In 1977, on the islands of French Polynesia, government authorities released a predatory snail. They hoped this introduction would effectively control another species of invasive snail, previously introduced to supply escargot.
Instead, by the early 1980s, scientists reported alarming declines of native snail populations. Within ten years, 48 native snail species (genus Partula) had been driven to extinction in the wild.
Floods are often seen as a force of destruction. From photographs of crops under water and houses being swamped by swollen rivers, to stories of road, business and public amenity closures, the news during flooding understandably emphasises human loss.
But as river ecologists, we find it hard not to see the positive side of flooding. Why? Because although floods cause destruction, they are also creators, of which we are all beneficiaries. Continue reading →
Lupa Capitolina: she-wolf with Romulus and Remus. Bronze, 12th century AD, 5th century BC (the twins are a 15th-century addition). Palazzo dei Conservatori, Hall of the She-Wolf.
The Ancient Romans are, I suppose, best known for their ambitious and sometimes mad emperors, military conquests, rather unsavoury treatment of Christians, gladiatorial contests and their chariot races. And their roads. Oh yes, and their aqueducts. We shouldn’t forget their aqueducts! But stop for a moment and try to think of a famous Ancient Roman artwork or even type of art. Not that easy, is it? Indeed, for most people, what springs to mind when they think of Ancient Roman art, is most likely architecture. It is true that the Romans produced stunning mosaics, and the wall paintings in Pompeii are renowned, as I have described in an earlier post. But much of what we think of as ‘Roman art’ was heavily influenced by Greek culture of the Hellenistic Age. Most of the ‘Ancient Greek’ statues in modern museums are actually Roman copies of the originals. And many Greek gods and myths were simply adopted by the Romans, with name changes, of course. The Romans, busy conquering the world, filled the cultural vacuum with all things Greek and relied on Greek artists to decorate their world. But their art did evolve. And their depiction of rivers is testament to that.
Some time ago, on a warm Friday afternoon, when my mind was wandering, I was gazing vaguely at some flow graphs, trying to prepare for a lecture for my River Ecology class the following Monday. The flow graphs were from a variety of river systems around the world. Some of the rivers, like the Amazon and Mississippi, had very regular ups and downs, like a regular heartbeat. Others, like the Darling and Cooper Creeks, had some serious irregularities. But it also occurred to me that the patterns of flow looked not unlike the top part of a sound wave. You know the one – like you see when they play a voice recording on the television, to give you some visuals with the sound. It was then the seed of an idea began to germinate. Continue reading →
The news arrived yesterday that one of Australia’s leading river ecologists, and also one of the most generous, kind and wise men I have known, died unexpectedly on Saturday 27 February. Keith Walker’s work in rivers spanned more than 40 years, much of it in the Murray-Darling Basin. For many, he was ‘Mr Murray’, because of his vast experience and knowledge of that river. He lectured and researched at the University of Adelaide for more than 30 years, and was fortunate enough to work (and publish) with Bill Williams, Jim Puckridge and many, many others. Keith edited The Ecology of River Systems (1986) with Bryan Davies and was an editor of River Research and Applications for twenty years. Keith sat on many, many committees advising on environmental issues and published more than 200 peer-reviewed and other articles. He had a long interest in freshwater mussels, and was always very happy to discuss these neglected, but important, animals. I was extremely fortunate to work closely with Keith, when we co-edited our book Ecology of Australian Freshwater Fishes (2013). His strength, tenacity and wisdom during those years, I will never forget. I learned so much, and was grateful every day to have his experience and gift for writing to guide us. His encouragement and enthusiasm never flagged, even when faced with the most recalcitrant of authors. All of those who knew Keith will miss him terribly. But we will also be grateful every day for knowing, and working with, a man such as him.
This site and blog is mostly about the science of rivers, although it will include cultural aspects of rivers when they catch my eye and take my fancy. It will highlight ideas, concepts and research of interest to students, researchers and managers.
Comments, corrections and additions are encouraged.