The shortlist for one of the world's leading photography prizes has been announced. The Prix Pictet focuses on photography that promotes discussion and debate on issues of sustainability. The prize of 100,000 Swiss francs (£68,034, $105,909, €96,254) is awarded for a body of work that speaks most powerfully about the theme of the award. This year's theme is disorder.

The winner will be announced by former secretary-general of the United Nations Kofi Annan on 12 November 2015, at the opening of an exhibition at the Musée d'Art Moderne de la Ville de Paris. IBTimesUK presents a gallery of the 12 shortlisted photographers, together with their artistic statements.

Brent Stirton, born in Durban, South Africa in 1969, lives and works in New York, USA: "Disorder in the natural world is man-made. Nature itself is always in balance, with animals as the innocents. Rebel groups manifest in wild spaces because they can hide there from authority, all the while exploiting the environment around them. In the Democratic Republic of Congo conservation rangers battle multiple paramilitaries inside Virunga National Park. This is Africa's first national park, a place that has been called the most dangerous conservation space on earth. There are 11 official paramilitary groups, a rebel army and the Congolese army, all inside this park. In these circumstances, 170 rangers have died in the last 10 years."

Prix Pictet 2015
Conservation rangers work with locals to evacuate the bodies of four mountain gorillas killed in Virunga National Park. July 2007, Bukima, Democratic Republic of CongoBrent Stirton/Prix Pictet Ltd 2015
Prix Pictet 2015
Michael Oryem, 29, is a recently defected Lord's Resistance Army fighter whose LRA group was involved in the poaching of ivory in Garamba National Park in the Democratic Republic of Congo. 17 November 2014, Nzara, South SudanBrent Stirton/Prix Pictet Ltd 2015

Maxim Dondyuk, born in Slavuta, USSR in 1983, lives and works in Nova Kabovka, Ukraine: "Winter 2013 changed Ukraine. Three months of bloody clashes, tears, fear, Molotov cocktails, burning car tyres and deaths. It wasn't just a protest in the support of EU. Ukrainian revolution brought new spirit, changed people and their minds, they became one organism that fights with a great passion and intensity for happy future. From the very beginning Euromaidan turned into a real performance, a battle of opposites. Good and evil, light and shadow, thick black smoke and whiteness of the February snow, orange helmets against black."

Prix Pictet 2015
Riot police began to storm Maidan after clashes on Shelkovichna Street. 18 February 2014, Kiev, UkraineMaxim Dondyuk/Prix Pictet Ltd 2015
Prix Pictet 2015
For a few days barricades on Hrushevskoho Street were burning, replenished all the time with new tyres and Molotov cocktails. 23 January 2014, Kiev, UkraineMaxim Dondyuk/Prix Pictet Ltd 2015

Gideon Mendel, born in Johannesburg, South Africa in 1959, lives and works in London, UK: "Drowning World is my long-term project – an attempt to explore the effects of climate change in an intimate way, and I have over the years made a series of what I call Submerged Portraits. In each of these the pose is conventional and while the flooded environment of my subjects is chaotic and disconcertingly altered I try to make the moment of the portrait calm and connected. I have endeavoured to visit flood zones around the world, travelling to Haiti, Pakistan, Australia, Thailand, Nigeria, Germany, The Philippines, Brazil, the UK and India, in search of these commonalities and differences."

Prix Pictet 2015
Christa and Salomon Raymond Fils. September 2008, Decade Village, Haiti. Christa and Salomon Raymond Fils inside their flooded home in Decade in southeast Haiti. Hurricane Gustave had damaged and flooded their home destroying all their possessions. In 2008 four hurricanes battered Haiti in quick succession (Hannah, Gustav, Ike and Fay) killing more than 800 people and causing extensive damage. The country is particularly vulnerable to flooding because the hillsides have been deforested for charcoal productionGideon Mendel/Prix Pictet Ltd 2015
Prix Pictet 2015
Shirley Armitage. February 2014, Moorland Village, Somerset, United Kingdom. She had left her home when there was an inch of water, and returning to find the water level so high was an immensely shocking experience for her. At the start of 2014 the UK experienced the wettest winter since records began. At least 6,000 properties were flooded, and large areas remained submerged for a number of weeksGideon Mendel/Prix Pictet Ltd 2015

Yang Yongliang, born in Shanghai, 1980, lives and works in Shanghai, China: Artificial Wonderland is a series started in 2012. Yang Yongliang uses images of architecture as brushstrokes; heavy mountain rocks with enriched details draw a faithful reference to Song Dynasty landscape painting.

Prix Pictet 2015
From the New World. 2014, Shanghai, Hong Kong, Taipei, etc. Series: Artificial WonderlandYongliang Yang/Prix Pictet Ltd 2015
Prix Pictet 2015
From the New World (detail). 2014, Shanghai, Hong Kong, Taipei, etc. Series: Artificial WonderlandYongliang Yang/Prix Pictet Ltd 2015

Pieter Hugo, born in Johannesburg, South Africa in 1976, lives and works in Cape Town, South Africa: Hugo photographed the people and landscape of an expansive dump of obsolete technology in Ghana. The area, on the outskirts of a slum known as Agbogbloshie, is referred to by local inhabitants as Sodom and Gomorrah, a vivid acknowledgment of the profound inhumanity of the place. When Hugo asked the inhabitants what they called the pit where the burning takes place, they repeatedly responded: "For this place, we have no name." This wasteland, where people and cattle live on mountains of motherboards, monitors and discarded hard drives, is far removed from the benefits accorded by the unrelenting advances of technology.

Prix Pictet 2015
Aissah Salifu, Agbogbloshie Market. 2010, Accra, GhanaPieter Hugo/Prix Pictet Ltd 2015
Prix Pictet 2015
Untitled, Agbogbloshie Market. 2009-10, Accra, GhanaPieter Hugo/Prix Pictet Ltd 2015

Matthew Brandt, born in Los Angeles, 1982, lives and works in Los Angeles, USA: "Honeybees is a project that began at the beach where I stumbled upon a swarm of bees — hundreds in the wet sand, dead and dying — scattered across the Santa Monica shoreline. At the time, the news was filled with bold headlines about colony collapse disorder — worker bees were disappearing from their colonies, causing honeybee colonies across North America to collapse and die, disrupting the natural cycle of pollination and procreation. As this dire ecological mystery was just coming into public awareness, I was confronted with the physical reality of a hive's collective death in a surreal scenario. As a way of remembering this profound experience, I decided to walk along the beach and collect the carcass of each dead bee that I saw. One year later I photographed these bees and made a print out of their bodies using an antiquated 19th century photographic process called gum-bichromate printing."

Prix Pictet 2015
Bees of Bees 2 (detail). 2012. Gum bichromate print with honeybees on paperMatthew Brandt/Prix Pictet Ltd 2015
Prix Pictet 2015
Bees of Bees (detail). 2009. Gum bichromate print with honeybees on paperMatthew Brandt/Prix Pictet Ltd 2015

Alixandra Fazzina, born in London, 1974, lives and works in London, UK: "Across the Horn of Africa, war, disorder, abuse and poverty make millions miserable and drive thousands to attempt to flee. With land borders cut off or closed, and surrounded by conflict on all sides, one of the only means of escape is by sea. This series is presented in the book A Million Shillings (Trolley 2010) and follows the journey of desperate emigrants, or tahrib, to their embarkation points with smugglers on the coast of Somalia, on a perilous voyage across the Gulf of Aden, and onward in the search for a better life."

Prix Pictet 2015
Omar, refugee smuggler. April-December 2008, Bosaso, Somalia. Linked to an international network of agents and traffickers, "big fish" Omar lights a cigarette. One of eight key human smugglers and traffickers working in Bosaso, he watches over a group of refugees at one of his safe houses as they prepare for the voyage to Yemen. He calls them "blood money"Alixandra Fazzina/Prix Pictet Ltd 2015
Prix Pictet 2015
Somali refugees departing Shimbiro Beach to board smugglers' boats to Yemen. April-December 2008, Shimbero, Somalia. Only 11 of the people who took this boat reached Yemen aliveAlixandra Fazzina/Prix Pictet Ltd 2015

Ilit Azoulay, born in Jaffa, 1972, lives and works in Tel Aviv-Jaffa, Israel: Imaginary Order is a series comprised of four large works that followed the renovation of a brutalist building in the northern Israeli town of Zichron Ya'akov, designed in the 1960s by Yaacov Rechter. The overhaul converted a convalescent home into an art centre and luxury hotel. Over the seven years of its renovation, Azoulay frequently visited this historical building and followed its transformation from a place built on egalitarian principles for all HMO members into a luxury hotel accessible only to the few who can afford it.

Prix Pictet 2015
Intoxication of Oblivion. 2012Ilit Azoulay/Prix Pictet Ltd 2015
Prix Pictet 2015
Howling for Beuys. 2014Ilit Azoulay/Prix Pictet Ltd 2015

Valérie Belin, born in Boulogne-Billancourt, 1964, lives and works in Paris, France: "In terms of sustainability, these still lifes offer a jarring commentary on the effects of our obsession with cheap objects, for not only is their material, plastic, emblematic of the wasteful use of raw materials, but it also represents a grotesque kind of immortality because of its non-biodegradable nature – an immortality that, one could say, is slowly killing the planet."

Prix Pictet 2015
Still life with shoes #140204Valérie Belin/Prix Pictet Ltd 2015
Prix Pictet 2015
Still life with mask #140209Valérie Belin/Prix Pictet Ltd 2015

Ori Gersht, born in Tel Aviv, 1967, lives and works in London, UK: The photographs in Blow Up depict the detonation of floral arrangements. Gersht's camera has managed not only to document but also to memorialise the event. The works are an overt reminder of the impermanence of innocence and beauty, since even the most sublime of scenarios can be surreptitiously corrupted by seemingly baseless acts of destruction and ruin. The images reference the still lifes of the 19th-century painter Henri Fantin-Latour. The flowers are red, white, and blue, a nod to the painter's French origins.

Prix Pictet 2015
Time After Time: Blow Up No 2. 2009Ori Gersht/Prix Pictet Ltd 2015
Prix Pictet 2015
Time After Time: Blow Up No 8. 2009Ori Gersht/Prix Pictet Ltd 2015

John Gossage, born in New York, 1946, lives and works in Washington DC, USA: "It's all about the ordinary now, the little things at the edge of your consciousness, the 'signs' all around you. Everyone everywhere now has a small thing that has changed for them. The big things, those things that always happen to someone else, the other people, the ones on the news. The earthquakes, the floods, the fires, the disasters, are all still there in their grand scale. But it's that the birds that used to come to your backyard are no longer there is what keeps you up at night. What I have been photographing are moments when the normal slips, and the disorder starts. Subtle things that whisper to you that things have started to change and in all likelihood not for the best."

Prix Pictet 2015
Kalorama, from the series: Should Nature Change. 2013, Washington, DC, United StatesJohn Gossage/Prix Pictet Ltd 2015
Prix Pictet 2015
Rochester, from the series: Should Nature Change. New York, United StatesJohn Gossage/Prix Pictet Ltd 2015

Sophie Ristelhueber, born in Paris, 1949, lives and works in Paris, France: "The raw material was video rushes from Iraq, taken by local Reuters correspondents. I was looking for pictures of the craters – the "tombs"– that open up in the ground in Iraq several times a week, or even a day. Working on stills taken from the rushes, I put together my own pictures, using computer techniques to reconstruct scenes that were both real and imaginary, and incorporating elements of my own earlier work."

Prix Pictet 2015
Eleven Blowups #5. 2006, Middle EastSophie Ristelhueber/Prix Pictet Ltd 2015
Prix Pictet 2015
Eleven Blowups #1. 2006, Middle EastSophie Ristelhueber/Prix Pictet Ltd 2015