Prof Giller has had a major involvement in a number of national and international bodies and committees: European Ecological Federation: founding committee member, Programme Secretary and Member of Executive Board and Council (1990-5). British Ecological Society: Council Member (1989-1992, 1999-2002), Secretary Aquatic Ecology Group (1980-1990); Member of Meetings committee (1980-1992); Assistant Meetings Secretary (1990-2); Member of Membership Committee (2016-2019). Natural Environment Research Council Freshwater Sciences Peer Review Committee, (1995-1999). Royal Irish Academy: Member of Publications Committee. Environmental Researchers Association of Ireland: Member of Council (1993-7), Vice-Chair (1995-7). Societe Internationale Limnologie: Member of SIL 1998 Dublin Congress Committee, Co-ordinator of the Scientific Programme (>1000 contributors). Freshwater Biological Association: Council Member, (1998-2002). Member of Co-ordination Committee for ESF Network "International Advancement of Community Theory (INTERACT), (Jan 2002-Dec 2004). Member of National Biodiversity Research Platform (Ireland) and member of the Working Group to deliver a national Research Agenda in Biodiversity (2003-2006, 2016-2019).