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Graham E. Forrester

Bio: Graham E. Forrester is an academic researcher from University of Rhode Island. The author has contributed to research in topics: Coral reef fish & Reef. The author has an hindex of 27, co-authored 62 publications receiving 3075 citations. Previous affiliations of Graham E. Forrester include University of California, Los Angeles & University of Sydney.


Papers
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Journal ArticleDOI
TL;DR: A heuristic model based on correlations between social, cultural, political, economic, and other contextual conditions in 127 marine reserves showed that high levels of compliance with reserve rules were related to complex social interactions rather than simply to enforcement of reserve rules.
Abstract: Marine reserves are increasingly recognized as having linked social and ecological dynamics. This study investigates how the ecological performance of 56 marine reserves throughout the Philippines, Caribbean, and Western Indian Ocean (WIO) is related to both reserve design features and the socioeconomic characteristics in associated coastal communities. Ecological performance was measured as fish biomass in the reserve relative to nearby areas. Of the socioeconomic variables considered, human population density and compliance with reserve rules had the strongest effects on fish biomass, but the effects of these variables were region specific. Relationships between population density and the reserve effect on fish biomass were negative in the Caribbean, positive in the WIO, and not detectable in the Philippines. Differing associations between population density and reserve effectiveness defy simple explanation but may depend on human migration to effective reserves, depletion of fish stocks outside reserves, or other social factors that change with population density. Higher levels of compliance reported by resource users was related to higher fish biomass in reserves compared with outside, but this relationship was only statistically significant in the Caribbean. A heuristic model based on correlations between social, cultural, political, economic, and other contextual conditions in 127 marine reserves showed that high levels of compliance with reserve rules were related to complex social interactions rather than simply to enforcement of reserve rules. Comparative research of this type is important for uncovering the complexities surrounding human dimensions of marine reserves and improving reserve management.

347 citations

Journal ArticleDOI
TL;DR: Overall reef fish density has been declining significantly for more than a decade, at rates that are consistent across all subregions of the Caribbean basin and in three of six trophic groups, indicating that Caribbean fishes have begun to respond negatively to habitat degradation.

270 citations

Journal ArticleDOI
01 Oct 1990-Ecology
TL;DR: An experimental study of the demography of juveniles of a small planktivorous damselfish, the humbug Dascyllus aruanus (Pomacentridae), was done at One Tree Reef, southern Great Barrier Reef, Australia, and suggests that complex effects of these factors on juvenile demography can modify recruitment patterns at small spatial scales.
Abstract: A notable recent development in marine ecology has been the suggestion that the size of demersal populations is limited and that patterns in demersal abundance are determined by the settlement of pelagic larvae (recruitment). Here I examine some factors potentially limiting and determining population density in a small coral reef fish. An experimental study of the demography of juveniles of a small planktivorous damselfish, the humbug Dascyllus aruanus (Pomacentridae), was done at One Tree Reef, southern Great Barrier Reef, Australia. Recently settled fish were transplanted to replicate units of habitat at three lagoonal sites. The interactive effects of initial recruit density, the presence of adults, and supplemental feeding on the growth, survival, migration, and maturation of the recruits were examined over the following 10 mo. Migration was apparently rare and thus unimportant. Effects of the factors on the growth and survival of recruits were complex. Survival of recruits was generally inversely related to their density but enhanced in the presence of adults. Average survival also varied among locations. Mean growth was generally depressed at high recruit densities and in the presence of adults but was enhanced by supplemental feeding. Maturation was related to size and so was influenced by effects on growth. The results suggest that regulatory interactions and shortages of food may limit the size of adult populations via their effect on growth rates. Effects of the factors on survival were slight. Total abundance may thus be limited primarily by recruitment unless effects on growth are ultimately translated to effects on demersal mortality. As a result of the effects on survival, there was some modification of the initial pattern of recruit abundance. The importance of these effects in determining patterns of abundance in unmanipulated populations depends on variation in recruitment at similar scales. The number of recruits entering the adult population under different treatments was highly modified from the pattern of initial recruit density. The number of recruits that became mature by the end of the experiment was totally unrelated to their initial density. In addition, that number was reduced in the presence of adults, and was limited by the availability of food. The results suggest that complex effects of these factors on juvenile demography can modify recruitment patterns at small spatial scales. They also suggest that these factors may have different effects on the adult and total demersal populations. In general terms, both recruitment and postrecruitment processes influence patterns in abundance.

250 citations

Journal ArticleDOI
TL;DR: In this article, the authors examined the extent to which spatial variation in the amount of suitable habitat predicted variation in abundance of the damselfish Dascyllus aruanus, an abundant planktivore that occupies live, branched coral throughout the Indo-Pacific.
Abstract: For species with metapopulation structures, variation in abundance among patches can arise from variation in the input rate of colonists. For reef fishes, variability in larval supply frequently is invoked as a major determinant of spatial patterns. We examined the extent to which spatial variation in the amount of suitable habitat predicted variation in the abundance of the damselfish Dascyllus aruanus, an abundant planktivore that occupies live, branched coral throughout the Indo-Pacific. Reef surveys established that size, branching structure and location (proximity to sand) of the coral colonies together determined the "suitability" of microhabitats for different ontogenetic stages of D. aruanus. Once these criteria were known, patterns of habitat use were quantified within lagoons of five Pacific islands. Availability of suitable habitat generally was an excellent predictor of density, and patterns were qualitatively consistent at several spatial scales, including among different lagoons on the same island, among different islands and between the central (French Polynesia and Rarotonga) and western (Great Barrier Reef, Australia) South Pacific. A field experiment that varied the amount of suitable coral among local plots indicated that habitat for settlers accounted for almost all of the spatial variation in the number of D. aruanus that settled at that location, suggesting that spatial patterns of abundance can be established at settlement without spatial variation in larval supply. Surveys of four other species of reef-associated fish revealed that a substantial fraction of their spatial variation in density also was explained by availability of suitable reef habitat, suggesting that habitat may be a prevalent determinant of spatial patterns. The results underscore the critical need to identify accurately the resource requirements of different species and life stages when evaluating causes of spatial variation in abundance of reef fishes.

221 citations

Journal ArticleDOI
TL;DR: This study has documented a previously unrecorded regulatory mechanism for reef fish populations (density-dependent adult mortality) and provided a particularly strong example of a well-established mechanism ( density-dependent recruitment), which have the potential to strongly regulate the abundance of this species and rule out the control of abundance by the supply of recruits.
Abstract: Debate on the control of population dynamics in reef fishes has centred on whether patterns in abundance are determined by the supply of planktonic recruits, or by post-recruitment processes. Recruitment limitation implies little or no regulation of the reef-associated population, and is supported by several experimental studies that failed to detect density dependence. Previous manipulations of population density have, however, focused on juveniles, and there have been no tests for density-dependent interactions among adult reef fishes. I tested for population regulation in Coryphopterus glaucofraenum, a small, short-lived goby that is common in the Caribbean. Adult density was manipulated on artificial reefs and adults were also monitored on reefs where they varied in density naturally. Survival of adult gobies showed a strong inverse relationship with their initial density across a realistic range of densities. Individually marked gobies, however, grew at similar rates across all densities, suggesting that density-dependent survival was not associated with depressed growth, and so may result from predation or parasitism rather than from food shortage. Like adult survival, the accumulation of new recruits on reefs was also much lower at high adult densities than at low densities. Suppression of recruitment by adults may occur because adults cause either reduced larval settlement or reduced early post-settlement survival. In summary, this study has documented a previously unrecorded regulatory mechanism for reef fish populations (density-dependent adult mortality) and provided a particularly strong example of a well-established mechanism (density-dependent recruitment). In combination, these two compensatory mechanisms have the potential to strongly regulate the abundance of this species, and rule out the control of abundance by the supply of recruits.

143 citations


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Book
01 Jan 2002
TL;DR: This chapter discusses the construction of Inquiry, the science of inquiry, and the role of data in the design of research.
Abstract: Part I: AN INTRODUCTION TO INQUIRY. 1. Human Inquiry and Science. 2. Paradigms, Theory, and Research. 3. The Ethics and Politics of Social Research. Part II: THE STRUCTURING OF INQUIRY: QUANTITATIVE AND QUALITATIVE. 4. Research Design. 5. Conceptualization, Operationalization, and Measurement. 6. Indexes, Scales, and Typologies. 7. The Logic of Sampling. Part III: MODES OF OBSERVATION: QUANTITATIVE AND QUALITATIVE. 8. Experiments. 9. Survey Research. 10. Qualitative Field Research. 11. Unobtrusive Research. 12. Evaluation Research. Part IV: ANALYSIS OF DATA:QUANTITATIVE AND QUALITATIVE . 13. Qualitative Data Analysis. 14. Quantitative Data Analysis. 15. Reading and Writing Social Research. Appendix A. Using the Library. Appendix B. Random Numbers. Appendix C. Distribution of Chi Square. Appendix D. Normal Curve Areas. Appendix E. Estimated Sampling Error.

2,884 citations

Journal ArticleDOI
TL;DR: A perusal of any recent textbook on ecology will not only confirm the importance of predation in modern ecology, but also illustrate the preeminence of the "lethal" perspective on predation.
Abstract: .P ]redator-prey interactions have long captured the attention of ecologists, and with good reason. Predation leads inevitably to the removal of prey individuals from ecological systems, which can have major impacts on prey population dynamics and on entire ecosystems. Interest in predator-prey interactions can be traced to the foundations of modern ecology, from early work on predator-prey population dynamics by historical figures such as Lotka, Volterra, and Gause (Taylor 1984) to classic work on the role of predation in regulating species diversity (e.g., Paine 1966). Ecologists continue to be greatly interested in predation and its effects on populations, communities, and ecosystems (Crawley 1992, Carpenter and Kitchell 1993). A perusal of any recent textbook on ecology will not only confirm the importance of predation in modern ecology, but also illustrate the preeminence of the "lethal" perspective on predation-that is, predation is seen as important only insofar as it results in the death of prey and their removal from the system. However, the obvious and sometimes dramatic lethal aspects of predation can obscure the nonlethal effects of the mere presence of predators in an ecological system. In the presence of predators, prey may alter their behavior so that they are more difficult

1,691 citations

Journal ArticleDOI
01 Feb 2005-Ecology
TL;DR: The results suggest that the costs of intimidation, traditionally ignored in predator-prey ecology, may actually be the dominant facet of trophic interactions.
Abstract: Predation is a central feature of ecological communities. Most theoretical and empirical studies of predation focus on the consequences of predators consuming their prey. Predators reduce prey population densities through direct consumption (a density- mediated interaction, DMI), a process that may indirectly affect the prey's resources, com- petitors, and other predators. However, predators can also affect prey population density by stimulating costly defensive strategies. The costs of these defensive strategies can include reduced energy income, energetic investment in defensive structures, lower mating success, increased vulnerability to other predators, or emigration. Theoretical and empirical studies confirm the existence of these induced costs (trait-mediated interactions, TMIs); however, the relative importance of intimidation (TMI) and consumption (DMI) effects remains an open question. We conducted a meta-analysis assessing the magnitude of both TMIs and DMIs in predator-prey interactions. On average, the impact of intimidation on prey de- mographics was at least as strong as direct consumption (63% and 51% the size of the total predator effect, respectively). This contrast is even more pronounced when we consider the cascading effects of predators on their prey's resources: density effects attenuated through food chains, while TMIs remained strong, rising to 85% of the total predator effect. Predators can thus strongly influence resource density even if they consume few prey items. Finally, intimidation was more important in aquatic than terrestrial ecosystems. Our results suggest that the costs of intimidation, traditionally ignored in predator-prey ecology, may actually be the dominant facet of trophic interactions.

1,557 citations

Journal ArticleDOI
01 May 2003-Ecology
TL;DR: The case for the broad mechanistic basis for TMIIs is developed and the direct evidence for T MIIs in various permutations of simple three- to four-species food webs is reviewed.
Abstract: In this paper we review the empirical studies documenting trait-mediated indirect interactions (TMIIs) in food webs. Basic models and empirical approaches that form the foundation of our conceptualization of species interactions generally assume that interactions are an intrinsic property of the two interacting species and therefore are governed by their respective densities. However, if a species reacts to the presence of a second species by altering its phenotype, then the trait changes in the reacting species can alter the per capita effect of the reacting species on other species and, consequently, population density or fitness of the other species. Such trait-mediated indirect interactions can reinforce or oppose density-mediated effects and have been largely overlooked by community ecologists. We first briefly develop the case for the broad mechanistic basis for TMIIs and then review the direct evidence for TMIIs in various permutations of simple three- to four-species food webs. We find strong evid...

1,515 citations

Journal ArticleDOI
TL;DR: This paper provides an exhaustive review of the literature on the responses of prey to predator chemosensory cues, primarily in tabular form, and highlights the most important studies on predator activity level and diet.
Abstract: It is well documented that animals take risk of predation into account when making decisions about how to behave in particular situations, often trading-off risk against opportunities for mating or acquiring energy. Such an ability implies that animals have reliable information about the risk of predation at a given place and time. Chemosensory cues are an important source of such information. They reliably reveal the presence of predators (or their presence in the immediate past) and may also provide information on predator activity level and diet. In certain circumstances (e.g., in the dark, for animals in hiding) they may be the only cues available. Although a vast literature exists on the responses of prey to predator chemosensory cues (or odours), these studies are widely scattered, from marine biology to biological control, and not well known or appreciated by behavioural ecologists. In this paper, we provide an exhaustive review of this literature, primarily in tabular form. We highlight so...

1,384 citations