Carpageddon: what you need to know about the release of carp herpes in Australia

Susan Lawler, La Trobe University

Yesterday’s announcement of funding for a National Carp Control Plan – including the release of the carp herpes virus – has generated a lot of interest in the media. I welcome plans to release the virus by the end of 2018. In January I wrote an article here explaining the concept and why I think it could work in Australia.

Since the announcement I’ve listened to discussions on radio and television highlighting the concerns of the public. I hope to address some of the confusion and set the record straight.

What will we do with piles of dead fish?

Among people who live near the Murray River or one of its tributaries, this is the main objection to the release of the virus. This in itself suggests that those close to the rivers understand the implications of carp being 80% of the biomass in the Murray Darling Basin. Many people have lived through black-water events (where oxygen levels drop resulting in large fish kills) and they know how unpleasant it is to have a lot of dead fish at one time.

Their concerns are justified. Fortunately, Science Minister Christopher Pyne is aware that hundreds of thousands, possibly millions of tonnes of dead carp will need to be cleaned up, and this will require community consultation and potential legislative changes. Pyne says we can use dead carp as fertiliser, as pet food or bury them in large graves. It is interesting to note that the fertiliser company Charlie Carp welcomes the move and may expand their business into South Australia so they can respond to large fish kills there.

The trick will be disposing of the fish quickly because after 48 hours they will begin to rot and will not be suitable for use. My reading of the announcement suggests that planning for this one time big carp kill will be a large part of the $15 million spent over the next two years.

How is the virus transmitted?

There were some giggles about how this virus is transmitted among fish, given that herpes is a sexually transmitted disease in humans. However, all the fish have to do is bump into one another to transmit the virus, and they can also be infected by the virus that lives in the water, although the virus will only survive for a few days outside of the body of a fish.

Once infected, any survivors will carry the carp-specific herpes virus for life. Stress can re-activate the virus, causing it to persist in the carp population and allowing it to spread rapidly under crowded conditions.

What a waste – we could have sold these fish overseas!

It is true that Australians resist eating carp due a perception that they are “junk” fish. Some say they have a muddy flavour, or that they are too bony. Neither of these issues stop people in Europe, the Middle East and Asia eating carp, where they are a common part of the diet.

There are two problems with the suggestion that we are missing a commercial opportunity here. The first is the economic viability of shipping fish to the other side of the world. We cannot get them there alive so we will need to freeze or can the carp, and once we’ve done that, consumers must pay enough to cover the processing and shipping.

I was on a committee with the NSW Department of Fisheries 15 years ago that was looking for markets for carp products. Enthusiastic investors with support from government could not find a way to make money with this export.

The second problem is that any industry relying on carp as a product will not remove carp from our rivers. Carp are causing enormous damage to the ecology of rivers and lakes across our continent and fishing alone will never remove enough of them to return those ecosystems to health.

But biological control never works, does it?

“Myxomatosis and cane toads – need I say more?” was a text to my local ABC radio station by someone concerned about the failure of biological control in the past. Yes, cane toads were a disastrous introduction to Australia and it is now clear that the problem was insufficient research prior to release. The carp herpes virus has been researched in Australian laboratories for 7 years so far. See my previous article for more on why this looks like a safe bio-control option.

Myxomatosis actually worked beautifully, killing 500 million rabbits in two years after the first release in 1950. Resistance did increase in the decades to follow and in 1996 another virus (calicivirus) was released to further reduce rabbit populations.

The rabbit plague of 1860 onward was the fastest spread of any mammal in the world. Rabbits had an enormous environmental and economic impact right across Australia, leading us to build the rabbit-proof fence. In 1887 the state of New South Wales was offering a reward of £25,000 for any successful method not previously known for exterminating rabbits. Although srabbits were useful for food in the depression and to make lots of hats, nobody wants to return to pre-myxomatosis times.

And no, we didn’t kill all the rabbits, just like we will not kill all the carp. However, a virus transmitted by water may be more effective as suggested by the government’s goal of a 95% carp reduction by 2045.

Carp are natural by now – our native fish rely on them for food

Australian native fish have been seriously impacted by carp. Many of them are visual predators, such as the magnificent Murray Cod. The turbidity created by carp reduces their ability to hunt and thrive, even though the high biomass of carp may give them plenty to eat.

The muddy river that runs through my home town is a hazard for swimmers and boaters because you can’t see the snags. This is due almost entirely to the presence of carp. None of us can remember when the Murray River ran clear and native fish were more common than introduced fish, but Senator Anne Ruston, Assistant Minister for Water Resources, recalls her mother and grandmother talking about being able to see the bottom of the river.

If you cannot imagine why anybody cares what type of fish are living in our rivers, remember that native Australian fish and plants are not adapted to the muddy rivers we have now. Let’s give them a chance to grow and thrive again in an environment more similar to the natural situation.

Sounds like a waste of money

Our Deputy Prime Minister Barnaby Joyce says that carp cost the economy up to $500 million per year. I don’t know how he got that figure but it may include the extra water treatment we need for river towns like mine and tourism losses due to reduced biodiversity and frequent algal blooms. Even if it is only half of that, spending $15 million to remove carp from the system seems like a sound investment.

The future of Australia’s waterways are at stake. Is there anything more precious than clean, fresh water?

The Conversation

Susan Lawler, Senior Lecturer, Department of Ecology, Environment and Evolution, La Trobe University

This article was originally published on The Conversation. Read the original article.


Nature is neglected in this election campaign – at its and our own peril

Don Driscoll, Deakin University and Euan Ritchie, Deakin University

The electioneering has begun. In a campaign set to be dominated by economic issues, the Coalition and Labor are locking horns over who can best manage our finances, protect jobs and make housing more affordable. The Greens predictably decry the major parties, including their cavalier climate-change policies.

These are important issues, but are they highest priority on the political agenda? An arguably even greater issue exists that nobody is seriously championing, but which impacts all of us, socially, environmentally and economically.

Our natural heritage – the plants, animals and other organisms that help define Australia’s identity – are in dire straits. Yet this biodiversity crisis is barely mentioned in political discourse, nor is it foremost in the public consciousness.

The world economy is losing €50 billion (A$73 billion) a year through lost ecosystem services. It is predicted to lose €14 trillion per year by 2050 without action now. With potentially 7% of global economic product at stake by mid-century, nature conservation must surely be on the agenda in this election.

Actions needed to conserve our natural heritage, and reap substantial rewards, will challenge some of our most cherished ideas about social and economic policy. This demands reforms to reverse creeping losses to our democratic process.

Nature is immensely valuable, but this is rarely appropriately costed nor accounted for by governments.

Looking at the major parties’ platforms, it is clear that nature is not on the agenda. Labor lists 23 positive policies, none of which deals directly with conserving Australia’s plants and animals. The Liberal-National Party has done slightly better, claiming to believe in preserving Australia’s natural beauty and environment for future generations. However, its federal platform, released last year, shows no evidence of this belief.

Public concern has also shifted away from nature issues and towards other concerns like terrorism, as well as traditional areas of focus such as health care and the economy. This shift can be seen in some surprising places, such as the major grassroots lobby group GetUp – of its ten current campaigns only one, the Great Barrier Reef program, is directly about conserving wildlife diversity.

Environmental riches, but for how long?

The value of biodiversity to humans is well established (for example, see here, here, and here). Biodiversity reduces stress, crime and disease. It also provides new economic opportunities and many other benefits, from climate control, to flood defence, to the many benefits delivered by birds.

These are just the tip of the iceberg, but like the polar ice they are at risk of disappearing through our neglect.

Examples of the many values (ecosystem services) nature provides

Despite biodiversity’s immense value, Australia’s natural heritage is not assured. Good news stories exist,
but as a succession of government State of the Environment reports over recent decades has shown, our natural heritage continues to be squandered.

The reports cite population growth, economic growth and climate change as key drivers of decline. Land clearing and invasive species also lead to biodiversity loss. All must be addressed to reverse the alarming trajectory of our wildlife.

These threats to our natural heritage should be high on the political agenda. But despite recent extinctions, caused in no small part by a failure to act quickly on conservation advice, bureaucrats and politicians have failed to rise to the challenge. Australia’s plants, animals and other wildlife continue to be swept aside with an enthusiasm and abandon reminiscent of the 19th-century pioneers.

Why the lack of action?

Nature is missing in action from the political agenda for many reasons. Here are two key ones: questionable political donations and processes, and the gagging of the public service, government and university scientists. Both issues go to the heart of our democracy.

Australia has some of the weakest electoral laws concerning political donations and spending. Time lags between receiving donations and declaring them means that appropriate scrutiny of policy motivations, particularly at election times, is uncommon. This is concerning, because links between political favours for donors, while hard to prove, are frequently noted.

These correlations are not surprising. Corporate political activities are typically not gestures of goodwill, but a widely accepted corporate strategy aimed at securing better outcomes. Because many companies depend on using land for activities such as digging up resources and clearing native vegetation, the success of their political donations can often be reflected in damage to nature.

Equally concerning is the deafening silence from people who really know how damaging government policies can be for the environment. Inconvenient truths might challenge government policies. So public servants, including government scientists, are prohibited from speaking, or tweeting. Governments will go to extremes more often seen in the pages of crime thrillers to track down and punish whistle-blowers.

Governments attempting to silence academics hit the spotlight over cattle grazing trials in Victorian national parks. A senior Victorian public servant reportedly threatened to withdraw further funding from the University of Melbourne if the university did not agree to oversee the government’s grazing trial, despite the trial being widely regarded as flawed and unnecessary. Faced with this type of pressure, many university scientists simply avoid public debate for fear of damaging their job prospects or government funding.

In this climate of silence, major biodiversity issues and damaging government policies aren’t appropriately aired. The public don’t hear about it and so can’t make informed decisions at the polling booth. Consequently, government and public service barriers to honest media coverage undermine an informed democracy.

Valuing and preserving nature are critical for our well-being and prosperity, but species continue disappearing at alarming rates to causes we could better manage.

There are things that can be done, at a political level, to help stop this erosion of Australia’s natural heritage before it’s too late. In addition to adequately funding conservation, we should reform political funding rules. We should also encourage, even legally require, honest and open disclosure of how government policy impacts our environment.

The Conversation

Don Driscoll, Professor in Terrestrial Ecology, Deakin University and Euan Ritchie, Senior Lecturer in Ecology, Centre for Integrative Ecology, School of Life & Environmental Sciences, Deakin University

This article was originally published on The Conversation. Read the original article.