Habitat Use by Migratroy Shorebirds at the Cabo Rojo Salt Flats, Puerto Rico

The Cabo Rojo Salt Flats, at the southwestern tip of Puerto Rico, provide important autumn stopover and wintering habitat for migratory shorebirds. I studied the abundance and distribution of shorebirds and their food resources at this site during autumn of 1990 and 1991. Small calidrids (primarily Calidris pusilla and C. mauri) were the most abundant shorebirds at the salt flats. The maximum weekly counts of small calidrids in 1990 (2,690) and 1991 (3,532) occurred in mid October. Calidrids foraged primarily in the Fraternidad lagoon system; roosting took place most often at the neighboring Candelaria Lagoon. The macroinvertebrate prey important to calidrids in the Fraternidad system were Dasyhelea (Diptera), Trichocorixa (Hemiptera), and Artemia (Anostraca). Changes in invertebrate abundance coincided with fluctuations in salinity. (100 page document

Bias in population growth rate estimation: Sparse data, partial life cycle analysis and Jensen\u27s inequality

Demographic matrix models have become an integral part of population viability analysis for threatened and endangered species, but their use is often limited by data availability. A common solution to this problem is to assume constant annual rates within a multi-year stage. Partial life cycle analysis (PLC), which incorporates only juvenile and adult stages, is a noteworthy example of this approach because it has been described in the literature as a reliable approximation of age-structured populations. However, we predict from Jensen\u27s Inequality that the required lumping of age classes leads to over- or underestimation of population fitness when survival rates are truly age-dependent. We illuminate this problem by comparing fitness estimates from Leslie matrix and PLC models for theoretical populations having different levels of age-dependence in their survival rates. We also propose a modification of the PLC approach to address this problem and demonstrate its applicability using data from a published long-term study of red deer Cervus elephas. © 2008 The Authors

Population genetic diversity and fitness in multiple environments

<p>Abstract</p> <p>Background</p> <p>When a large number of alleles are lost from a population, increases in individual homozygosity may reduce individual fitness through inbreeding depression. Modest losses of allelic diversity may also negatively impact long-term population viability by reducing the capacity of populations to adapt to altered environments. However, it is not clear how much genetic diversity within populations may be lost before populations are put at significant risk. Development of tools to evaluate this relationship would be a valuable contribution to conservation biology. To address these issues, we have created an experimental system that uses laboratory populations of an estuarine crustacean, <it>Americamysis bahia </it>with experimentally manipulated levels of genetic diversity. We created replicate cultures with five distinct levels of genetic diversity and monitored them for 16 weeks in both permissive (ambient seawater) and stressful conditions (diluted seawater). The relationship between molecular genetic diversity at presumptive neutral loci and population vulnerability was assessed by AFLP analysis.</p> <p>Results</p> <p>Populations with very low genetic diversity demonstrated reduced fitness relative to high diversity populations even under permissive conditions. Population performance decreased in the stressful environment for all levels of genetic diversity relative to performance in the permissive environment. Twenty percent of the lowest diversity populations went extinct before the end of the study in permissive conditions, whereas 73% of the low diversity lines went extinct in the stressful environment. All high genetic diversity populations persisted for the duration of the study, although population sizes and reproduction were reduced under stressful environmental conditions. Levels of fitness varied more among replicate low diversity populations than among replicate populations with high genetic diversity. There was a significant correlation between AFLP diversity and population fitness overall; however, AFLP markers performed poorly at detecting modest but consequential losses of genetic diversity. High diversity lines in the stressful environment showed some evidence of relative improvement as the experiment progressed while the low diversity lines did not.</p> <p>Conclusions</p> <p>The combined effects of reduced average fitness and increased variability contributed to increased extinction rates for very low diversity populations. More modest losses of genetic diversity resulted in measurable decreases in population fitness; AFLP markers did not always detect these losses. However when AFLP markers indicated lost genetic diversity, these losses were associated with reduced population fitness.</p

Progress and challenges in coupled hydrodynamic-ecological estuarine modeling

© The Author(s), 2015. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Estuaries and Coasts 39 (2016): 311-332, doi:10.1007/s12237-015-0011-y.Numerical modeling has emerged over the last several decades as a widely accepted tool for investigations in environmental sciences. In estuarine research, hydrodynamic and ecological models have moved along parallel tracks with regard to complexity, refinement, computational power, and incorporation of uncertainty. Coupled hydrodynamic-ecological models have been used to assess ecosystem processes and interactions, simulate future scenarios, and evaluate remedial actions in response to eutrophication, habitat loss, and freshwater diversion. The need to couple hydrodynamic and ecological models to address research and management questions is clear because dynamic feedbacks between biotic and physical processes are critical interactions within ecosystems. In this review, we present historical and modern perspectives on estuarine hydrodynamic and ecological modeling, consider model limitations, and address aspects of model linkage, skill assessment, and complexity. We discuss the balance between spatial and temporal resolution and present examples using different spatiotemporal scales. Finally, we recommend future lines of inquiry, approaches to balance complexity and uncertainty, and model transparency and utility. It is idealistic to think we can pursue a “theory of everything” for estuarine models, but recent advances suggest that models for both scientific investigations and management applications will continue to improve in terms of realism, precision, and accuracy.NKG, ALA, and RPS acknowledge support from the USGS Coastal and Marine Geology Program. DKR gratefully acknowledges support from NSF (OCE-1314642) and NIEHS (1P50-ES021923-01). MJB and JMPV gratefully acknowledge support from NOAA NOS NCCOS (NA05NOS4781201 and NA11NOS4780043). MJB and SJL gratefully acknowledge support from the Strategic Environmental Research and Development Program—Defense Coastal/Estuarine Research Program (RC-1413 and RC-2245)

Community science for coastal acidification monitoring and research

© The Author(s), 2021. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Gassett, P. R., O’Brien-Clayton, K., Bastidas, C., Rheuban, J. E., Hunt, C., Turner, E., Liebman, M., Silva, E., Pimenta, A., Grear, J., Motyka, J., McCorkle, D., Stancioff, E., Brady, D., & Strong, A. Community science for coastal acidification monitoring and research. Coastal Management, 49(5), (2021): 510-531, https://doi.org/10.1080/08920753.2021.1947131.Ocean and coastal acidification (OCA) present a unique set of sustainability challenges at the human-ecological interface. Extensive biogeochemical monitoring that can assess local acidification conditions, distinguish multiple drivers of changing carbonate chemistry, and ultimately inform local and regional response strategies is necessary for successful adaptation to OCA. However, the sampling frequency and cost-prohibitive scientific equipment needed to monitor OCA are barriers to implementing the widespread monitoring of dynamic coastal conditions. Here, we demonstrate through a case study that existing community-based water monitoring initiatives can help address these challenges and contribute to OCA science. We document how iterative, sequential outreach, workshop-based training, and coordinated monitoring activities through the Northeast Coastal Acidification Network (a) assessed the capacity of northeastern United States community science programs and (b) engaged community science programs productively with OCA monitoring efforts. Our results (along with the companion manuscript) indicate that community science programs are capable of collecting robust scientific information pertinent to OCA and are positioned to monitor in locations that would critically expand the coverage of current OCA research. Furthermore, engaging community stakeholders in OCA science and outreach enabled a platform for dialogue about OCA among other interrelated environmental concerns and fostered a series of co-benefits relating to public participation in resource and risk management. Activities in support of community science monitoring have an impact not only by increasing local understanding of OCA but also by promoting public education and community participation in potential adaptation measures.AGU Centennial Grant NOAA OAP OFFICE North American Association for Environmental Education Curtis and Edith Munson Foundation Sea Grant programs within the region Senator George J. Mitchell Center for Sustainability Solutions Funding acknowledgment: MIT Sea Grant award NA18OAR4170105 to Bastidas NERACOOS The WestWind foundation (to Rheuban) Woods Hole Sea Grant (NOAA Grant No. NA18OAR4170104

Ocean and coastal acidification off New England and Nova Scotia

Author Posting. © The Oceanography Society, 2015. This article is posted here by permission of The Oceanography Society for personal use, not for redistribution. The definitive version was published in Oceanography 28, no. 2 (2015): 182-197, doi:10.5670/oceanog.2015.41.New England coastal and adjacent Nova Scotia shelf waters have a reduced buffering capacity because of significant freshwater input, making the region’s waters potentially more vulnerable to coastal acidification. Nutrient loading and heavy precipitation events further acidify the region’s poorly buffered coastal waters. Despite the apparent vulnerability of these waters, and fisheries’ and mariculture’s significant dependence on calcifying species, the community lacks the ability to confidently predict how the region’s ecosystems will respond to continued ocean and coastal acidification. Here, we discuss ocean and coastal acidification processes specific to New England coastal and Nova Scotia shelf waters and review current understanding of the biological consequences most relevant to the region. We also identify key research and monitoring needs to be addressed and highlight existing capacities that should be leveraged to advance a regional understanding of ocean and coastal acidification.This project was supported in part by an appointment to the Internship/Research Participation Program at the Office of Water, US Environmental Protection Agency (EPA), administered by the Oak Ridge Institute for Science and Education through an interagency agreement between the US Department of Energy and the EPA. JS acknowledges support from NASA grant from NNX14AL84G NASA-CCS

2005. Effects of grouping behavior and predators on the spatial distribution of a forest floor arthropod. Ecology

Abstract. Spatial aggregations arising from social behavior or habitat patchiness are common in nature and have important implications for population dynamics, community stability, and conservation. Distinguishing between these behavioral and environmental causes of pattern is of general interest to spatial ecologists and continues to be a key unresolved issue. Despite the importance of this problem, systematic approaches for resolving the underlying mechanisms are not well developed. We demonstrate here the value of a three-tiered systematic approach involving descriptive spatial sampling, individualbased observation and diffusion modeling, and manipulative field experiments. We used this approach to test social-vs. habitat-driven hypotheses explaining spatial aggregation in the collembolan Orchesella hexfasciata. Our results show that aggregation is a gregarious behavior triggered by seasonal increases in soil moisture. Initial field observations suggested that aggregation was habitat driven and associated with soil moisture, but individual-based observations and modeling revealed that moisture was only a triggering mechanism for socially driven aggregation. This was corroborated in field experiments by testing hypotheses that were motivated by the individual-based analyses. Thus, the three-tiered approach led to a more complete understanding of aggregation than would any single technique