J. Wilson White

• Ph.D.
• Associate Professor at Oregon State University

Heatwaves are now pervasive stressors to marine ecosystems globally and it is urgent to consider mitigation tools that support ecosystem resilience and persistence in the immediate future. We modeled a system of kelp, herbivorous urchin, and predatory fish to compare how potential management mitigation actions (kelp seeding, urchin removal, and fis...

Marine reserves are increasingly used to address conservation and management goals globally. An emerging question is how reserves will interact with species that are shifting geographic ranges in response to warming ocean temperatures. Such range shifts can lead to negative interactions with existing resident species, and new harvest pressures, bot...

The number of marine protected areas (MPAs) implemented globally is rising, with calls to protect 30 % of the ocean by 2030. One potential benefit of MPAs is increased resilience to anthropogenic climate change impacts. However, realistic ecological expectations are needed to identify the conditions that may yield resilience benefits and determine...

Globally, decision‐makers are seeking management levers that can mitigate the negative effects of climate change on ecosystems that have already been transformed from their natural state by the effects of fishing. An important question is whether marine reserves can provide buffering (i.e., population‐level resilience) against climate disturbances...

Adaptively managing marine protected areas (MPAs) requires accurately assessing whether established MPAs are achieving their goals of protecting and conserving biomass, especially for harvested populations. Ecological MPA assessments commonly compare inside of the MPA to a reference point outside of and/or before implementation (i.e., calculating “...

Marine heatwaves are increasingly affecting marine ecosystems, with cascading impacts on coastal economies, communities, and food systems. Studies of heatwaves provide crucial insights into potential ecosystem shifts under future climate change and put fisheries social-ecological systems through “stress tests” that expose both vulnerabilities and r...

The Falkland Islands marine environment host a mix of temperate and subantarctic spe-cies. This review synthesizes baseline information regarding ontogenetic migration pat-terns and trophic interactions in relation to oceanographic dynamics of the Falkland Shelf, which is useful to inform ecosystem modelling. Many species are strongly influenced by...

Acute environmental stressors such as short-term exposure to pollutants can have lasting effects on organisms, potentially impacting future generations. Parental exposure to toxicants can result in changes to the epigenome (e.g. DNA methylation) that are passed down to subsequent, unexposed generations. However it is difficult to gauge the cumulati...

Understanding population responses to discrete ‘pulsed’ environmental disturbances is essential to conservation and adaptive management. Populations of concern can be driven to low levels by disturbance, and understanding interspecific differences in recovery trajectories is necessary for evaluating management options. We analysed single‐species mo...

Consistent spatial variation in phenotypes within a species can reflect local adaptation to gradients in selective pressures, or plastic responses to variable conditions. In benthic marine foundation systems with long, dispersive pelagic larval stages, the usual assumption is that the plastic strategy should dominate, yet surprising examples of loc...

Kelp habitat restoration is gaining traction as a management action to support recovery in areas affected by severe disturbances, thereby ensuring the sustainability of ecosystem services. Knowing when and where to restore is a major question. Using a single‐species population model, we consider how restoring inside marine protected areas (MPAs) mi...

Correctly identifying the effects of a human impact on a system is a persistent challenge in ecology, driven partly by the variable nature of natural systems. This is particularly true in many marine fishery species, which frequently experience large temporal fluctuations in recruitment that produce interannual variations in populations. This varia...

Adaptive management of marine protected areas (MPAs) to determine whether they are meeting their intended goals requires predicting how soon those goals will be realized. Such predictions have been made for increases in fish abundance and biomass inside MPAs. However, projecting increases in fishery yield (“fishery spillover”) is more complex becau...

Changing salinity in estuaries due to sea level rise and altered rainfall patterns, as a result of climate change, has the potential to influence the interactions of aquatic pollutants as well as to alter their toxicity. From a chemical property point of view, ionic concentration can increase the octanol–water partition coefficient and thus decreas...

Two types of physical disturbances that are impeding our understanding of ocean productivity are: 1) pulses of adverse conditions (e.g.,marine heat waves, pulses of low pH), and 2) changing frequencies of cycles in productivity (e.g.,ENSO fluctuations). Managers of fisheries and MPAs need to understand these better to maintain healthy oceans. We ha...

En ecosistemas terrestres, dulceacuícolas y marinos, los corredores ecológicos son una designación de conservación necesaria para asegurar la salud de los ecosistemas. Los corredores son elementos fundamentales de las redes ecológicas para la conservación y complementan los objetivos de las áreas protegidas y OMEC al conectar estos hábitats con otr...

Determining metapopulation persistence requires understanding both demographic rates and patch connectivity. Persistence is well understood in theory but has proved challenging to test empirically for marine and other species with high connectivity that precludes classic colonisation–extinction dynamics. Here, we assessed persistence for a yellowta...

La connectivité écologique est le mouvement sans entrave des espèces et le flux des processus naturels qui soutiennent la vie sur Terre. Il est impérieux que les pays du monde entier s’orientent vers une approche globale et cohérente de la conservation de la connectivité écologique, et qu’ils entreprennent de mesurer et de contrôler l’efficacité de...

The number of protected areas that restrict or prohibit harvest of wild populations is growing. In general, protected areas are expected to increase the abundance of previously-harvested species. Whether a protected area achieves this expectation is typically evaluated by assessing trends in abundance after implementation. However, the underlying a...

Marine Protected Areas (MPAs) are increasingly established globally as a spatial management tool to aid in conservation and fisheries management objectives. Assessing whether MPAs are having the desired effects on populations requires effective monitoring programs. A cornerstone of an effective monitoring program is an assessment of the statistical...

Many pollutants cause endocrine disruption in aquatic organisms. While studies of the direct effects of toxicants on exposed organisms are commonplace, little is known about the potential for toxicant exposures in a parental (F0) generation to affect unexposed F1 or F2 generations (multigenerational and transgenerational effects, respectively), par...

Executive summary: Ecological connectivity is the unimpeded movement of species and the flow of natural processes that sustain life on Earth. This definition has been endorsed by the Convention on Migratory Species (CMS, 2020) and underlines the urgency of protecting connectivity and its various elements, including dispersal, seasonal migration, fl...

Restoration of degraded estuarine oyster reefs typically involves deploying recycled oyster shell. In low‐salinity, low‐predation areas of estuaries, high‐volume shell deployments are known to improve flow conditions and thus oyster survival and growth. It is also hypothesized that the physical structure of restored reefs could suppress foraging by...

Recent warnings from scientists suggest there is limited time to enact policies to avert wide‐ranging ecological and social damage from climate change. In the United States, discussions about comprehensive national policies to avert climate change have begun, with “Green New Deal” proposals and climate plans put forth by members of Congress and pre...

The ability to predict how predators structure ecosystems has been shown to depend on identifying both consumptive effects (CEs) and nonconsumptive effects (NCEs) of predators on prey fitness. Prey populations may also be affected by interactions between multiple predators across life stages of the prey and by environmental factors such as disturba...

Fishing reduces the resilience of fish populations to environmental variability. This occurs in part due to ‘cohort resonance’: as older fish are removed, generation time shrinks, and the population becomes more sensitive to variability at frequencies occurring on time scales near the generation time. This leaves populations more vulnerable to incr...

Marine protected areas (MPAs) are increasingly implemented as a conservation tool worldwide. In many cases, they are managed adaptively: the abundance of target species is monitored, and observations are compared to some model‐based expectation for the trajectory of population recovery to ensure that the MPA is achieving its goals. Most previous an...

This chapter describes how models can aid in managing populations to prevent extinction, given uncertainty about their state. From previous chapters, it is clear that avoiding extinction requires keeping both abundance and the replacement rate high. However, for both, the question remains, how high? The question of how high abundance should be to a...

This chapter begins by revisiting the M’Kendrick/von Foerster model, but using size instead of age as the state variable. It then uses the lessons from that model to describe how individual growth and mortality rates determine both stand distributions (a population of mixed ages) and cohort distributions (all one age). In particular, incorporating...

Most ecological populations exist in a randomly fluctuating environment, and these fluctuations influence vital rates, thus changing population dynamics. These changes are the focus of this chapter. The primary practical concern about environmental variability is the possibility that it could cause a population to go extinct, so the chapter describ...

This chapter traces the evolution of models for fishery management, focusing on the problem of maintaining both replacement and a desirable level of yield. Early models from the 1950s led to management for maximum sustainable yield (MSY). Later, recruitment and egg production data from populations at low abundance were used to set critical replacem...

This chapter introduces basic concepts in population modeling that will be applied throughout the book. It begins with the oldest example of a population model, the rabbit problem, which was described by Leonardo of Pisa (“Fibonacci”) and whose solution is the Fibonacci series. The chapter then explores what is known about simple models of populati...

This chapter examines age-structured models with density-dependent recruitment. In particular, it focuses on populations with over-compensatory density dependence, such as may occur due to cannibalism or some types of space competition. When the slope (at the equilibrium point) of the relationship between egg production and subsequent recruitment i...

This chapter considers populations structured in a different dimension: space. This begins by representing population dynamics with a spatial continuity equation (analogous to the M’Kendrick/von Foerster model for continuity in age or size). If organisms move at random, this motion can be approximated as diffusion. This proves useful for modeling s...

This chapter describes how we can use models, and how complex models should be. It begins with the difference between strategic and tactical population models. It describes the logic underlying both the scientific and the practical use of models, which corresponds with implementing deductive and inductive logic, respectively. Both approaches demand...

This book is a quantitative exposition of our current understanding of the dynamics of plant and animal populations, with the goal that readers will be able to understand, and participate in the management of populations in the wild. The book uses mathematical models to establish the basic principles of population behaviour. It begins with a philos...

The chapter describes age-structured models that are linear (i.e. without density dependence). Like simple (non-age-structured) linear models they eventually either increase to infinity or decrease to zero. They are only appropriate when density dependence is not an important factor, such as recently introduced populations or those that have declin...

This chapter moves to models in which developmental stage is the individual state variable, and abundance at each stage is the population variable. Stage is a period within an individual life history (e.g. juvenile, adult); organisms may survive within a stage or “grow” to other stages. This movement and survival is represented by a projection matr...

This chapter describes some general ways of thinking about population dynamics as a coherent body of interrelated advances in understanding, as developed in the first eleven chapters. The first generality is that understanding population dynamics depends on the concept of a state variable. It also underscores that dynamics depend on time delays, th...

Linear age-structured models eventually grow geometrically, and reach a stable age distribution (as in Chapter 3). This chapter describes what happens before “eventually.” That is, it describes the short-term, “transient” dynamics that occur when a population is perturbed, then begins to return to its stable distribution. Transients involve eigenva...

Twenty years ago, the creation of a new scientific program, the Partnership for Interdisciplinary Studies of Coastal Oceans (PISCO), funded by the Packard Foundation, provided the opportunity to integrate—from the outset— research, monitoring, and outreach to the public, policymakers, and managers. PISCO’s outreach efforts were initially focused pr...

To support conservation practices, societal demand for understanding fundamental coastal ocean ecosystem mechanisms has grown in recent decades. Globally, these regions are among the world’s most productive, but they are highly vulnerable to extractive and non-extractive stresses. In 1999, we established the Partnership for Interdisciplinary Studie...

A major goal of the Partnership for Interdisciplinary Studies of Coastal Oceans (PISCO) has been to understand the impacts of climate change and variability on the coastal ecosystems of the inner shelf of the California Current Large Marine System in particular, and other marine and even nonmarine systems more generally. Insights can result from de...

The life cycle of most benthic marine species includes a planktonic larval stage. Movement, largely by ocean currents, and survival during this stage drive patterns of variability and long-term persistence in adult populations, as well as connectivity among spatially separated populations. Here, we describe recent advances- many by PISCO-in underst...

Despite progressive policies and continued advances in ocean management, numerous shifts associated with global changes have been observed in marine ecosystems in recent years, including warming, ocean acidification, and deoxygenation. As global change accelerates, science is needed to inform evidence-based management strategies for continued ecosy...

As the reality of climate change became obvious during the late 1900s, the need for understanding ecosystem pattern and dynamics at large scales and for long periods became increasingly evident. This realization inspired the genesis of the Partnership for Interdisciplinary Studies of Coastal Oceans (PISCO). PISCO research aimed to quantify intertid...

The interaction between science and policy is often iterative: policy defines the need for scientific information, and the resulting science shapes future policy. This evolution is exemplified by the history of marine protected areas (MPAs). We describe how some policy applications of MPAs have changed through time from focusing on fisheries to bec...

Disturbance plays a key role in ecological structure and function. Two important and often studied components of disturbance are frequency and magnitude. Despite the potential for non‐linear interactions between frequency and magnitude, their effects are often assumed to combine in a linear manner. Additionally, studies of disturbance have mainly e...

Adaptive management of marine protected areas (MPAs) requires developing methods to evaluate whether monitoring data indicate that they are performing as expected. Modeling the expected responses of targeted species to an MPA network, with a clear timeline for those expectations, can aid in the development of a monitoring program that efficiently e...

Marine Protected Areas (MPAs) are being implemented worldwide, yet there are few cases where managers make specific predictions of the response of previously harvested populations to MPA implementation. Such predictions are needed to evaluate whether MPAs are working as expected, and if not, why. This evaluation is necessary to perform adaptive man...

Most communities are structured not by a single process but by some combination of top–down, bottom–up and supply‐side (i.e. juvenile recruitment) factors. However, establishing how multiple processes interact remains a fundamental challenge. For example, the recruitment, growth, and mortality of estuarine species can vary along the steep and numer...

Environmental stress gradients can affect species distributions and interspecific interactions. Because environmental stress depends on both intensity and duration, understanding the consequences of stress requires experiments that simultaneously manipulate both dimensions. In Apalachicola Bay, Florida (U.S.A.) the southern oyster drill (Stramonita...

Predators commonly structure natural communities, but predation effects can vary greatly. For example, increasing predator densities may not reduce prey populations as expected if intraspecific predator interactions suppress foraging efficiency or if prey size refuges exist. In northeastern Florida (USA), outbreaks of the predatory crown conch Melo...

Complex spatial structure is widely viewed as an attribute that can contribute to stability in fish populations. Depending on aspects of stock demography and productivity, the existence of complete or partial spatial refugia can enable population persistence when faced with high rates of exploitation. The Southern Flounder Paralichthys lethostigma...

Reconstructing the movements of fish among different environments and incorporating patterns of spatial population structure contribute to improved accuracy in the assessment of marine fishery resources. The southern flounder Paralichthys lethostigma is a valuable flatfish throughout its range in the US South Atlantic and Gulf of Mexico, but stock...

Nearshore marine populations are structured in metapopulations that are connected through larval dispersal across national boundaries. One of the main challenges for effective management of these metapopulations is the need for partnerships between nations that share the same resource. By coupling large‐scale connectivity information to a dynamic p...

Predator outbreaks have increased in the past two decades in many ecosystems and are predicted to become more common with climate change. During these outbreaks, predator densities increase rapidly, and can cause large reductions in prey populations or shifts in prey size structure. However, unexpected interactions may occur at high predator densit...

Parasites can shape population, community, and ecosystem dynamics, especially if their hosts play a key role in the ecosystem. Multiple parasites frequently co-infect hosts that alter disease dynamics via a variety of mechanisms. Further, abiotic and biotic factors often differentially affect hosts and their associated parasites, with direct and/or...

Predator outbreaks are predicted to increasingly decimate economically and ecologically important prey populations because global climate change and food-web modifications frequently facilitate predators and stress prey. Natural systems are organized hierarchically, with processes operating at multiple scales giving rise to patterns of biodiversity...

Dietary preferences of grazers can drive spatial variability in top-down control of autotroph communities, because diet composition may depend on the relative availability of autotroph species. On Caribbean coral reefs, parrotfish grazing is important in limiting macroalgae, but parrotfish dietary preferences are poorly understood. We applied diet-...

O'Leary et al. (2016) sought to evaluate the scientific basis for global targets for marine protected area (MPA) coverage (e.g., 10% of marine habitats) using a meta-analysis of published MPA modeling studies. Unfortunately, their approach was flawed in both methodology and philosophy, as we explain in this letter. This article is protected by copy...

Predators can influence prey traits and behavior (nonconsumptive effects [NCEs]), often with cascading effects for basal resources and ecosystem function. But critiques of NCE experiments suggest that their duration and design produce results that describe the potential importance of NCEs rather than their actual importance. In light of these criti...

Assessing how endocrine disrupting compounds (EDCs) affect population dynamics requires tracking males and females (and sex-reversed individuals) separately. A key component in any sex-specific model is the ‘mating function’ (the relationship between sex ratio and reproductive success) but this relationship is not known for any fish species. Using...

Predators can influence prey traits and behavior (nonconsumptive effects, NCE), often with cascading effects for basal resources and ecosystem function. But critiques of NCE experiments suggest that their duration and design produce results that describe the potential importance of NCEs rather than their actual importance. In light of these critiqu...

Integral projection models (IPMs) have a number of advantages over matrix-model approaches for analyzing size-structured population dynamics, because the latter require parameter estimates for each age or stage transition. However, IPMs still require appropriate data. Typically they are parameterized using individual-scale relationships between bod...

Demographic connectivity is fundamental to the persistence and resilience of metapopulations, but our understanding of the link between reproduction and recruitment is notoriously poor in open-coast marine populations. We provide the first evidence of high local retention and limited connectivity among populations spanning 700 km along an open coas...

Most reef fishes begin life as planktonic larvae before settling to the reef, metamorphosing and entering the benthic adult population. Different selective forces determine survival in the planktonic and benthic life stages, but traits established in the larval stage may carry over to affect post‐settlement performance. We tested the hypothesis tha...

Foraging theory predicts which prey patches predators should target. However, in most habitats, what constitutes a 'patch' and how prey density is calculated are subjective concepts and depend on the spatial scale at which the predator (or scientist) is observing. Moreover, the predator's 'foraging scale' affects prey population dynamics: predators...

Endocrine disrupting compounds (EDCs) enter aquatic habitats from a variety of anthropogenic sources and can mimic, block, or modulate the synthesis of natural hormones. EDCs affect both reproductive and non-reproductive behaviors because hormones mediate responses associated with aggression and fear. We examined the effects of two EDCs on risk-tak...

Abstract Predicting connectivity patterns in systems with fluid transport requires descriptions of the spatial distribution of propagules. In contrast to research on terrestrial seed dispersal, where much attention has focused on localized physical factors affecting dispersal, studies of oceanic propagule dispersal have often emphasized the role of...

Models for marine reserve design have been developed primarily with 'reef fish' life histories in mind: sedentary adults in patches connected by larval dispersal. However, many fished species undertake ontogenetic migrations, such as from nursery grounds to adult spawning habitats, and current theory does not fully address the range of reserve opti...

Most models of fish population dynamics ignore differences between male and female fish. Yet many harvested species are protogynous hermaphrodites (older females change sex into males), so size-selective fishing will disproportionately remove males. This shifts the sex ratio, potentially disrupting reproduction. Some modeling studies have investiga...

Fundamental knowledge of mortality during the planktonic phase of the typical marine life cycle is essential to understanding population dynamics and managing marine resources. However, estimating larval mortality is extremely challenging, because the fate of microscopic larvae cannot be tracked as they develop for weeks in ocean currents. We used...

Concern over sustainable fisheries resources has motivated investigations of possible synergistic effects of climate variability and fishing on marine populations. While many studies suggest that fishing increases population sensitivity to climate forcing, the effects of climate variability on the population response to fishing is relatively unders...

California responded to concerns about overfishing in the 1990s by implementing a network of marine protected areas (MPAs) through two science-based decision-making processes. The first process focused on the Channel Islands, and the second addressed California's entire coastline, pursuant to the state's Marine Life Protection Act (MLPA). We review...

Understanding the impact of environmental forcing and fishing on population variability is a fundamental challenge in fisheries management. Analysis of stochastic age-structured models has identified cohort resonance as a dominant feature of the response of several marine species to environmental variability. Cohort resonance consists of greater se...

Background/Question/Methods There has been a tendency to explain behavior of marine populations such as cycles and increasing variability with fishing, in terms of populations that are deterministically unstable. The potential explanatory power of populations that are actually stable, but constantly perturbed by environmental variability has been...

Background/Question/Methods Non-equilibrium dynamics are an inherent problem in marine fisheries management, because fishing truncates the natural age structure of a fish population. When fishing is removed, the time required for those age classes to fill back in produces demographic lags in abundance and recruitment. Furthermore, larval recruitm...

Background/Question/Methods No-take marine reserves that rotate over space have recently come in vogue as a proposed way to preserve fish biomass without forever “locking away” the resource. However, implementation of periodically harvested or rotational schemes for the purpose of fisheries or conservation has been met with mixed results. Earlier...

Background/Question/Methods No-take marine reserves that rotate over space have been proposed as an approach for preserving fish populations and improving fishery yield. Earlier theoretical models have suggested that rotation schemes can allow fish biomass to repeatedly build up inside reserves and then be fished down, affording larger catches of...

Background/Question/Methods One key challenge in spatial statistics is the inherent scale-dependency of many metrics of density or aggregation. For example, calculating spatial density (organisms/unit area) requires defining an areal scale (e.g., cm2, m2) for the denominator. Measuring density at that scale may obscure patterns at smaller scales,...

Foraging theory predicts that predators should prefer foraging in habitat patches with higher prey densities. However, density depends on the spatial scale at which a "patch" is defined by an observer. Ecologists strive to measure prey densities at the same scale that predators do, but many natural landscapes lack obvious, well-defined prey patches...

The comment by Castrejón and Charles is a useful summary of older, less-well-known gray literature regarding Galapagos fisheries. Their comment adds a helpful historical perspective to our original paper, which presented the first quantitative analysis of historical catch data in those fisheries, but which was not intended as a comprehensive histor...

Marine reserve design often involves a tradeoff between meeting conservation goals (persistence of fished populations) and minimizing economic costs (lost fishing grounds). Optimization tools such as Marxan navigate that tradeoff by finding reserve configurations that minimize economic costs while protecting some minimum fraction of fish habitat. H...

Demographic connectivity is a fundamental process influencing the dynamics and persistence of spatially structured populations. Consequently, quantifying connectivity is essential for properly designing networks of protected areas so that they achieve their core ecological objective of maintaining population persistence. Recently, many empirical st...

Predation is a key process driving coral reef fish population dynamics, with higher per capita prey mortality rates on reefs with more predators. Reef predators often forage together, and at high densities, they may either cooperate or antagonize one another, thereby causing prey mortality rates to be substantially higher or lower than one would ex...

The cause of population cycles is a common question in ecology, and one especially puzzling case is the cycles over the past century in populations of sockeye salmon, Oncorhyncus nerka. Some populations of this semelparous species in British Columbia, Canada, exhibit a phenomenon termed cyclic dominance: every four years there is a dominant cohort...

Simulation models are widely used to represent the dynamics of ecological systems. A common question with such models is how changes to a parameter value or functional form in the model alter the results. Some authors have chosen to answer that question using frequentist statistical hypothesis tests (e.g. ANOVA). This is inappropriate for two reaso...