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Vincent F. Gallucci

Bio: Vincent F. Gallucci is an academic researcher from University of Washington. The author has contributed to research in topics: Population & Bycatch. The author has an hindex of 21, co-authored 36 publications receiving 1383 citations. Previous affiliations of Vincent F. Gallucci include North Carolina State University & University at Buffalo.

Papers
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Journal ArticleDOI
TL;DR: In this paper, the von Bertalanffy growth model is used to statistically compare the properties of growth in two spatial regions by examination of the estimates of the growth parameter k and the asymptotic length parameter L∞.
Abstract: If the von Bertalanffy growth model is used to statistically compare the properties of growth in two spatial regions by examination of the estimates of the growth parameter k and the asymptotic length parameter L∞, a possible compound null hypothesis H0, is H0: K1= k2 and L∞1 = L∞ 2 for regions 1 and 2. Since the results of this two-parameter test may be difficult to interpret, an alternative procedure is suggested. In addition, the interpretation of the test must be based upon the nature of the data as well as upon the parameter estimates. A regression fit of the model to real but “inappropriate” data may yield a very “good” statistical fit but unrealistic estimates. The use of a third parameter (for example, t0, the time when length is zero) is necessary to uniquely specify a solution; its inclusion always enhances the statistical fit. Because of the interdependence between parameters k and L∞, we reparameterize the von Bertalanffy model with a new parameter w = k˙L∞. The parameter corresponds ...

281 citations

Journal ArticleDOI
TL;DR: The mean spawning dates of coho salmon Oncorhynchus kisutch and chinook salmon O. tshawytscha at the University of Washington Hatchery have become earlier over the period of record at the UW Hatchery, apparently because of selection in the hatchery.
Abstract: Spawning date is a crucial life history trait in fishes, linking parents to their offspring, and it is highly heritable in salmonid fishes. We examined the spawning dates of coho salmon Oncorhynchus kisutch and chinook salmon O. tshawytscha at the University of Washington (UW) Hatchery for trends over time. We then compared the spawning date patterns with the changing thermal regime of the Lake Washington basin and the spawning patterns of conspecifics at two nearby hatcheries. The mean spawning dates of both species have become earlier over the period of record at the UW Hatchery (since the 1950s for chinook salmon and the 1960s for coho salmon), apparently because of selection in the hatchery. Countering hatchery selection for earlier spawning are the increasingly warmer temperatures experienced by salmon migrating in freshwater to, and holding at, the hatchery. Spawning takes place even earlier at the Soos Creek Hatchery, the primary ancestral source of the UW populations, and at the Issaquah ...

121 citations

Journal ArticleDOI
TL;DR: Size-at-instar, growth-per-molt, reproductive schedules, and morphometric allometries were investigated in four sympatric species of Cancer (magister, the Dungeness crab, gracilis, productus, and oregonensis) in Garrison Bay, North Puget Sound.
Abstract: Size-at-instar, growth-per-molt, reproductive schedules, and morphometric allometries were investigated in four sympatric species of Cancer (magister, the Dungeness crab, gracilis, productus, and oregonensis) in Garrison Bay, North Puget Sound. Complementary observations were made on mating systems, mortality, habitat utilization patterns, and feeding. Numerical methods were successfully employed to discriminate instars in size-frequency distributions. Growth pattern, contrary to our expectation, was determinate in the four species. Geographic variation in prereproductive growth rate of C. magister is attributed to environmental factors. It is suggested that an independent stock may inhabit the Strait of Georgia-North Puget Sound area. Observations on mating behavior suggest that these polygynic species have different types of mating systems, leaning towards resource defense in C. oregonensis, female defense in C. gracilis (and perhaps also in C. productus), and explosive breeding assemblages in C. magister. Degree of sexual dimorphism is consistent with this hypothesis. Adult males of C. gracilis, C. productus, and C. oregonensis have proportionally larger chelae than females; no significant dimorphism was detected in C. magister. Male C. gracilis and C. productus show two clear allometric phases in the chela-carapace size relation. Contemporary studies of diversity within decapod guilds have frequently been done with food-resource partitioning as an explicit or implicit hypothesis. In contrast, we stress the importance of habitat, mating systems, and sexual selection as primary mechanisms underlying the diversification of this genus. the genus Cancer originated during the Eocene, presumably in the Northeast Pacific, and was well diversified in the Miocene (about 15 million years ago) (Nations, 1975). Nations (1975, 1979) postulated a radiation from this area (center of origin) into the Northwest Pacific, the North Atlantic, the Southeast Pacific, and then to New Zealand. The genus is at present restricted to cold temperate waters, and is maximally diversified in the Northeast Pacific, where we conducted our studies. Four species coexist in Garrison Bay (the study area), a small, shallow embayment in North Puget Sound. There are many publications dealing with one of them, Cancer magister (the Dungeness crab), but little is known about the other three (C. productus, C. gracilis, and C. oregonensis). Nevertheless, even for C. magister there are unexplained discrepancies between the life-history schedules reported for different geographic areas. One goal of the present study was to assemble and compare (within and between species) such schedules for the four species. Whenever possible we tried to

103 citations

Journal ArticleDOI
TL;DR: A length-structured population model, which incorporates von Bertalanffy growth, is used to describe changes in population abundance over time and the parameter estimates of Pacific cod obtained from this algorithm were comparable with the values that were originally used to simulate the data.
Abstract: A length-structured population model, which incorporates von Bertalanffy growth, is used to describe changes in population abundance over time. The model is incorporated into a catch-at-length algo...

100 citations


Cited by
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01 Aug 2000
TL;DR: Assessment of medical technology in the context of commercialization with Bioentrepreneur course, which addresses many issues unique to biomedical products.
Abstract: BIOE 402. Medical Technology Assessment. 2 or 3 hours. Bioentrepreneur course. Assessment of medical technology in the context of commercialization. Objectives, competition, market share, funding, pricing, manufacturing, growth, and intellectual property; many issues unique to biomedical products. Course Information: 2 undergraduate hours. 3 graduate hours. Prerequisite(s): Junior standing or above and consent of the instructor.

4,833 citations

Book
01 Jan 1992
TL;DR: Quantitative fisheries stock assessment as mentioned in this paper, Quantitative fishery stock assessment: Quantitative fishes stock assessment, Quantitative fish stock assessment and stock assessment in the field of fishery management.
Abstract: Quantitative fisheries stock assessment : , Quantitative fisheries stock assessment : , مرکز فناوری اطلاعات و اطلاع رسانی کشاورزی

1,581 citations

Journal ArticleDOI
01 Mar 1982-Oikos
TL;DR: A new concept is introduced to analyse species' regional distributions and to relate the pattern of distributions to niche relations, which indicates that average local abundance is positively correlated with regional distribution, i.e. the fraction of patchily distributed population sites occupied by the species.
Abstract: A new concept is introduced to analyse species' regional distributions and to relate the pattern of distributions to niche relations. Several sets of data indicate that average local abundance is positively correlated with regional distribution, i.e. the fraction of patchily distributed population sites occupied by the species. This observation is not consistent with the assumptions of a model of regional distribution introduced by Levins. A corrected model is now presented, in which the probability of local extinction is a decreasing function of distribution, and a stochastic version of the new model is analysed. If stochastic variation in the rates of local extinction and/or colonization is sufficiently large, species tend to fall into two distinct types, termed the "core" and the "satellite" species. The former are regionally common and locally abundant, and relatively well spaced-out in niche space, while opposite attributes characterize satellite species. This dichotomy, if it exists, provides null hypotheses to test theories about community structure, and it may help to construct better structured theories. Testing the core-satellite hypothesis and its connection to the r-K theory and to Raunkiaer's "law of frequency" are discussed.

1,103 citations

Journal ArticleDOI
TL;DR: When the traditional assumption that the incidence rate is proportional to the product of the numbers of infectives and susceptibles is dropped, the SIRS model can exhibit qualitatively different dynamical behaviors, including Hopf bifurcations, saddle-node bifuriations, and homoclinic loop bifURcations.
Abstract: When the traditional assumption that the incidence rate is proportional to the product of the numbers of infectives and susceptibles is dropped, the SIRS model can exhibit qualitatively different dynamical behaviors, including Hopf bifurcations, saddle-node bifurcations, and homoclinic loop bifurcations. These may be important epidemiologically in that they demonstrate the possibility of infection outbreak and collapse, or autonomous periodic coexistence of disease and host. The possible mechanisms leading to nonlinear incidence rates are discussed. Finally, a modified general criterion for supercritical or subcritical Hopf bifurcation of 2-dimensional systems is presented.

747 citations

Journal ArticleDOI
TL;DR: It is shown that the high natural diversity and abundance of sharks is vulnerable to even light fishing pressure, and that large sharks can exert strong top-down forces with the potential to shape marine communities over large spatial and temporal scales.
Abstract: Whereas many land predators disappeared before their ecological roles were studied, the decline of marine apex predators is still unfolding. Large sharks in particular have experienced rapid declines over the last decades. In this study, we review the documented changes in exploited elasmobranch communities in coastal, demersal, and pelagic habitats, and synthesize the effects of sharks on their prey and wider communities. We show that the high natural diversity and abundance of sharks is vulnerable to even light fishing pressure. The decline of large predatory sharks reduces natural mortality in a range of prey, contributing to changes in abundance, distribution, and behaviour of small elasmobranchs, marine mammals, and sea turtles that have few other predators. Through direct predation and behavioural modifications, top-down effects of sharks have led to cascading changes in some coastal ecosystems. In demersal and pelagic communities, there is increasing evidence of mesopredator release, but cascading effects are more hypothetical. Here, fishing pressure on mesopredators may mask or even reverse some ecosystem effects. In conclusion, large sharks can exert strong top-down forces with the potential to shape marine communities over large spatial and temporal scales. Yet more empirical evidence is needed to test the generality of these effects throughout the ocean.

739 citations