Fishermen wear protective face masks as they prepare their nets next to a traditional fishing boat in the fishing village of Marsaxlokk, as Malta may be one of the countries added to a 'green' list where UK travellers will be able to visit with a negative coronavirus disease (COVID-19) test to be shown before travel but no quarantine needed after returning from holiday, Malta May 4, 2021. REUTERS/Darrin Zammit Lupi

A fisherman repairs a fishing net in Marina Grande, the main port of the island of Capri, a southern Italian island that relies heavily on foreign tourism, despite the loosening of the coronavirus disease (COVID-19) restrictions in much of the country, in Capri, Italy, April 27, 2021. REUTERS/Yara Nardi

A University of New South Wales research team sets a fyke net to conduct a platypus population survey in a creek near Bobin, Australia, April 7, 2021. Picture taken with drone on April 7, 2021. REUTERS/Loren Elliott

Dr. Gilad Bino, an ecologist from the University of New South Wales, sets a fyke net to conduct a platypus population survey in a creek near Bobin, Australia, April 7, 2021. Picture taken April 7, 2021. REUTERS/Loren Elliott

A University of New South Wales research team sets a fyke net to conduct a platypus population survey in a creek near Bobin, Australia, April 7, 2021. Picture taken April 7, 2021. REUTERS/Loren Elliott

A University of New South Wales research team sets a fyke net to conduct a platypus population survey in a creek near Bobin, Australia, April 7, 2021. Picture taken April 7, 2021. REUTERS/Loren Elliott

A University of New South Wales research team sets a fyke net to conduct a platypus population survey in a creek near Bobin, Australia, April 7, 2021. Picture taken with drone on April 7, 2021. REUTERS/Loren Elliott

Dr. Tahneal Hawke (L) and Dana Lanceman, members of a University of New South Wales research team, check a fyke net while conducting a platypus population survey in a creek near Bobin, Australia, April 8, 2021. Picture taken April 8, 2021. REUTERS/Loren Elliott

Dr. Gilad Bino, an ecologist from the University of New South Wales, sets a fyke net to conduct a platypus population survey in a creek near Bobin, Australia, April 7, 2021. Picture taken April 7, 2021. REUTERS/Loren Elliott

A University of New South Wales research team sets a fyke net to conduct a platypus population survey in a creek near Bobin, Australia, April 8, 2021. Picture taken with a drone on April 8, 2021. REUTERS/Loren Elliott

Dr. Tahneal Hawke, a research assistant from the University of New South Wales, checks a fyke net while conducting a platypus population survey in a creek near Bobin, Australia, April 7, 2021. Picture taken April 7, 2021. REUTERS/Loren Elliott

Dr. Tahneal Hawke, a research assistant from the University of New South Wales, prepares to set a fyke net to conduct a platypus population survey in a creek near Bobin, Australia, April 8, 2021. Picture taken April 8, 2021. REUTERS/Loren Elliott

Dr. Tahneal Hawke, a research assistant from the University of New South Wales, sets a fyke net to conduct a platypus population survey in a creek near Bobin, Australia, April 8, 2021. Picture taken April 8, 2021. REUTERS/Loren Elliott

A University of New South Wales research team sets a mesh net to conduct a platypus population survey in a creek near Bobin, Australia, April 8, 2021. Picture taken April 8, 2021. REUTERS/Loren Elliott

Britain's Prime Minister Boris Johnson catches a rugby ball during his visit at Net World Sports in Wrexham, Wales, Britain April 26, 2021. Rob Formstone/Pool via REUTERS

Britain's Prime Minister Boris Johnson passes a rugby ball during his visit at Net World Sports in Wrexham, Wales, Britain April 26, 2021. Rob Formstone/Pool via REUTERS

Britain's Prime Minister Boris Johnson holds a rugby ball during his visit at Net World Sports in Wrexham, Wales, Britain April 26, 2021. Rob Formstone/Pool via REUTERS

Britain's Prime Minister Boris Johnson holds a rugby ball as he talks to staff during his visit at Net World Sports in Wrexham, Wales, Britain April 26, 2021. Rob Formstone/Pool via REUTERS

Britain's Prime Minister Boris Johnson holds a rugby ball as he talks to staff (not seen) during his visit at Net World Sports in Wrexham, Wales, Britain April 26, 2021. Rob Formstone/Pool via REUTERS

Britain's Prime Minister Boris Johnson holds a rugby ball as he talks to staff (not seen) during his visit at Net World Sports in Wrexham, Wales, Britain April 26, 2021. Rob Formstone/Pool via REUTERS

Britain's Prime Minister Boris Johnson plays table tennis during his visit at Net World Sports in Wrexham, Wales, Britain April 26, 2021. Rob Formstone/Pool via REUTERS

Britain's Prime Minister Boris Johnson plays table tennis during his visit at Net World Sports in Wrexham, Wales, Britain April 26, 2021. Rob Formstone/Pool via REUTERS

Britain's Prime Minister Boris Johnson plays table tennis during his visit at Net World Sports in Wrexham, Wales, Britain April 26, 2021. Rob Formstone/Pool via REUTERS

Britain's Prime Minister Boris Johnson plays table tennis during his visit at Net World Sports in Wrexham, Wales, Britain April 26, 2021. Rob Formstone/Pool via REUTERS

Britain's Prime Minister Boris Johnson plays table tennis during his visit at Net World Sports in Wrexham, Wales, Britain April 26, 2021. Rob Formstone/Pool via REUTERS

Britain's Prime Minister Boris Johnson plays table tennis during his visit at Net World Sports in Wrexham, Wales, Britain April 26, 2021. Rob Formstone/Pool via REUTERS

Britain's Prime Minister Boris Johnson plays table tennis during his visit at Net World Sports in Wrexham, Wales, Britain April 26, 2021. Rob Formstone/Pool via REUTERS

Britain's Prime Minister Boris Johnson is accompanied by Wrexham Senedd candidate for the Conservatives Jeremy Kent and owner of Net World Sports Alex Loven during his visit in Wrexham, Wales, Britain April 26, 2021. Rob Formstone/Pool via REUTERS

Britain's Prime Minister Boris Johnson is accompanied by Wrexham Senedd candidate for the Conservatives Jeremy Kent and owner of Net World Sports Alex Loven during his visit in Wrexham, Wales, Britain April 26, 2021. Rob Formstone/Pool via REUTERS

Britain's Prime Minister Boris Johnson is accompanied by Wrexham Senedd candidate for the Conservatives Jeremy Kent and owner of Net World Sports Alex Loven during his visit in Wrexham, Wales, Britain April 26, 2021. Rob Formstone/Pool via REUTERS

Britain's Prime Minister Boris Johnson is accompanied by Wrexham Senedd candidate for the Conservatives Jeremy Kent, warehouse picking agent Molly Cross and owner of Net World Sports Alex Loven during his visit in Wrexham, Wales, Britain April 26, 2021. Rob Formstone/Pool via REUTERS

Britain's Prime Minister Boris Johnson is accompanied by Wrexham Senedd candidate for the Conservatives Jeremy Kent, warehouse picking agent Molly Cross and owner of Net World Sports Alex Loven during his visit in Wrexham, Wales, Britain April 26, 2021. Rob Formstone/Pool via REUTERS

Britain's Prime Minister Boris Johnson is accompanied by Wrexham Senedd candidate for the Conservatives Jeremy Kent, warehouse picking agent Molly Cross and owner of Net World Sports Alex Loven during his visit in Wrexham, Wales, Britain April 26, 2021. Rob Formstone/Pool via REUTERS

Britain's Prime Minister Boris Johnson is accompanied by Wrexham Senedd candidate for the Conservatives Jeremy Kent, warehouse picking agent Molly Cross and owner of Net World Sports Alex Loven during his visit in Wrexham, Wales, Britain April 26, 2021. Rob Formstone/Pool via REUTERS

Britain's Prime Minister Boris Johnson is accompanied by warehouse picking agent Molly Cross and owner of Net World Sports Alex Loven during his visit in Wrexham, Wales, Britain April 26, 2021. Rob Formstone/Pool via REUTERS REFILE - CORRECTING COMPANY NAME

Britain's Prime Minister Boris Johnson is accompanied by warehouse picking agent Molly Cross and owner of Net World Sports Alex Loven during his visit in Wrexham, Wales, Britain April 26, 2021. Rob Formstone/Pool via REUTERS REFILE - CORRECTING COMPANY NAME

Britain's Prime Minister Boris Johnson is accompanied by Wrexham Senedd candidate for the Conservatives Jeremy Kent and owner of Net World Sports Alex Loven during his visit in Wrexham, Wales, Britain April 26, 2021. Rob Formstone/Pool via REUTERS REFILE - CORRECTING COMPANY NAME

A Palestinian fisherman sleeps on covered nets after Israel restricted Palestinian fishing zone in response to Palestinian rockets, at the seaport of Gaza City April 26, 2021. REUTERS/Mohammed Salem

A Palestinian fisherman repairs his net after Israel restricted Palestinian fishing zone in response to Palestinian rockets, at the seaport of Gaza City April 26, 2021. REUTERS/Mohammed Salem

Palestinian fishermen rest on nets as boats are tied up after Israel restricted Palestinian fishing zone in response to Palestinian rockets, at the seaport of Gaza City April 26, 2021. REUTERS/Mohammed Salem

Emray Naquin casts his net at the Isle de Jean Charles, Louisiana, U.S., April 7, 2021. The Biloxi-Chitimacha-Choctaw tribe has lived on Isle de Jean Charles for nearly 200 years and is in the process of resettlement, which will be the nation's first federally-funded HUD climate resilience grant to relocate a Louisiana community affected by climate change. Picture taken April 7, 2021. REUTERS/Kathleen Flynn

Les achats nets quotidiens de SPACs par des investisseurs individuels ont diminué après avoir atteint un pic en janvier.

Fishermen clean their nets, amid the coronavirus disease (COVID-19) pandemic, on the island of Halki, Greece, April 13, 2021. Picture taken April 13, 2021. REUTERS/Louiza Vradi

A girl climbs a rope net during a training at a school in Syrian opposition-held village of al-Jeineh, Syria April 11, 2021. Picture taken April 11, 2021. REUTERS/Khalil Ashawi

A girl climbs a rope net during a training at a school in Syrian opposition-held village of al-Jeineh, Syria April 11, 2021. Picture taken April 11, 2021. REUTERS/Khalil Ashawi

Students of the Felix Rodriguez de la Fuente school sit next a fishing net before a class, as part of a project known as 'Aire Limpio' (Fresh Air) at the Playa de los Nietos (The Grandchildren's Beach), which aims to use better air quality for children during the coronavirus disease (COVID-19) pandemic, near Cartagena, southern Spain April 8, 2021. Picture taken April 8, 2021. REUTERS/Nacho Doce

A teacher and a retired fisherman (not pictured) teach the usage of a fishing net to students of the Felix Rodriguez de la Fuente school, as part of a project known as 'Aire Limpio' (Fresh Air) at the Playa de los Nietos (The Grandchildren's Beach), which aims to use better air quality for children during the coronavirus disease (COVID-19) pandemic, near Cartagena, southern Spain April 8, 2021. Picture taken April 8, 2021. REUTERS/Nacho Doce

Soccer Football - Serie A - Juventus v Genoa - Allianz Stadium, Turin, Italy - April 11, 2021 Juventus' Giorgio Chiellini falls into the net of a goal REUTERS/Massimo Pinca

Staff members move a net as they maintain the rink, at an ice hockey competition venue for the 2022 Olympic Winter Games, inside the National Indoor Stadium, in Beijing, China April 1, 2021. REUTERS/Tingshu Wang

Fishermen use a net to fish in Ismailia, Egypt, March, 29, 2021. REUTERS/Hanaa Habib

Cricket - England Nets - Maharashtra Cricket Association Stadium, Pune, India - March 25, 2021 England's Jonny Bairstow during nets REUTERS/Francis Mascarenhas

Cricket - England Nets - Maharashtra Cricket Association Stadium, Pune, India - March 25, 2021 England's Reece Topley during nets REUTERS/Francis Mascarenhas

Cricket - England Nets - Maharashtra Cricket Association Stadium, Pune, India - March 25, 2021 England's Jos Buttler during nets REUTERS/Francis Mascarenhas

Cricket - England Nets - Maharashtra Cricket Association Stadium, Pune, India - March 25, 2021 England's Jos Buttler and Jason Roy during nets REUTERS/Francis Mascarenhas

Cricket - England Nets - Maharashtra Cricket Association Stadium, Pune, India - March 25, 2021 England's Ben Stokes during nets REUTERS/Francis Mascarenhas

Cricket - England Nets - Maharashtra Cricket Association Stadium, Pune, India - March 25, 2021 England's Jos Buttler during nets REUTERS/Francis Mascarenhas

Cricket - England Nets - Maharashtra Cricket Association Stadium, Pune, India - March 25, 2021 England's Jonny Bairstow during nets REUTERS/Francis Mascarenhas

Cricket - England Nets - Maharashtra Cricket Association Stadium, Pune, India - March 25, 2021 England players during nets REUTERS/Francis Mascarenhas

Cricket - England Nets - Maharashtra Cricket Association Stadium, Pune, India - March 25, 2021 England's Ben Stokes during nets REUTERS/Francis Mascarenhas

Filipino bat ecologists Phillip Alviola and Kirk Taray set up a mist net near a bat roost at Mount Makiling in Los Banos, Laguna province, Philippines, February 18, 2021. "My goals are to encounter all the bat species in the Philippines and document their echolocation calls and survey the bats in different areas of the country especially in Mindanao," said Taray. REUTERS/Eloisa Lopez SEARCH "LOPEZ BATS" FOR THIS STORY. SEARCH "WIDER IMAGE" FOR ALL STORIES