
Carol ThornberUniversity of Rhode Island | URI · Department of Natural Resources Science
Carol Thornber
Ph.D. Biological Sciences, UC Santa Barbara
About
89
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Introduction
I am a marine community ecologist, focusing on ecological and evolutionary processes that impact macroalgal (seaweed) blooms, invasive species, climate change, and plant-herbivore interactions.
I am also the Director of University Research Operations, reporting directly to the VP of Research and Economic Development at URI. I handle large-scale research initiatives across our institution, among other responsibilities. I have served in senior research administrative positions since 2014 at URI.
Additional affiliations
April 2014 - present
August 2004 - June 2014
October 2001 - July 2004
Publications
Publications (89)
The marine algae Ulva spp. are commonly used as model biofouling organisms. As biofouling studies are primarily conducted using field-collected specimens, factors including species identity, seasonal availability, and physiological status can hinder the replicability of the results. To address these limitations, a protocol was developed for the on-...
The use of camera and video technologies for conducting underwater surveys has rapidly expanded over the past several decades. However, the utility of these systems can be significantly hampered by numerous logistical factors, including limited underwater visibility, rough bottom topography, and ease of use for the operator. Video studies can be di...
Marine macroalgae (seaweeds) are important primary global producers, with a wide distribution in oceans around the world from polar to tropical regions. Most of these species are exposed to variable environmental conditions, such as abiotic (e.g., light irradiance, temperature variations, nutrient availability, salinity levels) and biotic factors (...
Juvenile black sea bass Centropristis striata populations are increasing in southern New England estuaries of the northeastern USA with possible trophodynamic effects on labrid species: tautog Tautoga onitis and cunner Tautogolabrus adspersus . In this study, we examined the abundance, size-structure, and feeding ecology of juvenile sea bass and la...
Integrated aquaculture systems combining macroalgae with traditional fish and shellfish production represent an ecologically sound and economically attractive solution for farmers. To evaluate the potential of growing sugar
kelp (Saccharina latissima) at existing oyster (Crassostrea virginica) farms in Narragansett Bay (NB; Rhode Island, U.S.), we...
Sustainable aquaculture includes the aquaculture of non-fed crops that provide ecosystem services including nutrient extraction and water quality improvement. While shellfish are the most farmed sustainable aquaculture crops in the USA, shellfish farmers in the northeastern US have an interest in diversifying their crops and incorporating seaweeds...
Blue carbon ecosystems (BCEs) are important nature-based solutions for climate change-mitigation. However, current debates question the reliability and contribution of BCEs under future climatic-scenarios. The answer to this question depends on ecosystem processes driving carbon-sequestration and -storage, such as primary production and decompositi...
Coastal wetlands are known for exceptional productivity, but they also receive intense land-based nitrogen (N) loading. In Narragansett Bay, RI (USA), coastal ecosystems have received anthropogenic N inputs from wastewater for more than two centuries. Greenhouse gas fluxes were studied throughout a growing season (2016) in three coastal wetlands wi...
Ocean acidification and eutrophication have direct, positive effects on the growth of many marine macroalgae, potentially resulting in macroalgal blooms and shifts in ecosystem structure and function. Enhanced growth of macroalgae, however, may be controlled by the presence of grazers. While grazing under ocean acidification and eutrophication cond...
The authors have requested that this preprint be removed from Research Square.
Global climate change has led to increased sea surface temperatures and altered precipitation patterns worldwide. Concurrently, macroalgal blooms in coastal systems have been increasing in frequency and severity globally and are successful due to their fast growth rates and broad environmental tolerances. Here, we examine the responses of the bloom...
Sea level rise within New England is accelerating at a rate faster than the global average, leaving salt marshes particularly susceptible to degradation. Hydrological alteration is a type of climate change adaptation technique that has been implemented worldwide to combat the effects of sea level rise within salt marshes. Runnels (shallow channels)...
Caffeine is present in coastal environments worldwide and there is a need to assess its impact on marine organisms. Here, we exposed two species of ecologically important marine macroalgae (Chondrus crispus and Codium fragile subsp. fragile) to a suite of caffeine concentrations and measured their response. Caffeine concentrations of 10-100 ng L −1...
Due to climate change and other anthropogenic stressors, future conditions and impacts facing coastal habitats are unclear to coastal resource managers. Adaptive management strategies have become an important tactic to compensate for the unknown environmental conditions that coastal managers and restoration ecologists face. Adaptive management requ...
Aquaculture is an industry with the capacity for further growth that can contribute to sustainable food systems to feed an increasing global population. Sugar kelp (Saccharina latissima) is of particular interest for farmers as a fast-growing species that benefits ecosystems as a primary producer. However, as a new industry in the U.S., farmers int...
Climate change can alter salt marsh plant communities and their associated carbon flux dynamics via several mechanisms. Due to warming waters and sea level rise, macroalgal wrack accumulation rates in salt marshes are expected to increase. The smothering and shading effects of macroalgal wrack can have adverse effects on salt marsh vegetation. Most...
Introduced, or nonnative, marine species are a threat to local biodiversity, disrupt marine industries, and can have negative effects on coastal communities. Colpomenia peregrina (Sauvageau, 1927) is one of the most successful brown algal invaders in the world. Originating from the Northwest Pacific, Colpomenia peregrina was first collected in the...
Forests make up a large portion of terrestrial plant biomass, and the long‐lived woody plants that dominate them possess an array of traits that deter consumption by forest pests. Although often extremely effective against native consumers, invasive species that avoid or overcome these defenses can wreak havoc on trees and surrounding ecosystems. T...
Herbivore-induced changes in host quality mediate indirect interactions between herbivores. The nature of these indirect interactions can vary depending on the identity of herbivores involved, species-specific induction of defense-signaling pathways, and sequence of attack. However, our understanding of the role of these signaling pathways in the s...
ABSTRACT: Macroalgal blooms have increased in frequency worldwide due to anthropogenic activities. Algal blooms can disrupt recreational activities, interfere with fisheries, and deplete oxygen during decomposition. Narragansett Bay has experienced macroalgal blooms dominated by blade-forming Ulva for over a century. Evidence from other systems has...
Coastal ecosystems are subjected to global and local environmental stressors, including increased atmospheric carbon dioxide (CO2) (and subsequent ocean acidification) and nutrient loading. Here, we tested how two common macroalgal species in the Northwest Atlantic (Ulva spp. and Fucus vesiculosus Linneaus) respond to the combination of increased C...
All three macroalgal clades (Chlorophyta, Rhodophyta, and Phaeophyceae) contain bloom-forming species. Macroalgal blooms occur worldwide and have negative consequences for coastal habitats and economies. Narragansett Bay (NB), Rhode Island, USA, is a medium sized estuary that is heavily influenced by anthropogenic activities and has been plagued by...
1. Forest pests drive tree mortality through disruption of functional traits linked to nutrient acquisition, growth, and reproduction. The impacts of attack by individual or multiple aboveground herbivores on root functional traits critical to tree health have received little attention. This is especially true for exotic herbivores, organisms often...
The success of the invasive Asian shore crab, Hemigrapsus sanguineus, stems partly from its ability to exclude established crab species from preferred rocky and cobble intertidal habitat. Here, we assessed preference and competition for habitat types (cobble vs. sand) for H. sanguineus and two competitor species; the previous invasive green crab, C...
Intertidal crabs exhibit high occurrences of injury, including claw and leg loss. While it can
be challenging to determine the specific cause of such injuries, the resulting distribution of
injured individuals across habitat types is relatively easy to assess. We surveyed populations of
crabs along Rhode Island, USA rocky intertidal shorelines to d...
Temperature strongly affects performance in ectotherms. As ocean warming continues, performance of marine species will be impacted. Many studies have focused on how warming will impact physiology, life history, and behavior, but few studies have investigated how ecological and behavioral traits of organisms will affect their response to changing th...
Projected ocean acidification will have a detrimental impact on coral reef ecosystems, where fleshy algae are expected to replace corals. Of particular importance to reef ecosystems are fleshy turf algal communities, which have the potential to overgrow corals; few studies have investigated the community structure and diversity of turfs to climate...
Macroalgal blooms occur in shallow, low-wave energy environments and are generally dominated by fast-growing ephemeral macroalgae. When macroalgal mats undergo senescence and decompose they can cause oxygen depletion and release nutrients into the surrounding water. There are relatively few studies that examine macroalgal decomposition rates in are...
Macroalgal blooms occur worldwide and have the potential to cause severe ecological and economic damage. Narragansett Bay, RI is a eutrophic system that experiences summer macroalgal blooms composed mostly of Ulva compressa and Ulva rigida, which have biphasic life cycles with separate haploid and diploid phases. In this study, we used flow cytomet...
R code for ploidy analyses and model predictions.
(DOCX)
Ploidy biomass physical data for R.
(XLSX)
Herbivore impacts on macrophyte growth vary with the identity of the herbivores and macrophytes, as well as under different abiotic conditions. This interaction is further complicated by anthropogenic alterations to the environment, such as eutrophication. In this study, we utilized in situ herbivore exclusion experiments and mesocosm feeding prefe...
The introduction of the hemlock woolly adelgid (Adelges tsugae) in the eastern United States has caused extensive damage to eastern hemlock (Tsuga canadensis) stands. The presence of other herbivores can affect adelgid density and hemlock health. Here, we report the results of long-term work monitoring hemlock forests in a 7,500 km 2 latitudinal tr...
Concern over the relative importance of different sample preparation and storage techniques frequently used in stable isotope analysis of particulate nitrogen (δ15N) and carbon (δ13C) prompted an experiment to determine how important such factors were to measured values in marine organisms. We stored the marine macroalgae Ulva and Gracilaria in fou...
Resilience is currently a key theme within salt marsh ecological studies. Understanding the factors that affect salt marsh accretion and elevation gains is of paramount importance if management of these ecosystems is to be successful under increasing synergistic stresses of storm surge, inundation period, and eutrophication. We present the results...
Temperate coastal estuaries worldwide, such as Narragansett Bay, Rhode Island, are influenced by seasonal macroalgal blooms (e.g., Ulva) during warm months, whereas bloom-forming macroalgae are rarely encountered during winter. We assessed the ability of distromatic Ulva to overwinter through fragments, recruits, and/or microscopic propagules. We d...
Macroalgal bloom‐forming species occur in coastal systems worldwide. However, due to overlapping morphologies in some taxa, accurate taxonomic assessment and classification of these species can be quite challenging. We investigated the molecular and morphological characteristics of 153 specimens of bloom‐forming Ulva located in and around Narragans...
Blooms caused by the green macroalga Ulva pose a serious threat to coastal ecosystems around the world. Despite numerous studies of the causes and consequences of these blooms, we still have a limited understanding of Ulva bloom species richness and abundance due to difficulties in identifying Ulva species using morphological features. Along the no...
The recent invasion of the red alga Heterosiphonia japonica in the western North Atlantic Ocean has provided a unique opportunity to study invasion dynamics across a biogeographical barrier. Native to the western North Pacific Ocean, initial collections in 2007 and 2009 restricted the western North Atlantic range of this invader to Rhode Island, US...
Despite excessive growth of macroalgae in estuarine systems, little research has been done to examine the impacts of increased algal biomass that drifts into nearby salt marshes and accumulates on intertidal flats. The accumulation of macroalgal mats and subsequent decomposition-related releases of limiting nutrients may potentially alter marsh com...
The invasive Asiatic red alga Gracilaria vermiculophylla has recently spread rapidly around the globe. In the Northwest Atlantic, it was first collected in Virginia during 1998; in New England, it was first recorded from Narragansett Bay, Rhode Island in 2007. Until now, the specific dates of its introduction and current distribution in New England...
The United States is an ocean nation—our past, present, and future are inextricably connected to and dependent on oceans and marine resources. Marine ecosystems provide many important services, including jobs, food, transportation routes, recreational opportunities, health benefits, climate regulation, and cultural heritage that affect people, comm...
Considerable progress has been made in understanding physiological responses of marine organisms to climate change (Pörtner and Farrell, 2008; Somero, 2011) and in projecting future responses of individual species (Chown and Gaston, 2008; Helmuth, 2009). Key to this understanding are findings that indicate that multiple climate-related and non-clim...
Herbivores can facilitate macrophyte growth through stimulation of overcompensation pathways, removal of neighbouring or fouling competitors or increasing nutrient availability via nitrogenous waste inputs.
We examined the facilitative relationship between the mud snail I lyanassa obsoleta and two morphologically similar bloom‐forming U lva species...
Excessive growth of macroalgae in estuarine systems is becoming increasingly common among coastal communities throughout the world. Despite repeated observations of macroalgae growing or deposited among the stems of lower marsh plants, few studies have quantitatively documented the presence of macroalgae in salt marsh communities. We conducted mont...
In order to effectively study, manage, conserve, and sustain shallow-subtidal ecosystems, a spatial inventory of the basic resources and habitats is essential. Because of the complexities of shallow-subtidal substrates, benthic communities, geology, geomorphology, and water column attributes, few standard protocols are fully articulated and tested...
Marine assemblages are influenced by the rate and timing of species settlement and recruitment. Both abiotic factors and biotic
interactions can impact recruitment rates of marine species in a variety of systems. However, the impacts of species which
recruit at the same time upon each other are less well understood. We investigated the relationship...
Herbivory often has a negative effect on plants. However, there is a growing number of examples, primarily in terrestrial ecosystems, where herbivory causes an increase in plant size, growth rate, and/or reproductive output. In marine ecosystems, the positive effects of herbivores on macroalgae are not as well studied, although limited evidence exi...
Although invasive species can negatively impact communities via processes such as resource competition, they may also add new resources that facilitate the distribution and/or abundance of other organisms. In rocky intertidal systems, many benthic macroalgae compete for primary substrate, while providing secondary substrata to which sessile organis...
The high rate of HIV-1 mutation and the frequent sexual transmission highlight the need for novel therapeutic modalities with broad activity against both CXCR4 (X4) and CCR5 (R5)-tropic viruses. We investigated a large number of natural products, and from Sargassum fusiforme we isolated and identified palmitic acid (PA) as a natural small bioactive...
Accumulations of nuisance drift macroalgae along the open coast Atlantic beaches of the Cape Cod National Seashore have been observed on an anecdotal basis for over 50 years. This entire stretch of coastline is sandy, with no solid substrata for algal attachment. During the summer of 2006, we collected data on drift macroalgal accumulations repeate...
Primary producers such as plants and macroalgae can vary in palatability to their herbivorous grazers; this leads to variation in the intensity of herbivory, which can play an important role in setting the composition and diversity of producer assemblages. However, despite strong gradients in the composition and abundance of herbivores across inter...
Narragansett Bay has been heavily influenced by human activities for more than 200years. In recent decades, it has been one
of the more intensively fertilized estuaries in the USA, with most of the anthropogenic nutrient load originating from sewage
treatment plants (STP). This will soon change as tertiary treatment upgrades reduce nitrogen (N) loa...
The frequency and duration of macroalgal blooms have increased in many coastal waters over the past several decades. We used field surveys and laboratory culturing experiments to examine the nitrogen content and delta(15)N values of Ulva and Gracilaria, two bloom-forming algal genera in Narragansett Bay, RI (USA). The northern end of this bay is de...
Sargassum fusiforme (Harvey) Setchell has been shown to be a highly effective inhibitor of HIV-1 infection. To identify its mechanism of action, we performed bioactivity-guided fractionation on Sargassum fusiforme mixture. Here, we report isolation of a bioactive fraction SP4-2 (S. fusiforme), which at 8 mug/ml inhibited HIV-1 infection by 86.9%, w...
The frequency and duration of macroalgal blooms have increased in many coastal waters over the past several decades. We used field surveys and laboratory culturing experiments to examine the nitrogen content and d 15N values of Ulva and Gracilaria, two bloom forming algal genera in Narragansett Bay, RI (USA). The northern end of this bay is densely...
Problem Associational resistance can occur when the mortality risk of one species is reduced when it lives nearby (or in close contact with) another species. Evidence of associational resistance can be found in both marine and terrestrial sys-tems (Wahl & Hay 1995; Agrawal 2004; Poore & Hill 2005), and the impacts of this association can span a ran...
Many species of marine algae have life cycles that involve multiple separate, free-living phases that frequently differ in ploidy levels. These complex life cycles have received increasing scientific attention over the past few decades, due to their usefulness for both ecological and evolutionary studies. I present a synthesis of our current knowle...
Selective grazing by herbivores can have large effects on the population dynamics and community structure of primary producers. However, the ecological impacts of within-species herbivore preference for tissues of different phases (e.g., ploidy levels) or reproductive status remain relatively poorly known, especially among algae and other species w...
Anthropogenically induced global climate change has profound implications for marine ecosystems and the economic and social systems that depend upon them. The relationship between temperature and individual performance is reasonably well understood, and much climate-related research has focused on potential shifts in distribution and abundance driv...
Although human-mediated extinctions disproportionately affect higher trophic levels, the ecosystem consequences of declining diversity are best known for plants and herbivores. We combined field surveys and experimental manipulations to examine the consequences of changing predator diversity for trophic cascades in kelp forests. In field surveys we...
We develop and test models for the population dynamics of species that undergo regular alternations of generations between independent, free-living, haploid and diploid phases. The models are patterned after the dioecious, haploid–diploid lifecycle of many marine algae. If the two phases have equal demographic rates, all models (with or without den...
We combined field monitoring and laboratory experiments to examine the population ecology of both the microscopic and macroscopic stages of a new invasion of Undaria pinnatifida in California. Over the course of 1 yr, we observed 2 distinct recruitment pulses of individuals in the Santa Barbara harbor; the appearance of these pulses was strongly co...
Invasive algal species have the potential to change the structure and ecology of native algal communities. One well-known invader, the large Japanese kelp Undaria pinnatifida, has recently become established at several locations along the central and southern California coast (Monterey, Santa Barbara, Catalina, and others). Previous to its introduc...