Science topic

# Aquatic Science - Science topic

Explore the latest questions and answers in Aquatic Science, and find Aquatic Science experts.
Questions related to Aquatic Science
• asked a question related to Aquatic Science
Question
Hi All,
at the Museum of Nature South Tyrol, in Bolzano / Bozen, Italy, we're keeping in aquarium for more than 10,5 years 3 American horseshoe crabs Limulus polyphemus.
What is the maximum longevity of American horseshoe crab in aquarium?
Thank you!
Sincerely,
Massimo
Dear Daniel Taylor,
many thanks for your reply! I didn't know this paper. It is for me very interesting.
Sincerely,
Massimo
• asked a question related to Aquatic Science
Question
I'm working on cumulative risks assessment of lead, chronium, nickel in groundwater and drinking water.
Interesting
• asked a question related to Aquatic Science
Question
To reduce CO2 concentration and increase pH value of RO permeate water a CO2 stripper system shall be used. The stripper system includes a packed bed column that provides required surface for air-water contact and an air blower.
The analysis of influent water is as follows:
Temp= 20 C
CO2= 64.6 ppm
HCO3= 4.9 ppm
CO3= ~ 0.0 ppm
How can I measure the concentration of HCO3 and CO3 and the pH value of the effluent product? The concentration of CO2 in the effluent can be determined according to the CO2 content of inlet air and Henry’s law.
To my knowledge, using carbonate equilibrium equations there are four unknown parameters include CT, CO3, HCO3, and H concentrations, while there are just three equilibrium equations.
Regards
Dear Monsuru,
Thank you so much for your response. However, the system is not installed yet and pH measuring of product water is impossible.
I need to model and design the mentioned system.
• asked a question related to Aquatic Science
Question
If this equilibrium is correct,
CO2 +H2O <->H2CO3 <-> HCO3 + H <-> CO3+2H
it means that when CO2 is added then the equilibrium is shifted to the right, increasing HCO3 and H.
Could this lead to pH reduction?
when you are talking about CO2 and water, you will get both Hydogen cations and HCO3 anion. each one has its effect on pH with the same concentration they must not affect pH because one will shift it to one side by the same amount so it will not be deflected except if one of them been used in a reaction.
• asked a question related to Aquatic Science
Question
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.
I think it must be an experiment of 2 years.
• asked a question related to Aquatic Science
Question
I agree with the response of Dr. Pang. You need to investigate the causes for the fall in water level and thereby shrinkage in the water spread area of the lake. One has to study the historical data on the hydrological and developmental activities of the region and understand the spatial and temporal variation of its effect on the lake. Then try to extrapolate the same for future scenario.
• asked a question related to Aquatic Science
Question
I used dried and ground Sargasssum spp. to enrich surface sediments. Took sediment samples (that may have bits of Sargassum spp.) and determined chlorophyll-a spectrophotometrically. I am wondering if the chlorophyll-a could come from the dried Sargassum ssp., and not benthic diatoms.
There is likely to be chlorophyll-a in sediment samples from benthic microalgae such as diatoms. I would test the chlorophyll-a in sediments unenriched with your dry Sargassum spp (background). Also test the chlorophyll-a within your dried macroalgal powder. Then you will be able to see whether the chlorophyll-a signal from enriched sample is above the background + the macroalgal powder chl-a signal.
• asked a question related to Aquatic Science
Question
Most studies using eDNA in freshwater seems to be focus on detecting fish species currently occupying a lake/river system. I have read that there is a rapid degradation of eDNA within days to weeks in the water. But am wondering if it would be possible to detect historical eDNA from fish in freshwater sediment to determine how pristine fish communities looked like, say >1-300 years back in time?
Dear David,
there was a special issue of the journal Biological Conservation about eDNA with multiple papers that you might find useful (Biological Conservation, Volume 183, Pages 1-102 (March 2015), Special Issue: Environmental DNA: A powerful new tool for biological conservation, Edited by Caren Goldberg, Katherine Strickler and David Pilliod).
One of the papers in there even deals with the question of fish eDNA in sediments compared to the water column directly (Fish environmental DNA is more concentrated in aquatic sediments than surface water, Pages 93-102, Cameron R. Turner, Karen L. Uy, Robert C. Everhart), while others research questions about eDNA degradation in general.
Best wishes,
René
• asked a question related to Aquatic Science
Question
I would like to collect data for a review about development in the "lower" Crustacea: Decapoda, specifically shrimps or prawns classified within the Dendrobranchiata (penaeids and sergestids). I am particularly looking to collect information from studies reporting: (1) relative durations of different immature phases (egg/embryo, nauplius, protozoea, mysis, decapodid/postlarva) and/or stages within these phases (nauplius I, II, III, ...); and/or (2) how the number and duration of stages (and total development) is affected by temperature. I have been able to find a handful of relevant studies, although some of these are older and only give very broad ranges for stage durations. Any recommendations for studies/data sources would be greatly appreciated!
Favor escribir a la biologa marina Martha Janette Torres, marthamaury@hotmail.com, ella es la persona idónea por toda su experiencia con camarones de aguas marinas y estuarinas. De su mensaje favor enviar copia a mi correo, ricardoalvarezleon@gmail.com
• asked a question related to Aquatic Science
Question
Fish nursery grounds are significant for the life cycle of fishes and frequently these grounds are not particularly well examined or the processes understood. The juvenile stage of fish is frequently considered to be particularly hard to work on
• asked a question related to Aquatic Science
Question
The parasite was collected from a freshwater fish, Labeo bata inhabiting the riverine system of river Ramganga, northern India
These hooks shown at image_489 (first photo) reminds me of hooks present on the head of  Acanthocephala.
• asked a question related to Aquatic Science
Question
Morphometric and LWRs
Thank you Dr. Neethu
• asked a question related to Aquatic Science
Question
why inter-specific hybridization in fish or crustacean skews sex ratio to higher male population?
• asked a question related to Aquatic Science
Question
To calculate mean pH, you have to convert first to ion concentration, but the std. dev. you get cannot be converted back into pH (or at least isn't a logical number).
See Journal of Experimental Biology paper from 1980 for a comprehensive treatment of this topic. http://jeb.biologists.org/content/jexbio/84/1/335.full.pdf
Note that you CAN back calculate Standard Error or Deviation from the value for hydrogen ion concentration, but you have to perform this calculation separately for the +ve variance and the -ve variance.
• asked a question related to Aquatic Science
Question
Sturgeon biologists - I am studying early life history of white sturgeon (Acipenser transmontanus), and we are in the early stages of building an individual-based model to determine why juveniles do not live past about 6 months of age (recruitment bottleneck). What are your thoughts about the most important mechanisms for survival at this age?
Thank you Melissa.  It's been a while since I've commented on this topic; since I wrote last, we've begun to narrow the possible causes of recruitment failure.  We're honing in on the possibility that it may be related to habitat availability (substrate type) that does not match with the species' developmental stage.  As you keenly noted, hydrological influence is definitely a possible factor; sturgeon recruitment in this section of the Columbia River began to markedly decline once dams were built upstream in the Canadian section of the river.  We will be designing our model with 4 different life stages of white sturgeon - embryos, free embryos, early larvae, and late larvae.  We'll be simulating drift distance and behavior over various historical hydrologic regimes of the river (pre-dam) as well as post-dam to begin to tease out further hypotheses about mechanisms in recruitment failure.
• asked a question related to Aquatic Science
Question
I have just recently encountered and read on the concept magnetoreception in salmons. So far, the way of observing or detecting such is quite complicated. I'm wondering what is the simplest way possible that would be able to observe this phenomenon in aquatic animals?
That is an interesting question.  Our group has studied magnetoreception in a number of aquatic animals, including salmon.  In our experience it has been difficult to come up with "easy" tests for magnetoreception because most such experiments require precise manipulation of magnetic fields, and this in turn requires carefully designed coil systems and magnetometers (for measuring the fields).
That being said, what is needed (in principle) to demonstrate magnetoreception is just convincing evidence that the behavior of an animal changes in some way in response to different magnetic fields.  Thus, one could hypothetically use a magnet instead of a coil system to manipulate magnetic fields.  The caveat is that the fields produced by most magnets are much stronger than the magnetic field of the earth and the fields produced by magnets are not uniform in the same way that the earth's field is (instead, the field is much stronger close to the pole of the magnet).  For these reasons, it is possible that animals that detect the earth's magnetic field may not detect or respond to strong, irregular fields produced by magnets.
Two basic approaches have been used to demonstrate magnetoreception.  One approach takes advantage of naturally occurring behavior in an animal, such as the tendency of an animal to migrate in a certain direction using earth's magnetic field for  guidance.  By manipulating magnetic fields, researchers can then demonstrate that the behavior changes when the magnetic field changes.  In salmon, this approach was used successfully in early experiments by Tom Quinn at the University of Washington, and more recently by Nathan Putman at Oregon State University.  A second approach is to try to condition (train) animals to respond to magnetic field cues by performing behavior that does not occur naturally (for example, conditioning an animal to press a paddle or approach a target in the presence of an unusual magnetic field).  This approach has been used successfully in several experiments with animals such as chickens, bees, and pigeons, but it often takes considerable time to condition the animals, so this approach is not always easier than taking advantage of spontaneously occurring behavior.
As Joachim Pimiskern noted, a complication of experiments with magnetic fields is that changing a magnetic field also generates a transient electric field.  Salmon are not known to detect electric fields, but some fish are.  Thus, if you are working with a species that might have both magnetoreception and electroreception, then steps have to be taken to ensure that the animals are really responding to the sensory cue that is intended to elicit the response.
I hope you are able to discover an "easy" test for magnetoreception.  That would be a valuable discovery for those interested in learning how animals detect magnetic fields -- which is still not clearly understood in any animal!
Best regards,
Ken Lohmann
• asked a question related to Aquatic Science
Question
In what ways do they provide insight on the disposition of a given body of water? Are there certain characteristics that are common among these organisms that allow them to demonstrate the quality of the water?
Respiration strategy (e.g., tracheal gills, respiratory siphon, plastron, etc) is one crucial characteristic that plays into tolerance. Polluted waters are often low in oxygen and the adaptation of the organism for utilization of available O2 is important to focus on and is one of the main reasons EPT taxa are distinguished from other taxa when assessing water quality.
• asked a question related to Aquatic Science
Question
I have carried out plankton sampling in a natural stream and I can't see any organism? Is this situation feasible in nature? What can be the reasons?
Dear all,
the question is what Daniel means under plankton. If euplankton - so I agree with Russel. fast frowing water bodies are unsuitable. Esp for protistoplankton, picoplankton in general. In Trnthcarpathians the Tisza river real euplankton appear in the river near Chop city 240 km far from the issues...
As to syrton or pseudo-plankton its other. This appear from the benthic and periphytic communities, and from the banks ground. As well a source of appearance is satellite water bodiesof lentic type (like ox-bows, floodplane ponds etc.).
As well some water bodies are so shallow that do not give possibility to develop the ecoform of plankton - no three dimension habitat (streams, brooks, springs).
Other reason - absence of food - caves and deep marine habitats.
Can be as well other reasons of absence - due to toxic environment - some volcano lakes etc.
Andrey
• asked a question related to Aquatic Science
Question

I am  working on population genomics of freshwater shrimp, Paratya australiensis. I am trying to extract high quality, high molecular weight DNA (~3ug, &gt;50kb); from Paratya for RAD-sequencing. I have tried different extraction methods on fresh and frozen samples so far, e.g. Spin-Column extraction, CTAB extraction and Salt extraction. Besides, I have also tried an extended gDNA extraction procedure by incorporating a salting out step prior to phenol/chloroform cleanup. But unfortunately these methods have all produced what appears to be a smear of degraded DNA rather than high molecular weight band on agarose gels. Can anyone suggest me any other procedures that might help?
Hi, Sharmeen Rahman,
I am extracting DNA from shrimp frozen tissue that apply to GBS method. I used kit (Invitrogen), phenol: chloroform:isoamyl alcohol (25:24:1) but they appear to be a smear. Can you help me?
• asked a question related to Aquatic Science
Question
We have been monitoring a temperate lake during the winter and observing Daphnia under the ice, when normally they would not be found in the water column. Some of which still have asexual eggs.  The system is hyper-eutrophic which is leading us to think perhaps food conditions still permit growth even though temperature is cold.
Has anyone else observed Daphnia in winter or under the ice in lakes? Thanks.
Hi Brian
There is some literature also from other counties on daphnids spending the winter as adult females. For instance, Larsson & Wathne (2006) reported adult females during winter in oligotrophic mountain lakes.  They claimed that females that produced ephippia in the autumn have less reserve energy at that time, than those  spending the winter as adults. Furthermore, Lampert et al. (2010) hypothesized that females can exhibit a mixed strategy, first produce ephippia, then spend the winter in an active state. Hamrova et al. (2011), however, found strong clonal variation among populations regarding their reproductive strategy during unfavourable conditions. Thus, high food density appears not to be a prerequisite for adult females under ice in winter, but perhaps rich winter conditions may improve the survival of the adults during winter. Larsson & Wathne (2006) reported high mortality towards the end of the winter in oligotrophic, alpine lakes and assumed that this is due to lack of reserve energy in support of your hypothesis.
References
Hamrova et al. BMC 2011 11:231
Larsson & Wathne (2006) Arch Hydrobiol 167: 265-280
Lampert et al. (2010) in oligotrphic mountain lakes. Limnol. Oceanogr., 55(5): 1893–1900.
Bror
• asked a question related to Aquatic Science
Question
looking the types of fishes and crabs that exist on our rivers and sea... as we know sea water is salty but some species are able to survive.
Salinity has a huge effect on what species can exist in aquatic environments.  This subject is well documented and many papers can be found on sites such as google scholar.
Salinity can be natural, such as sea water and estuaries where incoming sea tides mix with outgoing freshwater's of river systems. There are some species that can adapt their bodies accommodate these salinity fluctuations.  Salmonids such as salmon and sea trout are good examples of this and migration from sea to freshwater is an essential part of their life cycle.
Salinity changes in aquatic systems can also be attributed to non-natural influences.  Climate change an water flows alter the speed of desiccation which then changes the water composition.  Reduced water, especially in rivers with dams or in areas of changing climates can increase the concentration of salinity.
Hope this gives you a few ideas to start looking.
Good luck
• asked a question related to Aquatic Science
Question
I want to collect samples on both benthos and aquatic insect's
Dear Andem,
Unified standard procedure for every purpose doesn’t exist. Why? You have to do with different water bodies, basins, artificial ponds, marine, shallow and deep water habitats. So, should limit the circle to the object.
1)      Object. Creek, spring, river, pond etc.
2)      Sampling net. Upper reaches, middle, lower if watercourse, transect over the pond or lake.
3)      Sampling station amount is depending on scale (size) of object.
4)      Frequency of sampling. Depends on the main goal and aims of study.
5)      If monitoring: short term needs mass sampling, long term should select basic stations, and other like control. Should cover seasons. Winter is  the very important as sometimes in running waters of esp mountain areas life is very active this period. Even primary production is maximum!
6)      Minimum sampling to have dynamic is 5-6 per year.
7)      For taxonomic purposes may be not so frequently but find not typical biotopes.
8)      If lake or pond should use Petersen or other sampler. If brook or stream – can use plastic (better) or glass jar with scaled area of sampling. For pebble we are using the following method: clean the stone from both sides by tooth brush in photo (or other) flat small basin, and measure its volume (sample) to have possibility to recalculate for the area.
9)      Use subsamples from this sample to calculate in camera. We use Bogorov camera for larvae of insects.
10)   Can fixate by formaldehyde or investigate alive, though keep in freezer.
11)   Calculate all, should immediately identify into groups, specimens should store in concave glass in solution of glycerin to avoid desiccation.
This approach gives you possibility to differ different trophic  levels and groups that is extra important in Hydrobiology, eg.  to differ  predators  incide taxocoenosis, level of consumption of primary production at al.
If good identification minimum into Genera, so can use automativ regime of calculation (if have some program). We have in DOS turbo-basic  elaborated with perfect database.
I hope, it will help.
Andrey
• asked a question related to Aquatic Science
Question
I am concerned if there is any formulated diet may it be commercial or experimental that is available for seahorse?
• asked a question related to Aquatic Science
Question
Hi all,
can anyone identify this coral species please?
best regards
Deepak
This could be Tubastrea sp belonging to Dendrophyllidae family. However, skeletal structure needs  to be studied for confirmation.
• asked a question related to Aquatic Science
Question
Hi everyone,
I am working with Daphnia magna and meet serious problems:
1/ 24 hours after feeding, medium started to be oily and have opaque light green (fig 2).
(3 months ago, I fed the same concentration of food (Chlorella vulgaris and YTC) but medium have very clean light green color after feeding 24 hours).
Concentration of food can be clearly observed in fig 1.
2/ Daphnia suddenly have smaller size than before although feeding is same.
3/ Daphnia have many eggs (brown eggs) but they stay long time in brood chamber until turn into "white eggs" (white color) (fig 3) and broken (death). So they can not hatch into babies.
Maybe it's caused by brood parasites? How can we solve this problem?
I am very thanksful for your help.
Dear all helpers,
I finally found out that my problem is in algea.
I tried to put 4 beakers as follows to check my troubles:
1/ only daphnia water
2/ daphnia water + YTC
3/ daphnia water + algea
4/ daphnia water +YTC +algea
then put all 4 beakers into chamber for 2 days. But no thing strange happen, so at that time I can not find the solution.
After that, I kept feeding old algea and changed new YTC but culture condition was still not good.
Then I kept feeding old YTC and changed new purchased algea (normally I use my available algea inoculated in my lab). Fortunately, daphnia population recovered strongly with many eggs/ clutch, and the babies after hatching swim activately.
Condition is still good until now.
So recently I  just try to overcome algea culture system while still use purchased algea for my daphnia's safety ^^
• asked a question related to Aquatic Science
Question
I am searching for an organism that is also easy to breed in the aquarium and reproduces relatively quickly (say up to 2 or 3 months is ok). I am open to both salt- and freshwater organisms!
I agree with Ana and Kantha. I would also suggest larval stages (pelagic stages) of species such as lobsters, carbs and bivalves which are really sensitive to acidification (decalcification etc..) Cheers,
• asked a question related to Aquatic Science
Question
Hello!  I would like to carry out experiments with live bithyniids (Bithynia spp., especially B. tentaculata and B. leachii), but I would need to separate the sexes for meaningful population dynamics analyses.  Is there a reliable way to separate males from females in vivo (based on either or both shell or soft body morphology) without damaging the snails?  I need them in good health for my experiment!  :)  Thanks a lot!
Dear Paolo,
According  Chitramvong (1989), the sexes of bithyniid snails may be determined as follows:. "The apexes of the snails' shells are  struck (with the right side of the snails up) into plasticene or modelling clay placed around the margin of a petri dish filled with dechlorinated water. Then, when the head-foot of the snail protrudes from the shell during the snail's attempt to right itself, the presence or absence of the relatively large verge (male intromittent organ) can be seen clearly. Males and females can then be marked appropriately."
Best regards and good luck in your studies!
Hudson
• asked a question related to Aquatic Science
Question
I am looking for any studies that has analysed what happens if a marine reserve is again opened to fishing. Any tips highly welcomed?
Hi Natalie and thanks for reply
Yes, it is a lot of studies of the effects of marine reserves. We are working closely with municipalities here in Norway to implement coastal marine reserves. However, the politicians (for obvious resons) want to have a time limit for how long the reserves should last. It would therefore be of interest if it was a good study out there documenting the effects of opening up a reserve.
• asked a question related to Aquatic Science
Question
We are planning to buy a new licence for Ethovision from Noldus, but we are not sure about its practical use for crayfish and fish.
I believe that it is useful, and we hopefully buy it.
Thank you very much for information.
Milos
• asked a question related to Aquatic Science
Question
I need some information on weights for marine investigations. Can you inform me - what types of weights do you use aboard research vessels at the sea? Are there any weights with resolution 0.1 g or higher? We used Pols with such resolution long time at PINRO, but now Pols is not exist. I will grateful if you can provide model name and producer (and site where it will be possible to see it).
Here in our lab at Cadiz we own one Pols scale with 0.01/0.02 g resolution, up to 0.130 kg.
This scale, under our usual sea conditions and ships performs reasonably well and we use it mainly to weigh anchovies and sardines and their gonads as well as many other species when appropiated. 0.1 g resolution is also used, mainly for mackerel, horse mackerel and friends up to 1.3 Kg I seem to remember (with triple resolution range, 0.1, 0.2 and 0.5 g)
Unfortunately Pols not longer exists (was, among others, phagocited by Marel) and it looks like Marel is not much interested in producing "high resolution", scientific grade scales. They are stuck to 3000 scale divisions so the highest resolution you can get from them is, as P. kainge has pointed out before is 0.1 g up to 0.3 kg.
And yes, they don't list the 0.1 g scale in the web but it exists for sure. We are on purchasing two marine scales for the lab this year and this ws one of the candidates. By the way, the actual name of the model is M2200 with platform PL2220, 0.1 g 0-300 g
Best regards
• asked a question related to Aquatic Science
Question
I am looking to find the latest techniques in breeding trout
• asked a question related to Aquatic Science
Question
I'm trying to calculate secondary production of freshwater benthic communities. Some times (nearly in 50% of cases) I got negative numbers. Does it means that destruction in bigger that production?
I'm want to understand if I have done the mistake or not.
@Irene: I reiterate that the formula does not work.
When you use B to estimate P (the P/B method), predator consumption is already accounted for (they ate some of the B of the non-predators). So the production available to fish is the sum of the production of predators and non-predators.
• asked a question related to Aquatic Science
Question
We use a short range DIDSON in Redwood Cr, and a long range ARIS in the Mad R. Redd surveys are independently counted in Redwood Cr. To date (3 yrs of data), we are not seeing any agreement with sonar counts and redd counts for Chinook salmon and steelhead trout. The redd counts are negatively biased, even if you take into account that not all salmon passing the sonar beam will spawn (pre-spawn mortality). I know there is similar work on the Secesh R in Idaho, and I am wondering if any other place has a similar study going on and what their results might be.
We contract annual redd surveys of spring Chinook salmon through Oregon Department of Fish and Wildlife. I PM'd you the POC as well as a DRAFT report. Typically to estimate the escapement for a reach the redd count is multiplied by 2.5. This conforms to the negative bias you are seeing. However, we don't have DIDSON monitoring, and instead use the video counts at barrier dams.
What is interesting is that the productivity and effective population size of fish transported above our projects can vary widely by watershed . We are monitoring this through parental based genetic studies. In one basin we transport over 500 adults yet the number of individuals contributing to the cohort for that brood year number lass than 100. This is likely due to a combination of PSM and losses during incubation. It is likely that the interbasin variation is likely due to the hydrological and geological differences. Our lowest performing subbasin has the combination of large floods during incubation, combined with a river channel that has a lot of bedrock.
We also have done a lot of investigations into pre-spawn mortality which I can provide if it would be useful.
v/r,
Griff
• asked a question related to Aquatic Science
Question
Recently, I downloaded ZooImage software for image analysis of freshwater zooplanktons. I want to know if anybody has used this software and whether this zooImage software is reliable ?
thank u harris.
• asked a question related to Aquatic Science
Question
I'm currently working in an area of rapid sedimentation, and I wonder which other factors can influence the density and distribution of mangrove species? I know the tide is one of those.
On the local scale, mangroves grow best on stable, penetrable substrates in the mid to high intertidal region. Local geomorphology would influence the hydroperiod and exposure, thus processes such as propagule dispersal (contributing to tree density). Mangroves also benefit from relief from salinity stress through some freshwater input. Differences among mangrove species in dealing with these factors therefore determine their local distribution.
On a broader spatial scale, mangrove distribution is restricted by low temperature, e.g. the frequency of frost. Biogeographic factors also influence mangrove diversity - the Indo-west-Pacific region supports much higher species richness and diversity than the Atlantic-east-Pacific region.
Lastly, anthropogenic pollution, sedimentation, and 'coastal squeeze' increasingly influence mangrove distribution, growth and their long-term viability.
• asked a question related to Aquatic Science
Question
there are several advancements in the analysis and monitoring of freshwater bodies in all over world; but i need to know the current advancements in the same. like modelling, analysis, prediction, statistical applications etc., can anyone help in this regard
Hi.
Some other current tools for assessing pollution status of aquatic ecosystems includes the use of cell lines (in situ biomonitoring), use of biometric ratios and sediment toxicity screening guidelines by US NOAA.
Trends are also moving towards the use of fish early life stages/embryos for monitoring sediment toxicity.
An example of a published paper in this regards is:
Matteo Minghetti, Sabine Schnell, Michael A. Chadwick,Christer Hogstrand and Nic R. Bury (2014). A primary FIsh Gill Cell System (FIGCS) for environmental monitoring of river waters. Aquatic Toxicology 154:184–192
Hope this helps. Regards.
• asked a question related to Aquatic Science
Question
Production of live food is not up to our expectations in alkaline water. Further the dosage for use of organic and inorganic fertilisers under this condition is also not clear.
So we need to know what is the total hardness in your water. If it is around the same then Daniel might guess right to talk about CaCO3.
• asked a question related to Aquatic Science
Question
A Didson video with an amazing target:  look at the 7 m range and follow the target: https://vimeo.com/99981009
Data were recorded in a river, in Britanny (France), in September 2013.
The target is around 50 cm in diameter, roughly. It moves in the water column, in different direction from the prevailing flow (if the other, small objects drifting in the same direction, from left to right, are really indications of the current). It is below some of these objects, and sufficiently above the river bed that it still appears in the shadows of the top-left objects. The shape of the target does not change significantly with time, which might argue for a single individual (not a shoal of fish). And, with a little bit of imagination, I can see something like a fin around 10-12 seconds into the video. So it is definitely biological, and I will leave to the zoology experts of this area to answer in more details (the velocity relative to the water current, and the depths at which it moves, might be additional indicators of what exact animal it can be). Very nice sonar video, at least. Well done!

• asked a question related to Aquatic Science
Question
When working with CG-TSD to analyse OPP in river water and groundwater is there a established range of concentrations necessary to work with? The European Union have established a concentration of 0.1 ug/L of those pesticides in water.
YOu could try a series of 5 or 10 concentration from 0.1ug to 10 ug.
• asked a question related to Aquatic Science
Question
I want to know associated parameters of mercury in urban environment.
[I] Coal combustion is the single largest source of mercury emissions to the air, due to the fact that mercury is contained as a trace element in coal.
[II]Cement production and waste disposal such as medical and municipal waste incineration are next most significant resources. Incinerator ashes and discarded products dumped at landﬁll sites create another source of potential exposure to soil and water.
[III]Health-care facilities are one of the main sources of mercury release into the atmosphere because of emissions from the incineration of medical waste.
[IV]After coal combustion, crematoria are among the most
signiﬁ cant contributors of mercury air emissions .
[V] Waste streams (used products, landﬁlls, emissions
from industrial sources) ends up in the sewage sludge
that is used as agricultural fertiliser. If contaminated
with mercury, it causes contamination of soil
[VI]Mercury emissions to air is caused from:
Non-ferrous metals (Zn,Pb),pig iron & steel;Waste disposal (incineration);
Cement production;Coal combustion ;Oil combustion;Power plants
Chlor-alkali
[VII]Mercury emissions – to water:
[A] Hg also enters the environment through discharges of waste from various
Industries; the Chlor-alkali industries being the major contributors.
[B]Then there are sediments, fish and Marine mammals.
[C] Another major source is the discharge dental waste
[D] Chemically, the reactive form of Hg in auatic environments is Hg(II). Where it is present as METHYL MERCURY and the phenomenon is called METHYLATION. In the aqutic conditions, SULPHATE REDUCING BATERIA have been identified as the most important Hg- METHYLATING ORGANISMS with COBALMIN BEING THE PRINCIPAL SOURCE OF METHYYL GROUP.
• asked a question related to Aquatic Science
Question
Currently my research project is focus more on fecundity aspect of Macrobrachium rosenbergii. The research main objective is to find the comparison value of potential fecundity form the target locations. However, my main concern now is how much individual sample that I should take off? Should it be more than 30 individual sample?
You should be looking at the potential (ovarian) versus the actual (berried) fecundity, the latter being the number of eggs that are actually carried. I think it is important to compare at least 20-30 individuals throughout a size range, as egg carrying capacity would be expected to increase with size. A paper below has some methods.
• asked a question related to Aquatic Science
Question
I tried to use the box model to estimate the salt budget of Iraqi marshes, which explained by the equation concentration of salt input - concentration of salt yield (plus/minus) changes in ground water recharge/discharge. I did the calculation for 10 months period but I think there is a missing content to this equation! Please check the attached file to have a better clue. Thanks in advance
Mr. Trivedi, do you suggest that have to change the equation in this matter?
the marshes have a good amount of turbulence so i don't think there is any differences in the salinity concentration of the outlets
• asked a question related to Aquatic Science
Question
Generally how is batch fecundity expressed? Is it calculated from the total of nos. of hydrated eggs from upper, middle, and lower part (sub samples) of the any (left or right) ovary or average of the results of three sub-samples as done in total fecundity calculations.
Hi,
The easiest way is to measure the number of hydrated oocytes in a weighed sub-sample and then to extrapolate to the total weight of the ovary (gravimetric measurement).
For a new species it is advisable to do a pilot study to assess the homogeneity of oocytes in the ovary (though comparing oocyte density from different parts of the ovary)
• asked a question related to Aquatic Science
Question
I am trying to isolate and cultivate strains of prasinophytes, cryptophytes, haptophytes, pelagophytes. The idea is to use this cultures to identify pigment profile and compare to HPLC data from field samples.
There are several modern and classical approaches. If you have access to a cell sorter you can easily produce many clonal cultures. Alternatively using a drawn out pippette you can isolate these on a microscope slide or depression plate at 60-400x depending on sizes. You can do a dilution method where you do serial dilutions (say 10-1 to 10-4 and hopefully isolate a single cell), or using agar plats with appropriate media do a spread or spray isolation. All these methods are easily accessible in the literature.
• asked a question related to Aquatic Science
Question
For observation purpose some 15 juveniles were placed in air tight plastic bag.What is the maximum number of days white leg shrimp vannamei could survive without aeration, feed when placed in closed airtight plastic bag with water from fish ponds?
Thanks, your answer says about the standard that are commonly followed while packing seeds for transportation. Whereas here I collected some water from fish pond resourced with abundant phytoplankton and zooplankton.
1. Temperature was 26 deg C.
2. DO-5.6 ppm initially.
3. Since it is not filtered water, fecal matter estimation not into consideration due to other organic wastes too will be available.
4. leaving no space to fill oxygen gas and bag was knotted tightly to avoid any atmospheric contact and placed in Styrofoam box to avoid any temperature and photoperiod fluctuation.
5. Water quantity of 500ml with 15 numbers of PL60 days old.
Here I would like to know how long days at maximum this number of animals can survive and anyone carried out trials to understand and any other factors helps to withstand long duration of survival.
• asked a question related to Aquatic Science
Question
How can we quantify the seaweeds as Caulerpa sp. or lithothamnion sp. (no. of individuals per unit area) using quad rate frame for the calculation of Shannon index?
Is there any specific reason to why individuals are needed for Shannon index (H)? From what I understand it you calculate H based on S= number of species and p(i) = proportion of S made up of the ith species. Couldn´t p(i) be proportion of area covered by each species, instead of proportion of individuals?
• asked a question related to Aquatic Science
Question
In Bangalore, India as many as 10 indigenous endangered fish can be found
Soon i will provide the names
• asked a question related to Aquatic Science
Question
I want to study on benthic invertebrates and their relation on shrimp
catch, but how i can estimate the relation? What statistical test should i
use? Is there any statistical way to estimate a model with data of
shrimp catch and biomass of benthic invertebrates?
You can try to use the regression analysis in the beginning, not only linear regression. It is more interesting if you can suppose any biological relation. Shrimp catches depend on fishery too
• asked a question related to Aquatic Science
Question
I am interested particularly in assessment of ecological status of hypersaline lakes according to the WFD. If there is a full description of a method based on aquatic macrophytes, I would be grateful. Any suggestions and commets concerning status of hypersaline lakes and/or reference conditions are also welcome.
Thank you - the paper is focused on ephemeral acid-saline lake, while I am working with hypersaline water bodies. But it was interesting to read the article!
• asked a question related to Aquatic Science
Question
I would like to use Ceriodaphnia cornuta and Bosminopsis deitersi for a series of experiments but the problem is that they tend to die within a week. I'd used "aged" tap water & distilled water as the culture medium. I monitored the pH, temperature etc. but still can't figure out what's the real problem. Any suggestions?
If you need an artificial medium, try this:
Klüttgen, B.; Dülmer, U.; Engels, M.; Ratte, H. T., ADaM, an artificial freshwater for the culture of zooplankton. Water Res. 1994, 28, (3), 743–746.
It works perfectly with Daphnia and Moina species.
• asked a question related to Aquatic Science
Question
Decreased light transparency is often associated with higher biomass/chlorophyll production and consequently reduced euphotic zone.
good luck...I believe you will not be disappointed. And please give us the feedback
• asked a question related to Aquatic Science
Question
Limited material preferable, power equipment unfortunately not a viable option
You could potentially use over the stream to induce a greenhouse, causing warming. However, you would probably need a pretty long reach of this warming setup as the water is (obviously) continually renewed. Many terrestrial climate change studies use plexiglass roofs to artificially increase temperature, but they don't have to deal with running water.
• asked a question related to Aquatic Science
Question
I want to conduct lab experiments on sediment nutrient fluxes under aerobic and anaerobic conditions.
Hello Pamela, I have used polycarbonate and acrylic to incubate sediment and seawater for metal and oxygen fluxes, I would expect either to be a good choice for macro-nutrients (nitrate, phosphate, silicate) too, as we routinely collect good nutrient data from sediment pore waters with these materials. Do beware of subtle variations in wall thickness of extruded acrylic however, (e.g. gravity core liner), which can affect the integrity of o-ring seals used to eliminate oxygen for instance... For this reason, polycarbonate would be my preferred option. Good luck.
• asked a question related to Aquatic Science
Question
Need some equipment that will measure these in an aquatic environment
Dear Pamela,
there is also a quite new/ less used application for field measurements based on the classical photometric analytical procedure. Deppending on your facilities in the field it is a good and quick option, of course you have to take the samples the classical way, but within one hour after sampling you could have results for all parameters.
Look into the papers "Miranda, K.M., Espey, M.G. & Wink, D.A. 2001. A Rapid, Simple Spectrophotometric Method for Simultaneous Detection of Nitrate and Nitrite. Nitric Oxide-Biology and Chemistry, 5, 62–71."
and "Laskov, C., Herzog, C., Lewandowski, J. & Hupfer, M. 2007. Miniaturized photometrical methods for the rapid analysis of phosphate, ammonium, ferrous iron, and sulfate in pore water of freshwater sediments. Limnology and Oceanography-Methods, 5, 63–71."
• asked a question related to Aquatic Science
Question
why is S. galilaeus one of the tilapiine species with a high occurrence or likelihood of hybridization? is there an ecological reason?
Is there a relationship with its wide habitat range and adaptibility and its tendency to hybridize?
• asked a question related to Aquatic Science
Question
Otoliths and vertebrae are common hard parts used to age fish, are there other ways of estimating fish age?
There is a simple method based on lenght frequencies.
Here you will find a comprehensive explanation:
• asked a question related to Aquatic Science
Question
What are the different target organs of lead and its mechanism of action of these different organs?
I've got your e-mail message and will send you 1pdf and 2 links tomorrow.
Good luck!
• asked a question related to Aquatic Science
Question
I have received information that a fishing club has been encountering large numbers of freshwater jellyfish in a dam in NSW, Australia. These organisms are considered to be rare and little is know of there biology and ecology.
Hi Matt, I have been working with the freshwater jellyfish and I still try to keep track of new records. Can you give me more detail on the location? And ist there any way to determine their sex? It would be at this point quite unncessary to mail them to Germany, but maybe you or someone else could take a close up pic of the jellyfish especially the gonads? Greetings Gisela
• asked a question related to Aquatic Science
Question
Specifically those used to handle grab sample data, but ability to handle "continuous" data would be a distinct advantage. Which products work, which ones allow integration with hydrometric data or databases, and how good are the GIS and visualisation tools?
Hi Neale
I've added some information on a water quality database package developed in Tasmania (in association with EPA and Bureau of Meteorology) that could be suitable for your needs. The information below is provide by Daniel Ray, from Aquatic Science, who co-developed and maintains the software (dray@aquaticscience.com.au). Please feel free to contact him if you have any further queries, or would like to be put in touch with an end-user for a reference (industry, EPA, or NRM groups)..
"The Schooner software package is a water quality database system that has been developed specifically for water quality data. The Schooner Package is made up of 3 sub programs called Splash-Back, Eddy and Spigot. The Splash-Back program enables users to run queries and carryout rapid and sophisticated analysis of the water quality data. Users that import data onto the database will also have to become familiar with the Eddy and Spigot programs.
The database handles grab or "point" data, depth profiles, time-series and calculation of mass loads.
The following webcast describe some of the functionality of the Splash-Back program, which is written with vba (Excel) and also utilises IDL for graphics.
The webcasts are 2 to 5 minutes each.
Introduction and ‘Parameters over Time’ analysis
‘Parameter versus Parameter’ analysis
‘Data Summary’ analysis
‘Multi-site Data Summary’ analysis
Multi-site box and whisker
Multi Date Range box and Whisker analyses
Depth Profile Analyses:
Multi-Parameter Depth Profile Analysis
Multi-Site Depth Profile Analysis
Multi-Date Depth Profile Analysis
The ‘Eddy’ and ‘Spigot’ program facilitates the rapid import of data from a wide variety of data outputs. Eddy is written with vba within Excel and utilises Excel functionality to enable the efficient handling of data while ‘Spigot’ is a java based program ensure that data integrity rules are strictly adhered to. The following webcast is an example of depth profile data being imported into the system.
Spigot also enables the manual entry of data and the calculation of mass loads (fluxes) from both spot flow measurement and time series data. Once mass loads are generated they can be viewed and analysed by Splash-back in the same manner as concentration data."
• asked a question related to Aquatic Science
Question
I was wondering if there is any website or portal where I can get information on the specific locations of marine aquaculture farms in Europe, as well as on their production per year.
Hi,
I dont know if this helps, but:
All aquaculture production businesses and authorised processing establishments are to be authorised, and Member States shall establish a publicly available register containing information on each farm, including information on the species kept and the health status of the farms as regards the diseases listed in Annex IV to Council Directive 2006/88/EC.
The link to Member States and EFTA states' web pages with register of aquaculture production businesses and authorised processing establishments in their territory can be found below:
All the best!
• asked a question related to Aquatic Science
Question
In a experiment, I have to estimate chlorophyll before and after the experiment and estimation cannot not be done at the same place.
So, is it possible to preserve the spirogyra (in what preservation and for maximum how long) for the later estimation for chlorophyll? Although I know, its good to estimate the chlorophyll content at the same time otherwise the chlorophyll content starts degrading.