I am a marine invertebrate behavioral ecologist. I am interested in how the behaviors of marine invertebrates are altered by environmental change, how that affects population structure, how that in turn affects the community, and how all this can be affected by the evolutionary history of the ecosystems. Currently, I am working on two projects:
1) Octopus movement and ecology in southern California
2) Restoration of endangered white abalone Supervisors: Dr. Ed Parnell and Dr. Paul Dayton
Understanding the reciprocal interactions between animal behavior and other inter-related systems... more Understanding the reciprocal interactions between animal behavior and other inter-related systems such as physiology, morphology, ecology, and evolution has been called a “Grand Challenge” for organismal biology. Behavior offers two unique contributions to our understanding of organism response to environmental change: 1) behavior is a rapid and reversible response, and 2) organisms can directly influence their surrounding environment, and thus the stimuli their physiological and morphological systems are exposed to, by “choosing” their environment. My dissertation utilizes the temperate octopus Octopus bimaculatus to understand the reciprocal interactions between behavior and ecology in a human-altered landscape. I use a combination of animal population surveys, dietary analysis, mathematical models, and acoustic telemetry to understand the feedback loops been behavior and ecology. Octopuses play a key predatory role in shaping communities that is unmatched by any other invertebrat...
Advances in Cephalopod Science: Biology, Ecology, Cultivation and Fisheries, 2014
Cephalopod life cycles generally share a set of stages that take place in different habitats and ... more Cephalopod life cycles generally share a set of stages that take place in different habitats and are adapted to specific, though variable, environmental conditions. Throughout the lifespan, individuals undertake a series of brief transitions from one stage to the next. Four transitions were identified: fertilisation of eggs to their release from the female (1), from eggs to paralarvae (2), from paralarvae to subadults (3) and from subadults to adults (4). An analysis of each transition identified that the changes can be radical (i.e. involving a range of morphological, physiological and behavioural phenomena and shifts in habitats) and critical (i.e. depending on environmental conditions essential for cohort survival). This analysis underlines that transitions from eggs to paralarvae (2) and from paralarvae to subadults (3) present major risk of mortality, while changes in the other transitions can have evolutionary significance. This synthesis suggests that more accurate evaluation of the sensitivity of cephalopod populations to environmental variation could be achieved by taking into account the ontogeny of the organisms. The comparison of most described species advocates for studies linking development and ecology in this particular group.
Predator–prey interactions exist on a variety of spatial and temporal scales; one of the earliest... more Predator–prey interactions exist on a variety of spatial and temporal scales; one of the earliest measurable responses to changes in these interactions is behavior. We examined the behavior of southern California kelp forest predators in response to a concentrated increase in the abundance of abalone during a restoration stocking experiment. We tested three hypotheses: (1) kelp forest predator density will increase following abalone stocking, (2) variations in predator characteristics will create an unequal impact on abalone, and (3) predation intensity will be greatest early in the experiment. Octopus discovered and exploited the influx of prey within the first week following stocking; their densities surged and then returned to pre-stocking levels after 2 months. This was not observed with any other predator. Damage from crustacean, fish, and octopus predation was observed on the recovered abalone shells, but were not correlated with predator densities. A larger percentage of recovered small shells had evidence of crustacean and fish predation, indicating there may be size-specific impacts of predators on abalone. Our results demonstrate that restoration stocking experiments can quantitatively test the predatory community's response to reintroductions, as well as predation risk of newly stocked prey species when exposed to a diverse suite of predators.
The spatial movement and ecology of highly mobile marine predators can strongly influence, and be... more The spatial movement and ecology of highly mobile marine predators can strongly influence, and be influenced by, a variety of ecological factors. Octopuses are voracious predators, and their predatory behavior can have significant impacts on the abundance and diversity of their prey communities. Nine Octopus bimaculatus (Verrill, 1883) were tagged and tracked during August 2014 using active tracking techniques. Octopus GPS position was recorded daily over the course of 12.9 ± 5.6 days (mean ± SD) and continuous movement was tracked for 20.8 ± 5.0 h (mean ± SD) for each animal. O. bimaculatus occupied an activity space of approximately 6000 ± 3000 km 2 (mean ± SD). Larger animals moved over larger areas, but activity space size was not correlated with octopus sex, habitat location, or time of day. Movement distances and diurnal movement patterns were highly variable for this species, both within and between individual octopuses. O. bimaculatus were highly mobile compared to other octopuses of similar size tracked in a similar way. These results are contradictory to previous estimates of movement and den fidelity for this species in this area, suggesting either a previous underestimate of O. bimaculatus movement, or a change in the way this species moves through its environment. This study pioneered the application of acoustic telemetry to octopuses in California ecosystems, and provides insight into the heterogeneity of octopus behavior and the potential impacts this heterogeneity may have on octopus prey and predator communities.
Cephalopod life cycles generally share a set of stages that take place in different habitats and ... more Cephalopod life cycles generally share a set of stages that take place in different habitats and are adapted to specific, though variable, environmental conditions. Throughout the lifespan, individuals undertake a series of brief transitions from one stage to the next. Four transitions were identified: fertilisation of eggs to their release from the female (1), from eggs to paralarvae (2), from paralarvae to subadults (3) and from subadults to adults (4). An analysis of each transition identified that the changes can be radical (i.e. involving a range of morphological, physiological and behavioural phenomena and shifts in habitats) and critical (i.e. depending on environmental conditions essential for cohort survival). This analysis underlines that transitions from eggs to paralarvae (2) and from paralarvae to subadults (3) present major risk of mortality, while changes in the other transitions can have evolutionary significance. This synthesis suggests that more accurate evaluation of the sensitivity of cephalopod populations to environmental variation could be achieved by taking into account the ontogeny of the organisms. The comparison of most described species advocates for studies linking development and ecology in this particular group.
Understanding the reciprocal interactions between animal behavior and other inter-related systems... more Understanding the reciprocal interactions between animal behavior and other inter-related systems such as physiology, morphology, ecology, and evolution has been called a “Grand Challenge” for organismal biology. Behavior offers two unique contributions to our understanding of organism response to environmental change: 1) behavior is a rapid and reversible response, and 2) organisms can directly influence their surrounding environment, and thus the stimuli their physiological and morphological systems are exposed to, by “choosing” their environment. My dissertation utilizes the temperate octopus Octopus bimaculatus to understand the reciprocal interactions between behavior and ecology in a human-altered landscape. I use a combination of animal population surveys, dietary analysis, mathematical models, and acoustic telemetry to understand the feedback loops been behavior and ecology. Octopuses play a key predatory role in shaping communities that is unmatched by any other invertebrat...
Advances in Cephalopod Science: Biology, Ecology, Cultivation and Fisheries, 2014
Cephalopod life cycles generally share a set of stages that take place in different habitats and ... more Cephalopod life cycles generally share a set of stages that take place in different habitats and are adapted to specific, though variable, environmental conditions. Throughout the lifespan, individuals undertake a series of brief transitions from one stage to the next. Four transitions were identified: fertilisation of eggs to their release from the female (1), from eggs to paralarvae (2), from paralarvae to subadults (3) and from subadults to adults (4). An analysis of each transition identified that the changes can be radical (i.e. involving a range of morphological, physiological and behavioural phenomena and shifts in habitats) and critical (i.e. depending on environmental conditions essential for cohort survival). This analysis underlines that transitions from eggs to paralarvae (2) and from paralarvae to subadults (3) present major risk of mortality, while changes in the other transitions can have evolutionary significance. This synthesis suggests that more accurate evaluation of the sensitivity of cephalopod populations to environmental variation could be achieved by taking into account the ontogeny of the organisms. The comparison of most described species advocates for studies linking development and ecology in this particular group.
Predator–prey interactions exist on a variety of spatial and temporal scales; one of the earliest... more Predator–prey interactions exist on a variety of spatial and temporal scales; one of the earliest measurable responses to changes in these interactions is behavior. We examined the behavior of southern California kelp forest predators in response to a concentrated increase in the abundance of abalone during a restoration stocking experiment. We tested three hypotheses: (1) kelp forest predator density will increase following abalone stocking, (2) variations in predator characteristics will create an unequal impact on abalone, and (3) predation intensity will be greatest early in the experiment. Octopus discovered and exploited the influx of prey within the first week following stocking; their densities surged and then returned to pre-stocking levels after 2 months. This was not observed with any other predator. Damage from crustacean, fish, and octopus predation was observed on the recovered abalone shells, but were not correlated with predator densities. A larger percentage of recovered small shells had evidence of crustacean and fish predation, indicating there may be size-specific impacts of predators on abalone. Our results demonstrate that restoration stocking experiments can quantitatively test the predatory community's response to reintroductions, as well as predation risk of newly stocked prey species when exposed to a diverse suite of predators.
The spatial movement and ecology of highly mobile marine predators can strongly influence, and be... more The spatial movement and ecology of highly mobile marine predators can strongly influence, and be influenced by, a variety of ecological factors. Octopuses are voracious predators, and their predatory behavior can have significant impacts on the abundance and diversity of their prey communities. Nine Octopus bimaculatus (Verrill, 1883) were tagged and tracked during August 2014 using active tracking techniques. Octopus GPS position was recorded daily over the course of 12.9 ± 5.6 days (mean ± SD) and continuous movement was tracked for 20.8 ± 5.0 h (mean ± SD) for each animal. O. bimaculatus occupied an activity space of approximately 6000 ± 3000 km 2 (mean ± SD). Larger animals moved over larger areas, but activity space size was not correlated with octopus sex, habitat location, or time of day. Movement distances and diurnal movement patterns were highly variable for this species, both within and between individual octopuses. O. bimaculatus were highly mobile compared to other octopuses of similar size tracked in a similar way. These results are contradictory to previous estimates of movement and den fidelity for this species in this area, suggesting either a previous underestimate of O. bimaculatus movement, or a change in the way this species moves through its environment. This study pioneered the application of acoustic telemetry to octopuses in California ecosystems, and provides insight into the heterogeneity of octopus behavior and the potential impacts this heterogeneity may have on octopus prey and predator communities.
Cephalopod life cycles generally share a set of stages that take place in different habitats and ... more Cephalopod life cycles generally share a set of stages that take place in different habitats and are adapted to specific, though variable, environmental conditions. Throughout the lifespan, individuals undertake a series of brief transitions from one stage to the next. Four transitions were identified: fertilisation of eggs to their release from the female (1), from eggs to paralarvae (2), from paralarvae to subadults (3) and from subadults to adults (4). An analysis of each transition identified that the changes can be radical (i.e. involving a range of morphological, physiological and behavioural phenomena and shifts in habitats) and critical (i.e. depending on environmental conditions essential for cohort survival). This analysis underlines that transitions from eggs to paralarvae (2) and from paralarvae to subadults (3) present major risk of mortality, while changes in the other transitions can have evolutionary significance. This synthesis suggests that more accurate evaluation of the sensitivity of cephalopod populations to environmental variation could be achieved by taking into account the ontogeny of the organisms. The comparison of most described species advocates for studies linking development and ecology in this particular group.
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accurate evaluation of the sensitivity of cephalopod populations to environmental variation could be achieved by taking into account the ontogeny of the organisms. The comparison of most described species advocates for studies linking development
and ecology in this particular group.
accurate evaluation of the sensitivity of cephalopod populations to environmental variation could be achieved by taking into account the ontogeny of the organisms. The comparison of most described species advocates for studies linking development
and ecology in this particular group.