December 1970: Start of the rehabilitation of young orphan seals
October 1974: Set up of the Seal Rehabilitation and Research Centre (SRRC) Foundation. The board members of this Foundation had an expertise either in the seal biology or in finances or politics
1974-1986: Cooperation with (international) scientists, veterinary and medical specialists started because the SRRC got more often sick and wounded seals
October 1981: ‘Visscher Neerlandia Award’ (Dutch-Belgian Cultural Award)
November 1981: ‘Decoration of the ANWB’ (Dutch National Award for environmental protection, presented by the Dutch Automobile Association)
1983: ‘Panorama Dierenpenning’ (Award for animal protection, presented by the National Panorama magazine)
June 1985: ‘Zilveren Anjer’ (Silver Carnation: Royal Award for environmental protection in the Netherlands, presented by His Royal Highness Prince Bernhard on behalf of the Prince Bernhard Foundation)
1986: Establishment of a Veterinary Advisory Board, a group of independent veterinarians and specialists from human hospitals
1988: Establishment of a Scientific Advisory Board, a board consisting of international scientists and experts in all areas of seals and their habitat
June 1993: Dutch ‘Woman of Europe’ Award (International Award, presented by the Women of Europe) and nominee for the European ‘Woman of Europe’ Award
1995: Member of the board of the Foundation for Protection of the Mediterranean Monk Seal (MOm, Greece) established by Prince Sadruddin Aga Khan
May 1996: ‘Officer of the Order of Oranje Nassau’ (very high National Royal Award, presented by the Royal Commissioner of the Queen)
February 1997: ‘Nieuwsblad van het Noorden’ award (Cultural Award, presented by the Dutch national newspaper Nieuwsblad van het Noorden)
November 1997: ‘Officer in the Order Of the Golden Ark’ (very high Award of the Golden Ark Foundation for ‘international effort for the flora and fauna on earth’, presented by His Royal Highness Prince Bernhard)
October 1998: ‘Lifetime Achievement award’ for Lenie ’t Hart from the National Wildlife Rehabilitators Association NWRA in the USA
December 1999: Founding of the Sea Alarm Foundation in cooperation with ITOPF and oil industries (to offer assistance in the broadest sense to marine mammals and other marine wildlife that is in acute distress as the result of a disaster)
October 2000: CBF certification for the center of Lenie ‘t Hart (official financial quality certificate)
March 2002: Premio N’AITUN (‘FREEDOM Award’: personal Award for ‘environmental protection’, presented by the ‘Corporal Artistas Pro Ecologia’ in Chile).
February 2004: Certification ISO 9001:2000 (quality certificate for the protocols and clinical procedures in the center of Lenie ‘t Hart)
September 2006: ‘Zilveren Erepenning’ (Silver Award of Honor) the highest possible Award of the Dutch Ministry of Agriculture, Nature Conservation and Food Quality ‘for ongoing efforts to protect marine mammals and the Wadden Sea’
November 2013: Founding of a new seal rehab center in the southern part of the Netherlands: Foundation ‘Aseal’ in Stellendam (near Rotterdam)
May 2014: Founding of the Lenie ‘t Hart Seal Foundation, an independent organization which supports all efforts of rescuers of marine mammals all over the world
September 2014: ‘Gouden Eeuw Award’ (Golden Century Award), Dutch Lifetime Achievement Award for Lenie’s ‘commitment to animal welfare in the Netherlands’
February 2016: Iranian official ‘Governmental Certificate of Appreciation’ for Lenie’s ‘efforts on global environment conservation and rehabilitation of Caspian seal species’
March 2016: Founding of two more seal rehab centers in the Netherlands, one on the island Terschelling (north of the Wadden Sea) and the second in the village Termunten, at the east part of the Wadden Sea. These measures are taken to avoid long journeys for sick and wounded seals through the Netherlands
1988 – today: Many international projects and assistance in marine mammal disasters, e.g. oil spills, virus outbreaks etc. in – among others – : Greece (monk seal rescue project), France (oil spill Erica), Germany (cooperation in seal rehab projects and oil spill Pallas), Uruguay (oil spill San Jorge and set up rehab facility), Galapagos (oil spill Jessica), Turkey (monk seal rescue and oil cleaning project), Shetland Islands (oil spill Braer), Orkney Islands (help in virus epidemic), Whales (oil spill Sea Empress), Namibia (help in research mass mortality), South Africa (support in rescuing sea lions from plastic straps), Mauritania (monk seal rescue project and research in mass mortality), Finland (Saimaa seal protection project), Russia Lake Baikal (help in research mass mortality), Russia Lake Ladoga (help in rehab Ladoga seal), Iran (support in wildlife rescue projects) and many other projects all over the world.