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At least 487 records · Page 27Linked to original sources
USGS2026

The WOAH global wildlife health collaborating centre network (WOAH-WildNet): A coordinated and transformative approach to global wildlife health challenges

Wildlife health is integral to functioning, complex ecosystems [ 1 ], directly and indirectly influencing the health of people, animals, plants, and the environment [ 2 – 4 ]. Healthy wildlife populations are essential for ecosystem services and are at the heart of the One Health approach [ 3 , 4 ], which aims to sustainably balance and optimize the health of people, animals, and ecosystems through multisectoral and transdisciplinary collaboration [ 5 ]. Despite its importance, wildlife health initiatives often operate in silos, limiting capacity to address transboundary threats such as emerging diseases, pollution, and environmental changes. Anthropogenic changes, including habitat loss, degradation, fragmentation, and unsustainable harvesting, exacerbate wildlife health challenges [6–9]. These pressures disrupt species biology and alter host-pathogen dynamics [10–12], underscoring the importance of coordinated collective action in addressing harmful effects on the health of wild animals. While local conservation efforts are vital, long-term success in safeguarding biodiversity requires a unified, global network. For instance, without harmonized surveillance and response systems, individual institutions cannot effectively track pathogens across borders or share diagnostic capabilities. The World Organisation for Animal Health (WOAH) Collaborating Centre Network for Wildlife Health—WOAH-WildNet—was established to bridge these gaps. By fostering global collaboration, sharing resources, and enabling data exchange, WOAH-WildNet provides a transformative, systems-based approach to wildlife health, managing risks, and enhancing ecosystem resilience. Central to this mission is breaking down silos to promote intersectoral coordinated responses to complex wildlife health challenges.

PLOS Sustainability and Transformation↗
USGS1993

Fluvial response to late Quaternary climatic fluctuations, central Kobuk Valley, northwestern Alaska

Much of northwestern Alaska remained unglaciated during the Pleistocene and thus offers a favorable setting for examining long-term records of high-latitude geological and biological change. Epiguruk, a large cut bank 3.5 km long and up to 36 m high on the Kobuk River south of the Brooks Range in eastern Beringia, exposes complex sedimentary successions representing cycles of upper Quaternary alluviation and eolian sedimentation, downcutting, and soil formation. A rich record of plants and mammals is also preserved in the section. Deposits of fluvial channels and flood plains, eolian dunes, sand sheets, loess, and ponds, as well as organic soils (Histosols) are represented. Parallel-bedded fine sand and coarse silt couplets that commonly contain root structures, ripple cross-lamination, and silt drapes are flood-plain sediments apparently deposited at the interface of fluvial and eolian environments. Multiple fluvial-to-eolian depositional sequences were caused by influx of eolian sediment to the river from intermittently active dune fields south of the Kobuk River. Alluviation in the Kobuk Valley was coeval with glaciation in the Brooks Range, whereas downcutting occurred during interstadials when dune stabilization limited sediment supply. The depositional model developed at Epiguruk may be useful in interpreting some of the widespread subhorizontally stratified late-glacial deposits of Europe and North America.

Alaska↗
USGS2013

Biology and impacts of Pacific island invasive species 9. Capra hircus , the feral goat, (Mammalia: Bovidae)

Domestic goats, Capra hircus , were intentionally introduced to numerous oceanic islands beginning in the sixteenth century. The remarkable ability of C. hircus to survive in a variety of conditions has enabled this animal to become feral and impact native ecosystems on islands throughout the world. Direct ecological impacts include consumption and trampling of native plants, leading to plant community modification and transformation of ecosystem structure. While the negative impacts of feral goats are well-known and effective management strategies have been developed to control this invasive species, large populations persist on many islands. This review summarizes the impacts of feral goats on Pacific island ecosystems, and the management strategies available to control this invasive species.

Pacific Science↗
USGS1989

Vegetation alteration along trails in Shenandoah National Park, Virginia

Most studies in the USA of vegetation alteration and human impact along trails have been located in large western wilderness areas. The objective of this study was to determine vegetation changes occurring along trails in an eastern ecosystem supporting second-growth deciduous forest. The location of this study was Shenandoah National Park in Virginia, which has a long history of trail use by humans. Located in different sections of the park, ten trails were chosen as study areas. In each, transects were established to measure ground flora in trailside, transition, and undisturbed areas perpendicular to the trail. Field data were collected on frequency, life-form, and percent cover for ground flora of 25 cm or less in height. Cover and species diversity increased toward the trail in eight out often cases. Competition for light and resistance to trampling were thought to influence the occurrence of plants along the transect. Plants found along the trail border were represented by low growthforms, early blooming, or graminoid characteristics, and hemicryptophyte, therophyte, or chamaephyte life-forms. Plants found in the undisturbed zone were represented by scattered cover and frequency, woody growth forms or delicate herbaceous forms, and phanerophyte or geophyte life-forms.

Virginia↗
USGS2013

Convergent responses of nitrogen and phosphorus resorption to nitrogen inputs in a semiarid grassland

Human activities have significantly altered nitrogen (N) availability in most terrestrial ecosystems, with consequences for community composition and ecosystem functioning. Although studies of how changes in N availability affect biodiversity and community composition are relatively common, much less remains known about the effects of N inputs on the coupled biogeochemical cycling of N and phosphorus (P), and still fewer data exist regarding how increased N inputs affect the internal cycling of these two elements in plants. Nutrient resorption is an important driver of plant nutrient economies and of the quality of litter plants produce. Accordingly, resorption patterns have marked ecological implications for plant population and community fitness, as well as for ecosystem nutrient cycling. In a semiarid grassland in northern China, we studied the effects of a wide range of N inputs on foliar nutrient resorption of two dominant grasses, Leymus chinensis and Stipa grandis . After 4 years of treatments, N and P availability in soil and N and P concentrations in green and senesced grass leaves increased with increasing rates of N addition. Foliar N and P resorption significantly decreased along the N addition gradient, implying a resorption-mediated, positive plant–soil feedback induced by N inputs. Furthermore, N : P resorption ratios were negatively correlated with the rates of N addition, indicating the sensitivity of plant N and P stoichiometry to N inputs. Taken together, the results demonstrate that N additions accelerate ecosystem uptake and turnover of both N and P in the temperate steppe and that N and P cycles are coupled in dynamic ways. The convergence of N and P resorption in response to N inputs emphasizes the importance of nutrient resorption as a pathway by which plants and ecosystems adjust in the face of increasing N availability.

Global Change Biology↗
USGS2025

Invasive hitchhiking organisms on aquarium plants: An emerging pathway of introduction

The aquarium trade is a global industry responsible for the movement of live plants and animals, but it also serves as a major pathway for the introduction and spread of aquatic invasive species. Invasive species contribute to biodiversity loss, disrupt ecosystems, and can have widespread economic and societal impacts. A significant but poorly understood invasion risk in the plant aquarium trade is the transport of hitchhiking species, which are organisms unintentionally transported along with a species of primary interest in trade. Aquatic hitchhikers can persist in aquaria and later be released into the wild, potentially establishing invasive populations. While some studies have identified hitchhiking as a pathway for aquatic species spread, it remains largely unrecognized in international regulations. Increased awareness, triggered by incidents such as zebra mussels found in aquarium plants, highlights the need for further investigation into this emerging pathway of concern. As a response, we reviewed the current state of knowledge regarding aquatic plants in the aquarium trade as vectors for transporting invasive hitchhiking species, with a particular focus on how morphological complexity of plants influences associated hitchhikers. We found that although awareness of hitchhiking species in the aquarium trade is increasing, few studies have empirically examined aquarium plants as vectors for invasive species. Understanding this pathway can help to inform invasive species management around the plant aquarium trade and to keep aquarium organisms in a sustainable manner.

Management of Biological Invasions↗
USGS2010

Characterization of Fish Creek, Teton County, Wyoming, 2004-08

Fish Creek, a tributary to the Snake River, is about 15 river miles long and is located in Teton County in western Wyoming near the town of Wilson (fig. 1). Public concern about nuisance growths of aquatic plants in Fish Creek has been increasing since the early 2000s. To address this concern, the U.S. Geological Survey, in cooperation with the Teton Conservation District, began studying Fish Creek in 2004 to describe the hydrology of the creek and later (2007?08) to characterize the water quality and the biological communities. The purpose of this fact sheet is to summarize the study results from 2004 to 2008.

Fact Sheet↗
USGS1998

Water-quality assessment of the Central Arizona Basins, Arizona and northern Mexico – Environmental setting and overview of water quality

The Central Arizona Basins study area in central and southern Arizona and northern Mexico is one of 60 study units that are part of the U.S. Geological Survey's National Water-Quality Assessment program. The purpose of this report is to describe the physical, chemical, and environmental characteristics that may affect water quality in the Central Arizona Basins study area and present an overview of water quality. Covering 34,700 square miles, the study area is characterized by generally north to northwestward-trending mountain ranges separated by broad, gently sloping alluvial valleys. Most of the perennial rivers and streams are in the northern part of the study area. Rivers and streams in the south are predominantly intermittent or ephemeral and flow in response to precipitation such as summer thunderstorms. Effluent-dependent streams do provide perennial flow in some reaches. The major aquifers in the study area are in the basin-fill deposits that may be as much as 12,000 feet thick. The 1990 population in the study area was about 3.45 million, and about 61 percent of the total was in Maricopa County (Phoenix and surrounding cities). Extensive population growth over the past decade has resulted in a twofold increase in urban land areas and increased municipal water use; however, agriculture remains the major water use. Seventy-three percent of all water with drawn in the study area during 1990 was used for agricultural purposes. The largest rivers in the study area-the Gila, Salt, and Verde-are perennial near their headwaters but become intermittent downstream because of impoundments and artificial diversions. As a result, the Central Arizona Basins study area is unique compared to less arid basins because the mean surface-water outflow is only 528 cubic feet per second from a total drainage area of 49,650 square miles. Peak flows in the northern part of the study area are the result of snowmelt runoff; whereas, summer thunderstorms account for the peak flows in the southern part. Ground water is the primary water supply in most of Arizona and the only source of drinking water used by communities in the southern half of the study area. Years of overpumping have caused water tables in basin fill to drop below once-perennial streams leaving streambeds dry, water too deep to pump economically, pumping of poorer quality water with depth, and earth fissures resulting from subsidence after dewatering of sediments. Natural processes-such as leaching of trace elements and major ions from geologic formations-and human activities-such as mining, agriculture, and urban development-have major effects on the quality of surface-water and ground-water resources in the Central Arizona Basins study area. Surface-water quality standards in Arizona are based on the designated use of the water such as full or partial body contact, fish consumption, aquatic and wildlife uses, and agriculture. Maintaining the biological integrity (health) of surface waters in Arizona is an important part of ensuring that these waters are suitable for designated uses. Important water-quality issues for surface water that are somewhat unique to Arizona include: (1) streamflows and riparian environments sustained by effluent from municipal wastewater-treatment plants that contains high concentrations of nutrients, potentially toxic trace elements and organic compounds, and fecal bacteria; (2) industrial, mining, agricultural, and municipal sources of contamination from Mexico; and (3) unpredictable high flows from major summer thunder storms causing stream-channel changes; high suspended-sediment concentrations and loads; sewage overflows; and breaching, erosion, and washout of landfills and mining operations. The quality of water in aquifers that are protected for drinking- water use is subject to standards that are in most cases equal to or more stringent than the primary drinking-water regulations of the U.S. Environmental Protection Agency. The general che

Arizona↗
USGS2007

Benthic habitats and offshore geological resources of Kaloko-Honokohau National Historical Park, Hawai‘i

Kaloko-Honokōhau National Historical Park (KAHO) is one of three National Park lands located along the western coast of the Island of Hawai‘i and the only one to include submerged lands and marine resources within its official boundaries. The park was established in 1978 and is 1,160 acres in size, including 596 acres of marine area. The submerged lands are currently managed by the State of Hawaii, Department of Land and Natural Resources, Division of Aquatic Resources (DLNR-DAR). Marine resources located within KAHO include coral reef and habitat for many marine animals, including the green sea turtle and a variety of fish and invertebrates. In addition, many archeological, cultural, and recreational resources are located within the marine realm of the park. Potential threats and stressors to the modern marine environment include ground-water and surface-water contamination, invasive plants and algae, fishing pressure and use of monofilament gill nets (which can ensnare marine life or become tangled on reefs and be left behind as fishing debris), and visitor use impacts, such as scuba diving and snorkeling. Illegal dumping, oil releases, boat groundings, and other physical damage to reef resources are potential threats from users of the nearby harbor. Special issues of concern for the park include establishing baseline conditions of the offshore resources before the development of adjacent coastal lands. Until this study, only a general knowledge of the distribution of benthic habitats and the characteristics of the offshore region of Kaloko-Honokōhau National Historical Park was available. In 2003, a collaborative project between the U.S. Geological Survey (USGS) Coastal and Marine Geology Program and the National Park Service (NPS) was initiated to develop detailed benthic-habitat classification maps for the marine lands within and adjacent to the park. The intent of this project is to provide baseline maps and a Geographic Information System (GIS) database and description of the biological and geological resources of these marine lands in order to facilitate the management, interpretation, and understanding of park resources. A benthic-habitat classification map was created for the park using existing color aerial photography, Scanning Hydrographic Operational Airborne Lidar Survey (SHOALS) bathymetric data, georeferenced underwater video, and still photography. Individual habitat polygons were classified using five basic attributes: (1) major structure or substrate, (2) dominant structure, (3) major biologic cover on the substrate, (4) percentage of major biological cover, and (5) geographic zone. Additional information regarding geology, morphology, and coral species were also noted. Marine resources located within KAHO include coral reef and habitat for many marine animals, including the green sea turtle and a variety of fish and invertebrates. In addition, many archeological, cultural, and recreational resources are located within the marine realm of the park. Potential threats and stressors to the modern marine environment include ground-water and surface-water contamination, invasive plants and algae, fishing pressure and use of monofilament gill nets (which can ensnare marine life or become tangled on reefs and be left behind as fishing debris), and visitor use impacts, such as scuba diving and snorkeling. Illegal dumping, oil releases, boat groundings, and other physical damage to reef resources are potential threats from users of the nearby harbor. Special issues of concern for the park include establishing baseline conditions of the offshore resources before the development of adjacent coastal lands. Until this study, only a general knowledge of the distribution of benthic habitats and the characteristics of the offshore region of Kaloko-Honokōhau National Historical Park was available. In 2003, a collaborative project between the U.S. Geological Survey (USGS) Coastal and Marine Geology Program and the National Park Service (NPS) was initiated to develop detailed benthic-habitat classification maps for the marine lands within and adjacent to the park. The intent of this project is to provide baseline maps and a Geographic Information System (GIS) database and description of the biological and geological resources of these marine lands in order to facilitate the management, interpretation, and understanding of park resources. A benthic-habitat classification map was created for the park using existing color aerial photography, Scanning Hydrographic Operational Airborne Lidar Survey (SHOALS) bathymetric data, georeferenced underwater video, and still photography. Individual habitat polygons were classified using five basic attributes: (1) major structure or substrate, (2) dominant structure, (3) major biologic cover on the substrate, (4) percentage of major biological cover, and (5) geographic zone. Additional information regarding geology, morphology, and coral species were also noted.

Hawai'i↗
USGS2023

Less is more: Less herbicide does more when biological control is present in Pontederia crassipes

An experiment along with simulation modeling was applied to study the combinations of herbicide treatment and biological control that best limit invasive water hyacinth ( Pontederia crassipes , formerly Eichhornia crassipes ) in freshwater aquatic systems. The experiment consisted of 14 different treatments of P. crassipes in 1.67 m 2 outdoor tank mesocosms. Seven treatments were with and seven were without insect biological control agents, Neochetina eichhorniae . In both of the sets of seven treatments, there was one no-herbicide treatment, a one-time full-strength herbicide treatment with 40 %, 80 % and 100 % coverage of the P. crassipes , and a one-time half-strength herbicide treatment with 40 %, 80 %, and 100 % surface area coverage. An overarching hypothesis was that leaving part of a tank unsprayed, providing habitat for the maintenance of biological control agents, would optimize control. Data from the experiment, measured on five days over the 167-day period, were used to calibrate a difference equation model of P. crassipes with and without the biological control agent. The model was then used to project longer term dynamics of the system. The model predicted that an initial one-time herbicide treatment, combined with application of the biocontrol agent at 80 % areal coverage, could maintain P. crassipes at levels lower than the carrying capacity of the plant's biomass over the long term, though not enough that N. eichhorniae would be considered, by itself, a highly effective control. However, the results suggest that a combination of biocontrol with 80 % spraying coverage every 600 days or so would be an effective integrated biocontrol strategy for maintaining decreased P. crassipes biomass at low levels over the long term.

Ecological Modelling↗
USGS2024

Trace organic contaminants in U.S. national park surface waters: Prevalence and ecological context☆

Surface water samples were collected from 264 sites across 46 U.S national parks during the period of 2009–2019. The number of sites within each park ranged from 1 to 31 and the number of samples collected within each park ranged from 1 to 201. Samples were analyzed for up to 340 trace organic contaminants (TrOCs), including pharmaceuticals, personal care products, pesticides, and various contaminants indicative of anthropogenic influence (e.g., fragrances, surfactants, flame retardants). A total of 155 TrOCs was detected in at least one sample with concentrations ranging from the reporting level of 10 ng/L (multiple contaminants) to 11,900 ng/L (p-cresol). Except for bisphenol A, DEET, theobromine, and gabapentin, TrOCs were detected in <20% of samples. Despite the relatively low detection frequencies, when TrOCs were detected, concentrations were similar to those reported from other regional or national studies. We compared detected concentrations to bioactivity concentrations and water quality benchmarks, when available, to identify occurrences of elevated concentrations and to estimate the potential for biological effects to aquatic biota. Elevated concentrations of 27 TrOCs, mostly pesticides, were detected throughout the study. To gain insight regarding potential sources, we related watershed characteristics (e.g., land cover, presence of point sources) to the number of TrOCs detected at each site. We found that the presence of wastewater treatment plants and the proportion of the watershed classified as agricultural land were the most influential variables for describing the number of pharmaceuticals and the number of pesticides present, respectively. This study represents the largest-scale study characterizing the presence and magnitude of TrOCs in U.S. national park surface waters, to date. These data provide a baseline that can be used to inform future monitoring within the parks and to assess changes in water quality.

Environmental Pollution↗
USGS1995

The role of wetlands as nearshore habitat in Lake Huron

Wetlands are generally considered to be among the most productive habitats on earth. As the landscape connection between upland and aquatic ecosystems, they posess many of the attributes of both systems and perform functions that extend beyond the wetland boundary into both systems. In Lake Huron, wetlands comprise a small fraction of the total area, but they provide nearshore habitat for many plant and animal species that are deemed important for the lake as a whole. Thus, their role is an important one. In this paper, after describing the general functions and types of wetlands, I will explore the importance of wetland habitat in Lake Huron by defining its extent, describing physical and biological processes, summarizing biological uses, and detailing management problems.

Book chapter↗
USGS2008

Do non-native plant species affect the shape of productivity-diversity relationships?

The relationship between ecosystem processes and species richness is an active area of research and speculation. Both theoretical and experimental studies have been conducted in numerous ecosystems. One finding of these studies is that the shape of the relationship between productivity and species richness varies considerably among ecosystems and at different spatial scales, though little is known about the relative importance of physical and biological mechanisms causing this variation. Moreover, despite widespread concern about changes in species' global distributions, it remains unclear if and how such large-scale changes may affect this relationship. We present a new conceptual model of how invasive species might modulate relationships between primary production and species richness. We tested this model using long-term data on relationships between aboveground net primary production and species richness in six North American terrestrial ecosystems. We show that primary production and abundance of non-native species are both significant predictors of species richness, though we fail to detect effects of invasion extent on the shapes of the relationship between species richness and primary production.

American Midland Naturalist↗
USGS2011

An adaptive approach to invasive plant management on U.S. Fish and Wildlife Service-owned native prairies in the Prairie Pothole Region: decision support under uncertainity

Much of the native prairie managed by the U.S. Fish and Wildlife Service (Service) in the Prairie Pothole Region (PPR) is extensively invaded by the introduced cool-season grasses smooth brome (Bromus inermis) and Kentucky bluegrass (Poa pratensis). The central challenge to managers is selecting appropriate management actions in the face of biological and environmental uncertainties. We describe the technical components of a USGS management project, and explain how the components integrate and inform each other, how data feedback from individual cooperators serves to reduce uncertainty across the whole region, and how a successful adaptive management project is coordinated and maintained on a large scale. In partnership with the Service, the U.S. Geological Survey is developing an adaptive decision support framework to assist managers in selecting management actions under uncertainty and maximizing learning from management outcomes. The framework is built around practical constraints faced by refuge managers and includes identification of the management objective and strategies, analysis of uncertainty and construction of competing decision models, monitoring, and mechanisms for model feedback and decision selection. Nineteen Service field stations, spanning four states of the PPR, are participating in the project. They share a common management objective, available management strategies, and biological uncertainties. While the scope is broad, the project interfaces with individual land managers who provide refuge-specific information and receive updated decision guidance that incorporates understanding gained from the collective experience of all cooperators.

Prairie Pothole Region↗
USGS2010

Biological phosphorus cycling in dryland regions

The relatively few studies done on phosphorus (P) cycling in arid and semiarid lands (drylands) show many factors that distinguish P cycling in drylands from that in more mesic regions. In drylands, most biologically relevant P inputs and losses are from the deposition and loss of dust. Horizontal and vertical redistribution of P is an important process. P is concentrated at the soil surface and thus vulnerable to loss via erosion. High pH and CaCO 3 limit P bioavailability, and low rainfall limits microbe and plant ability to free abiotically bound P via exudates, thus making it available for uptake. Many invasive plants are able to access recalcitrant P more effectively than are native plants. As P availability depends on soil moisture and temperature, climate change is expected to have large impacts on P cycling.

Book chapter↗
USGS2013

Plant invasions in protected areas of tropical pacific islands, with special reference to Hawaii

Isolated tropical islands are notoriously vulnerable to plant invasions. Serious management for protection of native biodiversity in Hawaii began in the 1970s, arguably at Hawaii Volcanoes National Park. Concerted alien plant management began there in the 1980s and has in a sense become a model for protected areas throughout Hawaii and Pacific Island countries and territories. We review the relative successes of their strategies and touch upon how their experience has been applied elsewhere. Protected areas in Hawaii are fortunate in having relatively good resources for addressing plant invasions, but many invasions remain intractable, and invasions from outside the boundaries continue from a highly globalised society with a penchant for horticultural novelty. There are likely few efforts in most Pacific Islands to combat alien plant invasions in protected areas, but such areas may often have fewer plant invasions as a result of their relative remoteness and/or socio-economic development status. The greatest current needs for protected areas in this region may be for establishment of yet more protected areas, for better resources to combat invasions in Pacific Island countries and territories, for more effective control methods including biological control programme to contain intractable species, and for meaningful efforts to address prevention and early detection of potential new invaders.

Hawaii↗
USGS2012

Nature's Notebook 2011: Data & participant summary

Introduction The USA National Phenology Network The USA National Phenology Network (USA‐NPN; www.usanpn.org) seeks to engage a diverse range of citizen scientist volunteers, federal, state, and non‐governmental organizations, educators and professional research scientists to collect phenological observations of plants and animals using consistent standards and to contribute their observations to a national data repository. To guide this effort, the USA‐NPN National Coordinating Office (NCO), based in Tucson, Arizona, implemented an online monitoring program for plants and animals, Nature's Notebook , and has developed phenology monitoring protocols and an information management system, which includes the National Phenology Database (NPDb). We are developing a diversity of materials, tools, techniques, and protocols to assist decision making and education related to ecology, wildlife, human health, ecosystem services, natural resource management, biological conservation, and climate change adaptation.

USA-NPN Technical Series↗
USGS2007

Diet induced differences in carbon isotope fractionation between sirenians and terrestrial ungulates

Carbon isotope differences (??13C) between bioapatite and diet, collagen and diet, and bioapatite and collagen were calculated for four species of sirenians, Dugong dugon (Mu??ller), Trichechus manatus (Linnaeus), Trichechus inunguis (Natterer), and the extinct Hydrodamalis gigas (Zimmerman). Bone and tooth samples were taken from archived materials collected from populations during the mid eighteenth century (H. gigas), between 1978 and 1984 (T. manatus, T. inunguis), and between 1997 and 1999 (D. dugon). Mean ??13C values were compared with those for terrestrial ungulates, carnivores, and six species of carnivorous marine mammals (cetaceans = 1; pinnipeds = 4; mustelids = 1). Significant differences in mean ??13C values among species for all tissue types were detected that separated species or populations foraging on freshwater plants or attached marine macroalgae (??13C values < -6???; ??13Cbioapatite-diet ???14???) from those feeding on marine seagrasses (??13C values > -4???; ??13Cbioapatite-diet ???11???). Likewise, ??13Cbioapatite-collagen values for freshwater and algal-foraging species (???7???) were greater than those for seagrass-foraging species (???5???). Variation in ??13C values calculated between tissues and between tissues and diet among species may relate to the nutritional composition of a species' diet and the extent and type of microbial fermentation that occurs during digestion of different types of plants. These results highlight the complications that can arise when making dietary interpretations without having first determined species-specific ??13Ctissue-diet values. ?? 2007 Springer-Verlag.

Marine Biology↗