Drought, the “creeping disaster”

 An interview with Senior Research Fellow, Professor Sam Lake

Karin Holzknecht spoke to Professor Sam Lake about his Fellowship, his research, and about Australia’s “creeping disaster”: drought.

To begin, could you please summarise your experience of being a Land & Water Australia Senior Research Fellow?

The Senior Research Fellowship was a wonderful opportunity to direct my attention to researching the impacts of drought on aquatic ecosystems. Throughout my academic career I’ve been interested in the impacts of disturbances, such as floods and pollution, on aquatic ecosystems. I became interested in droughts because my stream restoration experiments in 1997 were compromised by the streams drying out.

No one has previously attempted to pull all the literature about the impact of drought on aquatic ecosystems together, so I spent the first part of my fellowship finding the relevant research. Having the time to track down and read that large amount of material was a great impetus for me to think comprehensively about drought. Instead of rushing around giving lectures, marking exams, going to meetings and so on, the fellowship allowed me to sit in libraries and track down material. Some of the themes from this research and literature synthesis came across in the report I wrote for Land & Water Australia at the end of my fellowship.

In your 2006 report for Land & Water Australia you said that despite the frequency of droughts in Australia, this country is not a leader in drought science. Is that still the case?

Yes, that is still the case. There has been a lot of excellent research on Australian agriculture and drought (drought-proofing crops etc), and the climatology of drought has been well researched, but the knowledge of what drought does to natural ecosystems is not there. That is surprising, given that Australia is the most drought-prone continent in the world. In no way can we be said to be leading the world in any form of drought research. The stand-out leaders in drought science are the Americans.

For example, a group at the Lamont-Doherty Climate Centre (based in Columbia University, USA) has been looking at the likelihood of droughts with climate change. They are saying the mid-temperate zones in America are going to be the worst hit with droughts. If you transpose that to the mid-temperate zones of Australia, we are slap bang in the middle of it. I hate to be a doomsayer, but things may be going to change dramatically and we have to start getting ready for it now.

One of the problems with Australia is that we tend to be re-active to droughts. We don’t anticipate a drought in our planning. Instead of reacting we should be proactive. We know invariably that we’re going to have droughts, and that water demand is going to go up, whether by cropping, industry or urban development, so we have to start thinking now about how we can obtain more water and manage water without damaging aquatic ecosystems.

We need to realise that drought is going to be with us in terms of climate change. Droughts may become longer, or more frequent, or deeper, and surely it is time we started a similar initiative to the Americans—put meteorology, climatology, sociology and ecology together so we can see the whole impact of drought and we can see and implement ways to adapt to it.

To an extent, I think that the irrigation industry has been more responsive and proactive than urban authorities. In the irrigation industry a lot of farmers are really taking a hammering, but they are surviving and adapting, whereas the government is tending towards band-aid solutions at the moment. If that is a symptom of the way we are going to deal with climate change we could be in real trouble.

In your report you also say the public attitude to drought in Australia is changing. Do you still see evidence of this?

Yes and no. The past attitude about drought in Australia has been that as soon as it passes everyone forgets. Rather than saying, “well, that drought is gone, but we had better start planning for the next one”, we tend to say, “well, that drought has gone, and now it’s back to business as usual”. The Americans call the latter behaviour the ‘hydro-illogical cycle’—we become aware of a drought, become concerned about the drought, panic about the drought, and then the drought breaks and we go back to a state of apathy. The panic and concern switches off instead of driving change. The severe drought in 1982-83, culminating in Ash Wednesday and the ensuing floods, triggered the beginnings of a change in public attitude—people started to think about the damage a drought can do and how we could better prepare.

However, the fact is we have more energy invested in dealing with floods than droughts. Flood control is a major industry, with levies and dams and strengthening dams costing millions of dollars. But how much energy is going into anticipating and preparing for drought? The problem is that urban communities are quarantined from drought—we still get water down the tap. We may have grade three restrictions, the price of food and particularly vegetables may go up, but there is no great problem. We are immune from drought in the city: we get a sense of it on hot days, but we just switch the air-conditioners on. It is the people in rural communities who are aware of drought, the ones who have sheep and cattle without feed and water, who have wilting grapevines and burnt off crops.

Most of your research for Land & Water Australia was focussed on how drought affects aquatic ecosystems. Could you tell us about that?

Droughts are a winnowing process: some species get knocked down, some are rendered locally extinct. The most obvious example is the effect drought has on fish populations with populations being severely reduced. Droughts can be such extended disturbances that some aquatic organisms do not have effective adaptations to handle them, whereas others have an array of adaptations to allow them to survive droughts, even though their populations may be severely depleted. Droughts take water out of the stream, to the point where flow is stopped, and in that case, the organisms in the remaining pools are affected by water quality problems: de-oxygenation, high levels of nutrients, high water temperatures.

We know some fish and other aquatic populations rely on refugia—places where water persists through a drought—for their survival. These refugia are by no means ideal, however. Fish and other organisms seeking refuge are faced with the water quality problems, along with predators and an increasing number of parasites and diseases. Refugia are essential for fish to survive drought, but we don’t fully understand the recovery process.

We do know recovery may be hindered by dams and barriers across streams. Overseas studies suggest one essential part of recovery is movement or migration back into previously occupied areas. Not only have we extracted too much water from rivers, making them more drought-prone, but we have also made it harder for fish to respond to and recover from drought by putting barriers and locks in the rivers. We have to think of the impact of drought in the context of what humans have done to the river systems and wetlands. We have greatly reduced the impact and frequency of resuscitating flood events. We tend to think of rivers as single channels, when actually these rivers need to flood to stay healthy. Heavily regulating rivers makes it harder for aquatic ecosystems to survive even without drought.

Any ideas on how we could fix this situation?

It is complex, and we have been running away from the problem because it presents so many difficulties. One strategy currently being tried is installing fish ladders in weirs to alleviate the problem. We can also be more strategic with environmental water, if we can find any. Another option is to try and change the attitude of land-owners out on the floodplain who are resisting flooding. Think big! We could do what America has done with the Mississippi—buy back the land, so we can flood it. In our new economy, it may be that such conservation measures will be more economical than current forms of farming.

Why should we care about droughts and their impacts on rivers and aquatic ecosystems?

It comes down to this: do we care about Australia? Having healthy rivers and ecologically sustainable landscapes is part of nationhood, part of what we want our country to be. Do Australians want a land where the rural landscapes are bare, bereft and unproductive? I don’t think they do. Look at real estate values—people are willing to pay a lot of money for rural landscapes, for river access, for coast and sea access. We unconsciously show our preferences, but do not consciously accept the challenge in planning our society to maintain ecologically sustainable landscapes.

Having said this, there is always a bright side. The good thing about the current drought is that people are thinking more intensely about the issue. Climate change has captured a large part of the public imagination, and even the political imagination. We need some adroit, careful leaders to steer this societal awareness into building more ecologically sustainable communities and environments. Politicians need varied advice across a broad spectrum of problems so they can weave their way through this complexity, rather than just being persuaded by the expedient and the short-term solutions. It is certainly a challenge but hopefully an answerable one.

Finally, could you tell us a little about the book you are working on?

The book will be examining the impacts of drought on flowing water, standing waters, wetlands, riparian zones and estuaries, and how humans exacerbate drought. The book is funded partly by a grant from the Commonwealth Environment Research fund. Hopefully, it will be finished by the end of the year (December 2009).