My first experience of fisheries research was in 1965, when I left school and spent six weeks on an Icelandic research cruise doing a plankton and acoustic survey for Norwegian spring spawning herring. I gained a 1^st class Honours degree in Zoology and Oceanography at UCNW, Bangor in 1968 and spent the following year in the Indian Ocean, on Aldabra and Kenya, studying tides, polychaetes and the infauna of live and dead coral.

My PhD (UEA, Norwich and Lowestoft) was on population dynamics of cod in the Irish Sea and I started up the market sampling on a number of commercial species at Fleetwood, Whitehaven, Conwy and Milford Haven as the basis for fisheries assessments.  The Irish Sea fisheries are very mixed, with a large number of species contributing to the total catch, so I used surplus production models on the total demersal catch as well as single species assessments and models with multispecies and mixed fishery effects, particularly for cod and Nephrops.  I was in charge of fish stock assessment around the south and west of England and Wales from 1975 and also worked for FAO and the EC for short periods on collection of fisheries statistics, effects of 200 mile limits and establishment of the CFP. In 1978 I made a proposal that DG Fish should carry out a trial of regional fisheries management but it took 35 years before this was put in place. Two significant papers which came out in 1980 were on the need for an integrated ecosystem approach to management and on the disappearance of the common skate from the Irish Sea due to fishing.

I had become disillusioned with the routine of fish stock assessment, which seemed to do little more than add a scientific veneer to an ineffective fisheries management system.  It ignores environmental and ecosystem effects and diverts scientific resources from investigation of marine ecosystem functioning and operational research on overcoming the problems of overfishing.  I switched to research on plankton, early life histories of fish and recruitment, which led to involvement with GLOBEC, investigating the effects of ocean physics on marine ecosystems, with a particular emphasis on zooplankton and on the survival of early life stages of fish. Over the course of the GLOBEC programme (1990-2008) the emphasis changed steadily from climate variability (at scales of years to decades) to climate change.

Apart from a period as Fisheries Science Adviser to the Ministry of Agriculture, Fisheries and Food (now part of DEFRA) I worked on the ICES/GLOBEC Cod and Climate Change programme from 1993, moving to ICES as coordinator of the programme from 1996 to 2008 and then to DTU Aqua in Charlottenlund until retirement in 2012.

Over the past six years the main emphasis of my research has been on the synthesis and application of results.  I was lead author for the fisheries and marine ecosystem sections of the fourth IPCC report, for which we were awarded a share of the 2007 Nobel Peace prize. I was the 2013 Johan Hjort Professor of Marine Ecosystem Research and I continue to work and publish with scientists at DTU and from a number of other countries.