Cassandra E. Benkwitt

Lancaster University | LU · Lancaster Environment Centre

During major life-history transitions animals often experience high mortality rates due to predation, making predator avoidance particularly advantageous during these times. There is mixed evidence from a limited number of studies, however, regarding how predator presence influences settlement of coral-reef fishes and it is unknown how other potent...

Cross-habitat foraging movements of predators can have widespread implications for predator and prey populations, community structure, nutrient transfer, and ecosystem function. Although central-place foraging models and other aspects of optimal foraging theory focus on individual predator behavior, they also provide useful frameworks for understan...

Pacific red lionfish Pterois volitans have invaded Atlantic reefs and reached much greater population densities than on native reefs. We hypothesized that lionfish on invaded reefs would (1) experience higher kill rates and thus spend less time hunting, given the naivete of Atlantic prey, (2) consume a greater variety of prey, given the lack of nat...

Direct demographic density dependence is necessary for population regulation and is a central concept in ecology, yet has not been studied in many invasive species, including any invasive marine fish. The red lionfish (Pterois volitans) is an invasive predatory marine fish that is undergoing exponential population growth throughout the tropical wes...

One of the major goals of invasion biology is predicting the effects of invaders on native species, which is often accomplished by linearly scaling-up per-capita effects with invader abundance. However, the relationship between invader density and their ecolog-ical impact is poorly understood, and it is likely that the effects of invasive species s...

In 1983–1984, an unknown waterborne pathogen caused the mass mortality of long-spined sea urchin (Diadema antillarum) across the Caribbean and western tropical Atlantic. After approximately 15 years, urchin populations began to recover at some locations, yet few have reached pre-mortality densities. To date, no study has documented a recovery in th...

Alteration of benthic reef habitat after coral bleaching and mortality induces changes in fish assemblages, with implications for fisheries. Our understanding of climate impacts to coral reef fisheries is largely based on fish abundance and biomass. The rates at which biomass is produced and replenished (productivity and turnover) are also importan...

Mobile consumers are key vectors of cross-ecosystem nutrients, yet have experienced population declines which threaten their ability to fill this role. Despite their importance and vulnerability, there is little information on how consumer biodiversity, in addition to biomass, influences the magnitude of nutrient subsidies. Here, we show that both...

In a time of unprecedented ecological change, understanding natural biophysical relationships between reef resilience and physical drivers is of increasing importance. This study evaluates how wave forcing structures coral reef benthic community composition and recovery trajectories after the major 2015/2016 bleaching event in the remote Chagos Arc...

Climate change represents a planetary emergency that is exacerbating the loss of native biodiversity. In response, efforts promoting climate change adaptation strategies that improve ecosystem resilience and/or mitigate climate impacts are paramount. Invasive Alien Species are a key threat to islands globally, where strategies such as preventing es...

By improving resource quality, cross-ecosystem nutrient subsidies may boost demographic rates of consumers in recipient ecosystems, which in turn can affect population and community dynamics. However, empirical studies on how nutrient subsidies simultaneously affect multiple demographic rates are lacking, in part because humans have disrupted the m...

Biological invasions pose a threat to nearly every ecosystem worldwide.1,2 Although eradication programs can successfully eliminate invasive species and enhance native biodiversity, especially on islands,3 the effects of eradication on cross-ecosystem processes are unknown. On islands where rats were never introduced, seabirds transfer nutrients fr...

Given the recent trend towards establishing very large marine protected areas (MPAs) and the high potential of these to contribute to global conservation targets, we review outcomes of the last decade of marine conservation research in the British Indian Ocean Territory (BIOT), one of the largest MPAs in the world. The BIOT MPA consists of the atol...

Parrotfish provide important ecological functions on coral reefs, including the provision of new settlement space through grazing and the generation of sediment through bioerosion of reef substrate. Estimating these functions at an ecosystem level depends on accurately quantifying the functional impact of individuals, yet parrotfish feeding metrics...

Positive relationships between biodiversity and ecosystem functioning (BEF) highlight the importance of conserving biodiversity to maintain key ecosystem functions and associated services. Although natural systems are rapidly losing biodiversity due to numerous human-caused stressors, our understanding of how multiple stressors influence BEF relati...

Tropical forests and coral reefs host a disproportionately large share of global biodiversity and provide ecosystem functions and services used by millions of people. Yet, ongoing climate change is leading to an increase in frequency and magnitude of extreme climatic events in the tropics, which, in combination with other local human disturbances,...

Biological feedbacks generated through patterns of disturbance are vital for sustaining ecosystem states. Recent ocean warming and thermal anomalies have caused pantropical episodes of coral bleaching, which has led to widespread coral mortality and a range of subsequent effects on coral reef communities. Although the response of many reef-associat...

As the geographic ranges of species are increasingly altered by forces such as biological invasion and climate change, when and where will strong biotic interactions arise within reassembling communities? Prey selectivity data are often of limited use for predicting future consumptive interactions because they are specific to the identity and relat...

Cross‐ecosystem nutrient subsidies play a key role in the structure and dynamics of recipient communities, but human activities are disrupting these links. Because nutrient subsidies may also enhance community stability, the effects of losing these inputs may be exacerbated in the face of increasing climate‐related disturbances. Nutrients from seab...

Hackerott et al. (2017) report that Indo-Pacific lionfish “had no apparent effect on native prey communities” (p. 9) on continuous reef-sites of the Belizean Barrier Reef (BBR). Based on a lack of observational evidence, they challenge existing evidence for the effects of predation by lionfish on native prey community structure and assert that prev...

Hackerott et al. (2017) report that Indo-Pacific lionfish “had no apparent effect on native prey communities” (p. 9) on continuous reef-sites of the Belizean Barrier Reef (BBR). Based on a lack of observational evidence, they challenge existing evidence for the effects of predation by lionfish on native prey community structure and assert that prev...

Indo-Pacific lionfishes (Pterois volitans/miles) have undergone rapid population growth and reached extremely high densities in parts of the invaded Atlantic. However, their long-term population trends in areas without active management programs are unknown. Since 2005, we have monitored lionfish abundance in the Exuma Cays of the central Bahamas o...

Density-dependent changes in predator foraging behavior due to intraspecific competition for food can have important implications for population dynamics of both the predator and its prey. The Indo-Pacific red lionfish Pterois volitans is an invasive predatory reef fish that has reached high population densities and can cause large reductions in sm...

Invasive Red Lionfish (Pterois volitans) continue to spread along tropical and subtropical coasts of the Western Atlantic, Caribbean, and Gulf of Mexico. They may have escaped natural controls present in their native Pacific, thus facilitating their immense success as predators in the Atlantic. We hypothesized that such ecological release would tra...

The effect of recreational SCUBA diving on coral reefs is likely secondary to many of the commonly cited stressors that threaten the long-term survival of coral reefs, such as rising temperatures. However, recreational SCUBA diving has had documented effects on various benthic organisms. Most research on the effect of SCUBA divers has focused on br...

While there is a persistent inverse relationship between latitude and species diversity across many taxa and ecosystems, deviations from this norm offer an opportunity to understand the conditions that contribute to large-scale diversity patterns. Marine systems, in particular, provide such an opportunity, as marine diversity does not always follow...

With the ongoing crisis of biodiversity loss and limited resources for conservation, the concept of biodiversity hotspots has been useful in determining conservation priority areas. However, there has been limited research into how temporal variability in biodiversity may influence conservation area prioritization. To address this information gap,...

EXTENDED ABSTRACT Pacific red lionfish (Pterois volitans) have now spread throughout the Gulf of Mexico and the greater Caribbean region. Invasive lionfish are voracious and generalized predators of dozens of small fish species (Albins and Hixon 2008), including the juveniles of important fishery species, and are seafloor habitat generalists, occup...

Background/Question/Methods Patterns of biodiversity vary in space and time and are strongly influenced by human activities and climate conditions. Increasing human pressures on marine ecosystems and emphasis on ecosystem-based management (EBM) requires an evaluation of the drivers of biodiversity over large spatial scales. Specifically, we ask t...

Marine diets of juvenile coho (Oncorhynchus kisutch) and Chinook salmon (Oncorhynchus tshawytscha) in the northern California Current are made up primarily of micronekton prey including juvenile fish, adult euphausiids, and large crab megalopae. However, these animals are seldom caught in the conventional plankton gears used to define juvenile salm...

Juvenile salmon exhibit high growth rates upon their arrival into the marine environment. Dietary changes from freshwater and estuarine habitats to those derived from the marine environment may play an important role in ultimate adult survival. We measured the total lipid and fatty acid (FA) composition of juvenile Chinook salmon (Oncorhynchus tsha...

The diel feeding periodicity of juvenile Chinook salmon Oncorhynchus tshawytscha was determined from stomachs collected in coastal waters off Oregon in 2000 and 2003. Juvenile Chinook salmon exhibited a diurnal feeding pattern with morning and evening feeding periods. There were differences in the duration and magnitude of the dawn and dusk peaks b...