biologist melina maravilla regularly takes water samples here with alarming results. >> bacalar has suchid colors but if the pollution continues like this, this could get dangerous and very quickly. >> for a lg time, th place was an insid's tip, bunow the visitors have arrived and with them the hotels, garbage, , and sewage. the lack of sewage treatment plants and the shortage of water have become a huge problem and as of the tren maya is expected 2023, to bring thousands more tourists every day. >> we cannot afford mass tourism. even now, we can hardly protect our ecosystem. >> the railway is coming to yucatan. that much is clear. but there's still time to check the signals and change its course. >> shuttered shops and food markets. covid-19 is a huge headache for retailers and farmers. e-commerce is stepping into the breach. industry turnover is due to grow by over 25 percent this year to more than 2 trillion euros. in 2020, 3 .5 billion people are expected to shop online almost , half the world's population. the biggest market is china. >> his days of poverty are over. wu xiansheng wa