I’m not a fisherman. I can tie a few knots, but I wouldn’t know where to start with a reel and rod. I’ve never even caught a single fish. I don’t spend anywhere near as much time on boats or at the beach as I’d like. Like many biologists, I think of the world as Earth, when in fact most of our planet is Ocean.
Studying aquatic ecosystems is a difficult task: there are few fixed points, few observers, and the environment is ever changing. Measuring the effects of climate change on the ranges of aquatic species is especially tricky. Animal populations have always been on the move, and the impact of humans confounds the matter.
The complex interactions of water temperatures, currents, and chemistry make studying ocean biogeography an immensely complex task. In both terrestrial and marine environments, organisms can only live within particular environmental parameters, such as altitude, depth, temperature, salinity, and soil type. In a world where anthropogenic climate change is changing the oceanic environment, the home ranges of species are shifting.
Broadly speaking, as the polar regions become warmer, the species of the warmer equatorial regions are moving towards the higher latitudes. However, all species are reacting to the changing world in different ways, and it is impossible to monitor the mobile fishes of the sea in the same comprehensive manner as the stable plants of the land.
With these challenges in mind, a citizen science project- Redmap– is running in Australian waters seeking to learn more about how fish populations are moving around the oceans. Redmap gains its name not from the colour, but from the acronym: Range Extension Database and Mapping. Redmap connects research science experts with citizen marine nature experts: fishers and divers.
I had the good fortune of meeting Dr. Gretta Pecl at her office at the University of Tasmania Institute for Marine and Antarctic Studies, part of the University of Tasmania. The Taroona office of the Institute is several kilometres south of the capital city, and is situated in Australia’s southeastern corner looking out towards the sea.
In her studies of fisheries biology and ecological management, she is aware how difficult it is to understand change the accepted historical ranges for marine species. Unlike some species on dry land, it is near impossible to ever complete a survey that you can say confidently sampled the full range of the fish population. Their home ranges, historically and into the future, can often only be pieced together from scattered records.
She recounted that Tasmanian fishermen had been noticing the arrival of northern species such as red snapper in the colder waters around Tasmania, for quite a few years. Rather than discard these anecdotes as mere outliers, she built a system to organise and encourage attentive observers to contribute their sightings of fish and other marine species outside their historical ranges. This concept grew into Redmap. As these pieces of evidence accumulate, we have slightly more information about how these aquatic populations are moving around the waterscape.
They have published waterproof field guides and an online reference for several dozen species of interest, including some with such evocative names as the dusky morwong, the crimsonband wrasse, and the leafy seadragon. Critically, they are staying focused by not accepting data about every possible species, nor about species of interest within their accepted home range. Every animal included therefore has a geographical indicator, e.g. “if found south of Maria Island, Tasmania.”
When you visit the Redmap web page, you are greeted by a map showing the latest sightings from around Australia, along with the photograph sent in. If you encounter one of these animals, outside of their range, you can send in a photograph to be confirmed by a group of researchers with taxonomic expertise. As the project progresses, and the skills of volunteers suitably increase, Dr. Pecl envisions experienced participants potentially becoming involved in this confirmation process.
Redmap began as a Tasmanian-waters project, but its success has sparked funding to grow to an Australia-wide model. It has also expanded its scope from fish to include marine algae, reptiles, and invertebrates such as urchins. Besides winning awards from the University of Tasmania and the Zoological Society of New South Wales, the project has been covered extensively in Australian media.
Hobart, the Tasmanian city where the project is based, is home to several oceanographic and Antarctic institutions, as well as an active fishing industry and a recreational diving community. However, in both Tasmania and wider Australia, it is the recreational fishers and divers who are the largest contingent. In remote corners of the Australian coast, you can often find someone with a fishing rod, looking carefully and waiting patiently. By bringing all of these groups together, Redmap is aiming to monitor the massive, hidden, shift in distribution migrations of underwater animals as our waters warm.
You can learn more- and join the project! – by logging onto www.redmap.org.au