A swan paddles on Loch Faskally, Pitlochry, Scotland, Britain October 26, 2019. REUTERS/Russell Cheyne

A Pillar coral (Dendrogyra cylindricus) showing a small amount of tissue loss caused by Stony Coral Tissue Loss Disease (SCTLD) stands near the University of the Virgin Islands campus in St Thomas in the U.S. Virgin Islands, May 17, 2019. REUTERS/Lucas Jackson

Fatima, a two-year-old hippopotamus rescued from a circus, swims at the zoo in Managua, Nicaragua September 12, 2019. REUTERS/Oswaldo Rivas

Fatima, a two-year-old hippopotamus rescued from a circus, opens its mouth at the zoo in Managua, Nicaragua September 12, 2019. REUTERS/Oswaldo Rivas

Fatima, a two-year-old hippopotamus rescued from a circus, swims at the zoo in Managua, Nicaragua September 12, 2019. REUTERS/Oswaldo Rivas

Fatima, a two-year-old hippopotamus rescued from a circus, is fed at the zoo in Managua, Nicaragua September 12, 2019. REUTERS/Oswaldo Rivas

Fatima, a two-year-old hippopotamus rescued from a circus, shakes its head at the zoo in Managua, Nicaragua September 12, 2019. REUTERS/Oswaldo Rivas

A man paddles in the waters of the Ionian Sea near Sidari settlement on the island of Corfu, Greece July 26, 2019. REUTERS/Vasily Fedosenko

Large crocodiles are seen in the Tarcoles River, a river with one of the highest crocodile population in the world, in Tarcoles, province of Puntarenas, Costa Rica, July 16, 2019. REUTERS/Juan Carlos Ulate

A large crocodile is seen in the Tarcoles River, a river with one of the highest crocodile population in the world, in Tarcoles, province of Puntarenas, Costa Rica, July 16, 2019. REUTERS/Juan Carlos Ulate

A large crocodile eats a chicken given by Juan Cerdas, whose hobby is feeding them at the Tarcoles River, a river with one of the highest crocodile population in the world, in Tarcoles, province of Puntarenas, Costa Rica, July 16, 2019. REUTERS/Juan Carlos Ulate

A large crocodile is seen in the Tarcoles River, a river with one of the highest crocodile population in the world, in Tarcoles, province of Puntarenas, Costa Rica, July 16, 2019. REUTERS/Juan Carlos Ulate

A large crocodile is seen in the Tarcoles River, a river with one of the highest crocodile population in the world, in Tarcoles, province of Puntarenas, Costa Rica, July 16, 2019. REUTERS/Juan Carlos Ulate

A baby hippo stands in water near its mother Mona at Dvur Kralove Zoo, Czech Republic, June 12, 2019. Picture taken June 12, 2019. REUTERS/David W Cerny

A baby hippo stands in water at Dvur Kralove Zoo, Czech Republic, June 12, 2019. Picture taken June 12, 2019. REUTERS/David W Cerny

A baby hippo swims in a pond at Dvur Kralove Zoo, Czech Republic, June 12, 2019. Picture taken June 12, 2019. REUTERS/David W Cerny

A baby hippo swims in a pond near its mother Mona at Dvur Kralove Zoo, Czech Republic, June 12, 2019. Picture taken June 12, 2019. REUTERS/David W Cerny

Volunteers walk past a sunken plastic boat during in the Zero Plastiko Urdaibai ocean and coastal cleanup near Bermeo, Spain June 8, 2019. 2500 volunteers and 300 divers helped clean up the stretch of Basque coastline, according to organizers, as part of World Oceans Day. REUTERS/Vincent West

An image of the sunken boat "Mermaid" is seen during a news conference in Budapest, Hungary, June 3, 2019. REUTERS/Fedja Grulovic

Coral trout are seen inside Apollo Aquaculture Group's three-tiered vertical fish farm in northern Singapore, May 4, 2019. REUTERS/Loriene Perera

Vessels are washed up next to houses after a tsunami hit, in Anyer, Banten province, Indonesia December 25, 2018. REUTERS/Jorge Silva TPX IMAGES OF THE DAY

A sunken vessel is pictured after a tsunami hit Anyer in Banten province, Indonesia December 25, 2018. REUTERS/Jorge Silva

A boy wearing Santa Claus outfit watches a large fish tank at Sunshine Aquarium in Tokyo, Japan, December 18, 2018. REUTERS/Issei Kato

An excavator is partially submerged in a stream as civil defense members look for missing persons after rain storms unleashed flash floods, in Madaba city, near Amman, Jordan, November 10, 2018. REUTERS/Muhammad Hamed

People watch civil defense members as they look for missing persons after rain storms unleashed flash floods, in Madaba city, near Amman, Jordan, November 10, 2018. REUTERS/Muhammad Hamed

A moon jellyfish is seen at the Aquarium Pula, Croatia, July 25, 2018. Housed in a more than 130-year-old fort in Croatia, Aquarium Pula boasts species from the Adriatic as well as tropical marine zones and freshwater habitats. From seahorses delicately entwining themselves in the seagrass to the other-worldly jelly fish drifting in the deep blue water, the aquarium is home to around 250 species in 100 pools and tanks and attracts some 125,000 visitors a year. Picture taken July 25, 2018. REUTERS/Antonio Bronic

A starfish is seen at Aquarium Pula, Croatia, July 25, 2018. Housed in a more than 130-year-old fort in Croatia, Aquarium Pula boasts species from the Adriatic as well as tropical marine zones and freshwater habitats. From seahorses delicately entwining themselves in the seagrass to the other-worldly jelly fish drifting in the deep blue water, the aquarium is home to around 250 species in 100 pools and tanks and attracts some 125,000 visitors a year. Picture taken July 25, 2018. REUTERS/Antonio Bronic

Street lights partially submerged are seen along the Po river in Turin, Italy, November 6, 2018. REUTERS/Massimo Pinca

A damaged car is seen in the aftermath of the flooding of the Milicia river in Casteldaccia, near Palermo, Italy, November 4, 2018. REUTERS/Guglielmo Mangiapane

General view of the a house after the river Milicia flooded in Casteldaccia near Palermo, Italy, November 4, 2018. REUTERS/Guglielmo Mangiapane

Fish swim in the sea of Sidon, Lebanon November 2, 2018. REUTERS/Ali Hashisho

A destroyed car is seen at the bottom of the sea off the beach of Legrena, near Athens, Greece, October 21, 2018. Picture taken October 21, 2018. REUTERS/Stelios Misinas

A destroyed car is seen at the bottom of the sea off the beach of Legrena, near Athens, Greece, October 21, 2018. Picture taken October 21, 2018. REUTERS/Stelios Misinas

A destroyed engine is seen at the bottom of the sea off the beach of Legrena, near Athens, Greece, October 21, 2018. Picture taken October 21, 2018. REUTERS/Stelios Misinas

A destroyed car is seen at the bottom of the sea off the beach of Legrena, near Athens, Greece, October 21, 2018. Picture taken October 21, 2018. REUTERS/Stelios Misinas

A destroyed car is seen at the bottom of the sea off the beach of Legrena, near Athens, Greece, October 21, 2018. Picture taken October 21, 2018. REUTERS/Stelios Misinas

The Arab Baths monument is seen flooded after heavy rain and flash floods hit Ronda, southern Spain, October 21, 2018. REUTERS/Jon Nazca

A flooded field is seen after heavy rain and flash floods hit Campillos, southern Spain, October 21, 2018. REUTERS/Jon Nazca

A flooded field is seen after heavy rain and flash floods hit Campillos, southern Spain, October 21, 2018. REUTERS/Jon Nazca

A bird egg is seen on a street after a heavy rain and flash floods hit Campillos, southern Spain, October 21, 2018. REUTERS/Jon Nazca

A dead rat lies on a street after a heavy rain and flash floods hit Campillos, southern Spain, October 21, 2018. REUTERS/Jon Nazca

A dead bird lies on a street after a heavy rain and flash floods hit Campillos, southern Spain, October 21, 2018. REUTERS/Jon Nazca

A man shows a dead bird after a heavy rain and flash floods hit Campillos, southern Spain, October 21, 2018. REUTERS/Jon Nazca

A dead bird lies on a street after a heavy rain and flash floods hit Campillos, southern Spain, October 21, 2018. REUTERS/Jon Nazca

A flood level mark is seen inside a house after heavy rain and flash floods hit Campillos, southern Spain, October 21, 2018. REUTERS/Jon Nazca

A flood level mark is seen as mud stains the entrance of a house after heavy rain and flash floods hit Campillos, southern Spain, October 21, 2018. REUTERS/Jon Nazca

A car is seen in a hole with water at Balaroa neighborhood hit by the earthquake and liquefaction in Palu, Central Sulawesi, Indonesia, October 9, 2018. Picture taken October 9, 2018. REUTERS/Jorge Silva

A man swims underwater as warm autumn weather continues in Marseille, France, October 12, 2018. REUTERS/Jean-Paul Pelissier

A collapsed road between the villages of Arta and Can Picafort is seen after heavy rain and flash floods hit Sant Llorenc de Cardassar on the island of Mallorca, Spain, October 11, 2018. REUTERS/Enrique Calvo

A villager clears debris after heavy rain and flash floods hit Sant Llorenc de Cardassar on the island of Mallorca, Spain, October 11, 2018. REUTERS/Enrique Calvo

A ravaged local soccer field is seen after heavy rain and flash floods hit Sant Llorenc de Cardassar on the island of Mallorca, Spain, October 11, 2018. REUTERS/Enrique Calvo

A ravaged local soccer field is seen after heavy rain and flash floods hit Sant Llorenc de Cardassar on the island of Mallorca, Spain, October 11, 2018. REUTERS/Enrique Calvo

Mud and debris are seen after heavy rain and flash floods hit Sant Llorenc de Cardassar on the island of Mallorca, Spain, October 11, 2018. REUTERS/Enrique Calvo

A general view of Cheruthoni dam with one open gate is seen in Idukki, Kerala, India, September 5, 2018. REUTERS/Sivaram V SEARCH "SIVARAM DAMS" FOR THIS STORY. SEARCH "WIDER IMAGE" FOR ALL STORIES. TPX IMAGES OF THE DAY.

A man rides his motorbike over a damaged bridge in Idukki, Kerala, India, September 6, 2018. REUTERS/Sivaram V SEARCH "SIVARAM DAMS" FOR THIS STORY. SEARCH "WIDER IMAGE" FOR ALL STORIES.

Idukki Arch Dam is seen in Kerala, India, September 5, 2018. REUTERS/Sivaram V SEARCH "SIVARAM DAMS" FOR THIS STORY. SEARCH "WIDER IMAGE" FOR ALL STORIES.

Apung mosque is seen sinking after the tsunami next to the beach in Palu, Central Sulawesi, Indonesia, October 9, 2018. REUTERS/Jorge Silva TPX IMAGES OF THE DAY

Apung mosque is seen sinking after the tsunami next to the beach in Palu, Central Sulawesi, Indonesia, October 9, 2018. REUTERS/Jorge Silva

A man looks at a sunken house in the Petobo neighbourhood which was hit by an earthquake and liquefaction in Palu, Central Sulawesi, Indonesia, October 8, 2018. REUTERS/Jorge Silva