Image Credit: Isabell Schulz, CC BY-SA 2.0, Image Cropped
Salmon on the lam: Drivers of escaped farmed fish abundance in rivers (2020) Mahlum et al., Journal of Applied Ecology, https://doi.org/10.1111/1365-2664.13804
In a world with a growing human population and overfished seas, farming fish (aquaculture) could be a viable solution to our food security problems. Salmon aquaculture is already a massive industry worldwide, having grown substantially over the last half-century.
Yet the industry carries its own issues, one of which being its effect on wild salmon, which are of huge cultural importance to most lands that they’re found in. Wild salmon lifestyles see them migrate up rivers from the ocean to breed, with most salmon returning to the same rivers they were born in. Yet salmon escaping from fish farms have no spawning grounds to which to return, and can end up anywhere. This can result in deteriorating wild populations, with the farmed fish spreading disease and competing with the wild fish, as well as reducing wild fish health through interbreeding.
Because of this, figuring out where escaped salmon end up could be a major step forward for fish farms and local rivers alike. This week’s paper looks at what sort of variables lead to a river full of farmed salmon, and whether or not we can predict when and where they are likely to show up.
One of the few positives to come out of a recent spate of catastrophic weather events has been the fact that climate change is now nigh on undeniable, and more people than ever are working to prevent its future effects. Yet there are parts of the world in which climate change is more than the progenitor of random disasters, where it has become an everyday reality.
One such area is sub-Saharan Africa. Despite being one of the poorest regions of the world, it’s also a region that has enormous potential for agricultural transformation, helping to solve not only local food crises, but global ones as well. A prominent example is Kenya, where the agricultural sector contributes to over half of the Gross Domestic Product, and provides food and employment for more than 80% of the population. Working for Kenya and other countries in the region is the chance to avoid mistakes made by other regions in the past, as they benefit both from hindsight and improved technology. Yet working against them is that encroaching threat of climate change.
It’s a topic that Assistant Professor Esther Ngumbi, of the University of Illinois has been vocal about. Esther grew up on a farm in rural Kenya, and has witnessed the effects of increased drought and weather variability over the last decade. Esther’s work on food security in Africa has seen her work published in everything from the Journal of Chemical Ecology to Times Magazine.
At 2019’s BES Annual meeting, I got the chance to speak to Esther about everything from African governments to the shifting of climate baselines.
Image Credit: W.carter, CC0 1.0, Image Cropped
The farming industry has had a strange relationship with ecology over the years. They have been maligned by claims they shoot native species, suck up water greedily from nature and the people, and pollute our countryside with pesticides, all whilst producing the food many of us subsist on. So why haven’t ecologists worked with them more closely?
At the recent NØF 2019 Conference, Tanja Petersen and I sat down with Canadian ecologist Professor Andrew MacDougall, who has been working with the farming industry for the past six years to quantify their contribution to ecosystem services. We talked about the often damaging public perception of farmers, how his stereotypes were challenged by working with them, and the biggest problems the industry will face heading into the next fifty years.
On the left, a thriving wetland. The right, an arid forest. (Image Credit: Sam Perrin, CC BY 2.0)
I’m standing on the dry side of the Murrumbidgee floodplain in country Australia. I say dry side, because whilst I’m standing on the harsh, dusty platform of soil and desiccated leaves that is pretty standard for this area, 15 metres away there’s a thriving wetland environment. It boasts waterbirds, a flock of emus, thirsty kangaroos, and fish. All that’s separating the wetland and dry land on which I stand is a road, only about half a metre above water level.
The American Mink is pretty much a Norwegian mainstay these days. So what sort of impact have they had? (Image Credit: Ryzhkov Sergey, CC BY-SA 4.0, Image Cropped)
Fur farming isn’t a topic we’ve had much cause to touch on so far in this series. But today, we look at a species that was introduced specifically for that purpose, whose presence in Europe is disliked by ecologists and animal rights activists alike.