kindly text the species or genus name of the plankton. Also I need e-book to identify fresh water and marine diatoms.


    Erra Sunitha Babu

    dear karnan. i have only seen first two ur images and it shows Rhizosolenia setigera.

  • Michael Adelana added an answer:
    What is the maximum load on dissolved minerals (chlorides, sulphates) in drinking water humans can deal with to survive in desert environments?

    Regarding adaptions of prehistoric hominins to drinking water resources, what is the maxima in brackish waters modern humans from native and indigene groups living in such environments can deal with? References regarding this question would be appreciated, thank you in advance!

    Michael Adelana

    Great to hear you're sorted. Let's know when you publish on this aspects. Kind regards,


  • Cui Xu added an answer:
    Why is it important to quantify the stoichiometry of species in aquatic ecosystems?

    In aquatic ecosystem, nutrient limitation has a long research history. I am wondering the reason why it is important to quantify the stoichiometry of a specie or species. Would anyone help me to understand this topic?

    Cui Xu

    Yes, I am referring to elemental stoichiometry.  I have read the book "Ecological Stoichiometry" by Sterner and Elser. In this book, they did describe what is ecological stoichiometry and why they focus on it. I think It's interesting to know deeper about the differences of ecological stoichiometry among different autotrophic or heterotrophic species.

    However, I can't understand the meaning of this differences. Are the differences demanstrate competitive ability of species? or other meanings?

  • Gustavo Enrique Chiaramonte added an answer:
    Can anybody help me with a nomenclatural problem?

    I am facing a nomenclatural problem and I need help. During my masters, I did a taxonomic review of two freshwater stingrays, P. orbignyi and P. dumerilii. As a conclusion of my work I proposed that they were synonyms. However, I did not know which name had precedence over the other since both were originally described in the same work by Catelnau in 1855. Consulting the ICZN (article 24) they proposed that this nomenclatural act should be resolved by the principle of the “First Reviser”. Carvalho et al. (2003) (in a checklist) proposed P. orbignyi as a senior synonym of P. dumerilii (acting as the “first reviser”) and as a consequence I gave precedence to the name P. orbignyi and included P. dumerilii as a junior synonym. However, P. dumerilii was described in a previous page (p. 101) to P. orbignyi (p. 102). In this case, does the P. dumerilii have precedence over the P. orbignyi since it was described in a page previous to it (nullifying the decision of the “First Reviser”), or should I accept the decision of the “first reviser”? None of the names has fallen in disuse and both have been used in the present literature, with some researchers still considering P. dumerilii as a valid species. How to proceed in this case?

    Gustavo Enrique Chiaramonte

    Dear João, I understand you perfectly, and hope you can publish the results of your master successfully. I'll be waiting for them. Meanwhile, I'll take your opinion into account in any future work that may involve this / these species. Thank you very much. Regards


  • Andre Barreto added an answer:
    Does anyone know of a disease/condition that affects bottlenose dolphins (tursips sp) where a "fleshy, seaweed-type growth" protrudes from the mouth?

    I have run across a number of anecdotes of this growth affecting some Tursiops aduncus bottlenose in/around the Broadwater estuary on the Gold Coast, Australia, around 10-15 years ago (2000-2005). No-one has been able to provide me with pictures. The growth protruding from their mouth made it impossible to accept food from boaters who tried to provision them. Not surprisingly, they disappeared fairly quickly.

    I've found one passing reference to a similar condition but the study simply made mention of a male, on its own, with the growth, and didn't study or investigate further.

    I'd be interested of any other sightings of such a condition, any thoughts on what it might be, or any photos.

    Andre Barreto

    Since you don't have photos, it's difficult to know what the cause of the condition you mention. However, the video and photo from Simon seems to me to be stalked barnacles. They have been described in many cetaceans, and I've found in franciscanas (Pontoporia blainvillei) from my area. You can see a photo of it at

  • P.J. Mudie added an answer:
    What age correction is needed for mollusc C-14 dates from Black and Marmara Sea lacustrine phases?

    High resolution dating of events in the Black and Marmara Seas during non-marine phases requires appropriate correction of C-14 ages because shells are not in equilibrium with global values of ca. 400 yr. Proposed values range from 0 (fully mixed, in equilibrium with atmosphere, no correction needed) to 1000 yrs (benthos contain old bottom water or river transported carbon). Peat (grows in equilbrium with atmosphere) compared to in-situ shell from the same sample   indicates a reservoir correction of ca. 850 yrs is needed for shells. Which correction value is correct for A) Black Sea? B) Marmara Sea with overflow water.

    • Source
      [Show abstract] [Hide abstract]
      ABSTRACT: Dating of major sea-level changes using shells or calcareous microfossils is prone to errors in semi-enclosed marine environments where inputs of seawater and river water vary over time and space. The need to refine mollusc-based age estimates for the rate of the Holocene marine transgression in the Black Sea is the focus of multiple palaeoceanographic and archaeological studies. This ongoing “dating game” seeks to clarify conflicting evidence for a hypothetical catastrophic marine flood that forced the emigration of Neolithic farmers from the shores of a Holocene freshwater lake in the Black Sea. The potential importance of confirming or rejecting this megaflood hypothesis has led to multiple attempts at refining the chronology of the marine transgression and quantifying the palaeosalinity of the Black Sea surface water during the Holocene. Here we report that six new AMS radiocarbon ages of 8890 ± 50 to 8450 ± 40 yr BP were obtained for wood, grass and sedge leaves from peat layers in Core 342 at 33.16 - 32.71 m below present sea level on the Ukrainian Shelf. These plant materials provide critical new ages for quantifying Black Sea carbon reservoir issues. The accuracy of our new AMS wood/peat ages is independently supported by palynochronological correlation. The ages of our plant materials have ~100 years precision and are ~420 - 520 years younger than those previously reported for unsorted detrital peat in Core 342. Paired mollusc—wood ages for brackish—freshwater Dreissena polymorpha shell from detrital peat also shows that an inaccuracy of >1120 yr can arise for shells during times when carbon reservoir values in the semi-isolated, brackish-water Black Sea could depart significantly from global average. Our revised sea level curve shows a gradual early Holocene transgression from water depths of −45.9 to −32.8 m, with initial Mediterranean inflow by 8.9 ka BP.
      Open Journal of Marine Science 01/2014; 4(1):1-7. DOI:10.4236/ojms.2014.41001
    P.J. Mudie

    Thanks for all your answers. In Marmara Sea we have new cores with lacustrine sediment containing shells next to tephra layers dated by wood. These may provide a more accurate reservoir correction value for the late Pleistocene interval.

  • Raymond K. Timm added an answer:
    What relationship exergy and primary production and destruction?

    I explore generalized parameters of aquatic ecosystems to assess the evolution of their state under anthropogenic effect. What parameters are preferable?

    Raymond K. Timm

    Mikhail - I love your research question! Of course no model is adequate to describe all the interactions in constantly perturbed environments.  If you could stack integrals from 0 to infinity you could model ecosystem behavior. Every independent variable is also dependent on every other.  For example, high stream discharge can be disastrous for incubating embryos of lithophillic spawning fish.  But, high discharges provide hydrologic connectivity for rearing juveniles.  And of course, not every place is equally productive or safe.  So, you have to incorporate space and time and life history stage(s).  One statistical approach I have used is classification and regression trees.  They can overfit relationships.  But, who cares.  In ecosystem studies, really what you want to know is the hierarchy of importance between dependent and independent variables.  I've attached 2 papers that illustrate my thinking.  The first quantifies the spatial and temporal nature of a physical disturbance in a river.  The second shows how fish responded to that disturbance when placed in the context of the whole river.

    I hope these are helpful for you.  Please feel free to email me directly if you have any questions.

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  • Xiaowei Jin added an answer:
    Does anyone have any papers about the development of low-cost ecotoxicological test with aquatic invertebrates?

    I'm reviewing information on the issue of low-cost methods in ecotoxicology, and I have some studies on it, such us Mills CL et al. 2006 Development of a new low cost high sensitivity system for behavioural ecotoxicity testing Aquatic Toxicology 77: 197-201 I would like to know other studies on it.

    many thanks


    Xiaowei Jin

    A Simple Low-Cost Field Mesocosm for Ecotoxicological Studies on Earthworms. 

    PHYSIOL C PHARMACOL TOXICOL ENDOCRINOL , vol. 117, no. 1, pp. 31-40, 1997
    DOI: 10.1016/S0742-8413(97)85596-X

    GamTox: A Low-Cost Multimetric Ecotoxicity Test with Gammarus spp. for in and ex situ Application

    International Journal of Zoology
    Volume 2011 (2011), Article ID 574536, 7 pages

  • Najat Alomari added an answer:
    Can anyone identify this sea slug?

    can anyone please do identify this sea slug(is it really a sea slug??) i got this from chennai beach. it weighs arroung 127g. has a scaly appearance like a snake. and these scales are brown colour with brown dot in the middle of the scale. near to the mouth it has more than 10 tentacles.
    thank you for identifing it.

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    Najat Alomari

    This is sea cucumber  belongs to the family Holothuriidae it seems to be holothurian??

  • João Paulo Medeiros added an answer:
    Has anyone amplified COI successfully from freshwater oligochaetes?

    I already tried universal primers (Folmer et al., 1994) and others like COI-E and AnnCOIF used in published papers, with different temperature programs but without results. Does anyone has a PCR protocol that already used and worked sucessfully for these annelids?

    João Paulo Medeiros

    Thank you for your answers... I will try both Svante and Jonathan protocols and see the results :-)

  • Muthuswamy Jaikumar added an answer:
    Is there data other than USEPA literature values LC50 for Selenium for marine species ?

    I have searched literature values for Selenium (Sodium selenate). I got USEPA literature 2004. I need other than USEPA: Australian, ASEAN and New Zealand water quality criteria for selenium lc50.

    Muthuswamy Jaikumar

    Dear Arif thank you for sending a link in that i seen same USEPA data. Like USEPA i need literature values neither like Australian, ASEAN and New Zealand water quality criteria for selenium lc50 for marine water species. 

    Thank you for sharing this information 

  • Ted Swift added an answer:
    What are potential research implications of landscape community genomics on stream/river ecology and riparian ecology?

    Landscape commuity genomics is related to eco-evolutionary processes in complex environments, such as stream and riparian ecosystems. However, its framework is not clear at the moment, because we don't know how genomic variation is affected by dynamic interactions between abiotic (environmental) and biotic (community) effects..

    Ted Swift

    Thanks to Francis for linking in Hand et al.'s essay. Very interesting, and one of those concepts that's obvious...after it's pointed out. As Edward Tufte reminds us "It's More Complicated Than That!". The research implications? As usual, it's a case of a big idea that needs to be translated into testable hypotheses on scales that can be studied on practical levels. In riparian corridors, you might expect -for example- genetic variation to be more highly correlated along the corridor, where conditions are similar, than across a stream-to-upland gradient. Or maybe the opposite, depending on the organism.

  • Francisco Lakay added an answer:
    What are good standard methods for calculating MPNs from sediments?

    I am looking to run survival experiment  of bacteria in a lake mesocosm and would like to count viable cell numbers over time in sediments. Ideally, I would like to be able to calculate CFU/ml and not CFU/g so I can compare to growth in lake water as well. I have tried Beat Beating with 2mm beads but my recovery is very low. Any suggestions or ways people get around the mass to volume comparisons!? 

    Francisco Lakay

    Hi, if you are only looking at bacteria, you can use differential centrifugation. You first spin down at 2500 rpm to pellet all the larger cells and debris, with the bacteria still in solution. After decanting the solution to a new container, spin down at 10 000 rpm to pellet any bacteria in solution.

    Although this is a very basic method, it allows you to study bacteria in any environment, minus some of the background noise. You can also combine diff. centrif. with bead beating - that way you know that most of your extracted DNA will be from bacteria.

    I would also suggest using DAPI to stain only viable cells.



  • Domenico Voltolina added an answer:
    What's the name of this microorganism identified by microscope?

    The short chain chain alkanes C15,C16 and C17, likely derived from algae, bacteria, dominate the n-alkane composition in lake sediment. Now, We have already identified  some microbials (the round object in the attached picture) with microscope in lake sediemnts at Zigetang Co on Tibetan Plateau, but we are not sure what's they are. Someone guess this is the head of Copepods (Zooplankton) Would you please tell us if you know? Thanks a lot.

    Domenico Voltolina

    on an afterthought, Kamal and Lofti are right. Not a cyanobacteria, but I would go for a green. To me, the area around the central part might indicate a cyst, I agree with Roman's suggestion: examine fresh samples and if possible isolate these cells. Cysts resist harsh treatment, so treat your samples with peroxide or with acid and see what happens. you might get lucky and get living, swimming cells.. Here goes something you might find of interest. good luck

  • Jorge Ramirez added an answer:
    What is a good modeling program for trace contaminants in large river systems?

    I am studying the concentrations of sucralose, an artificial sweetener, in the Ohio River. There will be 25 sampling sites between Pittsburgh (PA) and the Mississippi River confluence.

    Jorge Ramirez

    Hi Ben,

    If you use CAESAR, keep in mind that the tracer component only tracks contaminant that binds to sediment.


  • Hartmut Nies added an answer:
    Does anyone have any links on the further degradation of microplastics in the marine environment?

    I'm currently working on an assignment on the degradation of microplastics in the marine environment, I have found a good breadth of background knowledge and literature on the degradation of plastic debris to microplastics but i'm having trouble finding literature on the further degradation microplastics to nanoplastics and thir impacts etc. Any help would be greatly appreciated!

    Hartmut Nies

    Recently, GESAMP published a report about Micro-plastics in the ocean. You can download the report with an assessment here:

  • Phillip Haubrock added an answer:
    Does anyone know an expert of european and asian newts?

    While collecting insects I found two small newts in a pond near Kassel, Germany.
    The species looks a lot like Cynops, but I would like to know if someone is able to identify it more properly.
    Please send me an e-mail adress and I will send pictures as soon as possible, since I am currently unable to upload any pictures.

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    Phillip Haubrock

    At first, we thought it might be C ensicauda or C. pyrrhogaster, but was later then classified as Cynops pyrrhogaster. We suppose, that it is unlikely that C. pyrrhogaster can survive a long time (couploe of years) in this climate, but we do not outrule it yet.
    Therefore I will keep monitoring this pond, but so far, I was unable to find any other newt species. Sadly I do not know if there were any other newts in this specific pond, so it is hard to make any suggestions.

  • NPP Liyanage added an answer:
    Can aquaculture water quality be tested on its own without relating to reared specimens?

    I've encountered several journal articles and studies that show aquaculture water quality is not usually studied on its own and the studies show results are tied to specimen immune response. 

    NPP Liyanage

    I believe you can get a clear answer if you can elaborate the question little bit.

    Anyway, any kind of aquaculture totally depend on the water quality (WQ). therefore it is essential to monitor the WQ. Frequency of monitoring is depend on the intensity of aquaculture. Intensive culture required more accurate frequent monitoring while extensive cultures neglect WQ monitoring.

    However, since ambient WQ affect on growth and health of culture spp in many ways it is essential to monitor WQ. Bad WQ will stress fish by creating unfavorable environmental conditions. So due to this stress, there immune system might get weekend and may cause diseases.

  • Florian Koch added an answer:
    Are you aware of studies on naturally (acidic) vs. anthropogenically (acidified) low pH estuaries?

    The question revolves around the concept of acidification of estuaries, as an ecological process which may be induced by human activities. In tropical conditions, high rainfall, heat and high primary production and specific geological settings may determine soil acidic conditions, which may control relatively low pH conditions in estuaries (i.e., in the lower tract of hydrogeographic basins). I am looking for the available literature and an overview/discussion on the state of art of this topic.

    Florian Koch


    IN my old lab they are spending a lot of time with exactly these kind of questions.  I would look at the Christopher Gobler’s Laboratory page at Stony Brook University and his recent publications.  Also his PhD student Ryan Wallace has done a lot of work in Jamaica Bay, Long Island Sound and many of the Islands numerous barrier island estuaries with regards to pCO2, alkalinity and DIC measurements in addition to numerous other environmental parameters.  Check out their lab page and publications and maybe shoot them an email.

    Cheers and good luck.

  • John J. Hains added an answer:
    Does anyone know of techniques of publications for gap filling dissolved oxygen data in freshwater habitats?

    We are currently using D-Opto dissolved oxygen sensors in marsh habitats to measure continuous seasonal changes in dissolved oxygen.  Power issues and occasional sensor issues leads to gaps in our data set, which we would like to fill in order to conduct the appropriate time series analysis.  Unfortunately, literature searches have yielded little information regarding methods for gap filling dissolved oxygen data.  For this reason I am reaching out to the Research Gate community for advice.  Thanks :)  

    John J. Hains

    What is the frequency of measurement during normal operation? How long are the gaps? You need to provide a little detail. 

  • Sandipan Gupta added an answer:
    Is Mystus gulio (locally known as Nuna Tengra) a threatened native estuarine catfish?

    Yes. According to IUCN (2000) Mystus gulio (locally known as Nuna Tengra) a threatened native estuarine estuarine catfish, enjoys a high consumer preference fish in many Asian countries including Bangladesh.

    Sandipan Gupta

    The ratio with which Mystus gulio was stocked is not clear from this paragraph. To analyze this I think few factors to be considered, i) the feeding niche of the fish species poly cultured, ii) stocking density. As per the information provided in T2 and T3 Mystus gulio was cultured with O. niloticus and R. corsula (with varying stocking density); so how can it be concluded or rather to be compared; for this you will have to culture Mystus gulio with O. niloticus (in one experiment) and with R. corsula (in another experiment). Then one can compare the growth difference.

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marine and freshwater aquatic ecology and hydrobiology

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