Carolynn M Harris | Dartmouth College (original) (raw)
Papers by Carolynn M Harris
Goldschmidt2022 abstracts, 2022
Goldschmidt2022 abstracts, 2022
Goldschmidt2022 abstracts
ABSTRACT Zostera marina (also known as eelgrass) is an important primary producer in near shore e... more ABSTRACT Zostera marina (also known as eelgrass) is an important primary producer in near shore ecosystems in the Gulf of Maine, providing both habitat and nutrients for a variety of organisms (e.g., crustaceans, polychaetes, gastropods, and fish). The purpose of this study is to use compound specific delta13C analyses of essential amino acids to determine the degree to which organic matter derived from isotopically distinct primary producers (e.g., eelgrass, phytoplankton, and epiphytic algae) contribute to the diets of snails, shrimp, and fish in an eelgrass system in Casco Bay. Maquoit Bay, located in northwestern Casco Bay, in the Gulf of Maine, is a shallow estuarine system that is characterized by silt and clay sized sediments and the presence of extensive eelgrass beds. Amino acid concentrations and delta13C compositions were determined for a variety of sample-types collected in July-August, 2010, from three sites in the study area, including muscle tissue from Tautogolabrus adspersus (cunner), Gasterosteus aculeatus (3-spined stickleback), Nassarius obsoletus (snail), and Mysis spp. (shrimp), seston (i.e., phytoplankton), Z. marina, and epiphytic algae. TFAA amino acid derivatives of the total hydrolyzate were analyzed by GC-FID for amino acid concentration, and by GC-c-IRMS- for carbon isotope composition. Muscle tissue was dominated by glutamic and aspartic acids, and leucine, whereas Zostera marina was dominated by aspartic and glutamic acids, and proline. Phenylalanine and leucine in Z. marina are approximately 10 0/00 enriched in 13C relative to these same amino acids in the seston. The carbon isotope values of these essential amino acids are significantly more enriched in 13C for N. obsoletus than for T. adspersus, G. aculeatus, and Mysis spp. These data suggest that organic matter derived from Z. marina and/or epiphytic algae is more important in the diets of N. obsoletus, and organic matter derived from seston is more important for the diets of T. adspersus, G. aculeatus, and Mysis spp. These isotopic relationships provide a means to interpret essential amino acids extracted from well-preserved archaeological remains.
Marine Ecology Progress Series, 2013
Global and Planetary Change, 2012
The Journal of Island and Coastal Archaeology, 2017
ABSTRACT Zooarchaeological faunal remains are commonly examined to investigate harvesting behavio... more ABSTRACT Zooarchaeological faunal remains are commonly examined to investigate harvesting behavior. We determined limpet (Patella vulgata) shell size and shape, and estimated shell age from several middens at the Late Norse Sandwick South Site, Unst, Shetland, UK, whose strata represent distinct occupational phases (Phase 1: AD 1100–1200, Phase 2: AD 1200–1250, Phase 3: AD 1250–1350). Our goal was to determine if the many limpets found there could provide insight into Norse harvesting behavior. Shell length, conicity, and modeled age all declined between Phases 1 and 2, suggesting intensive, size-selective harvesting of limpets and a shift to harvesting lower in the intertidal zone between phases. Length and conicity varied in Phases 2 and 3 and no major changes seem to have occurred over these periods, indicating that harvesting maintained the limpet population at an impacted level throughout the later phases. The conicity decline between Phases 1 and 2 may also have been caused by increased storminess that accompanied the onset of the Little Ice Age. The mean length of modern limpet populations near the Norse site did not differ from the archaeological phases, but did vary among collection years. Limpets were 26% larger in 2015 than in 2012 and 2013, indicating that large interannual variations in population structure can occur over short time periods. Potentially the result of extreme storms removing small limpets, this result raises the possibility that size and conicity changes during the Sandwick South Site occupation, as well as in other early populations, could also be the result of environmental factors rather than human harvesting alone. We feel, however, that the most parsimonious explanation for the patterns we document is human harvesting.
Ecosphere, 2016
Seasonal trophic linkages in Arctic marine invertebrates assessed via fatty acids and compound-sp... more Seasonal trophic linkages in Arctic marine invertebrates assessed via fatty acids and compound-specific stable isotopes.
Estuaries and Coasts, 2016
Shallow estuarine lagoons characterize >70 % of the eastern Alaskan Beaufort Sea coastline and, l... more Shallow estuarine lagoons characterize >70 % of the eastern Alaskan Beaufort Sea coastline and, like temperate and tropical lagoons, support diverse and productive biological communities. These lagoons experience large variations in temperature (−2 to 14°C) and salinity (0 to >45) throughout the year. Unlike lower latitude coastal systems, transitions between seasons are physically extreme and event-driven. On Arctic coastlines, a brief summer open-water period is followed by a 9-month ice-covered period that concludes with a late-spring sea ice breakup and intense freshwater runoff. From 2011 to 2014, we examined interannual variations in water column physical structure (temperature, salinity, and δ 18 O) in five lagoons that differ with respect to their degree of exchange with adjacent marine waters and magnitude of freshwater inputs. Temperature, salinity, and source water composition (calculated using a salinity and δ 18 O mixing model) were variable in space and time. During sea ice breakup in June, water column δ 18 O and salinity measurements showed that low salinity waters originated from meteoric inputs (50-80 %; which include river inputs and direct precipitation) and sea ice melt (18-51 %). Following breakup, polar marine waters became prevalent within a mixed water column over the summer open-water period within all five lagoons (26-63 %). At the peak of ice-cover extent and thickness in April, marine water sources dominated (75-87 %) and hypersaline conditions developed in some lagoons. Seasonal runoff dynamics and differences in lagoon geomorphology (i.e., connectivity to the Beaufort Sea) are considered key potential drivers of observed salinity and source water variations.
Frontiers in Astronomy and Space Sciences
Past environments on Mars contained abundant water, suggesting certain regions may have been cond... more Past environments on Mars contained abundant water, suggesting certain regions may have been conducive to life as we know it and implying the potential for microbial inhabitants. Gale and Jezero craters, home of the Perseverance and Curiosity rovers, hosted ancient lakes that experienced periods of active hydrologic cycling and prolonged drying intervals. Exploration of these basins (and future operations on Mars) will benefit from detailed characterizations of analogous environments on Earth, where life detection strategies at various spatial scales (i.e., rover to orbiter) can be tested and validated. Investigations of terrestrial analogs are critical for understanding (1) how microorganisms generate chemical biosignatures in environments characterized by multiple extreme conditions; (2) the impact of environmental conditions and mineralogy on biosignature preservation; and (3) what technologies and techniques are needed to detect biosignatures remotely or in situ. Here, we survey...
Analysis of the Size, Shape, and Modeled Age of Common Limpets (Patella vulgata) from Late Norse Middens at Sandwick, 2017
Zooarchaeological faunal remains are commonly examined to investigate harvesting behavior. We det... more Zooarchaeological faunal remains are commonly examined to investigate
harvesting behavior. We determined limpet (Patella vulgata) shell
size and shape, and estimated shell age from several middens at the
Late Norse Sandwick South Site, Unst, Shetland, UK, whose strata represent
distinct occupational phases (Phase 1: AD 1100–1200, Phase 2:
AD 1200–1250, Phase 3: AD 1250–1350). Our goal was to determine
if the many limpets found there could provide insight into Norse harvesting
behavior. Shell length, conicity, and modeled age all declined
between Phases 1 and 2, suggesting intensive, size-selective harvesting
of limpets and a shift to harvesting lower in the intertidal zone
between phases. Length and conicity varied in Phases 2 and 3 and no
major changes seem to have occurred over these periods, indicating
that harvesting maintained the limpet population at an impacted
level throughout the later phases. The conicity decline between Phases
1 and 2 may also have been caused by increased storminess that accompanied the onset of the Little Ice Age. The mean length of
modern limpet populations near the Norse site did not differ from the
archaeological phases, but did vary among collection years. Limpets
were 26% larger in 2015 than in 2012 and 2013, indicating that
large interannual variations in population structure can occur over
short time periods. Potentially the result of extreme storms removing
small limpets, this result raises the possibility that size and conicity
changes during the Sandwick South Site occupation, as well as in
other early populations, could also be the result of environmental
factors rather than human harvesting alone. We feel, however, that
the most parsimonious explanation for the patterns we document is
human harvesting.
Do high Arctic coastal food webs rely on a terrestrial carbon subsidy, 2018
Lagoons are a prominent feature of Arctic coastlines, support diverse benthic food webs, and prov... more Lagoons are a prominent feature of Arctic coastlines, support diverse benthic food webs, and provide vital feeding grounds for fish, migratory birds, and marine mammals. Across the Arctic, loading of terrestrial/freshwater-derived organic carbon (C T) from watershed runoff and coastal erosion is predicted to increase with global warming, and may subsidize marine organic carbon as an energy source. To assess the importance of C T , we analyzed the trophic links and carbon assimilation pathways of twenty genera in five trophic guilds (suspension and filter feeders (Su/FF), surface and subsurface deposit feeders (Ss/De), epibenthic omnivorous invertebrates (Ep/Om), omnivorous fishes (Fish), and mammalian carnivores (Mam/Carn) as well as end-member organic matter (OM) sources. Because end-members had distinct carbon and nitrogen isotopic ratios, we employed a Bayesian stable isotope mixing model (simmr) to determine the contributions of C T , shelf OM, and marine microphytobenthos, to the diets of resident fauna. Ss/De and Ep/Om mainly assimilated marine-derived OM end-members. Su/FF, Fish, and beluga whales derived large portions of their diet from C T (N40%). We conclude that (1) coastal food webs are characterized by a high degree of omnivory and plasticity, (2) C T is an important OM subsidy to food webs, and (3) omnivorous fish transfer C T from lower to upper trophic levels.
Salinity and Temperature Regimes in Eastern Alaskan Beaufort Sea Lagoons in Relation to Source Water Contributions, 2017
Shallow estuarine lagoons characterize >70 % of the eastern Alaskan Beaufort Sea coastline and, l... more Shallow estuarine lagoons characterize >70 % of
the eastern Alaskan Beaufort Sea coastline and, like temperate
and tropical lagoons, support diverse and productive biological
communities. These lagoons experience large variations in
temperature (−2 to 14 °C) and salinity (0 to >45) throughout
the year. Unlike lower latitude coastal systems, transitions
between seasons are physically extreme and event-driven.
On Arctic coastlines, a brief summer open-water period is
followed by a 9-month ice-covered period that concludes with
a late-spring sea ice breakup and intense freshwater run-off.
From 2011 to 2014, we examined interannual variations in
water column physical structure (temperature, salinity, and
δ18O) in five lagoons that differ with respect to their degree
of exchange with adjacent marine waters and magnitude of
freshwater inputs. Temperature, salinity, and source water
composition (calculated using a salinity and δ18O mixing
model) were variable in space and time. During sea ice breakup
in June, water column δ18O and salinity measurements
showed that low salinity waters originated from meteoric inputs
(50–80 %; which include river inputs and direct precipitation)
and sea ice melt (18–51 %). Following breakup, polar
marine waters became prevalent within a mixed water column over the summer open-water period within all five lagoons
(26–63 %). At the peak of ice-cover extent and thickness in
April, marine water sources dominated (75–87 %) and hypersaline
conditions developed in some lagoons. Seasonal runoff
dynamics and differences in lagoon geomorphology (i.e., connectivity
to the Beaufort Sea) are considered key potential
drivers of observed salinity and source water variations.
Goldschmidt2022 abstracts, 2022
Goldschmidt2022 abstracts, 2022
Goldschmidt2022 abstracts
ABSTRACT Zostera marina (also known as eelgrass) is an important primary producer in near shore e... more ABSTRACT Zostera marina (also known as eelgrass) is an important primary producer in near shore ecosystems in the Gulf of Maine, providing both habitat and nutrients for a variety of organisms (e.g., crustaceans, polychaetes, gastropods, and fish). The purpose of this study is to use compound specific delta13C analyses of essential amino acids to determine the degree to which organic matter derived from isotopically distinct primary producers (e.g., eelgrass, phytoplankton, and epiphytic algae) contribute to the diets of snails, shrimp, and fish in an eelgrass system in Casco Bay. Maquoit Bay, located in northwestern Casco Bay, in the Gulf of Maine, is a shallow estuarine system that is characterized by silt and clay sized sediments and the presence of extensive eelgrass beds. Amino acid concentrations and delta13C compositions were determined for a variety of sample-types collected in July-August, 2010, from three sites in the study area, including muscle tissue from Tautogolabrus adspersus (cunner), Gasterosteus aculeatus (3-spined stickleback), Nassarius obsoletus (snail), and Mysis spp. (shrimp), seston (i.e., phytoplankton), Z. marina, and epiphytic algae. TFAA amino acid derivatives of the total hydrolyzate were analyzed by GC-FID for amino acid concentration, and by GC-c-IRMS- for carbon isotope composition. Muscle tissue was dominated by glutamic and aspartic acids, and leucine, whereas Zostera marina was dominated by aspartic and glutamic acids, and proline. Phenylalanine and leucine in Z. marina are approximately 10 0/00 enriched in 13C relative to these same amino acids in the seston. The carbon isotope values of these essential amino acids are significantly more enriched in 13C for N. obsoletus than for T. adspersus, G. aculeatus, and Mysis spp. These data suggest that organic matter derived from Z. marina and/or epiphytic algae is more important in the diets of N. obsoletus, and organic matter derived from seston is more important for the diets of T. adspersus, G. aculeatus, and Mysis spp. These isotopic relationships provide a means to interpret essential amino acids extracted from well-preserved archaeological remains.
Marine Ecology Progress Series, 2013
Global and Planetary Change, 2012
The Journal of Island and Coastal Archaeology, 2017
ABSTRACT Zooarchaeological faunal remains are commonly examined to investigate harvesting behavio... more ABSTRACT Zooarchaeological faunal remains are commonly examined to investigate harvesting behavior. We determined limpet (Patella vulgata) shell size and shape, and estimated shell age from several middens at the Late Norse Sandwick South Site, Unst, Shetland, UK, whose strata represent distinct occupational phases (Phase 1: AD 1100–1200, Phase 2: AD 1200–1250, Phase 3: AD 1250–1350). Our goal was to determine if the many limpets found there could provide insight into Norse harvesting behavior. Shell length, conicity, and modeled age all declined between Phases 1 and 2, suggesting intensive, size-selective harvesting of limpets and a shift to harvesting lower in the intertidal zone between phases. Length and conicity varied in Phases 2 and 3 and no major changes seem to have occurred over these periods, indicating that harvesting maintained the limpet population at an impacted level throughout the later phases. The conicity decline between Phases 1 and 2 may also have been caused by increased storminess that accompanied the onset of the Little Ice Age. The mean length of modern limpet populations near the Norse site did not differ from the archaeological phases, but did vary among collection years. Limpets were 26% larger in 2015 than in 2012 and 2013, indicating that large interannual variations in population structure can occur over short time periods. Potentially the result of extreme storms removing small limpets, this result raises the possibility that size and conicity changes during the Sandwick South Site occupation, as well as in other early populations, could also be the result of environmental factors rather than human harvesting alone. We feel, however, that the most parsimonious explanation for the patterns we document is human harvesting.
Ecosphere, 2016
Seasonal trophic linkages in Arctic marine invertebrates assessed via fatty acids and compound-sp... more Seasonal trophic linkages in Arctic marine invertebrates assessed via fatty acids and compound-specific stable isotopes.
Estuaries and Coasts, 2016
Shallow estuarine lagoons characterize >70 % of the eastern Alaskan Beaufort Sea coastline and, l... more Shallow estuarine lagoons characterize >70 % of the eastern Alaskan Beaufort Sea coastline and, like temperate and tropical lagoons, support diverse and productive biological communities. These lagoons experience large variations in temperature (−2 to 14°C) and salinity (0 to >45) throughout the year. Unlike lower latitude coastal systems, transitions between seasons are physically extreme and event-driven. On Arctic coastlines, a brief summer open-water period is followed by a 9-month ice-covered period that concludes with a late-spring sea ice breakup and intense freshwater runoff. From 2011 to 2014, we examined interannual variations in water column physical structure (temperature, salinity, and δ 18 O) in five lagoons that differ with respect to their degree of exchange with adjacent marine waters and magnitude of freshwater inputs. Temperature, salinity, and source water composition (calculated using a salinity and δ 18 O mixing model) were variable in space and time. During sea ice breakup in June, water column δ 18 O and salinity measurements showed that low salinity waters originated from meteoric inputs (50-80 %; which include river inputs and direct precipitation) and sea ice melt (18-51 %). Following breakup, polar marine waters became prevalent within a mixed water column over the summer open-water period within all five lagoons (26-63 %). At the peak of ice-cover extent and thickness in April, marine water sources dominated (75-87 %) and hypersaline conditions developed in some lagoons. Seasonal runoff dynamics and differences in lagoon geomorphology (i.e., connectivity to the Beaufort Sea) are considered key potential drivers of observed salinity and source water variations.
Frontiers in Astronomy and Space Sciences
Past environments on Mars contained abundant water, suggesting certain regions may have been cond... more Past environments on Mars contained abundant water, suggesting certain regions may have been conducive to life as we know it and implying the potential for microbial inhabitants. Gale and Jezero craters, home of the Perseverance and Curiosity rovers, hosted ancient lakes that experienced periods of active hydrologic cycling and prolonged drying intervals. Exploration of these basins (and future operations on Mars) will benefit from detailed characterizations of analogous environments on Earth, where life detection strategies at various spatial scales (i.e., rover to orbiter) can be tested and validated. Investigations of terrestrial analogs are critical for understanding (1) how microorganisms generate chemical biosignatures in environments characterized by multiple extreme conditions; (2) the impact of environmental conditions and mineralogy on biosignature preservation; and (3) what technologies and techniques are needed to detect biosignatures remotely or in situ. Here, we survey...
Analysis of the Size, Shape, and Modeled Age of Common Limpets (Patella vulgata) from Late Norse Middens at Sandwick, 2017
Zooarchaeological faunal remains are commonly examined to investigate harvesting behavior. We det... more Zooarchaeological faunal remains are commonly examined to investigate
harvesting behavior. We determined limpet (Patella vulgata) shell
size and shape, and estimated shell age from several middens at the
Late Norse Sandwick South Site, Unst, Shetland, UK, whose strata represent
distinct occupational phases (Phase 1: AD 1100–1200, Phase 2:
AD 1200–1250, Phase 3: AD 1250–1350). Our goal was to determine
if the many limpets found there could provide insight into Norse harvesting
behavior. Shell length, conicity, and modeled age all declined
between Phases 1 and 2, suggesting intensive, size-selective harvesting
of limpets and a shift to harvesting lower in the intertidal zone
between phases. Length and conicity varied in Phases 2 and 3 and no
major changes seem to have occurred over these periods, indicating
that harvesting maintained the limpet population at an impacted
level throughout the later phases. The conicity decline between Phases
1 and 2 may also have been caused by increased storminess that accompanied the onset of the Little Ice Age. The mean length of
modern limpet populations near the Norse site did not differ from the
archaeological phases, but did vary among collection years. Limpets
were 26% larger in 2015 than in 2012 and 2013, indicating that
large interannual variations in population structure can occur over
short time periods. Potentially the result of extreme storms removing
small limpets, this result raises the possibility that size and conicity
changes during the Sandwick South Site occupation, as well as in
other early populations, could also be the result of environmental
factors rather than human harvesting alone. We feel, however, that
the most parsimonious explanation for the patterns we document is
human harvesting.
Do high Arctic coastal food webs rely on a terrestrial carbon subsidy, 2018
Lagoons are a prominent feature of Arctic coastlines, support diverse benthic food webs, and prov... more Lagoons are a prominent feature of Arctic coastlines, support diverse benthic food webs, and provide vital feeding grounds for fish, migratory birds, and marine mammals. Across the Arctic, loading of terrestrial/freshwater-derived organic carbon (C T) from watershed runoff and coastal erosion is predicted to increase with global warming, and may subsidize marine organic carbon as an energy source. To assess the importance of C T , we analyzed the trophic links and carbon assimilation pathways of twenty genera in five trophic guilds (suspension and filter feeders (Su/FF), surface and subsurface deposit feeders (Ss/De), epibenthic omnivorous invertebrates (Ep/Om), omnivorous fishes (Fish), and mammalian carnivores (Mam/Carn) as well as end-member organic matter (OM) sources. Because end-members had distinct carbon and nitrogen isotopic ratios, we employed a Bayesian stable isotope mixing model (simmr) to determine the contributions of C T , shelf OM, and marine microphytobenthos, to the diets of resident fauna. Ss/De and Ep/Om mainly assimilated marine-derived OM end-members. Su/FF, Fish, and beluga whales derived large portions of their diet from C T (N40%). We conclude that (1) coastal food webs are characterized by a high degree of omnivory and plasticity, (2) C T is an important OM subsidy to food webs, and (3) omnivorous fish transfer C T from lower to upper trophic levels.
Salinity and Temperature Regimes in Eastern Alaskan Beaufort Sea Lagoons in Relation to Source Water Contributions, 2017
Shallow estuarine lagoons characterize >70 % of the eastern Alaskan Beaufort Sea coastline and, l... more Shallow estuarine lagoons characterize >70 % of
the eastern Alaskan Beaufort Sea coastline and, like temperate
and tropical lagoons, support diverse and productive biological
communities. These lagoons experience large variations in
temperature (−2 to 14 °C) and salinity (0 to >45) throughout
the year. Unlike lower latitude coastal systems, transitions
between seasons are physically extreme and event-driven.
On Arctic coastlines, a brief summer open-water period is
followed by a 9-month ice-covered period that concludes with
a late-spring sea ice breakup and intense freshwater run-off.
From 2011 to 2014, we examined interannual variations in
water column physical structure (temperature, salinity, and
δ18O) in five lagoons that differ with respect to their degree
of exchange with adjacent marine waters and magnitude of
freshwater inputs. Temperature, salinity, and source water
composition (calculated using a salinity and δ18O mixing
model) were variable in space and time. During sea ice breakup
in June, water column δ18O and salinity measurements
showed that low salinity waters originated from meteoric inputs
(50–80 %; which include river inputs and direct precipitation)
and sea ice melt (18–51 %). Following breakup, polar
marine waters became prevalent within a mixed water column over the summer open-water period within all five lagoons
(26–63 %). At the peak of ice-cover extent and thickness in
April, marine water sources dominated (75–87 %) and hypersaline
conditions developed in some lagoons. Seasonal runoff
dynamics and differences in lagoon geomorphology (i.e., connectivity
to the Beaufort Sea) are considered key potential
drivers of observed salinity and source water variations.