Invasive freshwater fish (Leuciscus leuciscus) acts as a sink for a parasite of native brown trout Salmo trutta (2020) Tierney et al. Biological Invasions. https://doi.org/10.1007/s10530-020-02253-1
From house cats to cane toads, invasive species are one of the biggest threats worldwide to native plants and wildlife, second only to habitat destruction. There are a few different definitions of an invasive species, but two consistent tenets are a) that they are a living organism spreading and forming new populations outside of their native range and b) causing some kind of damage to the native ecosystem, economy or human health. As humans move around the globe with increasing ease (these last two months aside), the spreading of invasive species is increasingly common in our globalised world.
The spread of invasive species creates new ecological interactions between native and invasive species that can impact how our native ecosystems function, including disease dynamics. One key set of interactions that can be completely changed by the introduction of the invader are that of parasites and their hosts. If development and transmission of native parasites is different in invasive hosts compared to their usual native hosts, the parasite dynamics of the whole system can be altered.
Image Credit: California Department of Fish and Wildlife, CC BY 2.0, Image Cropped
Angling as a source of non-native freshwater fish: a European review (2019) Carpio, De Miguel, Oteros, Hillstrom & Tortosa, Biological Invasions, doi.org/10.1007/s10530-019-02042-5
People love fishing. It’s an intrinsic part of some people’s lives, whether as a livelihood or a past-time. People who have grown up fishing often have specific species that they enjoy fishing for. Nothing wrong with that.
Yet people’s desire to go after one fish species will often lead them to move that species around. This can happen on a small scale, with people moving a species from one lake to another slightly closer to their homes. Or it can happen on a massive one, with a species being transported to new continents.
This has shaped entire freshwater communities in modern-day Europe, where 195 species now reside that have no natural range in the continent. Most of these have been introduced since the nineteenth century, which is around the time that fishing became a popular recreational activity. This week’s authors wanted to find out what the role of recreational fishing was in shaping the make-up of today’s invasive freshwater fish populations in Europe.
Fishing is an important part of Australian society. So is communication between fish scientists and fishers strong enough? (Image Credit: State Library of Queensland, Image Cropped)
Last Thursday, I posted an article on the need for more contact communication the fish scientist community and the fishing community, which you can find here. It gives a breakdown of why better communication between the two groups is mutually beneficial, and how it could be improved. The piece was written after talks with a number of prominent Australian fish biologists, whose thoughts I’ve shared in more detail below.
Some fish scientists, like recent ASFB delegate Jarod Lyon, have regular contact with fishers who benefit from the work academics and researchers carry out on fish. But is there enough of this sort of communication between the fish science community and fishers? (Image Credit: Mallee Catchment Management Authority, CC BY-SA 4.0, Image Cropped)
When a food source provides almost half a planet with protein, you can expect the people who deliver that food source to play an important role in society. Fishing is no exception. Any country that has a marine or freshwater ecosystem in close proximity will have a fishing community, and that community can play a variety of roles, from something as simple as putting food on people’s tables to campaigning heavily to keep your country from joining the EU.
So it makes sense that fishers should have access to good fish science, at every level. If you’re a multi-million-dollar corporation, you need to know how fish stocks will respond to certain catch levels over a sustained period. If you’re a local or specialised fishing community, you need to know how available your catch will be in five years given temperature increases. And if you’re one person on a boat in a river, you might want to know how best to treat an over- or under-sized fish to ensure it survives being released.
It follows, then, that there should be open communication between fish scientists and fishers. At this year’s Australian Society of Fish Biology conference, I asked a variety of delegates a simple question: Is there open communication?