Daniel Pauly

University of British Columbia | UBC · Institute for the Oceans and Fisheries

The conventional view of spawning in iteroparous bony fish, i.e., the “reproductive drain hypothesis,” is based on the observation that somatic growth (in length) slows down noticeably at approximately the time fish attain maturity, and hence the assumption is made that investment in gonadal development slows down growth. However, when this is tran...

Despite its importance for our understanding of the ecology and evolution of past life, ontogenetic data on early diverging euarthropods is distinctly lacking, as reconstructing life histories of fossil animals is often challenging. Here we report the growth trajectory of frontal appendages of the apex predator Amplectobelua symbrachiata, one of th...

Some comments on the suitability of stocks for analysis with CMSY++ It is important to realize that every method, when applied to unsuitable data, will fail to provide reasonable results. Thus, this document attempts to provide some insights into the applicability of the data-limited CMSY++ method, by taking a closer look at the features of some st...

Following an introduction to the nature of fisheries catches and their information content, a new development of CMSY, a data-limited stock assessment method for fishes and invertebrates, is presented. This new version, CMSY++, overcomes several of the deficiencies of CMSY, which itself improved upon the “Catch-MSY” method published by S. Martell a...

Historical ecology draws on a broad range of information sources and methods to provide insight into ecological and social change, especially over the past ~12,000 years. While its results are often relevant to conservation and restoration, insights from its diverse disciplines, environments, and geographies have frequently remained siloed or under...

Oceans are increasingly warming through climate change. Fish and invertebrate ectotherms respond to ocean warming through poleward and depth-related migrations, a consequence of which is disruption of fisheries catch compositions. Mean temperature of the catch (MTC) is an index of change in catch composition, from colder to warmer water species. MT...

Fishing has been practiced in Egypt for several millennia in the Nile and various lakes, the Mediterranean, and the Red Sea. Here, the marine fisheries catch from the area corresponding to Egypt's current Exclusive Economic Zone in the Mediterranean were re-estimated for the shorter period from 1920 to 2019. This study covers reported and formerly...

Historical fishing effort has resulted, in many parts of the ocean, in increasing catches of smaller, lower trophic level species once larger higher trophic level species have been depleted. Concurrently, changes in the geographic distribution of marine species have been observed as species track their thermal affinity in line with ocean warming. H...

FishBase (www.fishbase.org) is a global, open access information system about fishes that contains published scientific data on topics such as physiology and behaviour, life-history characteristics, and species distributions. Since its creation in the late 1980s, FishBase has evolved into a highly dynamic and versatile tool for scientists and the p...

Rising temperatures, drought, and oxygen depletion may be the greatest threats to aquatic animals in the twenty-first century. As a robust body of literature suggests, large-bodied fish are among the most vulnerable organisms in times of rapid climate change. While earlier studies showed an interspecific correlation between body size and sensitivit...

The Socotra Archipelago (Yemen), a group of four islands off the north-eastern tip of Africa in the western Indian Ocean, has a population that relies heavily on small-scale fishing for livelihoods and food security. However, the reporting of fisheries catches by Yemen has consistently been incomplete, with artisanal (small-scale, commercial) catch...

The well-established temperature-dependence of growth parameters and maximum sizes of fish and other water-breathing ectotherms (WBEs) form the basis for various “temperature-size rules” for fish and WBEs. Numerous adaptationist interpretations of these rules exist, but their biochemical basis is largely ignored. One fundamental, but frequently ove...

White et al. (Science 377, p. 834-839, 2022) propose that reproduction reduces the somatic growth of animals. This contradicts the common observations that non-reproducing adults are not larger than those that reproduced as well as the very example the authors provide of a fish that reproduces while its growth continues to accelerate, which is comm...

The highly toxic orange-spotted toadfish Torquigener hypselogeneion (Bleeker 1852) [conspecific Torquigener flavimaculosus Hardy & Randall, 1983] is now a very common invasive fish in the Eastern Mediterranean. Its small size, well under 20 cm, may have concealed the danger it represents, and little is known about its biology or ecology. Here, the...

Catches have remained relatively high in the Gulf of Thailand and the Bohai Sea, China, despite severe biomass declines (around 95%) evidenced by fishery-independent surveys. Such high production at very low stock sizes is not predicted by simple-surplus production theory, but can be explained by age-structured models that predict high recruitment...

Key traits of functional biodiversity are examined for 31,134 species of fishes. These traits are maximum body weight, productivity, and trophic level. A new, simple framework is presented that shows the combined usage of these traits, in ordinal categories, for close to 90% of extant species of fishes. Most species are clustered tightly along an e...

Gill surface area (S) and respiration (R) in juvenile and adult crustaceans scale with their body weight (W) such that S ∝ R ∝ Wd, with d ranging mostly between 0.6 and 0.9, but always <1, as in other water-breathing ectotherms (WBE). The growth of adult crustaceans therefore approaches an asymptote, whether or not seasonal growth oscillations are...

Among fishery biologists and even ichthyologists, maturation and spawning of fish are viewed as processes that use “energy” that would otherwise be applied to somatic growth, which is supposed to explain why post-maturity growth in length tends to decline. This widespread conceptualization may be called the “reproductive drain hypothesis” (RDH). Ho...

The recent rapid growth in aquaculture production reported by the United Nations Food and Agriculture Organization may have inadvertently generated what we denote here as aquaculture over-optimism. An extreme form of this is the notion that we need not worry about sustaining wild fish stocks because we can meet the global need through farming. Here...

This account serves as the introduction to a Special Issue of the journal Environmental Biology of Fishes. It includes 18 contributions, 12 of which deal predominantly with warming, four explicitly with deoxygenation, one providing the framework, and one addressing how warming and deoxygenation—which all contributions view, implicitly or explicitly...

The current conception of sustainable fisheries focuses on single "stocks" targeted by industrial fisheries to supply growing global markets, including those for fishmeal. Sustainable fisheries should be reimagined to minimize exploitation and prioritize artisanal and subsistence fishing that feeds people.

The length–weight relationships (LWR) and other morphological traits for 6417 specimens in 74 fish species collected seasonally, from July 2020 to April 2021, in the mangrove of Dongzhaigang Bay, Hainan Province, China, are presented. This involved, for all species, a sample size, and minimum and maximum lengths; in addition, for most species, it i...

This study used catch/effort (CPUE) and length-frequency (L/F) data to evaluate the status of 26 fish species in the mangroves of the Dongzhaigang National Reserve, Hainan Province, China, sampled in 2009 (16 species), 2014 (18 species) and 2020 (15 species) using CPUE and the length-based Bayesian biomass (LBB) method. The CPUE, both in number and...

While numerous Marine Protected Areas (MPA) have been created in the last decades, their effectiveness must be assessed in the context of the country’s biodiversity conservation policies and must be verified by local observations. Currently, the observations of local stakeholders, such as those from non-governmental organizations (NGOs), academics,...

Rebuilding overexploited marine populations is an important step to achieve the United Nations' Sustainable Development Goal 14-Life Below Water. Mitigating major human pressures is required to achieve rebuilding goals. Climate change is one such key pressure, impacting fish and invertebrate populations by changing their biomass and biogeography. H...

A length–frequency sample ( n = 295) from a fossil population of the Ordovician trilobite Triarthrus eatoni Hall, 1838, assembled and analyzed by J. L. Cisne in 1973 is here reexamined using methods of length–frequency analysis commonly used in fishery science and marine biology. Theoretical considerations and the empirical data at hand suggest tha...

Warming increases the metabolic rates of fishes and drives their oxygen demands above environmental oxygen supply, leading to declines in fish growth and smaller population sizes. Given the wide variability in species' sensitivity to changing temperature and oxygen levels, warming and oxygen limitation may be altering the composition of fish commun...

To bridge physiological and evolutionary perspectives on size at maturity in fishes, we focus on the approximately invariant ratio between the estimated oxygen supply at size at maturity (Qm) relative to that at asymptotic size (Q∞) among species within a taxonomic group, and show how two important theories related to this phenomenon complement eac...

Fishing provides the world with an important component of its food supply, but it also negatively impacts the biodiversity of marine and freshwater ecosystems, especially when industrial fishing is involved. To mitigate these impacts, civil society needs access to fisheries data (i.e., catches and catch-derived indicators of these impacts). Such da...

In our original contribution, we used a new simple method (CMSY, Froese et al., 2017) and the time series of catches of Hutchings and Myers (1995) to analyse five centuries of cod catches in eastern Canada (Schijns et al., 2021). Holm et al. (2022) point out that there was actually an improved historical time series that we had overlooked. As we no...

Climate change is altering the distribution and composition of marine fish populations globally, which presents substantial risks to the social and economic well-being of humanity. While deriving long-term climatic baselines is an essential step for detecting and attributing the magnitude of climate change and its impacts, these baselines tend to b...

Migrations of large pelagic fishes across the Pacific are usually inferred from tagging or genetic studies. Even though these techniques have improved over time, they still fail to demonstrate large transoceanic migrations, usually proposing ‘routes’ that do not cycle seasonally. The current study uses the concept of ‘philopatry’ in 11 large pelagi...

An assessment of the stock status and historical changes in abundance of Coilia mystus and C. nasus in the Yangtze River Estuary, China, was carried out based on field surveys conducted in 2019–2020 and published length-frequency (L/F) data from earlier periods. These two species’ current and past relative biomasses (B/BMSY) were estimated using a...

The length–weight relationships (LWR) of the common seadragon Phyllopteryx taeniolatus (Lacepède, 1804) and the leafy seadragon Phycodurus eques (Günther, 1865), Syngnathidae, are presented in this paper, based on specimens raised in the Birch Aquarium at Scripps, La Jolla, California. Furthermore, we used the length at known age of 40 specimens of...

The Eastern Mediterranean Sea is the most invaded sea on the planet, with 666 nonindigenous species now recorded in the region. However, not all of these become successful in their new environments. Success here is defined by wide geographical spread, increased abundances, and larger maximum sizes than their native range. The silver-cheeked toadfis...

Over the past 4 decades there has been a growing concern for the conservation status of elasmobranchs (sharks and rays). In 2002, the first elasmobranch species were added to Appendix II of the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES). Less than 20 yr later, there were 39 species on Appendix II and 5 o...

Global warming affects the phenology of the Earth’s flora and fauna, notably by advancing the date at which many plants and animals tend to reproduce. We use fish, where this reproductive acceleration is well-documented, to present a simple approach based on sine curves to predict, in spring spawning fish, the minimum number of days (Δdmin) that sp...

The fishing for commercial sponges (genera Spongia and Hippospongia of the family Spongiidae) is reviewed, with emphasis on the second half of the 20th century, when catches declined from a level in 1950 that was already much lower than near the end of the 19th century. The review covers the local and distant-water catch of Greek sponge fishers, th...

A report by leading fisheries experts shares novel analysis on the scale, context, and impacts of the age-old fishing practice of bottom trawling. The report shares new data and analysis combined with policy recommendations to inspire constructive action around this controversial practice.

The Chaetognatha are a marine invertebrate phylum including 132 extant, carnivorous species in nine families and two orders, but with unclear protostomian affinities in the animal kingdom. We document the gradual recognition of the distinctiveness of chaetognaths by early taxonomists, with some emphasis on the often-overlooked studies by Chinese ma...

The prevailing determinant of maturation in fishes is thought to be a redirection of energy from growth to reproduction. Instead, the Gill Oxygen Limitation Theory predicts that maturation, and thus reproduction, is induced when a fish reaches a critical ratio of oxygen supply to demand (Qm/Qmaint). The consistency of this critical ratio has been p...

Invasive species pose threats to either human health or inflict ecological and/or economic damage. The silver-cheeked toadfish (Lagocephalus sceleratus), a Lessepsian species, is one of the most harmful species in the Mediterranean Sea, because of its potent neurotoxin, impacts on marine biodiversity, and the increased costs and labor they inflict...

Following a brief review of their biology, this contribution is an attempt to provide a global overview of the catches of mesopelagic fishes (of which 2.68 million tonnes were officially reported to the FAO) throughout the world ocean from 1950 to 2018, to serve as a baseline to a future development of these fisheries. The overview is based on a th...

The standard response to the question “why do fish reach first maturity when they do” is that, at some point (or age), they perceive environmental stimuli, which are converted via the pituitary and the hypothalamus into triggers for a hormonal cascade leading to gonadal maturation and the release of gametes. Yet, the question rarely asked is why fu...

Iraq has very rich freshwater resources, among the most abundant in the Middle East, due to the Tigris and Euphrates Rivers, the Basrah River and the Mesopotamian marshes, which serve as nursery grounds for a number of diadromous fish. Jointly, these rivers and the marshlands provide crucial nutrients to the fisheries of the northern Gulf, particul...

The fishery for Northern Atlantic cod (Gadus morhua) off Newfoundland and Labrador, Eastern Canada, presents the most spectacular case of an exploited stock crashed in a few decades by an industrial bottom trawl fishery under a seemingly sophisticated management regime after half a millennium of sustainable fishing. The fishery, which had generated...

In the last decades, several targets for marine conservation were set to counter the effects of increasing fishing pressure, e.g., protecting 10% of the sea by 2020, and establishing large-scale marine protected areas (LSMPAs). Using the ‘reconstructed’ catch data for 1950 to 2018 made available by the Sea Around Us initiative, we show that the dec...

To make sound decisions about the future of fisheries, managers need to have a good understanding of the amount of fish that have been caught over long periods. Unfortunately, current stock assessment processes are often flawed, as they are frequently based on data time series that do not represent the full range of change. The process of selecting...

We report a sudden explosive rise in abundance off southeastern China of a fish species that is hypoxia-tolerant, Bombay duck (Harpadon nehereus, Family Synodontidae), belonging to an Order (the Aulopiformes) encompassing overwhelmingly deep-sea fishes, but which predominantly occurs in coastal water. We suggest that this is made possible by the ve...

The Mozambique Channel region in East Africa has diverse marine ecosystems and serves as a migratory corridor for economically important species. Local and foreign industrial fisheries operate in the Mozambique Channel, but regional small-scale fisheries are the crucially important fisheries that provide food security, livelihoods, and economic opp...

This contribution applies the “mean tem-perature of the catch” (MTC) concept of Cheung et al. (Nature 497:365–368, 2013) to fish catch data for Lake Peipsi, Estonia/Russia, covering the years 1931 to 2019. The preferred temperature of each of the ten target fish species was obtained from the literature, and combined with the species-specific catch...

In countries like Sierra Leone, where fisheries-independent stock assessments and complex population models are financially and technically challenging, catch statistics can approximate fluctuations in fish stocks where more precise data is not available. However FAO FishStat, the most widely-used time-series data on global fisheries catch landings...

The fisheries of the Arabian Sea Large Marine Ecosystem, which includes the northern part of the western Indian Ocean, from the Horn of Africa to India’s Malabar Coast are described, along with some of the physical parameters impacting on their productivity. The bulk of fishing and thus the majority of catches in the Arabian Sea occur within the ex...

In the summer of 2019, environmental journalist Andrew Reeves, author of Overrun: Dispatches from the Asian Carp Crisis, was invited by a leading Canadian daily, The Globe & Mail, to speak with Daniel Pauly, a fisheries biologist at the University of British Columbia, about his latest book Vanishing Fish: Shifting Baselines and the Future of Global...

Our societies will change following the COVID-19 crisis, as well as ocean management. Here we present 10 action points in a marine context, to re-energize our economies and avert the biodiversity and climate change crises of which the present COVID-19 crisis represents a portend: (1) promote carbon neutral economies to mitigate global warming; (2)...

Fish generally mature of a smaller fraction of their maximum sizes than birds and mammals. In farmed tilapia (Family Cichlidae), which can tolerate very adverse conditions, the stunting caused by these conditions also cause them to spawn at very small sizes. Such spawning at small sizes (or 'early spawning') is usually perceived as a unique feature...

The gill-oxygen limitation theory (GOLT) provides mechanisms for key aspects of the biology (food conversion efficiency, growth and its response to temperature, the timing of maturation, and others) of water-breathing ectotherms (WBEs). The GOLT’s basic tenet is that the surface area of the gills or other respiratory surfaces of WBE cannot, as two-...