♪ host: welcome to “global 3000.” octopus as a delicacy -- the highly intelligent creatures are threatened with extinction. what can be done? discarded treasure -- could human waste replace chemical fertilizer in the future? and, water stress -- how people in california are adapting to long-term drought. dried-up riverbeds, vanishing lakes -- in many parts of the

world, water is becoming scarce. almost half of europe's land surface is affected by drought. more than 750,000 hectares of land there have been destroyed by wildfires. california has suffered drought for years. but this year its effects are particularly visible. lake mead, the area's most important reservoir, has shrunk dramatically. its water level has dropped by more than 40 meters. the situation impacts the lives of millions. many are looking for creative solutions. reporter: san diego, the eighth largest city in the united states. 1.4 million people live here, with another two million in the suburbs. they all need water. but it's scarce. that's why nancy and ken cavanah planted native plants. all of them drought resistant. ken: it's pretty low maintenance.

we're not watering that much, so. it's just easy. nancy: maybe once a month we have to come out and really trim things. it just depends on the season. reporter: nine years ago, they decided their front lawn had to go. it required too much water. an offer from the region of san diego came at the right time -- a $43 bonus per square meter from the water authority. ken: all of this was lawn. this was all grass. and it's about 1700 square feet. we took it all out. this is all the bags of mulch i had to buy which is going to cover this whole area after the plants are in. reporter: for the cavanahs, the transformation has been worth it. they only had to put $50 of their own money into the project.

they're trying to get others interested, but not everyone cares. some still have a lawn that needs regular watering. or they have artificial turf and rock gardens that seal off the ground. it makes nancy angry. nancy: i have a mission. always on a mission. to save the planet, you know? reporter: they even try to save water at home, something also supported by the city. at first glance, everything looks normal. but there are water saving toilets in the bathrooms, as well as special shower heads. more than 600,000 residents have registered with the city to take part in the program. nancy: any little bit i can do throughout my daily life, whether it be in my bathroom or my kitchen, outside in my yard, the tiny steps -- it's only baby steps you have to take to

try to conserve on water. reporter: the drought is here stay. california has been suffering from a lack of water for 20 years. any land not being watered turns to desert. saving on drinking or groundwater is no longer enough to meet the needs of cities on the u.s. west coast. that's w the world's second largest desalinization plant was built here, outside san ego. engineer nathan faber shows us the plant. he knows it's energy intensive, a target for criticism from environmental activists. but he also knows there's no alternative. nathan: i could be surfing in the ocean and two hours later, the water is converted to drinking water and going to the residents of san diego county. reporter: two hours? nathan: two hours. reporter: the plant turns 190 million liters of seawater into drinking water for the region every day. it flows through 16,000 filters

in this pipe, in a process called reverse osmosis. it's one strategy of many for securing enough fresh water. nathan: since the 1990's, our per person water use has dropped in half. even though our population has increased and we've had these stressors like climate change and drought. one of the main factors is education. teaching people, and san diego county residents how to use less water and be more efficient. so with irrigation, with showers, really just changing their attitudes towards water use. reporter: the city oversees 500 kilometers of pipes, using sensors that sound an alarm if there's a leak anywhere. nathan faber is convinced that the measures being taken by the city work well together. nathan: the stress test showed that until 2045, and maybe even beyond, that the region has an adequate supply. we've invested in storage, we've invested in desalination, we've looked at recycled water.

reporter: collecting water and purifying it -- next to saving water, it's the issue in the san diego region. especially because it only gets around 25 centimeters of rain per year. emily and chris sears save every drop in two large tanks. that's enough to take care of their garden. they've created a green oasis with lots of fruit and vegetables. chris: i fear for the day where this is the only way to go, where we have to grow our own food because there's going to be such water shortages in the future, especially in the western states here. this is an ongoing crisis out here, so it makes a ton of sense to use water intelligently. reporter: garden designer brook sarson installed an irrigation system underneath chris und emily's beds that transports water from the house, directly to the fruit trees. brook: with how much laundry water they would be using every week, and we decided that would water about three fruit trees. so, there's a lot of nutrients in that grey water, from the

soaps and whatever's coming off of our clothes. it's basically, like, free fertilizer. reporter: depending on whether emily uses bleach for washing or organic detergent, this lever controls whether the wastewater is pumped into the sewer, or her garden. chris: this is actually feeding the root systems below. and it's also helping feed the entire main area around here and keep the ground more hydrated. reporter: like many san diego residents, they're combatting the drought any way they can, because they have no other choice. host: it's something we all have to do, often more than once a day. in germany, an average of six liters of drinking water washes the contents of our toilets down the drain. roughly a ird of the per capita drinking water consumption of 128 liters is

simply flushed away. and it's not just water that's wasted. human excreta contains many important nutrients which could perhaps be put to better use. take phosphorus. it's essential for plant growth. each year, 50,000 tons of it end up in sewage treatment plants. many countries are already starting to use human feces to produce biogas. and research is underway into its potential use in agriculture. that's not yet permitted in germany, but a revolution is under way. reporter: time for the morning trip to the toilet at this music festival in northern germany. these toilets are collecting a valuable resource -- fecal matter. here, it's not considered waste, rather, a raw material. during the summer, sanitation start-up finizio has been sending the toilets from festival to festival. that explains the empty hall at

the company's office in eberswalde, near berlin, leaving ceo florian augustin with time to tinker. florian: the raw materials we're talking about are urine, and of course feces that's collected here. just enormous amounts of nutrients. it's good stuff that comes out of us. but we just flush it away and don't want to have anything to do with it. but it's something we really have to start dealing with again. reporter: that's exactly the goal of the state-sponsored research project zirkulierbar, which finizio is also a part of. ariane krause coordinates the project to gather human waste from public toilets, and turn it into a useable resource. instead of flushing the waste with water, it's covered with pulverized straw. florian: i can do a demonstration, as if someone were peeing. reporter: inside the toilet, the urine

runs into a separate container. that means the feces stays dry. keeping them separate makes them easier to purify. ariane: the point of the project is to collect human waste, and to bring the nutrients in it onto the fields as fertilizer. there's huge recycling potential in human waste. reporter: zirkulierbar's research happens here, on the edge of eberswalde. this is where nutrients such as potassium, phosphorus, nitrogen, and many others that people excrete every day are being recycled, turning the plants that feed us back into fertilizer. the collected fecal matter is composted along with green waste and transformed into humus fertilizer for agricultural use. ariane: why do we want to recycle nutrients? if we look at minerals such as phosphorus or potassium, we typically get them from mines, and when it comes to phosphorus, resources are extremely scarce. nitrogen is another nutrient that we really need to be recycling, because it's an

essential nutrient that every plant needs to grow. reporter: and that would normally be extracted in an energy-intensive way. during composting, bacteria create heat. florian: so we're currently at 67 degrees. the goal is to reach 75 degrees, because that's when you have the greatest inactivation rate for pathogens. reporter: killing off the pathogens is key. that's just one of the things monitored by claudia kirsten's lab team at the biomass research center in leipzig. claudia: heavy metals should definitely not be present. we also check there's no mercury or lead, or traces of medication or resistant germs. when all goes well, they're usually killed off during the purification process and the temperatures in the compost. reporter: regulations in germany currently forbid the use of human waste in agricultural fertilizers. that's due to hygiene concerns. claudia:

we want to show that it's safe, and that it's possible to eliminate pollutants and comply with all the limit values, in line with the regulations. and to show that, after the composting and purification processes, you can use this material as fertilizer on fields. reporter: following her initial analysis, claudia kirsten is optimistic. zirkulierbar received special permission to use its fertilizer. now, the corn on the trial field is ready for harvesting -- earlier than expected, due to the drought. the soil mixed with the experimental fertilizer appears to have done a better job at supplying moisture to the corn than the untreated soil. zirkulierbar plans to focus next on using urine as a resource, which right now still has to be disposed of in the sewage system

ariane: that would actually be the perfect combination, if we were able to bring all the nutrients we excrete together again in the form of agricultural fertilizer that's used to produce more food. this now has a good smell of soil. that means the composting has gone well. the material has turned back into soil. reporter: the team is working on improving and automating urine composting, in order to start processing larger amounts. ariane krause and florian augustin never lose sight of the big picture, to make their products so good and so clean that they'll be put to use on fields. and the festivals are providing more than enough raw material. announcer: two children. two continents.

one giant problem. >> [speaking foreign language] >> [speaking foreign language] announcer: how will climate chance affect us and our children? learn more at dw.com/water. host: it's time to head to thailand for a tasty snack. reporter: bangkok. over eight million people live here in the capital of thailand. but even more come to visit. with over 20 million tourists arriving very year, bangkok is the most visited city in the world. one of the things it is most famous for is its street food. it's always busy at ahmad market. sasithorn samran opened her stall here one year ago.

she sells a snack that many people love, but only a few still make -- kanom krok. business is good. sasithorn: i chose to make this snack because it's hard to find and i like eating it. so i studied how to make it. reporter: the dough is traditionally made from coconut milk, rice flour, baking soda, and a little sugar. the recipe hasn't changed since it was first invented. while the halves of the dough balls are baked in the special kanom krok pan, sasithorn samran takes care of the toppings. in addition to fresh coconut shavings, there is corn and spring onions on offer. after about five minutes, the kanom kroks are golden brown and crispy on the outside, but still soft on the inside. the halves each are cut out individually, then assembled into balls. they are sold in cardboard boxes of seven to 10 pieces

each for the equivalent of about 1 euro and 10 cents. sasithorn samran doesn't just like making the snack, she enjoys eating them, too. sasithorn: people like eating it because the flavor is consistent and traditional. you also get the nice smell of coconut milk. and the texture of the corn and coconut makes it mellow and delicious. reporter: sasithorn samran sells about 50 pans a day. like the recipe, the spherical shape of kanom kroks hasn't changed a bit. literally translated, kanom krok means “snack mortar.” while a mortar is not used to prepare the dish, the round shape of the snacks is like that of a mortar bowl. and so, the tradition still lives on today. over time, only the savory fillings have changed.

>> whenever i see this snack, i buy it immediately. >> it's easy to eat and it's tasty. it's a thai snack that i often ate growing up, and even now i still eat it. it's not messy and it's easy to eat. reporter: khanom krok tastes best when the balls are still hot out of the pan. enjoy. host: an average of 19.2 kilos of fish are consumed per person per year -- that's about twice as much as 50 years ago.?? there are also twice as many people on the planet as back then, which means that overall fish consumption has effectively quadrupled. the un's food and agriculture organization reports that 31% of the world's fish stocks are overfished. could aquaculture be the answer? today, half of all the fish we consume comes from controlled breeding farms. but that doesn't always mean it's sustainable.

the construction of fish farms often means the destruction of natural fish habitats. chemicals, antibiotics, and excrement create pollution. conventional aquaculture also contributes to overfishing -- the farmed fish are often fed wild fish. and not all marine creatures can easily be bred in captivity. we head to mexico, where scientists are trying to do just that, with one particular local species. reporter: the octopus, a type of cephalopod, is a fascinating creature. it has three hearts and eight arms. those arms also contain most of its brain, with 500 million nerve cells and real superpowers. octopuses are highly intelligent. depending on their environment, they can change their shape, color, pattern, and even the

texture of their skin. carlos: they can turn into rocks, looking like they're covered in algae. or make themselves huge, and turn completely red. reporter: at an unam university satellite campus in the mexican coastal town of sisal, biologist carlos rosas is researching the octopus's ideal living conditions. results so far show the sensitive animal reacts dramatically to rising water temperatures by laying fewer eggs. this could become a problem if climate change progresses. carlos: we know today that the caribbean sea and the gulf of mexico are warming because of climate change. we want to create models that can predict whether the number of octopuses will decrease in

the future. reporter: there are still plenty of them here along the coast of yucatan, but that could change. demand for the low-fat delicacy is rising worldwide. and in some asian regions, they've already been overfished. for octopus catcher antonio coc in sisal, business is better than ever this season. antonio: it always depends on how long you want to work. i'm usually full by 1:00 p.m., and i earn around 500 pesos, 600 pesos. the people who stay out all afternoon make 2000 pesos, or 3000 pesos. reporter: but antonio coc is also worried about whether extensive fishing can go on forever. that's why he's working with the university's scientists to sell octopus raised in a breeding station instead of capturing them out at sea.

antonio: it's an ambitious project, but it will work. reporter: farming octopus is one of the biggest challenges facing the global seafood industry. unlike salmon and shrimp, they're sensitive to captivity and die quickly. but the mexican researchers have one advantage -- the local species, the maya, is particularly robust. carlos: this one is already two months old. the maya octopus is a very pleasant species. for one thing, they have no problem being in these tanks together. they get along very well. and besides, they don't emerge from the eggs the females hatch as larvae, but as fully developed tiny octopuses. reporter:

other octopus species are born as paralarvae. at that stage of development, massive numbers of them tend to die. here in sisal, where the hatchlings skip the larval stage, they breed surprisingly well. the heart of the university station. soon, new little maya octopuses will emerge from these eggs. if you look closely, you can see small black dots, the tiny eyes of the baby creatures. and new eggs are already on the way again. carlos: we have 32 tanks here, and in each one there is a pregnant female. now we're waiting for them to lay their eggs. reporter: the scientists capture the pregnant females in the open sea. they're just one year old and die after laying their eggs. they starve themselves to death, here in the breeding

station as in the wild. but keeping octopuses in captivity, even if only at the end of their lives, is always a source of controversy. the animals are so intelligent that critics consider it morally wrong to confine them. carlos rosas sees things differently. carlos: we've anthropomorphized the octopus, through movies and other stories that are spread. and that's a problem. reporter: in southern mexico, the octopus is regarded as a resource. it's a source of income and food for many people in the village. silvia: in a moment, you'll see how delicious this is. reporter: the coc family is having it for lunch today. silvia: here in yucatan, you'll be offered octopus everywhere you go, also in restaurants.

reporter: silvia coc serves fried octopus with her escabeche sauce. in other mexican regions, octopus is served in sushi, a popular dish in mexico. the world's appetite is huge -- some 420,000 tons of octopus are eaten annually. antonio and silvia coc come to the unam university research fality every day and volunteer to help raise the octopuses. they're learning how to successfully breed and raise them in this artificial environment. silvia: 1.6 grams. 1.8 grams. the very small ones get stressed out very quickly. reporter: while the scientists focus on their research and collect data, antonio coc and his wife

have now founded the moluscos del mayab cooperative to expand octopus farming commercially. the other catchers in the village were not very enthusiastic about the project at first. silvia: they said it was crazy. just a waste of time. they didn't believe in the project. reporter: now, almost 10 octopus catchers are organized within the cooperative. with the help of support funding, they were recently able to finance their own site. the tanks are already in place, but they still need money to get things up and running. antonio: we want to expand our project so that we can increase our market. selling nationally and internationally. that's my dream, preferably starting tomorrow. reporter: this project could secure the future for many fishing families, and perhaps also be a model for other regions affected by overfishing and climate change. host: and that's all from “global 3000” this week.

it was great to have you with us. drop us a line and tell us what you thought of the show. you can reach us at global3000@dw.com and we're on facebook too, dw global ideas. see you next time. take care. ♪ [captioning performed by the national captioning institute,

from berlin. russia formally and illegally annexes four regions of ukraine. president putin signs decrees to recognize them as russian territory and promises to defend them with all available means. western leaders say they will never recognize the move. fears of a coup in burkina faso. soldiers are on the streets and explosions have been heard near the presidential palace. the west a