Author: BBC World Service

Russian forces in the forested exclusion zone around the Chernobyl nuclear site may be receiving potentially dangerous levels of radiation. After the nuclear accident trees were felled and radioactive material was buried across the site. As the forest regrew its took up much of that radiation - making it the most radioactive forest in the world according to Tom Scott from Bristol University who studies radiation levels in the region. The troop's activities, from digging trenches to lighting fires as missiles are fired, may be releasing radiation. Its unclear how dangerous this is, but those with the greatest and most immediate exposure risk are the troops themselves.

Australia’s iconic Great Barrier Reef has suffered a mass bleaching event – where coral can be killed by rising temperatures. This is the latest in a series of such events which also affect other reefs. Kate Quigley from The Australian Institute of Marine Science is working to breed corals that can be more heat tolerant. However, she says this is not a solution in itself without addressing climate change and continued ocean warming.

Understanding the human genome has reached a new milestone, with a new analysis that digs deep into areas previously dismissed as ‘junk DNA’ but which may actually play a key role in diseases such as cancer and a range of developmental conditions. Karen Miga from the University of California, Santa Cruz is one of the leaders of the collaboration behind the new findings.

And can fish do maths? Yes according to Vera Schlussel from the University of Bonn. Her group managed to train fish in both addition and subtraction. Many animals undertake remarkable migratory journeys; travelling thousands of miles only to return to same burrow or beach they departed from. Yet, unlike humans, they don’t have digital or paper maps to guide their way, so how are they able to orientate themselves with such accuracy?

In the second part of this migration story, CrowdScience’s Anand Jagatia explores how animals are able to navigate using the sun, stars, smells, landmarks and magnetism to help guide them. Anand journeys to the coast of Florida where he helps to place a satellite tracker on a sea turtle in order to follow the long-distance journeys of these animals. He then visits a lab in North Carolina to meet a team that is recreating the earth’s magnetic fields to examine how sea turtles might be using these forces to find their feeding and nesting grounds.

Anand wades into the hotly contested topic of just how birds may be sensing magnetic fields – and hears about one of the latest theories that suggests birds eyes may be exploiting quantum physics. The range of navigational tools we encounter throughout the animal kingdom from whales to ants is beguiling, Anand asks what does our increased understanding of these feats might mean for animal conservation as well as human development of mapping systems.

(Image: Radiation hazard sign in Pripyat, a ghost town in northern Ukraine, evacuated the day after the Chernobyl disaster. Credit: Getty Images)

Many animals undertake remarkable migratory journeys; travelling thousands of miles only to return to same burrow or beach they departed from. Yet, unlike humans, they don’t have digital or paper maps to guide their way, so how are they able to orientate themselves with such accuracy?

In the second part of this migration story, CrowdScience’s Anand Jagatia explores how animals are able to navigate using the sun, stars, smells, landmarks and magnetism to help guide them. Anand journeys to the coast of Florida where he helps to place a satellite tracker on a sea turtle in order to follow the long-distance journeys of these animals. He then visits a lab in North Carolina to meet a team that is recreating the earth’s magnetic fields to examine how sea turtles might be using these forces to find their feeding and nesting grounds.

Anand wades into the hotly contested topic of just how birds may be sensing magnetic fields – and hears about one of the latest theories that suggests birds eyes may be exploiting quantum physics. The range of navigational tools we encounter throughout the animal kingdom from whales to ants is beguiling, Anand asks what does our increased understanding of these feats might mean for animal conservation as well as human development of mapping systems.

Contributors: David Godfrey – Sea Turtle Conservancy Rick Herren – University of Florida Tim Guilford – University of Oxford Ken Lohmann – University of North Carolina Kayla Goforth – University of North Carolina Henrik Mouritsen – University of Oldenburg

(Photo: Sea Turtles. Credit: Getty Images)

Russian forces in the forested exclusion zone around the Chernobyl nuclear site may be receiving potentially dangerous levels of radiation. After the nuclear accident trees were felled and radioactive material was buried across the site. As the forest regrew its took up much of that radiation - making it the most radioactive forest in the world according to Tom Scott from Bristol University who studies radiation levels in the region. The troop's activities, from digging trenches to lighting fires as missiles are fired, may be releasing radiation. Its unclear how dangerous this is, but those with the greatest and most immediate exposure risk are the troops themselves.

Australia’s iconic Great Barrier Reef has suffered a mass bleaching event – where coral can be killed by rising temperatures. This is the latest in a series of such events which also affect other reefs. Kate Quigley from The Australian Institute of Marine Science is working to breed corals that can be more heat tolerant. However, she says this is not a solution in itself without addressing climate change and continued ocean warming.

Understanding the human genome has reached a new milestone, with a new analysis that digs deep into areas previously dismissed as ‘junk DNA’ but which may actually play a key role in diseases such as cancer and a range of developmental conditions. Karen Miga from the University of California, Santa Cruz is one of the leaders of the collaboration behind the new findings.

And can fish do maths? Yes according to Vera Schlussel from the University of Bonn. Her group managed to train fish in both addition and subtraction.

(Image: Radiation hazard sign in Pripyat, a ghost town in northern Ukraine, evacuated the day after the Chernobyl disaster. Credit: Getty Images)

Presenter: Roland Pease Producer: Julian Siddle

Wherever you are in the world you are probably near an animal that has undertaken a remarkable migratory journey, be that a butterfly, bird or sea turtle. But what CrowdScience listener Moses in Kenya wants to know is why they bother making such long and precarious voyages - and how they're able to reliably navigate over hundreds and sometimes even thousands of miles. In this first of two episodes, presenter Anand Jagatia travels to the Americas to meet the scientists finding and tracking these animals in order to solve the puzzle of where they go and why.

Deep in the lush and noisy Belizean jungle, Anand joins avian biologist Abidas who is collecting data on the beautiful birds that visit tropical forests to escape harsh winters. Here, using misting nets, Abidas and her team carefully catch birds to measure their health and status before tagging and releasing them so they can continue stocking up on jungle food. Anand finds out why having long term data on migrant birds can help in understanding why some birds, like the wood thrush, have been declining in their native homes further north.

Anand then jumps aboard a turtle boat in Florida where scientists from the Sea Turtle Conservancy have been collecting data on these dinosaur-like creatures. But finding them is harder it might seem. They move fast, so Anand accompanies the research team who are experienced in safely catching them, will he be lucky and find one of these magnificent creatures?

Presented by Anand Jagatia and produced by Melanie Brown

Contributors: David Barrie – Navigator & author Tim Guilford – University of Oxford Abidas Ash – University of Belize Kristen Ruegg - Colorado State University David Godfrey – Sea Turtle Conservancy

[Image credit: BBC Staff, Melanie Brown]

Unseasonably high temperatures have been recorded in both polar regions. Glaciologist Ruth Mottram discusses why they might be occurring now and the potential impact on her own work measuring climate change in Greenland.

Erica Ollmann Saphire from the La Jolla Institute for Immunology tells us about her work developing new treatments for Ebola, she is looking to develop drugs which work not just on Ebola but also a range of related Viruses.

And Eugene Koonin from the United States National Institutes of Health shows us how his computer modelling of the mutations of Sars Cov -2 suggest some good news - that the virus might not be able to mutate into further dangerous forms – at least not with its current set of genetic tools.

Eugene is originally from Russia and both he and President Obama’s science advisor John Holdren are keen to keep up ties with scientists in Russia despite the international sanctions now being applied over the war in Ukraine. Both point out that many Russian scientists have opposed the war, and that curtailing scientific collaboration could have a detrimental effect not just on science in Russia but elsewhere as well.

Image: Penguins on an ice float, Paradise Harbor, also known as Paradise Bay, behind Lemaire and Bryde Islands in Antarctica. Credit: Leamus via Getty Images)

Presenter: Roland Pease Producer: Alex Mansfield