October 15, 2021
Fish Must Breathe - Outline of the Gill-Oxygen Limitation Theory (GOLT).
Dr. Daniel Pauly
Professor, University of British Columbia
Abstract
The Gill-Oxygen Limitation Theory (GOLT) is presented to provide mechanisms for key aspects of the biology (food conversion efficiency, growth and its response to temperature, the timing of maturation, migrations, and others) in water-breathing ectotherms (WBE, i.e., fish and aquatic invertebrates). The GOLT’s basic tenet is that the surface area of the gills or other respiratory surfaces of WBE cannot, as 2-dimensional structures, supply them with sufficient oxygen to keep up with the growth of their 3-dimensional bodies. Notably, the reduced oxygen supply per body weight induces sexual maturation, and later a slowing and cessation of growth, all accompanied by an increase of physiological processes relying on glycolytic enzymes and a declining role of oxidative enzymes. Aside from having a wide theoretical scope, the GOLT has potential practical applications, e.g., in optimizing the way fish farmers aerate their ponds, and in predicting how WBE populations will react to the warming and deoxygenation of the waters they inhabit[1]. The GOLT still needs to be refined and put on a solid quantitative basis, but this can only occur after the misconceptions surrounding it are put to rest.
Biosketch
Dr. Daniel Pauly is the Sea Around Us Principal Investigator and Killam Professor at the University of British Columbia’s Institute for the Oceans and Fisheries.
He is a French-Canadian citizen who completed his high school and university studies in Germany. His doctorate (1979) and habilitation (1985) are in Fisheries Biology, from the University of Kiel.
He did his first intercontinental travel in 1971 (from Germany to Ghana for field work related to his Masters) and has since experienced a multitude of countries, cultures, and modes of exploiting aquatic ecosystems in Africa, Asia, Oceania and the Americas. This perspective allowed him to develop tools for managing data-sparse fisheries.
Through the 1980s and early 1990s, Daniel Pauly worked at the International Center for Living Aquatic Resources Management (ICLARM), in Manila, Philippines. In 1994, he became a Professor at the Fisheries Centre of the University of British Columbia, Vancouver, Canada, of which he was the Director for five years (Nov. ’03-Oct. ’08). Since 1999, he is also Principal Investigator of the Sea Around Us Project (see www.seaaroundus.org), funded for 15 years by the Pew Charitable Trusts and devoted to studying, documenting and promoting policies to mitigate the impact of fisheries on the world’s marine ecosystems (see AMBIO, 34: 290-295, 2007).
The concepts, methods and software that Daniel Pauly co-developed, documented in over 1000 scientific and general-interest publications, are used throughout the world, not least as a result of his teaching a multitude of courses, and supervising students in four languages on five continents. This applies especially to the Ecopath modeling approach and software (www.ecopath.org) and FishBase, the online encyclopedia of more than 30,000 fish species (www.fishbase.org), the latter recently complemented by SeaLifeBase (www.sealifebase.org).
Two books, reflecting his current interests were published in 2010: Five Easy Pieces: Reporting on the Global Impact of Fisheries and Gasping Fish and Panting Squids: Oxygen, Temperature and the Growth of Water-Breathing Animals. In January 2016, with Dirk Zeller, he published an article titled “Catch reconstruction reveal that global marine fisheries catches are higher than reported and declining” (DOI: 10.1038/ncomms10244), a summary of what later appeared in the Global Atlas of Marine Fisheries, concluding a decade-long activity of the Sea Around Us.
Daniel Pauly’s body of work has been recognized in various profiles, notably in Science (Apr. ’02); Nature (Jan. ’03); The New York Times (Jan. ’03), in developing countries, and by numerous awards, among them honorary doctorates from four universities, being elected a Fellow of the Royal Society of Canada (Academy of Science; ‘03) and awarded the Sir John William Dawson Medal (‘17); receiving the Award of Excellence of the American Fisheries Society (‘04); the International Cosmos Prize, Japan (‘05), the Volvo Environmental Prize, Sweden (‘06), the Excellence in Ecology Prize, Germany (‘07), the Ramon Margalef Prize in Ecology, Spain (‘08), an Ocean Award in the Science category (‘16); and being named one of France’s Chevaliers de la Légion D’Honneur (‘17).