Tag Archives: environmental

Using eDNA to Avoid Being Eaten on the Job

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Image Credit: pxfuel, CC0 1.0, Image Cropped

Monitoring the silver carp invasion in Africa: a case study using environmental DNA (eDNA) in dangerous watersheds (2020) Crookes et al., NeoBiota, http://doi.org/10.3897/neobiota.56.47475

The Crux

One thing the last two months have taught us all is that testing for a problem is crucial. The earlier you catch a problem, the more of a chance you have to stop that problem spreading. Coronavirus is one example, invasive species is another. Detecting an invader arriving early on means you can potentially remove it before it has become properly established, saving millions of dollars down the line.

But often testing isn’t practical. Take freshwater environments. Sometimes a river may be hard to get to. Sometimes it may be infested with crocodiles and hippos. Makes regular testing methods like electrofishing or gillnetting a bit tricky.

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Studying Sustainability in Norway  

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Image Credit: Alexey Topolyanksiy, Public Domain, Image Cropped

The Norwegian Aquaculture Review Council is an academic collective comprised of NTNU students Danielle Hallé, Myranda O’Shea, Bastian Poppe, Emmanual Eicholz and Peter Anthony Frank.

I think it’s fair to say that most of Norway looks like the postcards. If you can peel your eyes away from the views, you’ll notice the aquaculture sea cages along the fjords, sheep grazing in the outfield, the seemingly endless network of trails, wind parks off in the distance, or a happy forger with a bucket full of mushrooms. The natural landscape offers myriad, well-utilized benefits, which makes for an interesting location for studying sustainable development and our coexistence with nature. The course The Sustainable Management of Ecosystem Services at NTNU offered an opportunity to do just that.

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Using eDNA to Monitor Fish Dispersal

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Environmental DNA is a hot topic in biomonitoring. But what is it exactly, and how can it be used to monitor the dispersal of a reintroduced fish species? (Image credit: Gunnar Jacobs, CC BY-SA 2.0, Image Cropped).

Guest post by Christopher Hempel

Using environmental DNA to monitor the reintroduction success of the Rhine sculpin (Cottus rhenanus) in a restored stream (2019) Hempel et al., PeerJ, https://peerj.com/preprints/27574/

The Crux

The term “environmental DNA (eDNA)” is currently booming in molecular ecology. But what exactly is this technological marvel? Essentially, eDNA comprises all DNA released by organisms into their environment, and originates from mucus, scales, faeces, epidermal cells, saliva, urine, hair, feathers – basically anything an organism might get rid of during its life. The eDNA can be collected from the environment, extracted, and analyzed to detect species using molecular approaches. As this is a very sensitive and non-invasive approach, it is a very hot topic for biomonitoring.

eDNA can be collected from any animal (in theory), but aquatic organisms in particular have been shown to be good target individuals (as eDNA is easiest to handle in water samples). Consequently, there are many studies using eDNA to monitor the activity of fish, reaching from the presence of invasive species to the effects of aquaculture. Here, we applied eDNA analysis to monitor a reintroduced fish species, the Rhine sculpin. The sculpin’s poor swimming ability make it useful as a bioindicator of the passability of streams and rivers. We wanted to investigate the potential of using eDNA to monitor the dispersal of the species in a remediated stream on a fine spatial and temporal scale.

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Towards Gender Equity in Ecology: Part Two

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Professors Amy Austin, Eva Plaganyi, Anne Sverdrup-Thygeson, Prue Addison and Johanna Schmitt (not pictured) share their views on gender equity in ecology (Image Credit from left: Amy Austin, CSIRO, NMBU, Synchronicity Earth; All images cropped, CC BY-SA 2.0)

In Part Two of our ongoing look at gender equity in ecology, four prominent female ecologists share their thoughts on how gender equity in ecology has progressed, and where it needs to go from here.

For Part One of this series, click here.

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If You Can’t Stand the Heat, Get Out of the Pond

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Dragonflies like this Western Pondhawk female are particularly vulnerable to warming due to climate change. (Image Credit: Eugene Zelenko, CC BY-SA 4.0, Image Cropped)
Simulated climate change increases larval mortality, alters phenology, and affects flight morphology of a dragonfly (2018) McCauley et al., Ecosphere, doi:10.1002/ecs2.2151

The Crux

Climate change is something that we hear about on a daily basis. The dire warnings tend to concern sea levels rising and temperatures varying so much that we have more intense and deadly storms than before, but these are all direct effects of the climate. Another thing that climate change can do is have indirect effects on organisms.

Organisms with complex life cycles spend the juvenile part of their lives in one environment before moving on to the adult stage in another environment. The researchers in this study wanted to know how simulated climate change during the juvenile stage of the organisms lifetime could affect the adult stage.

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Changing with the Climate

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An immature female blue-tailed damselfly (Ischnura elegans)

An immature female blue-tailed damselfly (Ischnura elegans) (Image Credit: Charles J Sharp, CC BY-SA 4.0, Image Cropped)

Signatures of local adaptation along environmental gradients in a range-expanding damselfly (Ischnura elegans) (2018) Dudaniec et al., Molecular Ecology http://doi:10.1111/mec.14709

The Crux

Terrestrial organisms aren’t always stationary entities, they often move around the landscape searching for food, potential mates, or more ideal environments. Over time, these movements may introduce the species into new environments, as some change allows the species to expand their historical range.

An interesting aspect of this shifting of the species range is how the organisms at the edge of the distribution are maladapted to the novel environments, as most of the species will be adapted to conditions at the core of the species range. To overcome this, they must adapt to the new conditions. Successful adaptation is dependent on changes in gene frequencies away from the historical genotypes, with an increase in genes that promote survival in the new habitats. The authors in this study used molecular techniques to identify genes that new environments might select for.

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