Predators are fundamentally important for regulating and driving prey population dynamics as well as structuring ecological communities. Over-exploitation of marine resources has caused dramatic depletions of predatory fish species and shifts in marine community composition, with attendant declines in productivity and diversity of marine ecosystems. Despite the important ramifications of...
Because many coral-reef fishes are observable in situ, are amenable to transplantation, have small home ranges and short generation times, they provide a excellent system to investigate many topics within general ecology, fisheries biology, and conservation biology. The primary goal of this dissertation was to use the coral-reef fishes system...
There is increasing awareness that human activities are altering the ways that natural systems operate and that local shifts in species composition and abundance can lead to abrupt and irreversible global change. Therefore, understanding the processes that buffer biological communities from critical shifts and how our actions affect natural stabilizing...
Understanding the dynamics of open marine populations is difficult. Ecological processes may vary with the spatial structure of the habitat, and this variation may subsequently affect demographic rates. In a series of observational and experimental studies in the Bahamas, I examined the roles of emigration, mortality, and predation in the...
Although only a minority of introduced species become established and have noticeable consequences in their new communities, some can displace native species, alter food webs, and cause local extinctions. Studying these invasive species can provide new insights into basic ecological questions as well as inform management strategies. Pacific lionfish (Pterois...
Many species have complex life cycles in which a dispersive larval stage is
followed by a relatively sedentary adult stage. For such species, reproductive output
is often high and large variation in survivorship throughout early life-history phases
(eggs and larvae) can lead to dramatic fluctuations in recruitment which may in...
During karyokinesis in the ciliate, Tetrahymena pyriformis, strain GL-I, an extranuclear chromatin body (ECB) is frequently formed as an excluded mass between the two dividing daughter macronuclei. The formation and fate of ECB's were followed by means of Feu lgen, toluidine blue 0, and euchrysine staining and autoradiography (³H-thymidine). The...
Invasive species are a growing global economic and ecological problem. Invasive Indo-Pacific lionfish (Pterois spp.) are known to have extreme negative effects on coral-reef communities in the Bahamas, so understating their distribution within and among reefs, what limits their local movements, and the effects they have on native prey species...
The influence of loss of diversity on community dynamics and ecosystem functioning has recently received considerable attention. Although study of biodiversity has a long history within ecology, empirical investigations exploring consequences of loss have been rare. Because many factors confound diversity comparisons, experimental manipulations of diversity offer the most direct...