Could a million freshwater turtles help clean up some of Australia's polluted rivers? A team of scientists believes, they could!

by Larry Powell

The freshwater turtle, Emydura macquarii. Credit: Claudia Santori.

For well over a century, freshwater fish from Europe - carp (originally from China) - have been released, either deliberately or accidentally from fish farms, into Australian waterways. The fish, now widely regarded as pests, are thriving. 

Their habitat includes rivers flowing through the Murray-Darling Basin of New South Wales. Those vast waterways support, through irrigation and other means, about 40% of agricultural production for the entire country - not to mention vital aquatic eco-systems and drinking water for about three million people. 

Baby Emydura macquarii. Credit: Tom Burd.

By contrast, the clock is ticking for Australia's native freshwater turtles. The new study says the most common species has declined by up to 91 percent in the past 40 years. It blames urbanization, which damages their habitat and makes the turtles more vulnerable to mass die-offs from disease. They're also being run over by vehicles on roadways. And foxes, like the carp, also introduced from elsewhere, are destroying their nests. 

Ironically, the scientists have now discovered that the turtles could play a vital role in any plan to rid the rivers of the nuisance carp. As carp die, they decompose and give off ammonia, which is toxic to other creatures.

An experiment the researchers carried out showed, convincingly, that the turtles could act as an effective "clean-up crew." Turns out, they have a huge appetite for the carcasses of the fish, a trait which would improve water quality, to everyone's benefit.

Day nine of the experiments - with turtles present in the water, 

the carp carcass has been completely devoured. 

Credit: Ricky Spencer and Claudia Santori.

The researchers built "artificial wetlands" made up of several large tanks like the one above. They placed dead carp in all of them. Then they put the turtles, in groups of four, in some. The tanks were monitored, either until the carcasses had fully decomposed or been completely eaten by the turtles.

The results, as documented in a study, now published in the journal, Nature, 
are striking.

The turtles stripped carp carcasses to skeletons within five days, whereas, without turtles present, the carcasses took more than 27 days - more than five times longer - to decompose. In the tanks with the turtles, ammonia levels fell and dissolved oxygen levels - which aquatic animals need to survive, recovered. Without turtles, the water progressively deteriorated and became very dirty. While crayfish, prawns, and shrimp act similarly, none are as effective as the turtles. 

The leader of the research team, Ricky Spencer of Western Sydney University, believes, a plan by the Australian Government to use a biological agent to get rid of the carp, could be devastating. That's because, without lots of turtles doing the scavenging, mounds of dead fish rotting in the rivers would only emit more ammonia and compound problems of water pollution.

“We’re not just talking about the health of our rivers here," Prof. Spencer adds.  "We’re talking about human health. These are river systems that supply our drinking water and irrigate the fruit and vegetables we eat. So turtles are critical to sustaining the health of humans, as well as our rivers.”

But, with turtle populations on the decline, finding enough to do an effective job, will be daunting. So, the research team is proposing what it calls "Australia's largest, community-empowered conservation program. Local communities will lead 'expansionary conservation,' where we aim to release more than one million extra turtles throughout southeastern Australia each year." A crowd-funding program has been launched to pay for the effort.

Lethal algae blooms – an ecosystem out of balance

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The Guardian

Toxic formations across the US and the Baltic are part of a worrying trend linked to the climate crisis and farming methods Story here.

Lk. Winnipeg, Manitoba, Canada, with Reindeer Is. in the lower right.
Photo credit - European Space Agency.

Mekong Turns from Brown to Blue-Green

In late 2019, the river started to turn colours due 

to a reduced sediment load and algae blooms.

NASA Earth Observatory.

RELATED:

IN HOGS WE TRUST - Part 1V 

"The environmental costs of intensive livestock operations.".

Lakes worldwide are experiencing more severe algal blooms

PHYS ORG

Lake Winnipeg. Satellite photo by European
Space Agency.

The intensity of summer algal blooms has increased over the past three decades, according to a first-ever global survey of dozens of large, freshwater lakes. Story here.

'Act before it's too late': The prairie province of Saskatchewan, Canada at high risk of water shortages, says global study

CBC News

Climate change, resource extraction, agriculture among causes of potential water shortage, says author. Story here.

Echo Lake, SK. Photo by Joe Mabel from Seattle.

Microplastics in freshwaters

PHYS ORG

Microplastics in sediments from the rivers Elbe (A), Mosel (B), Neckar (C), and Rhine (D).Note the diverse shapes (filaments, fragments, and spheres) and that not all items are microplastics (e.g., aluminum foil (C) and glass spheres and sand (D), white arrowheads). The white bars represent 1 mm. PhotoS by Martin Wagner et al.

As small as a grain of dust—but of great global significance. The word microplastics is familiar to many, but the dangers are virtually unexplored. In recent years, plastic pollution has become an ever-increasing burden on the environment. Countless videos and media reports draw attention to this problem. While the dangers of large plastic pieces for animals are impossible to overlook, there is practically nothing about the dangers posed by microplastics. But what are microplastics anyway? Get the answer here.

While Nestlé extracts millions of litres from their land in Ontario, Canada, residents have no drinking water

The Guardian

Just 90 minutes from Toronto, residents of a First Nations community try to improve the water situation as the beverage company extracts from their land. Story here.

Climate change affecting fish in Ontario lakes, study reveals

PHYS ORG

A lake in northwestern Ontario. Photo by PinP.

Warmer temperatures are having a ripple effect on food webs in Ontario lakes, according to a new University of Guelph study. Story here.

Beavers do 'dam' good work cleaning water

ScienceDaily

A PinP photo.

Beavers could help clean up polluted rivers and stem the loss of valuable soils from farms, new research shows. More here.

Melbourn's water supply at risk due to "collapse" of forests caused by logging.

The Guardian

Logging in Australia. Photo by Peter Campbell

Tree-felling helped trigger ‘hidden collapse’ of mountain ash forests, ecologists say. More here.

"In Hogs We Trust." Part 1V

Last October, just before the provincial government relaxed regulations to allow for many more hogs to be produced in this province, George Matheson, Chair of the industry group, “Manitoba Pork,” testified before a legislative committee. 

In an astonishing display of corporate hype, Matheson seemed to think he could, with a single statement, obliterate years of solid scientific research, conducted in his own province.

“Hog manure is not getting into our rivers and lakes,” he declared. “The vast majority…about 85 per cent, is injected into the soil of farmland or immediately incorporated into the soil. This method of application essentially stops manure from running off the land. I cannot overemphasize this point. This means manure does not get into rivers and lakes. In fact, it is illegal for manure to leave a field.”  

In her long career with the University of Winnipeg’s biology department, Dr. Eva Pip (below) has come to a dramatically different conclusion. After visiting more than 400 sites in Manitoba and publishing a series of meticulous, detailed studies, the veteran water quality expert has found, “The two land use categories with the highest nitrate concentrations bleeding into adjacent surface waters were urban sewage and livestock/poultry operations.”

Dr. Eva Pip taught biology at the U of W for more than 
50 years before retiring in 2016. She has published almost 
100 peer-reviewed articles in her career. More than 800 scientists in 
serious academic circles around the world have cited her work, 
as a building block for their own.

Nitrates act as nutrients which promote the rapid growth of harmful and often poisonous algae. As Dr. Pip explains, “These mar beaches, overgrow submerged surfaces, clog filters and fishing nets, and foul drinking water with objectionable tastes, odours and toxins. Local fish and invertebrate kills have occurred both in summer and under winter ice.” 

Many big livestock operations, including hog “mega-barns,” have been operating in southern Manitoba for years. This doesn’t make sense to Dr. Pip. “Our provincial government was irresponsibly allowing barns where periodic flooding was very likely, even certain. Since floodwaters flow into Lake Winnipeg, and also to Lake Manitoba via the Portage Diversion, this means that waste affects a very large area, not just the immediately adjacent waters.” Epic flooding in the Red River Valley in 1997 washed a host of human-related contaminants into those lakes, including waste from hog lagoons. 

A study Dr. Pip supervised in 2006, confirmed that three substances harmful to water quality “increased significantly during flooding.” They were, dissolved solids and different forms of the two main nutrients, nitrogen and phosphorous. And human and animal waste were also “major factors” directly affecting water quality near the shore at 90 sites she surveyed along the southern half of Lake Winnipeg. Communities of mollusks (snails and native freshwater mussels), considered important indicators of environmental health, were dwindling, and many are endangered. She recommended another look be taken at management policies affecting the lake, in order to “reduce further habitat decline.” 

In 2012, she published another study showing even more clearly, just how baseless Matheson’s testimony was. For an entire ice-free season, she and one of her students took water samples both upstream and downstream of a small hog and poultry operation in southeastern Manitoba. The farm, complete with waste lagoons and fields where the waste was sprayed, was located between the Brokenhead River and one of its tributaries, Hazel Creek. The study detected significantly higher levels of several substances harmful to water quality in the downstream samples, compared to upstream. These included phosphorous, some nitrogen, solids and fecal coliform bacteria, which increased when it rained. “ The study suggested that environmental loading of livestock waste adversely altered natural stream water quality.” And it called for producers to spread manure “during drier weather conditions, to minimize the large-scale escape events.”  

“Our study demonstrated unequivocally," explains Dr. Pip, "that manure was getting into those waterways from the spread fields after the manure had been spread, and not just small amounts either.” 

David Schindler is a Rhodes scholar and 

internationally celebrated scientist, with 

a Ph.D in ecology. He co-authored the 

book, “The Algal Bowl: Overfertilization 

of the World’s Freshwaters and Estuaries.”

The Brokenhead River flows into Lake Winnipeg, the subject of another study published in 2012. Entitled, “The rapid eutrophication of Lake Winnipeg,” it was conducted by a team of researchers headed by another water quality expert, Dr. David Schindler of the University of Alberta (above). It concluded that toxic blue-green algae (cyanobacteria) “have nearly doubled in size in that lake since the mid 1990s,” thanks to rapid increases in phosphorous levels." (See graph.)

                                          

What is eutrophication? Harmful algal blooms, dead zones and fish kills are the results of a process called eutrophication, which begins with increased load of nutrients to estuaries and coastal waters. (A NOAA video.)

In 2007, Manitoba's Clean Environment Commission found that hog wastes spread on fields as a nutrient, “constitute the most serious environmental sustainability issues facing the industry.” 

But, could human health be at risk here, too? 

Further research by Dr. Pip less than four years ago, shows that indeed, it could be. It found a dangerous neurotoxin called BMAA at three places near the shore of Lake Winnipeg’s south basin. Levels of it were found to increase significantly after heavy “blooms” of the blue-green algae and when solids were suspended in the water. BMAA is found worldwide, wherever the algae are found. It has been linked to human ailments including Parkinson’s and ALS (Lou Gehrig’s disease). It has also been found in the hair and brain tissue of Canadian Alzheimer’s patients.

There are several troubling pathways humans could be exposed to this toxin. These include consuming the milk or meat of livestock or waterfowl who’ve drunk tainted water in dugouts or wetlands, or even bathing in it! Of the three locations studied, the highest levels were found at Patricia Beach, a popular spot for bathers.

As bad as they sound, BMAA toxins are not the end of the story, as Dr. Pip explains. “We found other more important algal toxins in Lake Winnipeg (microcystins, anatoxins) that are much more immediate and potent, and these should be mentioned. We found that microcystins were related to phosphorus and nitrogen in the water. They can be inhaled, absorbed through skin, or ingested.  

A dog swims in a poison 

soup of blue-green algae.

soup of blue-green algae.

They've been known to sicken people and kill animals. Many communities as well as cottagers draw their drinking water from the lake.” Coliform bacteria (such as E coli) were also associated with phosphorus levels.

Despite all this, Premier Brian Pallister, like the industry, seems more than willing to simply write off all those years of collective scientific wisdom. When announcing last spring his government would relax important environmental regulations so thousands more hogs could be produced in Manitoba, he told reporters, “There’s no compelling evidence that any of these changes will put water at risk."

Lake Winnipeg with Reindeer Island at bottom right. 

European Space Agency.

Meanwhile, Lake Winnipeg (above), the world's 10th largest freshwater lake, gets increasingly polluted with algal blooms that can be seen from space. 

And, a report commissioned by the Government of Manitoba in 2011 concluded that phosphorous levels in the lake were “three times higher than they were in Lake Erie when that lake was described as dead!”

What about water quantity?

Quite apart from the role big hog operations play in harming the quality of our water, is the question of the volumes needed to water the livestock and clean the barns. The amounts are staggering. Figures on volumes already being consumed are hard to come by. But we are already getting a taste of what an expanded industry will look like. Applications are now pouring in for new barns and permission to expanded existing ones. The big pork processing company, HyLife alone, has applied to build no less than 16 big barns, housing some 50,000 hogs in the RM of Killarney, in the southwest. The company estimates all those barns, together, will require something like 48,000,000 imperial gallons per year! (218,212,320  litres!) The hogs will produce well over 31 million gallons of slurry, to be stored in several new earthen lagoons the company proposes to dig. The water will come from new wells. The barns are to be located in the Pembina River watershed and built on land which is currently in crop production. 

While Canada is not at the top of the list of the many countries now threatened by water shortages, can we afford to ignore the warning signs? As the Guardian newspaper  reports, “Across the globe, huge areas are in crisis today as reservoirs and aquifers dry up.”

And almost everywhere, animal agriculture plays a role. As the Dutch-based “Water Footprint Network”puts it, “Animal products generally have a larger water footprint than crop products.” While cattle require the most water of all livestock, pigs still need almost six thousand (5,988) litres to produce a single kilogram of pork!

What about the stink?

But are the threats being posed by the Pallister government's crusade to expand the hog industry, confined to our waterways only? What about the stench produced by massive quantities of hog manure? The industry claims, expansion will do little to worsen that problem.

Yet odours from intensive livestock operations nationwide, have been recognized as a problem in Canada for well over 20 years. In its “Handbook on Health Impacts,” (2004), Health Canada notes, “Among all the animal production sectors, hog farming, given its constant growth since the 1970s and its expansion in many rural and even near-urban areas, is often publicly perceived as one of the most polluting agricultural activities. The number of complaints about odours from animal production operations has increased sharply since the 1970s, mainly because of the transition from solid (manure) to liquid (slurry) waste management. As a result, in 1995, odours from buildings and slurry storage facilities were 5.2 times stronger than they were in 1961; and odours from spreading activities were 8.2 times stronger.”

But hog barn odours can be more than just a nuisance. The Handbook warns that gases including ammonia, hydrogen sulphide and methane can not only irritate the eyes and upper respiratory tract, they can, in high enough concentrations, be lethal. “Half of all cases of severe manure gas poisoning are fatal,” it states. “And a few farm workers in Canada die from such poisoning each year,” usually while cleaning out confined spaces such as manure gutters below the barns.

Hard figures are not available. But it's believed, in Manitoba, more slurry is now injected directly into the ground, rather than being spread above-ground, as is being done here on farmland near Lake Erie, US in 2014.

Related: 
"In Hogs We Trust."  

A critique of Manitoba’s “runaway” hog industry.

Part 1 - Antibiotic Overuse.

Part 11 - The price we pay for corporate pig$. 

Part 111 - From Malaysia to Manitoba - the global magnitude of livestock diseases.

Part V - What’s behind Manitoba’s drive to expand? 

Water Stress is Driving Conflict and Migration. How Should the Global Community Respond?

World

Resources

Institute

Lake Erie

We are running up against the limits of our freshwater resources. We are mismanaging our water resources too, through waste and pollution. Story here.

Thawing permafrost causing the 'browning' of northern lakes

Science Daily

As the ice melts, the organic carbon found in permafrost is being released once again after ages of confinement in the soil. It is making its way into Arctic and subarctic lakes and ponds, and modifying their composition. More here.

Arctic Lake. A US Fish & Wildlife photo.

Oil Spill From Sanchi May Have Reached Japan

EcoWatch

Oil from the stricken oil tanker Sanchi, which exploded and sank in the East China Sea, may have now reached the shores of Japan, according to the country's Coast Guard. More here.

Group calls for the government of Manitoba not to ease hog rules

The Winnipeg SUN

A group that fears relaxed hog rules will heighten water pollution has united to fight against the proposed changes. Story here.

7 reasons we face a global water crisis

Nation of Change

Lake Winnipeg, the world's 10th-largest freshwater lake. In serious trouble due to pollution. Greenpeace photo.

Along with fresh water, political will and public pressure are critical resources in ensuring a sustainable future for all. Story here.

Lake Trout adjust their behaviour in the face of a changing climate, new Canadian study reveals.

UM TODAY

                    News

The scientists observed a reduction in the fish’s growth and condition, which can impact their reproductive success. Story here.

Camper concerned for the health of a Manitoba lake after a chemical appears to have killed off aquatic life.

QC Country

"Residents were shovelling away dead crayfish" according to Denise Melnyk. Story here.

Industrial Pollution Costs Cattle Producers Access to a River in Saskatchewan, Canada.

The Western Producer

Several cattle producers along the Wood River in south-central Saskatchewan have to move about 1,000 head to different pastures after water quality in the river declined unexpectedly. Story here.

Blue-Green Algae Fouling Lake Winnipeg Beaches Again 2017

H2O: Ideas & Action for Canada's Water

A blog about the Lake Winnipeg Watershed 

The hot summer weather in Manitoba has brought along another reminder that all is not well in our great Lake Winnipeg, the 10th largest freshwater lake in the world. Story here.