Moon and Earth’s magnetic field guide European eels on their epic migration

first_imgArticle published by Rhett Butler European eels use an electromagnetic “sixth sense” to navigate during their long migration, two new studies propose.The electrical “shadow” of a new moon may help eels cross the continental shelf of Europe to shore. Then, in the brackish waters of an estuary, young eels can imprint on the unique magnetic signature to navigate upstream.Piecing together the eels’ directional cues could help fisheries managers create more effective conservation plans for this critically endangered species. Far out in a featureless sea, the light of the moon is a beacon for migrating eels. They’re aiming for coastal estuaries, gateways to freshwater rivers where they will live for decades. When visibility becomes poor, eels can read an estuary’s unique magnetic map to navigate upstream.New research led by Alessandro Cresci, a Ph.D. candidate in biological oceanography at the University of Miami in Florida, is highlighting two key stages in the migration of European eels (Anguilla anguilla), an IUCN Critically Endangered species.“There’s a lot of work on how eels respond to patchy stimuli like light,” Cresci said of past research. “But we wanted to look into more stable navigational cues.”Glass eels are one phase in the complex life history of the European eel (Anguilla anguilla). Figure adapted from Cresci et al. (2019a).The first study, published in a recent issue of Communications Biology, describes eel navigation using magnetic fields in brackish waters. The second, published in Royal Society Open Science, identifies lunar cues that guide eels at sea.European eels begin as leaf-shaped larvae riding the Gulf Stream across the Atlantic Ocean, from the Sargasso Sea near Bermuda to the continental shelf off western Europe. Over the two-year crossing, they metamorphose into transparent glass eels just 7 centimeters (3 inches) long. Hundreds of millions arrive each year at coastlines from Scandinavia to Morocco.Navigating up estuaries toward inland rivers, glass eels turn a camouflaging brown. They live for 5 to 30 years in the same river, growing from immature yellow adults into silver eels up to 1 meter (3 feet) long. Finally, these mature eels return to the Sargasso Sea to spawn and die. Their lifelong migratory loop tops 10,000 kilometers (6,200 miles).Passing from open ocean into murky rivers, eels must rely on all of their senses to navigate. Scientists have shown that eels use smell, temperature and tides to find rivers close to shore, and many are thought to respond to the lunar cycle.However, while magnetic and lunar navigation has been studied heavily in other species like salmon, according to Cresci, “the marine phase of the eel migration is really a black box.”A single eel swims in a transparent observation chamber during an experiment. Photo courtesy of Alessandro Cresci.To study their navigation in the open ocean, Cresci and his team collected 203 glass eels from the Austevoll Archipelago in Norway. Drifting over the continental shelf, they deployed a transparent chamber that mimicked natural conditions for the eel inside while compasses logged its preferred swimming direction. Tests were run in daylight during the four phases of the moon: new, first quarter, full and third quarter.Most eels swam in a purposeful, non-random direction. The trend was strongest during the new moon, when 96 percent of all eels swam quickly towards the moon’s position above the horizon.This caused the eels to generally swim southward, the average direction of the moon’s path across the sky from east to west. Glass eels are pulled northward by the powerful Gulf Stream, and while they can’t overcome this current, angling in a southern direction makes it more likely they will land somewhere favorable.However, the new moon rises with the sun and casts very little light. Cresci and his colleagues think eels follow the moon’s electrical signal, not its faint glow.Positioned between Earth and the sun, a new moon is exposed to solar winds that blow negative electrical charges to Earth’s surface. In effect, said Cresci, this forms a “shadow” that the eels’ sensitive receptors can detect.It’s likely, he added, that the light of the full moon helps orient the eels as well. They are preparing to conduct the same tests at night, when the full moon rises above the horizon.But once eels reach the muddy bends of an estuary, the moon isn’t useful. Estuaries flow with tidal rhythms, and the motion of sea water across Earth’s magnetic field creates small electric currents that are also detectable by fish.Because European eels settle in one river, Cresci thought young eels might imprint that river’s specific electromagnetic signature to form a lifelong, rudimentary map to navigate back to the Sargasso Sea as adults.Cresci and his team collected another 222 eels from estuaries in Norway flowing along different compass axes. In a remote facility designed to study magnetic orientation in aquatic organisms, they manipulated electric coils to randomize the magnetic field and recorded how eels oriented in the invisible magnetic current.About 70 percent of eels oriented to the tidal conditions taking place in their home estuary at that moment. If the tide was ebbing, eels oriented one way; if the tide was flowing, they shifted their bearing by 180 degrees, a response to the change in the electric field caused by the reversal of flowing water. Glass eels remembered the tidal signature of their estuary and responded to it even when removed.Together, these studies paint eels as multifaceted navigators.“I think they can sense a lot, but they use specific cues at each step depending on the environment,” Cresci said.The work is “good research by good scientists,” said Paul Coulson, Director of Operations for the UK-based Institute of Fisheries Management, who was not involved in either study.A recent report highlights a sharp increase in international smuggling of glass eels. The left figure shows kilograms of fish smuggled (visualized by thickness of the line) between 2013-2017, while the right shows only the period between 2017-2019. Graphic courtesy of TRAFFIC.Understanding eel navigation is essential to their conservation, Coulson said. Overfishing has reduced European eels to less than 10 percent of their historical population. The European Union ended international commercial trading in 2010, but the wildlife trade monitoring group TRAFFIC recently reported a surge in glass eel smuggling. Coulson calls it “by volume, the largest wildlife crime of animals on the planet.”The EU is also implementing a restocking program. Countries like France with large glass eel fisheries must retain 60 percent of their catch to help repopulate the eels’ historic range. Cresci’s results suggest that moving eels from their home rivers could disorient them.“We relocate millions of animals each year, so the imprinting results are quite important,” Coulson said. “Keeping them on the same migratory track is something we should consider.”As each link creates a fuller picture of how eels navigate a shifting environment, Cresci says he feels confident in their resilience: “Nature can be surprising, and this ancient and mysterious creature of a few inches can accomplish incredible things.”Glass eels are a juvenile form of the European eel (Anguilla anguilla), a species that undergoes an incredible 10,000 kilometer (6,200 mile) migration. Photo courtesy of Alessandro Cresci.CITATIONSCresci, A., Durif, C.M., Paris, C.B., Thompson, C., Shema, S., Skiftesvik, A.B. & Browman, H.I. (2019a) The relationship between the moon cycle and the orientation of glass eels (Anguilla anguilla) at sea. Royal Society Open Science 6(10). https://doi.org/10.1098/rsos.190812Cresci, A., Durif, C.M., Paris, C.B., Shema, S., Thompson, C., Bjelland, R., Skiftesvik, A.B. & Browman, H.I. (2019b). Glass eels (Anguilla anguilla) imprint the magnetic direction of tidal currents from their juvenile estuaries. Nature Communications Biology 2(366). https://doi.org/10.1038/s42003-019-0619-8Amanda Heidt (@Scatter_Cushion) is a graduate student in the Science Communication Program at the University of California, Santa Cruz. Other news stories by UCSC students can be found at https://news.mongabay.com/list/ucsc/. Animal Behavior, Animals, Ecological Beauty, Fish, Fishing, Illegal Fishing, Oceans, UCSC, Wildlife center_img Popular in the CommunitySponsoredSponsoredOrangutan found tortured and decapitated prompts Indonesia probeEMGIES17 Jan, 2018We will never know the full extent of what this poor Orangutan went through before he died, the same must be done to this evil perpetrator(s) they don’t deserve the air that they breathe this has truly upset me and I wonder for the future for these wonderful creatures. So called ‘Mankind’ has a lot to answer for we are the only ones ruining this world I prefer animals to humans any day of the week.What makes community ecotourism succeed? In Madagascar, location, location, locationScissors1dOther countries should also learn and try to incorporateWhy you should care about the current wave of mass extinctions (commentary)Processor1 DecAfter all, there is no infinite anything in the whole galaxy!Infinite stupidity, right here on earth.The wildlife trade threatens people and animals alike (commentary)Anchor3dUnfortunately I feel The Chinese have no compassion for any living animal. They are a cruel country that as we knowneatbeverything that moves and do not humanily kill these poor animals and insects. They have no health and safety on their markets and they then contract these diseases. Maybe its karma maybe they should look at the way they live and stop using animals for all there so called remedies. DisgustingConservationists welcome China’s wildlife trade banThobolo27 JanChina has consistently been the worlds worst, “ Face of Evil “ in regards our planets flora and fauna survival. In some ways, this is nature trying to fight back. This ban is great, but the rest of the world just cannot allow it to be temporary, because history has demonstrated that once this coronavirus passes, they will in all likelihood, simply revert to been the planets worst Ecco Terrorists. Let’s simply not allow this to happen! How and why they have been able to degrade this planets iconic species, rape the planets rivers, oceans and forests, with apparent impunity, is just mind boggling! Please no more.Probing rural poachers in Africa: Why do they poach?Carrot3dOne day I feel like animals will be more scarce, and I agree with one of my friends, they said that poaching will take over the world, but I also hope notUpset about Amazon fires last year? Focus on deforestation this year (commentary)Bullhorn4dLies and more leisSponsoredSponsoredCoke is again the biggest culprit behind plastic waste in the PhilippinesGrapes7 NovOnce again the article blames companies for the actions of individuals. It is individuals that buy these products, it is individuals that dispose of them improperly. If we want to change it, we have to change, not just create bad guys to blame.Brazilian response to Bolsonaro policies and Amazon fires growsCar4 SepThank you for this excellent report. I feel overwhelmed by the ecocidal intent of the Bolsonaro government in the name of ‘developing’ their ‘God-given’ resources.U.S. allocates first of $30M in grants for forest conservation in SumatraPlanet4dcarrot hella thick ;)Melting Arctic sea ice may be altering winds, weather at equator: studyleftylarry30 JanThe Arctic sea ice seems to be recovering this winter as per the last 10-12 years, good news.Malaysia has the world’s highest deforestation rate, reveals Google forest mapBone27 Sep, 2018Who you’re trying to fool with selective data revelation?You can’t hide the truth if you show historical deforestation for all countries, especially in Europe from 1800s to this day. WorldBank has a good wholesome data on this.Mass tree planting along India’s Cauvery River has scientists worriedSurendra Nekkanti23 JanHi Mongabay. Good effort trying to be objective in this article. I would like to give a constructive feedback which could help in clearing things up.1. It is mentioned that planting trees in village common lands will have negative affects socially and ecologically. There is no need to even have to agree or disagree with it, because, you also mentioned the fact that Cauvery Calling aims to plant trees only in the private lands of the farmers. So, plantation in the common lands doesn’t come into the picture.2.I don’t see that the ecologists are totally against this project, but just they they have some concerns, mainly in terms of what species of trees will be planted. And because there was no direct communication between the ecologists and Isha Foundation, it was not possible for them to address the concerns. As you seem to have spoken with an Isha spokesperson, if you could connect the concerned parties, it would be great, because I see that the ecologists are genuinely interested in making sure things are done the right way.May we all come together and make things happen.Rare Amazon bush dogs caught on camera in BoliviaCarrot1 Feba very good iniciative to be fallowed by the ranchers all overSponsoredlast_img read more

Pumpkin ideas perfect for the day that’s in it – Pumpkin Day!

first_imgby Cliodhna HarveyHalloween is almost upon us, and today is a great time to celebrate the symbolic seasonal vegetable as it is World Pumpkin Day. We’ve found a tasty recipe to try out that is simple and sweet and doesn’t involve scooping out those nasty seeds. We’ve also sourced some top tips for carving the perfect pumpkin so you can get creative and bring your own element of spooky fun to the home. Happy Halloween! Pumpkin Rice Krispie Treats RecipeHere’s a fun way to make snacks or treats for Halloween parties, created by CincyShopper.com.Ingredients6 cups Rice Krispie cereal3 tbs butter10 oz marshmallows (approx 1 Bag)Red and yellow food colouring (to make orange color)12 Tootsie Rolls1 green fruit roll-up (you will only be able to find the blue/green combo)Method Melt your butter in a large sauce pan over low heatAdd marshmallows and stir constantly until meltedRemove from heatAdd approx 4 drops of red food colouring and 2 drops yellow food colouring – add until you have a nice bright orange colorMix in Rice KrispiesForm small balls into the shape of a pumpkin (Tip: Add non-stick cooking spray to your hands before forming the balls)Cut Tootsie Roll in half and add a half into each pumpkin while still warmCut small leaves from the green portion of your fruit roll-upRecipe source: http://cincyshopper.com/pumpkin-rice-krispie-treats/Here are seven easy pumpkin carving tips from FamilyHoliday.net  1. Good carving starts with the right pumpkinChoose one that is fresh plump round shape with a rich, orange color, with a sturdy stem as this will later serve as an important design feature and no bruises-blemish-free- and that has a flat bottom so it won’t roll. But in case if you have an idea what type of faces you may be interested in carving, you may take the shape of the pumpkin into consideration; tall, triangular, flat, cone shape….2. Cut out the top (or bottom);When cutting out the top or the bottom of your pumpkin make sure you cut a simple shape… a square and it should be big enough so that you will be able to easily scoop out the guts (the seeds and membrane) of the pumpkin. Angle your carving tool or knife when cutting out the lid cut on an angle, not straight up and down so that the outside edge is a bit larger than the inside. This ensures that the lid will not fall through once it is cut out and your lid won’t drop inside! A boning knife works best for this.3. Scooping out the pumpkin:Use an ice cream scoop will do just fine instead buying a special “claw”. Starting at the top, scrape the seeds and membrane on the sides of the pumpkin, so the inner wall of the “face” area to 1 1/4-inch thick and the interior of the pumpkin is smooth and clean and the bottom (inside) of the pumpkin flat.4. Designing your masterpieceIf you’re going for high art, don’t start carving free-style – use a marker pen to print or draw your design onto the pumpkin first. If you want your lantern to look really professional, draw a paper template, and then tape it onto the pumpkin.Then use a sharp pointed tool to trace the design through the paper and onto the pumpkin to poke holes around the design so the paper can be removed or sketch your design directly onto the pumpkin with a dry-erase or water-based marker. Use a knife with a thin, long blade to cut out your design, starting at the center and working outwards. Take your time and be careful as you carve. 5. Keep your pumpkin last longer and freshA pumpkin can last for about a week once it is carved. Spread petroleum jelly on the cut edges to prolong its life a few extra days by sealing in its moisture, this works as a barrier and delays rotting.* Petroleum jelly is flammable so wait until it sets or coat the pumpkin before you place the candle inside6. To keep your Jack indoorsSprinkle a little cinnamon nutmeg and cloves inside the lid. When you light the candle, your jack-o-lantern will smell like an autumn air freshener.Source: http://www.familyholiday.net/Pumpkin ideas perfect for the day that’s in it – Pumpkin Day! was last modified: October 26th, 2016 by Rachel McLaughlinShare this:Click to share on Facebook (Opens in new window)Click to share on Twitter (Opens in new window)Click to share on LinkedIn (Opens in new window)Click to share on Reddit (Opens in new window)Click to share on Pocket (Opens in new window)Click to share on Telegram (Opens in new window)Click to share on WhatsApp (Opens in new window)Click to share on Skype (Opens in new window)Click to print (Opens in new window)Tags:Carving PumpkinsHalloweenNational Pumpkin DayPumpkin Rice Krispie Treatslast_img read more

Redevelopment bylaws to ease friction, streamline process

first_imgThe Maharashtra government has issued bylaws to facilitate the smooth redevelopment of old housing societies. The new rules are likely to streamline disputes in societies and encourage redevelopment of thousands of old structures, officials said. The changes were made following complaints of non transparency, disputes on appointment of contractors, violation of the redevelopment rules, delays in tendering, among others. The rules, issued by the Maharashtra Co-operation, Textiles and Marketing Department this week, have reduced the consent clause to 51% from 70% of society members. The government has already relaxed the consent clause in other redevelopment schemes such as that of a slum, but it has been done for housing societies only now.The bylaws also list the procedures and modalities for the managing committee of a society, streamlining procedures for conducting meetings to granting sanction to redevelopment. The bylaws have fixed the minimum quorum required for a meeting of the managing committee at one-fifth of the membership strength. A special general body meeting must be called within two months of receipt of the application for redevelopment, and its minutes circulated among all the members within seven days.The redevelopment blueprint needs to be be uploaded by all societies and mailed to the members. Similarly, once the contractor and architect are appointed, they must be given an appointment letter in less than 30 days. Experts and citizens are happy with the new rules. “I welcome this progressive decision of the chief minister. It will help streamline disputes in societies and encourage redevelopment of old, dilapidated buildings for safe habitation,” said Manoj Kotak, Bharatiya Janata Party Member of Parliament from Mumbai North East, who has been receiving a lot of complaints on disputes between the managing committee of a society. However, some still feel the rebate in cess given to old structures under Rule 33 (7) of the Development Control Rules in the island city must be extended to structures in the suburbs. “The government has taken the onus of repair of cessed structures in the island city, but in suburban areas, the buildings do not pay cess and come under Rule 33 (7). The government must remove this injustice against old buildings in the suburbs,” said Parag Alavani, Member of the Legislative Assembly from Vile Parle.last_img read more

NBA legend Julius Erving defends LeBron James’ NBA Finals record

first_img“Dr. J” Julius Erving (left) with fellow NBA legends Oscar Robinson and Bill Russell  (AP Photo/Frank Franklin II)Despite taking part in the National Basketball Association’s (NBA) last six Finals—with eight total appearances overall—LeBron James has drawn flak for his subpar 3-wins-and-5-losses championship record.Although his individual greatness on the court cannot be questioned, the NBA’s premier superstar remains hounded by pundits questioning his presumed lack of success on the league’s grandest stage.ADVERTISEMENT Trump strips away truth with hunky topless photo tweet “So, 3-5 doesn’t mean anything. I’m more impressed with eight Finals than I am with the record in the Finals,” he said.“If he was 0-for-8 in Finals, that would still be an amazing achievement. That’s like going to eight Super Bowls.”  Khristian Ibarrola /raSports Related Videospowered by AdSparcRead Next NCAA: Letran scrapes past EAC for first win Don’t miss out on the latest news and information. Makabayan bloc defends protesting workers, tells Año to ‘shut up’ PLAY LIST 02:11Makabayan bloc defends protesting workers, tells Año to ‘shut up’00:50Trending Articles01:50Palace defends Duterte’s absences from Asean events02:49Robredo: True leaders perform well despite having ‘uninspiring’ boss02:42PH underwater hockey team aims to make waves in SEA Games01:44Philippines marks anniversary of massacre with calls for justice01:19Fire erupts in Barangay Tatalon in Quezon City01:07Trump talks impeachment while meeting NCAA athletes02:49World-class track facilities installed at NCC for SEA Games Church, environmentalists ask DENR to revoke ECC of Quezon province coal plant FEU Auditorium’s 70th year celebrated with FEU Theater Guild’s ‘The Dreamweavers’ MOST READ LATEST STORIES Ethel Booba on hotel’s clarification that ‘kikiam’ is ‘chicken sausage’: ‘Kung di pa pansinin, baka isipin nila ok lang’ Lacson: SEA Games fund put in foundation like ‘Napoles case’ View comments National Coffee Research Development and Extension Center brews the 2nd National Coffee Education Congress El Nido residents told to vacate beach homes Hotel says PH coach apologized for ‘kikiam for breakfast’ claim Having won titles in both the NBA and ABA (American Basketball Association), Julius Erving put in his two cents on James’ record and what it means for his legacy.The retired legend, best known as “Dr. J,” who experienced several Finals setbacks of his own as a member of the Philadelphia 76ers, said that LeBron’s past shortcomings do not entirely fall on his shoulders.FEATURED STORIESSPORTSSEA Games: Biñan football stadium stands out in preparedness, completionSPORTSPrivate companies step in to help SEA Games hostingSPORTSWin or don’t eat: the Philippines’ poverty-driven, world-beating pool stars“The game is a team sport, so individuals don’t win championships. Teams win championships,” he told FS1’s Undisputed. “You’re only as good as the team can take you. You can only go as far as the team can take you.”Knowing first-hand how hard it is to contend for a championship on a consistent basis, the NBA Hall of Famer also lauded James’ efforts throughout his storied career.last_img read more

4 Tips on Using Photos Online

first_imgAs promised in yesterday’s post, Bryan at Collective Lens has been kind enough to provide these tips, as well as these stunning photos, generously shared by the talented Shehzad Noorani and Kathy Adams.copyright Shehzad NooraniSathi’s (8 years old) face is blacked with carbon dust from recycled batteries. Often she looks so black, that children in her neighborhood call her ghost. She works in battery recycling factory at Korar Ghat on the outskirts of Dhaka. She earns less than Taka 200 ($3.50 approx) per month.Kathy Adams, Empowerment InternationalLook Mom, I CAN count! Empowerment International works with not just students in Nicaragua but also their parents. Getting the parents involved and supportive of their child’s education is one key to success in completing at least primary school (in a nation where only 50% of the enrolled 1st graders complete 5th grade).– Use photos to tell a story. “A picture is worth 1000 words,” as they say. Imagery can go much further than written text to bring out the events and emotions of a particular cause or issue. One photo can describe a pressing situation, warm the heart of the viewer, or cause your audience to react and respond. Furthermore, with multiple photos organized into a photo essay, an entire story can be told from the big picture to the smallest details in an efficient and effective manner.– Use photos to grab the attention of the viewer. In today’s media-driven society, words alone can not compete for the attention of your desired audience. With television, movies, YouTube, texting, and millions of competing websites, your message must make an instantaneous impact. This is especially true if you are vying for the attention of today’s youth. If your message is text only, you should not expect most people to read more than five sentences. Lead with a powerful photo.– Use photos to create an emotional impact. Human faces attract the viewer’s eye faster than any other subject matter. Use this to your advantage, and display photos that showcase the human impact of an important issue and the work that your organization is doing around it.– Copyright issues are extremely important. If you see a photo on the web, you are most likely not allowed to use it. The photographer has full copyrights to the photo unless otherwise noted. However, it doesn’t hurt to ask for permission! Many photographers would be delighted to hear from you, especially if you’re using the photo for a good cause. Keep in mind that the production of good photography costs money and is a career for many people. Also, many websites such as Collective Lens and Flickr allow photographers to mark their photos with Creative Commons licenses, and then allow the public to search for photos marked with these licenses. These licenses allow others to freely use the photos, but only under certain conditions, and always with attribution. For example, a photo marked with a Creative Commons Non Commercial license (CC-BY-NC) can not be used for commercial or advertising purposes. However, it is permissible to use it in an editorial story. It is also important to note that the people in the photos have rights as well. If a photo is to be used for commercial purposes, then every identifiable person in the photo must sign a release. If a photographer does not have releases, then he or she should have marked the photo with a Creative Commons Non Commercial license. Sometimes copyright rules can get complicated, but don’t let that deter you from asking questions if you have doubts about a photo. If all else fails, email the photographer and ask for permission.last_img read more

Game theory that applies to you

first_imgAt the Independent Sector session, “Developing Online Simulations, Creating Real World Change” Stephen Bennett, President and CEO of United Cerebral Palsy discussed their game for simulating care giving – Ruby’s Bequest. I liked some of the principles he used to design the game. They apply to just about anything online. I paraphrase them here:1. Don’t create a new destination if you want to reach a lot of people from the get-go2. Connect existing groups already predisposed toward your issue3. Let people stay where they are virtually when they interact with you4. Make it easy for people to engagelast_img read more