Welcome to the blog that is going to keep you informed about water issues! Political, social, economic, human health, land use… you name it! It has been my personal goal to educate the public to the need to understand that our water health is dependent on our actions and inaction.
Your community CANprotect your water!
Exploring real world environmental concerns must also include social, economic, political, human health, and natural resource implications. This allows for a comprehensive understanding of complicated environmental matters that do not stop at man-made state lines, or international lines of delineation. Water, genetically modified organisms (GMOs), waste, industrial farming, disaster relief, air quality, carbon sequestration, energy production, and fishing industries, to name a few, all encompass multiple disciplines in both its onset and its potential solutions. Educating the public to environmental sciences as a single discipline, taught from a text, within a classroom, whose antithesis is business, does not convey the entire picture.
The GET WET! Project addresses residential water needs by collaborating with local universities, government representatives, businesses, conservation commissions, ENGOs, parents, and community volunteers to assure all interested parties are heard. Focusing on local environmental issues through school-centered, community-based curriculum increases participation and opens a dialogue regarding local resources, jobs, human health, politics, and economics. Allowing the community to decide which of the concerns they feel deserves the most attention provides an autonomy that may be more palatable.
Human wastewater poses a global threat to seafood safety and the financial stability of the aquaculture industry. A recent study by researchers at the Dauphin Island Sea Lab and the University of South Alabama, in collaboration with the U.S. Food and Drug Administration, tested multiple indicators of wastewater contamination to identify potential sources of contamination to local shellfish farms and aid management efforts.
Successful management of wastewater contamination relies on understanding the sources of wastewater to a system. Established metrics to assess water quality and wastewater sources include bacterial and viral indicators, nutrient concentrations, and stable isotope ratios.
Along with these sources, the team tested artificial sweetenersas a wastewater indicator. The analysis of artificial sweeteners emerged recently as a method to better trace human-specific wastewater sources. Artificial sweeteners, such as acesulfame and sucralose, are slow to degrade and are not found in nature. They are also rarely found in commonly used fertilizers or livestock feed.
Individually, these water quality indicators provide some evidence of the presence of wastewater and associated microbes of human concern. The research team found that using multiple indicators in combination provided a greater potential for source identification and detected seasonal variation in contamination risk.
The study focused on shellfish farms in Portersville Bay, Alabama, in Mississippi Sound on the northern Gulf of Mexico coast, but has implications for shellfish farms in any system potentially affected by multiple sources of wastewater contamination. Potential wastewater sources sampled for the study included a wastewater treatment plant outfall and industrial, residential, and agricultural areas near the shellfish farms. To understand how environmental conditions may affect wastewater source contributions, samples were collected in wet and dry conditions and during warm and cold periods.
Overall, indicator source dominance depended on environmental conditions, with wastewater treatment plant outfall and residential sources conveying human-specific indicators to farms year-round, while agricultural and industrial sites contributed additional fecal coliforms during cold wet periods. The study additionally found evidence that disturbance such as some types of construction activity may contribute fecal indicators to adjacent waters.
The use of multiple indicators will aid managers to detect and define wastewater sources, identify targets for monitoring or remediation, and manage shellfish areas in estuaries with a mosaic of land-derived wastewater sources.
Beavers could make an important contribution to improving the condition of Scotland’s rivers, including helping to improve water quality and limiting the effects of drought.
The positive role they can play in water resource management, as well as in creating habitat, carbon sequestrationand river restoration, is highlighted in a report produced by scientists at the University of Aberdeen and the James Hutton Institute. They have collated evidence from 120 studies of beaver populations worldwide, as part of a large-scale review of their effects on streams and rivers.
In Scotland, beavers have already taken up residence in a few areas, including Tayside and Knapdale. While sometimes their presence has been welcomed, in other situations there has been conflict, for example where their activity affected intensively managed landscapes.
Until now, evidence of the role of beavers in helping to manage river ecosystems in Scotland has been minimal. But by identifying trends associated with the effects of beaver dam building on water quantity and quality—while factoring in the characteristics of Scottish rivers—the scientists who produced the report have provided detailed evidence to help policymakers consider the benefits and limitations of beaver expansion in Scotland, including where trade-offs are required.
In November last year the Scottish Government announced a revised beaver policy which included the development of a new national strategy for beavers. The research leading to the publication of the report was requested by NatureScot and funded by the Scottish Government via the Centre of Expertise for Waters.
Dr. Josie Geris, from the University’s School of Geosciences, led the study. She said: “We found that, by modifying physical processes in streams and rivers, beaver dam building could help to address several important water management challenges in Scotland, including water supply and, by trapping sediment and contaminants, water quality.
“Locally, beaver activity may also limit the effect of extreme events such as drought, which is expected to increase with climate change and can carry an economic impact—for example during the dry summer of 2018 when numerous private water supplies to communities and businesses were affected.
“Achieving the potential of the positive effects of beaver activity may involve some challenges and the need to find solutions. And while most of the evidence points to positive contributions to river ecosystems locally, the report recommends that more work is needed on understanding how the effects of beavers across multiple sites sum up to affect rivers at larger scales.”
Angus Tree from NatureScot said: “This is a significant study that clearly demonstrates the unique ways in which beavers engineer ecosystems. It backs up evidence we’ve gathered over the years and will help our work with stakeholders as we develop the best ways to live with, and benefit from, beavers. We are committed to continuing work to restore and manage beavers, as one important way to protect Scotland’s environment and respond to the climate emergency.”
Poor water quality in English rivers is the result of chronic underinvestment and multiple failures in monitoring, governance and enforcement, a report from the UK Parliament’s Environmental Audit Committee has claimed.
The report includes evidence from The University of Manchester’s Professor Jamie Woodward, whose research demonstrated a direct link between poor wastewater management and high levels of microplastic pollution in UK rivers.
The report states that only 14% of English rivers meet good ecological status, with pollution from agriculture, sewage, roads and single-use plastics contributing to a dangerous “chemical cocktail” coursing through the waterways. Not a single river in England has received a clean bill of health for chemical contamination.
Budget cuts to the Environment Agency have hampered the ability to monitor water quality in rivers and detect permit breaches or pollution incidents from the water industry and farming. There has also been a lack of political will to improve water quality, with successive governments, water companies and regulators seemingly turning a blind eye to antiquated practices of dumping sewage and other pollutants in rivers.
The report recommends that the Environment Agency work with water companies to ensure that easily accessible information on sewage discharges, in as near to real time as possible, is made available. The MPs are also calling on the government actively to encourage the designation of at least one widely used stretch of river for bathing in each water company area by 2025.
The impact of rural agricultural pollution is the most common thing preventing rivers from achieving good ecological status. Intensive livestock and poultry farming is putting enormous pressure on particular catchments, such as that flowing into the River Wye, as it may be raising the river’s phosphorus levels. The Committee is calling for each catchment to have a nutrient budget calculated, and for new poultry farms to not be granted planning permission in catchments exceeding their nutrient budgets.
The Committee encourages the newly-established Office for Environmental Protection to use the powers it has been granted by Parliament to drive improvements in the regulatory and enforcement regimes which govern the state of England’s rivers.
“Our inquiry has uncovered multiple failures in the monitoring, governance and enforcement on water quality,” said Environmental Audit Committee Chairman, Rt Hon Philip Dunne MP. “For too long, the government, regulators and the water industry have allowed a Victorian sewerage system to buckle under increasing pressure.
“We are calling for these relevant bodies to come together and develop a system fit for the future. Monitoring regimes need to be reviewed, enforcement needs to be ramped up, and even public awareness needs boosting on what can and cannot be poured down drains or flushed down the toilet. So many emerging pollutants are being missed by inadequate and insufficient monitoring, and court actions against polluters have fallen dramatically.”
Water quality in rivers is affected by underpinning ‘natural’ hydrogeological and biogeochemical processes, as well as interactions between people and their environment that are accelerating stress on water resources at unprecedented rates.
Pollutants can move at different speeds and accumulate in varying quantities along rivers where the mix of the complex ‘cocktail’ of chemicals that is making its way towards the ocean is constantly changing, a new study reveals.
Researchers have discovered characteristic breakpoints—often found when a tributary joins the main river or significant point sources exist—can change the behavior of some compounds, causing the concentration of these chemicals to change drastically, depending on where they are on their journey down the river.
Experts discovered the phenomenon after piloting a new, systematic approach to understanding hydrogeochemical dynamics in large river systems along the entire length of India’s River Ganges (Ganga)—from close to its source in the Himalayas down to the Indian Ocean.
This new research approach proven successful at the iconic Ganga can be applied to other large river systems across the world—hopefully shedding new light on how to tackle the global challenge of aquatic pollution by multiple interacting contaminants.
Publishing its findings in Water Research, the international research team, which includes experts from the Universities of Birmingham and Manchester and other Indian and UK collaborators, reveals that chemicals including nitrate, chloride, sulfate, calcium, sodium and strontium are cut and boosted in different proportion by a series of breakpoints along the Ganga.
They found that mixing, dilution and weathering are key processes controlling major hydrochemistry—identifying four major breakpoints which alter the concentration of at least four chemicals in the river. Five minor breakpoints affect the water mix of 2-3 chemicals, with two ‘single’ locations impacting on just one parameter.
Stefan Krause, Professor of Ecohydrology and Biogeochemistry at the University of Birmingham, commented that “Large river systems, such as the Ganga, provide crucial water resources with important implications for global water, food and energy security. Understanding the complex dynamics of such systems remains a major challenge.”
“The breakpoints we have identified in India change the behavior of some compounds, altering the composition of the cocktail of chemicals flowing down the Ganga to the ocean.”
“Breakpoint analysis could be a game changer in understanding how pollutants travel along major watercourses—allowing us to identify the ‘hotspots’ which will shed new light on the behavior of aquatic pollution and how better to tackle this global challenge.”
Informed by a 2019 post-monsoonal survey of 81 bank-side sampling locations, researchers identified five major hydrogeochemical zones—characterized, in part, by the inputs of key tributaries, urban and agricultural areas, and estuarine inputs near the Bay of Bengal.
Dr. Laura Richards, the study’s lead author from the University of Manchester, commented that their “research helps to understand the downstream transitions in the chemistry of the River Ganga providing important baseline information and quantification of solute sources and controls. In addition to improving the understanding of a river system as environmentally and societally important as the Ganga, the systematic approach used may also be applicable to other large river systems.”
The researcher’s novel research approach brings systematic insight into the factors controlling key geochemistry in the Ganga—one of the world’s largest and most important river systems, flowing over 2,500 km from the Himalayas to the Bay of Bengal, through one of the world’s most densely populated areas.
As a major source of livelihood, the river is a key water source to more than 400 Million people and very important to many social and religious traditions in India, but faces increasing environmental challenges associated with rapid development, climate change, increasing urbanization, water demand and agricultural intensity.
Today, the federal government is due to report back to UNESCO on its efforts to protect the Great Barrier Reef. The government’s announcement last week of A$1 billion of additional funding is welcome, but it will do little to allay UNESCO’s concerns.
Climate change is the number one threat to the Great Barrier Reef. While the new funding is meant to address other threats to the natural wonder and may improve its resilience, failing to address the climate threat is both disappointing and nonsensical.
The Great Barrier Reef came close last year to being put on a list of World Heritage “in danger” sites. The funding announcement seems primarily about appeasing UNESCO, with one eye also on the upcoming federal election. But saving the Great Barrier Reef is not about throwing money at it—what matters is how the dollars are spent.
By the numbers
The $1 billion package proposed by the government comprises:
58% to address the land-based causes of water quality issues impacting the World Heritage Area
26% to reduce crown-of-thorns starfish and prevent illegal fishing
The measures to be funded are all important. But they’re nowhere near as important as addressing the root cause of climate change: greenhouse gas emissions. Most of the $1 billion should have been used to help Australia phase out fossil fuels.
What’s more, the federal and Queensland governments continue to approve new coal and gas projects. Doing all this, while knowing the grave threat climate change poses to the Great Barrier Reef, demonstrates the incoherence of government policies.
Devil in the detail
When we drill further into the detail, it becomes even more clear the funding package is not as impressive as it may first appear.
The $1 billion funding has been allocated over nine years. This is far beyond the time frame to which any government can sensibly commit, given four-year election cycles. A major funding increase is needed urgently, and certainly within a single term of government.
Also, federal Labor’s funding proposal for the Great Barrier Reef must be increased.
Another concern is the funding allocation for new scientific technologies such as coral seeding, developing heat-resistant corals and cloud brightening. Some of these technologies may have produced positive results at a small scale. But none has yet proved feasible at the wide scale necessary to make a real difference for the Great Barrier Reef.
Efforts to address water quality are important. After climate change, poor water quality is the most pressing problem facing the reef. It’s largely caused by nutrients, pesticides and sediment runoff from agriculture and coastal development.
But governments have already spent hundreds of millions trying to improve water quality, with only limited success. Reducing water pollution requires more effective spending, not just more funds.
This is just one example of how money alone cannot fix all the Great Barrier Reef’s problems. Improving water quality requires the right balance between voluntary industry-led approaches and enforcing the rules.
The Queensland government must greatly increase its compliance and enforcement on matters such as fertilizer runoff entering creeks that flow to the reef. While many farmers are doing the right thing, others clearly are not.
And to improve water quality, governments must be prepared to limit clearing and agriculture expansion in reef catchment areas.
Learning from our mistakes
For years, the federal government has known the pressures facing the Great Barrier Reef. But it continues to maintain a “business as usual” attitude in the face of the worsening climate crisis. Governments worldwide must dramatically increase their climate ambitions—and for the Great Barrier Reef, this action should start at home.
As the Murray-Darling Basin experience shows, throwing funding at an environmental catastrophe does not fix the problem, especially if the core issue remains unaddressed.
The government must also better allocate funds to achieve effective and timely “adaptive management.” This involves decision-making that can be adjusted as outcomes become better understood.
A bill changing state policy toward Everglades restoration, and pitting the Senate president’s priorities against the governor’s, advanced through its single committee stop Wednesday morning despite hours of passionate protest from clean water advocates.
Dozens of fishing guides dropped their charters for the day—one captain estimated about $40,000 in daily business was lost—and told the Senate Appropriations Committee they believed this bill would ruin water quality and their livelihoods by favoring farmers‘ interests over restoration.
“If you vote yes for this bill, you will single-handedly take away years of work to better our state,” said Lee Richardson, a restaurant owner from Charlotte County. “Was that all smoke and mirrors? If you vote yes on this, I’ll have my answer… You care more for the sugar industry than you do the tourists who keep coming here and powering our state.”
The sponsor of SB 2508, which would change the way state agencies advocate for federal Everglades policy and affect the way state dollars are released for restoration projects, rebuffed all criticism and insisted the fishing guides were misled.
“Let me set the record clear, let’s wipe away any smoke and lay aside any mirrors,” said Sen. Ben Albritton, a Republican and citrus farmer from Bartow. “Asking for accountability from an agency that received 70% of its budget from the state government? That’s good government.”
The Senate Appropriations Committee approved the bill 16-4. The primary effect of the measure would be to force the South Florida Water Management District, the state agency that works most closely with the federal government on Everglades Restoration, to change its position and advocate for more water for agriculture users if it wants to receive state funding for restoration projects.
Water levels in Lake Okeechobee are controlled by the federal government through the Army Corps of Engineers, and in the past, federal rules have forced the agency to send large blasts of that polluted water east and west, causing toxic and economically disastrous surges of blue-green algae.
That changed in 2017, when legislators passed Senate Bill 10 in response to the toxic algae blooms. The plan was to build a deep reservoir for holding polluted discharges from Lake Okeechobee on state-owned land south of the Everglades Agricultural Area.
For the last three years, the Corps has been working on a new set of rules that would reduce the amount of water it would have to send east and west by more than a third, and it would triple the amount of water sent south to recharge the thirsty Everglades and restore healthy conditions to Florida Bay, which many of the fishing guides depend on.
Senate president, governor on opposite sides
The water management district has publicly supported the direction the rules are headed in, which is not finalized yet, and said its priority is “balance” among all users. Those efforts have the support of Gov. Ron DeSantis, who appoints its board and who has made Everglades restoration a priority of his administration. The governor created a Blue-Green Algae Task Force to combat the toxic blooms and pushed for dedicating an unprecedented amount of state funds for the restoration and water quality efforts.
But the plan has come under fire from farmers in the Everglades Agricultural Area and Senate President Wilton Simpson, a Republican from Trilby who owns an egg farm and is running for agriculture commissioner.
The bill, sponsored by Albritton with the bipartisan support of Senate leadership, would require that in order to receive hundreds of millions of dollars in state funding, the district must certify to the Senate and House that it officially recommends the Army Corps does not cut water levels to or “adversely affect” farmers.
The major farmers in the area in question are sugar cane and sugar beet producers, some of whom sued the federal government over this same issue last summer, arguing that the new reservoir would deprive them of the water they need for irrigation.
Florida’s largest industrial farms are among the biggest contributors to the political campaigns of legislators in both parties. They have contributed more than $5 million to legislators, their political committees and political parties for the 2022 election cycle.
The largest contributors were U.S. Sugar, which has given $2.2 million to date, and Florida Crystals, which has donated $2.1 million.
Everglades supporters speak out
Eric Eikenberg, head of the Everglades Foundation, told the committee that no member of the Senate or its staff attended any of the 30 public meetings over the last three years, making this bill the first time the Senate has weighed in, mere months before the process ends.
“This bill says if you do not convince the Army Corps of Engineers to put a security blanket back in for the sugar industry in LOSOM [Lake Okeechobee System Operating Manual] then you cannot receive money for Everglades restoration,” Eikenberg told the committee. “It would tie the hands of the water management district.”
Chauncey Goss, chairman for the SFWMD, told senators that his agency was not consulted about this bill in advance and said he had “concerns,” but when pressed by senators would not elaborate.
Another Everglades concern in Albritton’s bill focuses on a controversial giant reservoir designed to hold tens of thousands of gallons of polluted Lake Okeechobee water, further reducing algae-causing discharges. DeSantis has called the Everglades Agricultural Area reservoir “a top priority” and recently picked a fight with the federal government for not funding its part of the project faster.
For more than 40 years, an underground coal mine discharged poorly treated wastewater directly into the Wollangambe River, which flows through the heart of the Blue Mountains World Heritage area.
Much of this spectacular wild river was chronically polluted, with dangerously high levels of zinc and nickel. Few animals were able to survive there.
My colleagues and I had been calling for tougher regulations to clean-up the wastewater flow since 2014, after we first sampled the river for our research. Finally, with the Blue Mountains community rallying behind us, the New South Wales Environment Protection Agency (EPA) enforced stronger regulations in 2020.
Our latest research paper documents the Wollangambe River’s recovery since. Already we’ve seen a massive improvement to the water quality, with wildlife returning to formerly polluted sites in stunning numbers.
In fact, the long fight for the restoration of this globally significant river is the focus of a new documentary, Mining the Blue Mountains, released this week (and online in coming days).
But while the recovery so far is promising, it remains incomplete. Much more action is needed to return the river to its former health.
When the federal government nominated the Blue Mountains to be inscribed on the World Heritage list in 1998, it claimed “some coal mining operations occur nearby, but do not affect the water catchments that drain to the area.”
Our research has shown this not to be true, and the pollution of this river has generated international concern. In 2020, the International Union for Conservation of Nature—an official advisor to UNESCO—identified the coal mine as a major threat to the conservation values of the Greater Blue Mountains World Heritage area.
So, how bad was the pollution? Our previous survey conducted nine years ago investigated both water quality and river invertebrates—mostly aquatic insects.
Wastewater from the underground coal mine Clarence Colliery entered the Wollangambe River about 1.5 kilometers upstream of the World Heritage area boundary. The nature of the pollution was complex, but of most serious concern was the increased concentrations of nickel and zinc in the river.
These metals were unusually enriched for coal wastewater, with both at concentrations more than 10 times known safe levels. The pollution remained dangerous for more than 20km downstream, deep within the World Heritage area.
Compared to upstream and unaffected reference streams, we found the abundance of invertebrates in the Wollangambe fell by 90%, with the diversity of invertebrate families 65% lower below the mine waste outfall.
There was also a build-up of contaminants into the surrounding foodchain. For example, one of our studies detected metals accumulated in plants growing on the river bank. Another founda build-up in the tissue of aquatic beetles below the mine outfall.
Life returns to the river
In 2014 we not only shared our published research findings with the NSW EPA, but also with the Blue Mountains community. This triggered a letter writing campaign from the Blue Mountains Conservation Society urging the EPA to take action.
After five long years, the EPA finally issued stringent regulations requiring Clarence Colliery to make enormous reductions in the release of pollutants, particularly zinc and nickel, in the colliery waste discharge.
And it worked! We collected samples 22km downstream of the river, and were very surprised at the speed and extent of ecological recovery. Not only has water quality improved, but animals are coming back, too.
The improved treatment resulted in a very significant reduction of zinc and nickel concentrations in the mine’s wastewater, which continues to be closely monitored and publicly reportedby the colliery.
The most pollution-sensitive groups of invertebrates—mayflies, stoneflies and caddisflies—had a steep increase (256%) in their abundance compared to when we conducted our earlier research in 2012 and 2013.
This could have positive implications for the surrounding plants and animals, as river invertebrates are a major food source for water birds, lizards, fish and platypus.
However, the road to recovery is a long one. River sediments remain contaminated by the build-up of four decades of zinc and nickel enrichment, up to 2km downstream of the mine outfall.
To help speed up the river’s recovery, contaminated sediment should be removed from the river below the mine outfall, similar to a 12-month clean-up operation conducted after a major spill from the mine in 2015.
Pollution doesn’t often end when mines do
Sadly, there are closed mines in the Blue Mountains that continue to release damaging pollution, such as Canyon Colliery and several in the Sunny Corner gold mine area, as the documentary explores.
Canyon Colliery closed in 1997, and contaminated groundwatercontinues to be discharged from its drainage shafts into the Grose River, which is part of the Blue Mountains World Heritage Area.
Likewise, most Sunny Corner mines closed over a century ago, and yet severe pollution still seeps from the mines into waterways.
The pollution here is at extreme concentrations and includes arsenic, copper, lead and zinc. It’s dangerous to life in waterways, surrounding soil and contact with this pollution is hazardous to human health.
What can we learn from this?
Rehabilitating these closed mines are expensive, and often with limited success. But the Wollangambe River case study is an encouraging sign that clean-up is possible for even the most polluted environments.
Solid independent scientific research and community involvement are critical for these efforts. The community is the eyes and ears of the environment, and has an important role holding industry and government regulators to account.
The environmental regulators, such as NSW EPA, have enormous power to address pollution and trigger positive change. It’s important researchers and the community engages with them—and it helps to be patient as action can take years to happen.
And finally, we congratulate Centennial Coal, the owners of the Clarence Colliery, for making enormous improvements to their operation and complying with tough new environmental regulations.
Nitrogen fertilizers are critical for growing crops to feed the world, yet when applied in excess can pollute our water for decades. A new study provides six steps to address nitrogen pollution and improve water quality.
Since nitrogen persists for so long, management efforts may seem futile and unattractive because it can take a long time to see results. The study from the University of Waterloo appearing in Nature Geoscienceprovides a roadmap for scientists, policymakers, and the public to overcome the challenges associated with this legacy nitrogen for faster improvements to our water quality.
“We have to think about the legacy we leave for the future in a strategic way from both the scientific and socio-economic angles,” said Nandita Basu, a professor of Earth and Environmental Sciences and Civil and Environmental Engineering at Waterloo and the study’s lead author. “This is a call to action for us to accept that these legacies exist and figure out how to use them to our advantage.”
The study recommends the following six steps:
Focus research to quantify the length of time the nitrogen stays in our ecosystems to adjust our expectations for conservation timelines.
Find ways to use the legacy nitrogen as a resource for growing crops instead of adding new nitrogen fertilizers to our ecosystems with already high levels of nitrogen.
Target conservation strategies to get the maximum water quality improvement instead of a widespread blanket approach.
Combine conservation methods that reduce the amount of nitrogen that has already left the farm fields, such as in wetlands, with methods that harvest nitrogen from past legacies accumulated in the soil.
Monitor water quality at both large and small scales so that short-term results can be seen at scales like a farm field and long-term results downstream at river basins can also be tracked.
When assessing the economic impacts of conservation strategies, incorporate both short- and long-term cost-benefit analyses.
Nitrogen legacies are different around the world depending on the climate and historical land use, and land management patterns. While theoretical knowledge of these legacies has existed for decades, measurements and monitoring have not yet been widespread enough to understand these differences and support water quality policies, where there is still an expectation of short-term water quality improvement.
“It’s time we stop treating nitrogen legacies as the elephant in the room and design watershed management strategies that can address these past legacies,” said Basu. “We need to ask ourselves how we can do better for the future.”
Marine scientists have found removing macroalgae from reefs can help coral larvae settle and has great possibilities as a citizen-science project to help coral reefs survive.
James Cook University’s Hillary Smith and Associate Professor David Bourne led the study. They said declining coral cover on tropical coral reefs often results in an increase in macroalgae (seaweed).
“When macroalgae proliferates outside regular seasonal growth, it can shift the ecosystem dominance away from corals. Seaweed can prevent or reduce coral settlement and survival, and so these reefs struggle to recover once seaweed is established,” said Ms Smith.
She said physical removal of macroalgae has been proposed to overcome this, but evidence for its effectiveness was lacking.
Ms Smith said a team of scientists and citizen scientists from Earthwatch Institute manually removed macroalgae from twelve 25-square-meter plots on a degraded reef off Townsville’s Magnetic Island.
“We did this prior to coral mass spawning across two years and recorded the number of coral recruits to settlement tiles and natural substrata. Four months after each spawning event, we found a threefold increase in coral recruits compared to control plots where macroalgae remained,” said Ms Smith.
Assoc Prof Bourne said at small scales on the Great Barrier Reef, macroalgae have shown increasing dominance at the expense of corals in recent decades and such community shifts are predicted to become more common as human-caused impacts increase.
“Longer-term monitoring and further research is needed, but at this point macroalgae removal looks like an accessible, cost-effective reef management method that requires minimal training. It’s labor-intensive, but it may be an attractive proposition for reef practitioners, the public, communities, or citizen science programs,” said Assoc Prof Bourne.
He said although reversing human damage on a large scale (i.e. global climate change and local impacts such as water quality) is the true solution to the reef crisis, the macroalgae removal approach looks promising as a means to help improve reef health.
A new analysis of the River Ganges in West Bengal, India, highlights how wastewater flowing into the river impacts its water quality, and how that influence shifts with seasons and tides. Sayanti Kar of Jadavpur University and Asutosh College in Kolkata, India, and colleagues present these findings in the open-access journal PLOS Water on February 15, 2022.
Flowing through India and Bangladesh, the Ganges is the most sacred river in Hinduism. However, wastewater from nearby cities severely pollutes the river. The Ganges empties into the Bay of Bengal, in the Indian Ocean, and is therefore influenced by tides. Seasonal monsoons also affect the river.
To better understand the impact of tides and seasons on the River Ganges, Kar and colleagues conducted a comprehensive water quality analysis between 2014 and 2018. They focused specifically on a stretch of the river in West Bengal, India, located between Howrah Station—a major railway station near Kolkata—and Khardah, another city near Kolkata.
In 2014, after an extensive survey, the researchers selected five major outfalls where city wastewater flows into the Ganges. At each outfall, for the next four years, they monitored river waterquality according to several different parameters, including measurements known as dissolved oxygen and biochemical oxygen demand, as well as concentrations of various heavy metals and fecal coliform level—an indicator of potential contamination by human feces.
The analysis, which included GIS mapping, showed that dissolved oxygen and biochemical oxygen demand, as well as levels of nitrate nitrogen and chloride, were significantly higher at each of the five sites prior to monsoon season than during monsoon season. Additionally, heavy metal and fecal coliform levels were strongly correlated with each other, and measurement of one could be used to predict the other. The researchers were also able to use their data to mathematically model the influence of tides on various water quality parameters at the five sites.
Overall, the analysis provides new insights into how outfall wastewater impacts water quality in this stretch of the Ganges, depending on seasonal and tidal conditions. This information could help inform new guidelines for safe usage of river water.
The authors add: “River Ganges is not only a symbol of faith and hope for millions of people but is also used for daily human usage and livestock management. A collaboration between Asutosh College, Jadavpur University, and Navajo Technical University investigated the influence of river flow, tidal dynamics, and seasons on distribution of pollutants entering the river from different discharge points (city outfalls) at selected river stretches to prepare river water usage guidelines.”