Tag Archives: freshwater

The Summer of the Russian (Fish) invasion

Title Image Credit: Earl Steele, CC BY-NC-ND 2.0, Image Cropped

Every time fighter jets fly overhead here in Central Norway, either my wife or I nearly always make a dry remark about the Russians finally invading. It’s a slightly dark reference to former Norwegian occupations, but not something that’s likely to occur anytime soon.

Yet this summer, the papers were filled with constant sensational references to very real and ongoing Russian invasions. Luckily, they’re referring to the pink (or humpback) salmon, and not to any human army marching across the borders.

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The Stream Microbiome: An Ecosystem’s Health Report Card

Image Credit: mstk east, CC BY 2.0, Image Cropped

Thanks to DNA sequencing, there is no escape from the reality that every organism is an ecosystem. I like to think of myself as an individual human organism but actually, I am a holobiont, playing host to thousands of other species. Back in college, my body was an ecosystem in distress. A diet of coffee, beer, and bagels coupled with a steady dip of stress led to a series of health issues and an eventual diagnosis of ‘dysbiosis’. Dysbiosis is a term that describes a loss of microbial biodiversity or departure from a balanced ecology.

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How Influential is the Platypus in Freshwater Dynamics?

Image Credit: Maria Grist, CC BY-SA 4.0, Image Cropped

Platypus predation has differential effects on aquatic invertebrates in contrasting stream and lake ecosystems (2020) McLachlan-Troup, Scientific Reports, https://doi.org/10.1038/s41598-020-69957-1

The Crux

A trophic cascade occurs when a predator’s effects of its prey goes on to affect ‘lower’ levels of that ecosystem. A great example is the effect that sea otters have on kelp: the sea otters prey extensively on sea urchins, which in turn increases the populations of kelp, which the sea urchins prey on. While this is a result of direct predation by otters, often this can occur through a prey species changing its behaviour to avoid the predators.

Yet most ecosystems are more complex than a simple three-level trophic system. Cascades are therefore more likely to occur when the ecosystem is less complex, or when there are well-defined relationships between species, as a result of a predator having preferred prey species or only a few groups of species making up an ecosystem.

This week’s authors investigated how the platypus (our recently-found-to-be-fluorescent friend) influences the abundance and species richness of invertebrates across both rivers and lakes, and whether it’s capable of affecting an ecosystems algae and sediments as well.

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Rebuilding Our Relationship With Urban Rivers With Dr. Cecilia Medupin

Rivers have played a monumental role in determining where people live. Their importance in providing water, transportation and a raft of other ecosystem services has meant that even today most of the world’s largest cities are situated close to a major source of freshwater, from Sydney to Delhi, Quebec to Karachi.

Yet despite their role in our history, urban rivers today are often facing increasing levels of pollution as a result of human activity. As well as often being a huge tourist drawcard, and an ongoing resource for fishers, joggers and portable BBQ toters, freshwater ecosystems carry a disproportionate number of aquatic species, which makes this trend increasingly worrying.

After meeting at last year’s British Ecological Society Annual Meeting, I got in touch with Dr. Cecilia Medupin, a freshwater ecologist at the University of Manchester. Cecilia works to increase peoples understanding of rivers, including the project Our Rivers, Our City. I asked Cecilia abut our connection with rivers, the challenges they face, and how to inspire research and change in urban rivers.

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On Fish Dispersal and the Perpetual Evil of the Duck

Image Credit: Norbert Nagel, CC BY-SA 3.0, Image Credit

Woe betide my fishy ancestors, for I am come here today to vent my grievances at a paper so dastardly it has cast a tepid patina of anxiety on a LOT of the structured squabbling my colleagues and I call ‘research’.

Actually, I shouldn’t vent too harshly on the sarcopterygiites, those ancient lobe-finned ancestors of ours and their close cousins the regular fish. Birds, as always, are the main culprit here. An abhorrent series of mutations that messed up a perfectly good reptile.

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The Mystery of the Sabertoothed Salmon

Image Credit: Jacob Biewer, Sankey et al., 2015

The charisma of enormous, slashing teeth is undeniable. Despite the fact that there are a myriad of fascinating prehistoric carnivores, the big mammals that the documentaries, big-budget films and kid’s shows seem to come back to are the sabre-toothed carnivores. Massive slashing teeth are actually a trait that has popped up a lot over the course of the Earth’s history, with at least three different groups of cat or cat-like mammal evolving them as a hunting mechanism. As well as a fish.

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The 2020 Oikos Write-Up: Ecology in the Anthropocene

My lord Iceland is gorgeous. There could not have been a better setting for the 2020 Nordic Oikos Society’s Annual Meeting. Driving through deserts of snow that ring of the kind of quiet isolation you’d expect from a town in a depressing British murder mystery was a wonderful experience.

As was the conference itself, of course. So let’s recap some of my highlights from this year’s meeting, titled ‘Ecology in the Anthropocene’.

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Water-Based Recreation Can Promote Non-Native Introductions

Image Credit: Manfred Antranias Zimmer, Pixabay licence, Image Cropped

Invasion of freshwater ecosystems is promoted by network connectivity to hotspots of human activity (2019) Chapman et al., Global Ecology and Biogeography, https://doi.org/10.1111/geb.13051

The Crux

The spread of invasive species throughout freshwater ecosystems is a topic we’ve looked at before on Ecology for the Masses. In a previous paper breakdown we talked about how recreational is heavily responsible for the presence of non-native fish at a European scale.

Our paper this week takes a more local approach. Can we predict the presence of non-native birds, invertebrates and fish by looking at the presence of human activity, and where that human activity is present?

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