Monday, November 01, 2021

 

ITF Joins Call for Climate Action

ITF smoke
File image

PUBLISHED OCT 29, 2021 4:42 PM BY THE MARITIME EXECUTIVE

 

As world leaders prepare to gather in Scotland for the COP26 conference next week, the International Transport Workers’ Federation (ITF) has added its voice to the industry's call for action on climate-changing emissions. 

The shipping industry needs to set ambitious targets to help prevent damage from climate change, ITF cautioned in a new position paper launched Friday. 

There are over 50,000 cargo ships on the world’s oceans, the vast majority of which run on VLSFO or HFO. Taken together, these ships emit as much greenhouse gas into the atmosphere as some nations.

After a concerted industry effort to keep shipping's CO2 under the governance of IMO, vessel emissions were removed from the Paris Agreement before its passage in 2015. Six years later, the ITF is calling for the industry and its regulators to commit to the Paris target of zero carbon by 2050 - a goal substantially more ambitious than the IMO "ambition" of a 50 percent reduction by 2050.  

“People who work at sea witness the impacts of climate change every day and are extremely concerned that their industry is not acting quickly enough,” said Stephen Cotton, the ITF’s General Secretary. “Huge changes are needed swiftly to switch the shipping industry away from fossil fuels. Seafarers have the passion, knowledge and ideas to help move the industry to a carbon-free future . . . As working people, we deserve a planet that is safe to live on.” 

The ITF’s position paper set out eight "fundamental principles for a just transition" to make sure the decarbonization of the industry includes workers. The shift will reshape skills and career pathways as the industry shifts employment from fossil fuels to alternative fuel bunkering systems.

Technical change will have significant implications for seafarers. The union calls for a careful review of the safety of new alternative fuels, which will have a direct impact on the safety of people who work at sea. New training will be required. In addition, ITF hopes that the transition will not become a new opportunity to reduce manning. 

“Seafarers want to be part of the solution,” said David Heindel, ITF Seafarers’ Section chair and the Federation’s Sustainable Shipping Working Group chair. “We want to be proud of the action taken by our industry. We want to lead the transition.”

 

NOAA Funds New Research on Costly and Toxic Algal Blooms

national ocean service
One of Monterey Bay Aquarium Research Institute's AUVs makes its way through the green, algae-rich waters of Lake Erie, 2019 (Ben Yair Raanan / MBARI / NOAA)

PUBLISHED OCT 31, 2021 12:58 PM BY NOAA NATIONAL OCEAN SERVICE

 

NOAA is announcing $15.2 million in funding for harmful algal bloom (HAB) research projects throughout U.S. coastal and Great Lakes waters. Algal blooms can produce toxins or cause other harmful effects that can damage ecosystems, disrupt our seafood supply, impact economies, and threaten human health.  Marine and fresh waters of the United States are increasingly impacted by HABs with blooms reported in nearly every state.  They cause annual economic losses up to $100 million on average and costs from a single major HAB event can reach tens of millions of dollars.  

NOAA’s National Centers for Coastal Ocean Science (NCCOS) is allocating $12.4 million for harmful algal bloom research. Funded projects will optimize early warning of shellfish-killing algae; enhance detection of toxins; test the use of control methods in marine and freshwater; improve forecasts; and investigate the social and economic impacts. 

“New projects will begin in Florida, Louisiana, Ohio and Washington to investigate the effectiveness of clay dispersal as a technology to control Karenia brevis blooms in the coastal environment of Southwest Florida; enhance the freshwater HAB toxin detection capabilities of autonomous underwater vehicles; and optimize an early warning system to support the mitigation of shellfish-killing HAB toxins in the Pacific Northwest," said David Kidwell, NOAA NCCOS Competitive Research Program director. 

NOAA’s U.S. Integrated Ocean Observing System Office (IOOS) is also allocating $2.8 million for National Harmful Algal Bloom Observing Network’s activities to support detection, forecasting, and monitoring. 

“Projects funded this year cover most of the U.S. continental coast, including the Great Lakes, and Alaska.  These have been developed by the IOOS Regional Associations in partnership with local communities and research institutions to address known needs and coverage gaps in their region,” said Carl C. Gouldman, Director, U.S. IOOS Office. 

The Gulf of Mexico testbed is a first of its kind effort to develop capacity to improve detection and forecasting of harmful algal bloom species such as Karenia brevis and potential unidentified HAB species in the gulf. Over the course of this three-year pilot project, researchers will deploy a small suite of autonomous instruments to test their suitability in the turbid waters of the gulf, and build both the instrument and personnel capacity to operate, maintain and interpret data from the systems.

This article appears courtesy of NOAA's National Ocean Service and may be found in its original form here

The opinions expressed herein are the author's and not necessarily those of The Maritime Executive.

 

Video: NOAA Finds Wreck of Lost WWII Tanker

okeanos explorer
Courtesy NOAA Ocean Exploration

PUBLISHED OCT 31, 2021 11:08 PM BY THE MARITIME EXECUTIVE

 

The NOAA research ship Okeanos Explorer may have located the wreck of the lost WWII tanker SS Bloody Marsh, one of the hundreds of merchant ships that were sunk by German U-boats off the eastern seaboard of the United States during the first years of World War II.

SS Bloody Marsh was a standard T2 tanker built at Sun Shipbuilding and deployed in coastwise service. In June 1943, on her maiden voyage, she departed Houston with a cargo of 100,000 barrels of fuel oil and headed for New York. On July 2, as she passed up the coast of South Carolina, she encountered the Nazi U-boat U-66, captained by Kapitänleutnant Friedrich Markworth. U-66 fired a torpedo and struck Bloody Marsh's engine compartment, killing three men and rupturing the hull along the port side. About 20 minutes later, U-66 fired a second torpedo into the tanker's port side amidships, breaking her in half and sinking her rapidly. 

The surviving crew managed to abandon ship successfully, and they were spotted by a U.S. Navy blimp. The 110-foot sub chaser USS SC-1048 was directed to come to their assistance, and it recovered the survivors from their lifeboats. 

A crewmember of USS SC-1049 looks out on an empty lifeboat from SS Bloody Marsh (USN / National Archives)

SS Bloody Marsh and dozens of other WWII-era tanker wrecks are considered to have significant potential for pollution, given their contents and the slow decay of their steel hulls. Bloody Marsh is on a NOAA list of 87 high-priority wrecks, and Okeanos Explorer has been tasked with locating the site. 

In an earlier expedition in 2019, the research vessel visited the location of a promising sonar target of about the same size and dimensons as a T2 tanker. It was 500 feet long, and sited in about the same region where Bloody Marsh was lost. However, on an inspection with an ROV, the target turned out to be a rock outcropping, and the search team returned to the drawing board.   

This month, Okeanos Explorer returned to the waters off South Carolina to look again. On the second try, her crew did indeed find a wreck, and they believe that it is the vessel they have been attempting to locate. Video from the search shows extreme damage, with the seabed littered with piles of broken steel plates.

"Based on evidence surveyed, participating scientists are reasonably certain that it is SS Bloody Marsh," NOAA Ocean Exploration said Thursday.

 

Report: Zim Kingston Was Waiting in a Gale Due to Port Congestion

zim kingston
Refrigerators from Zim Kingston on the beach, Cape Palmerston, B.C. (Canadian Coast Guard)

PUBLISHED OCT 31, 2021 9:24 PM BY THE MARITIME EXECUTIVE

 

The container ship that spilled 109 boxes off the Strait of Juan de Fuca on October 22 was at sea in a storm because of port congestion, according to a new report.

Using satellite AIS data, Seattle public radio station KUOW found that the boxship Zim Kingston loitered off the strait's entrance in gale conditions, moving at three knots on a course beam-to the prevailing winds for about six hours.  

While she was orbiting on a north-south racetrack path off the Strait, significant wave height was about 16 to 20 feet and sustained wind speeds were in the range of 35-40 knots. Zim Kingston began to roll through 35 degrees, and with extreme forces acting on her stacked deck cargo, she lost more than 100 boxes over the side.

At least four of these containers have washed up in a wilderness area on the northern tip of Vancouver Island, along with a large volume of loose household goods and packing material from broken boxes. Some of the containers that remained on board were damaged in the incident, and they caught fire after she reached a safe anchorage. 

Debris from Zim Kingston at Cape Palmerston (Canadian Coast Guard)

A spokesperson for the U.S. Coast Guard VTS office for Puget Sound confirmed that Zim Kingston was out at sea at the time of the casualty because of port congestion. All major West Coast container ports (with the exception of Oakland) have unprecedented backlogs due to extreme demand for foreign-made consumer goods. 

"The [Zim Kingston] was sort of in a holding pattern out there because the anchorages in both the U.S. side and the Canadian side of the border are pretty full," said Laird Hail, director of the Puget Sound VTS, speaking to KUOW. "We've not always had room for vessels to be able to come into anchor, so many of them are holding off shore, waiting for a turn to come into either Canadian waters or US waters to anchor."

Cleanup efforts

Four of Zim Kingston's lost containers have washed ashore near Cape Scott Provincial Park, a wilderness area at the remote northwestern tip of Vancouver Island. A Canadian Coast Guard helicopter deployed to the scene and obtained photos of the boxes, allowing officials to match container numbers with the ship's inventory to determine the contents.  Luckily, the markings on the four containers indicate that they do not contain dangerous goods, the CCG confirmed Thursday. One of the four boxes - a containerload of refrigerators - has broken open, releasing dozens of mini-fridges onto the beach. 

At nearby Cape Palmerston, photos taken by a local resident show rafts of consumer goods and styrofoam packing material washing up on shore. 

 

 

Canadian authorities say that they are not asking for volunteers to help with cleanup at this time. The shipowner, Danaos, has contracted for professional cleanup services and that effort is now under way. The company has also hired a salvor to address the remaining wreckage aboard Zim Kingston and to remove the grounded containers from the beach. 

Two of the containers that remain missing are filled with dangerous goods, including a potentially hazardous ore processing chemical, potassium amyl xanthate. The public is advised not to open any containers that may wash up on shore. 

 

'Affective polarization' increasingly leaks into social situations, says new study

political parties
Credit: Pixabay/CC0 Public Domain

Partisanship is a particularly potent source of group identity in contemporary American politics, and a new paper co-written by a University of Illinois Urbana-Champaign expert in political psychology says the growing chasm between opposing groups isn't limited to interactions in the political realm.

Mounting evidence suggests that "affective " leaks into and colors social situations—barbecues, book clubs, sporting events and the like—that previously existed beyond the reach of partisan politics, said Thomas J. Rudolph, the Lincoln Distinguished Professorial Scholar of Political Science at Illinois.

"Consistent with other recent research, this study confirms that affective polarization along partisan lines is real and that it exists in both political and nonpolitical settings," Rudolph said.

Affective polarization is "the tendency of people identifying as Republicans or Democrats to view opposing partisans negatively and co-partisans positively," according to the paper.

"Affective polarization means you're more likely to view the other party as ideologically extreme, and that elections have high stakes and their outcomes are consequential," Rudolph said. "Although it's not confined to the U.S., it's a phenomenon that has increased and become more prevalent domestically over time."

Using a survey experiment of more than 280 undergraduate students in fall 2018 to analyze partisans' affective evaluations, Rudolph and co-author Marc J. Hetherington, of the University of North Carolina, Chapel Hill, found that the dominant mechanism of affective polarization varies depending on the context.

"We show that while affective polarization exists across both political and nonpolitical settings, its magnitude is nearly twice as large in political settings," Rudolph said. "Although affective polarization reflects a blend of both in-party love and out-party hate, we find that in-party love is the dominant source in nonpolitical settings and out-party hate dominates in political settings. Since the U.S. is essentially a two-party system, everyone's focus is always concentrated on the same political rivalry."

The findings are both comforting and disquieting, Rudolph said.

"On the one hand, it's reassuring that partisan polarization in  is not as pronounced as it is in political settings," he said. "On the other hand, the fact that such polarization exists at all in social settings is somewhat troubling."

Although the public is accustomed to seeing partisan animosity on display during election season or at political events such as rallies or protests, "we've seen comparatively little of such animosity expressed in normal social settings," Rudolph said.

"Regrettably, that may be changing somewhat as polarization has increasingly leaked into nonpolitical domains," he said. "Consider the sports world. Sports used to be a place where Republicans and Democrats could check their politics at the turnstile and focus on watching a ballgame and cheering for their favorite player or team. Today, athletes have become frequent targets of partisan criticism—or praise—for their positions on personal decisions such as whether to stand for the national anthem or whether to get vaccinated.

"In recent weeks, the sports world has become even more politically charged, as evidenced by the anti-Joe Biden chants that have been sweeping sports stadiums across the country and gone viral on the internet."

According to Rudolph, we should be concerned that polarization continues to seep into the nonpolitical domain.

"Our study definitely shows that there's partisan polarization in the social world and that it's a real, measurable phenomenon," he said. "Social settings like sporting events, book clubs, schools and the workplace provide regular opportunities for people to come into contact with others who may think differently than they do. Such interactions are healthy because they expose people to diverse viewpoints about the world, including the political world. But if partisan polarization permeates every corner of the social world, people may retreat to their  corners and be less willing to engage with members of the opposing team, and as a result, be less able to understand or appreciate them.

"And that may bleed into the political realm, thereby making it harder to reach compromise on some issues where there might otherwise be common ground. The net effect is that we see less and less of that among our leaders at the local, state and federal level, which is quite unfortunate."

The paper was published in the International Journal of Public Opinion Research.How political partisanship governed in-person schooling during pandemic

More information: Thomas J Rudolph et al, Affective Polarization in Political and Nonpolitical Settings, International Journal of Public Opinion Research (2020). DOI: 10.1093/ijpor/edaa040

 

Identifying ways to make equestrian sport safer for horses and riders

equestrian sport
Credit: Pixabay/CC0 Public Domain

In the first study of horse falls in over 20 years, University of Bristol academics have identified some simple interventions to reduce the risk of injury in equestrian sport—making it safer for both horses and riders.

The study pinpointed characteristics associated with an increased  of falls in eventing, such as higher-level events, longer courses, more starters at cross-country phase and less experienced horses and athletes.

Identifying these  allows riders and event organizers to assess the level of risk for individual horse, rider and event combinations. The study, published in the Equine Veterinary Journal, recommends simple mitigations such as adjusting minimum eligibility requirements (MERs) to ensure horses and riders always compete at a level appropriate to their ability.

Led by Bristol Veterinary School's Dr. Euan Bennet and Professor Tim Parkin, with Dr. Heather Cameron-Whytock of Nottingham Trent University, and funded by Federation Equestre Internationale (FEI), it is the first large scale study using a global data set of every FEI eventing competition over an 11-year period.

This data included every horse start worldwide in all international, championship, Olympics and World Equestrian Games competitions between January 2008 and December 2018. This amounted to over 200,000 horse starts, allowing researchers to specifically analyze the cross-country phase and identify any common factors.

Of 202,771 horse starts during this period, 187,602 started the cross-country phase. Of these, 1.5 percent recorded a fallen horse and 3.5 percent had an unseated .

At least 50 riders and 109 horses have died since 2000 across all levels of competition worldwide.

Bristol Veterinary School's Dr. Euan Bennet said: "Eventing is an exciting equestrian sport, but horses and riders sometimes get injured during competitions. Occasionally they are very seriously injured, even fatally. We have gained a detailed understanding of the risk factors that make horses more likely to fall, so that we can provide actionable advice to governing bodies on how to reduce the number of horse falls, and therefore injuries and fatalities among horses and riders.

"This data is about probabilities and we would never say don't ride because you're going to have a fall, but we might say what we can see is according to your risk profile you're in the top 5% at risk of a fall."

The study identified the following factors as contributing to a fall:

  • Horses competing at higher levels.
  • Horses competing over longer cross-country course distances.
  • A higher number of starters at the cross-country phase.
  • Mares were at increased odds compared with geldings.
  • Horses whose previous start was longer than 60 days ago.
  • Horses who had previously made fewer starts at the level of their current event.
  • At the human athlete level, male athletes were at increased odds of experiencing a fall, compared with female athletes.
  • Younger athletes were at increased odds compared with older athletes.
  • Less experienced athletes were more likely to fall than their more experienced counterparts.
  • Athletes whose previous start was more than 30 days ago were at increased odds compared with athletes who last started within 30 days.
  • Athletes who did not finish their previous event, for any reason, were at increased odds compared with those who successfully finished their previous event.
  • Horse- combinations who recorded a score in the dressage phase that was higher than 50 (i.e. poor performance) were at increased odds of falling during the cross-country phase compared with combinations who recorded a dressage score of 50 or less.

The researchers now hope the FEI will use this new evidence to implement evidence-based rules for eventing which protect the safety of athletes and horses without compromising on competitiveness.

Study demonstrates the need to monitor the bit area of event horses

Provided by University of Bristol 

 

The Parkes dish is still making breakthroughs 60 years after it first gazed at the skies

60 years after it first gazed at the skies, the Parkes dish is still making breakthroughs
Credit: CSIRO, Author provided

The CSIRO's 64-meter Parkes Radio Telescope was commissioned on October 31 1961. At the time it was the most advanced radio telescope in the world, incorporating many innovative features that have since become standard in all large-dish antennas.

Through its early discoveries it quickly became the leading instrument of its kind. Today, 60 years later, it is still arguably the finest single-dish   in the world. It is still performing world-class science and making discoveries that shape our understanding of the Universe.

The telescope's origins date back to wartime radar research by the Radiophysics Laboratory, part of the Council for Scientific and Industrial Research (CSIR), the forerunner of the CSIRO. On the Sydney clifftops at Dover Heights, the laboratory developed radar for use in the Pacific theater. When the second world war ended, the technology was redirected into peaceful applications, including studying  from the Sun and beyond.

In 1946, British physicist Edward "Taffy" Bowen was appointed chief of the Radiophysics Laboratory. He had been one of the brilliant engineers, dubbed "boffins," who developed radar as part of Britain's secret prewar military research. The Radiophysics Laboratory had a dedicated radio astronomy group, led by the brilliant Joseph (Joe) Pawsey. Many of the group's members went on to become leaders in the nascent field of radio astronomy, including Bernie Mills, Chris Christiansen, Paul Wild, Ruby Payne-Scott (the first female radio astronomer), and John Bolton.

While the group's initial research focused on radio waves from the Sun, Bolton's attention soon shifted to identifying other sources from farther afield. By the early 1950s, the Dover Heights radar dishes had discovered more than 100 sources of radio emissions from the Milky Way and beyond, including the signals from supernova explosions. These observations established the Radiophysics Laboratory as a world-leading center of radio astronomy.

By 1954, the technology at Dover Heights was outdated and obsolete, prompting Bowen to initiate the next step for Australian radio astronomy: a state-of-the-art new radio telescope.

He decided the most versatile option was to build a large, fully steerable dish antenna. The eventual price tag was A$1.4 million (A$25.6 million in today's terms)—far beyond CSIRO's budget at the time.

60 years after it first gazed at the skies, the Parkes dish is still making breakthroughs
1955 design notes by Barnes Wallis. Credit: CSIRO, Author provided

The Menzies government agreed to fund the project, provided at least 50% of the money came from the private sector. Using his wartime contacts, Bowen secured A$250,000 each from the Carnegie Corporation and Rockefeller Foundation, plus a range of private Australian donations.

British firm Freeman Fox and Partners produced the detailed design, incorporating suggestions from legendary engineer Barnes Wallis, of "dambusters" fame. Based on the available budget and desired functionality, a diameter of 64 meters was agreed for the dish.

The chosen site was near the town of Parkes, about 350km west of Sydney. This location had favorable weather conditions and was free of local radio interference. The local council also enthusiastically offered to cover the cost of some of the earthworks.

In 2020, the local Wiradjuri people named the telescope Murriyang, a traditional name meaning "Skyworld."

The telescope's construction began in September 1959 and was completed just two years later. On October 31 1961, the Governor-General William Sidney, Viscount De l'Isle, officially opened the telescope in a ceremony attended by 500 guests.

Decades of discovery

John Bolton was appointed the founding director of the telescope. Under his dynamic, decade-long tenure, astronomers made a string of significant discoveries that established the dish as the premier scientific instrument in Australia.

60 years after it first gazed at the skies, the Parkes dish is still making breakthroughs
Parkes tracking the Apollo Moon mission in 1969. Credit: CSIRO, Author provided

Astronomers revealed the immense magnetic field of our Milky Way galaxy. A few months later, the telescope detected quasars, the most distant known objects in the Universe—a discovery that increased the size of the known Universe tenfold. To cap off a memorable first year, Parkes tracked the very first interplanetary space mission, Mariner 2, when it flew past Venus in December 1962.

In the 1970s, researchers discovered and mapped the immense molecular clouds interspersed through our galaxy. The study of pulsars—rotating stars that emit beams of radio waves, rather like a lighthouse—became a major field of research. Parkes has discovered more pulsars than all other radio observatories combined, including the only known double pulsar system, spotted in 2003.

In the 1990s, the distribution of galaxies was mapped to a distance of 300 million light years, revealing the complex structure of the Universe. More recently, Parkes discovered the first Fast Radio Burst—a short, intense blast of radio waves created by an as-yet unknown process. The telescope has also been involved in the Search for Extra-Terrestrial Intelligence (SETI), including the ten-year Breakthrough Listen project, which began in 2016.

To the public, the telescope is perhaps best known for its space tracking, especially its role in the Apollo lunar missions. But it has also supported other significant missions such as NASA's Voyager 2, which flew past Uranus and Neptune in the 1980s and crossed into interstellar space in 2018. In 1986, Parkes was the prime tracking station for the European Giotto mission to Halley's Comet. And next year, Parkes will track some of the first commercial lunar landers.

Originally intended to operate for 20 years, the telscope's longevity is a result of constant upgrades. Recent improvements include a new ultra-wideband receiver that can scan a huge range of radio frequencies, and CSIRO-developed "phased array feeds" (PAFs) that allow the telescope to observe up to 36 points in the sky at once. Work is now under way on a cryogenically cooled PAF that, when installed in 2022, will double this number. With these upgrades in place, a single receiver can be used to deliver more than 90% of current Parkes operations.

It's hard to say how long the Parkes dish will continue to work. It depends on future upgrades and whether the telescope's structure remains in good working order. But astronomers will always have a need for a large single-dish antenna.

Parkes has maintained its world-leading position in radio astronomy by constantly adapting to meet new requirements. Today it stands as an icon of Australian science and achievement. Sixty years after it first trained its eye on the sky, the future still looks bright at Parkes.Strange radio waves emerge from the direction of the galactic center

Provided by The Conversation 

This article is republished from The Conversation under a Creative Commons license. Read the original article.The Conversation

 

High-resolution climate system model reproduces tropical cyclone activities better

tropical cyclone
Credit: CC0 Public Domain

Tropical cyclones (TC) are extreme weather phenomena that feature intense wind speeds and heavy rainfall, causing severe economic losses and human casualties.

Tropical cyclones have become more intense and frequent under the backdrop of global warming. However, there are still challenges in accurately simulating and predicting tropical cyclone activities.

Researchers from the Institute of Atmospheric Physics (IAP) of the Chinese Academy of Sciences (CAS) have developed a new generation global climate system model of LASG named CAS FGOALS-f3-H. This 25 km high-resolution model can simulate the global TC activities in finer ways, capturing and reproducing more realistic features of TC activities.

The study was published in Geoscientific Model Development on Oct. 12.

Based on the FGOALS-f3 simulation in the low resolution (CAS FGOALS-f3-L, the horizontal resolution is about 100 km) and the high resolution (CAS FGOALS-f3-H, the average horizontal resolution is about 25 km), they quantitatively evaluated the impact of the horizontal resolution of the FGOALS-f3 on tropical cyclone simulation capabilities and analyzed the possible causes.

"We found that FGOALS-f3 can resolve tropical cyclone activities in both high- and low-resolution conditions, and has outstanding performance in terms of the number, generating positions, tracks, and life cycles of global ," said Dr. Li Jinxiao, the first author of the study. The tropical cyclone horizontal structure became clear when the horizontal resolution was increased from 100 km to 25 km.

The researchers also found that the fidelity of the tropical cyclone genesis potential index was improved when the models' horizontal resolution increased. Further analyses revealed the possible physical linkage between the performance of the tropical cyclone simulation and the horizontal resolution.

"By comparison, the FGOALS-f3-H shows excellent performance in depicting the global tropical  activities. We intend to establish a high- coupled dynamic prediction system based on FGOALS-f3-H to improve the prediction skill of tropical cyclones on subseasonal to seasonal scales," said Prof. Bao Qing, the corresponding author of the studyGMMIP simulations on global monsoon interannual variability show higher skill than historical simulations

More information: Jinxiao Li et al, Effect of horizontal resolution on the simulation of tropical cyclones in the Chinese Academy of Sciences FGOALS-f3 climate system model, Geoscientific Model Development (2021). DOI: 10.5194/gmd-14-6113-2021

Provided by Chinese Academy of Sciences 

 

Parasitic wasps turn other insects into 'zombies,' saving millions of humans along the way

Parasitic wasps turn other insects into 'zombies,' saving millions of humans along the way
The diaphanous wings and striking markings of this parasitic wasp (Arotes decorus) belie 
its gruesome nature. Credit: Shutterstock

Wasps have a reputation for being jerks because of their perceived aggressiveness and ability to sting repeatedly. They're often negatively compared with the honey production and agricultural pollination of bees.

If  are jerks, however, they are positively saintly compared to their parasitic brethren.

Parasitic wasps sting to inject their eggs into a host, often accompanied by venom and a virus. Their larvae grow and eventually emerge from the unwitting host—usually killing it. Then they becoming adults and fly off to continue the cycle.

Some wasps go further, controlling their host's behavior, effectively "zombifying" them to help the larva survive. After studying the behavior of ichneumon wasps, which lay their eggs in moth larvae, naturalist Charles Darwin wrote that they were so evil that they were proof against the idea that God was directing evolution:

"I cannot persuade myself that a beneficent & omnipotent God would have designedly created the Ichneumonidæ with the express intention of their feeding within the living bodies of caterpillars."

While no wasps are known to lay eggs in humans (although some flies do), they have inspired films like the Alien franchise and the recently released monster survival video game House of Ashes.

But whether inspiring horror or metaphysical questions,  also save millions of human lives.

Ridley Scott’s 1979 movie ‘Alien’ centred on a parasitic alien species.

Parasitic wasps to the rescue

In the 1970s, the cassava mealybug (Phenacoccus manihoti) entered Western and Central Africa as an invasive pest species from Brazil. It rapidly spread across cassava fields causing crop losses as high as 80 percent. The cassava plant is a staple food crop because it is drought-resistant. The mealybug invasion threatened the food base of 200 million people.

The Swiss entomologist Hans Rudolf Herren, who was conducting research in the area, found a wasp parasitizing the mealybug (Epidinocarsis lopezi). The parasitic wasp posed little risk to sub-Saharan species.

After rearing the wasps and gathering funding, Herren bought planes and co-ordinated strategic airdrops and ground release of wasp cocoons to areas affected by the mealybug. From those locations, the wasp populations grew and spread on their own, reducing the mealybug population to manageable levels for years.

This effort saved an estimated 20 million lives, billions in crops and avoided the . Herren received the World Food Prize in 1995 for his efforts.

Biocontrol heroes

Biocontrol is the use of one organism to combat a pest, and this was far from the only successful case of wasps as biocontrol. Wasps have successfully defended against many crop pests in Chinese agriculture.

The samurai wasp (Trissolcus japonicus) was being studied for potential use against the brown marmorated stinkbug, a threat to many crops across the continental United States. However, the wasp preempted this, moving into stinkbug territories on its own.

Wasps are even being deployed to prevent moths from damaging historical sites and their artifacts. Here in Canada, at least four wasp species have been released to control the emerald ash borer, a cause of deforestation across Canada.

David Attenborough describes the habits of parasitic wasps for BBC Earth.

Pros and cons

Biocontrol has several advantages over pesticides. Populations can grow and spread on their own, as demonstrated by the samurai wasps, whereas pesticides typically need humans to spread them. Organisms can maintain their presence over the long-term without human intervention, while pesticides often require repeat applications. Pests can also evolve to resist pesticides in as few as 20 generations. And as biocontrol uses another organism, they can evolve in response the 's defenses.

Biocontrol is not free from issues. It often introduces a new invasive species to deal with an existing one. It can be difficult to predict the effects of a new species on an unprepared ecosystem.

For example, the  was introduced in Australia to eat several  there. Instead, the poisonous toad became a lethal meal for several native species, disrupting many other parts of the ecosystems there.

Parasitic wasps turn other insects into ‘zombies,’ saving millions of humans along the way
A laughing kookaburra eats a cane toad. Some kookaburras die from ingesting the 
poisonous toads. Credit: Shutterstock

Parasites may avoid some of these issues as, unlike predators, they are often limited to a single or very few host species, making them less likely to go off-target and affect  other than the intended one.

Given that most agricultural pests are insects and most pest insects are targeted by at least one parasitic wasp (there are an estimated 750,000 parasitic wasp species), this gives a legion of options to study for safe and effective pest management.

So next time you're online and see wasps being unfairly maligned, consider the millions of humans across the world who are alive and able to feed themselves because of them. And maybe this upcoming Halloween, should you encounter the spirit of a certain 1800s English naturalist going on about the theological implications of parasitic wasps' evil, tell him of the good they can do.Wasps are valuable for ecosystems, economy and human health (just like bees)

Provided by The Conversation 

This article is republished from The Conversation under a Creative Commons license. Read the original article.The Conversation