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Topic: Land-sea Interactions
The ocean is a soup of its resident species' genetic material, cast off in the forms of metabolic waste, shed skin cells, or damaged tissue. Sampling this environmental DNA (eDNA) is a potentially powerful means of assessing whole biological communities, a significant advance over the manual methods of environmental sampling that have historically dominated marine ecology and related fields. Here, we estimate the vertebrate fauna in a 4.5-million-liter mesocosm aquarium tank at the Monterey Bay Aquarium of known species composition by sequencing the eDNA from its constituent seawater. We find that it is generally possible to detect mitochondrial DNA of bony fishes sufficient to identify organisms to taxonomic family- or genus-level using a 106 bp fragment of the 12S ribosomal gene. We conclude that eDNA has substantial potential to become a core tool for environmental monitoring, but that a variety of challenges remain before reliable quantitative assessments of ecological communities in the field become possible.
Characterization of fecal concentrations in human and other animal sources by physical, culture-based, and quantitative real-time PCR methods
The characteristics of fecal sources, and the ways in which they are measured, can profoundly influence the interpretation of which sources are contaminating a body of water. Although feces from various hosts are known to differ in mass and composition, it is not well understood how those differences compare across fecal sources and how differences depend on characterization methods. This study investigated how nine different fecal characterization methods provide different measures of fecal concentration in water, and how results varied across twelve different fecal pollution sources. An in silico exercise was performed to assess how different characterization methods can impact identification of the dominant fecal pollution source in a mixed source sample. This potential for disagreement in minor or dominant source identification based on different methods of measurement represents an important challenge for water quality managers and researchers.
Emerging frontiers in social-ecological systems research for sustainability of small-scale fisheries
Current Opinion in Environmental Sustainability
Small-scale fisheries (SSF) account for most of the livelihoods associated with fisheries worldwide and support food security for millions globally, yet face critical challenges from local threats and global pressures. Here, we describe how emerging concepts from social-ecological systems thinking can illuminate potential solutions to challenges facing SSF management, with real-world examples of three key themes: (1) external drivers of change; (2) social-ecological traps; and (3) diagnostic approaches and multiple outcomes in SSF. The purpose of this article is to aid practitioners by moving a step closer toward making these theoretical concepts operational and to stimulate thinking on how these linkages can inform a transition toward sustainability in small-scale fisheries.
Claudia L. Peñaloza, Omar Hernández, Rodolfo Espín, Larry B. Crowder, and Guillermo R. Barreto.
We quantified illegal and unmonitored harvest of three endangered sideneck turtles (Podocnemis spp.) by examining discarded turtle shells in 29 riverine communities both up- and down-river from the Arrau Turtle Wildlife Refuge in the Middle Orinoco, Venezuela. Considering historical accounts of widespread turtle husbandry in the area, Podocnemis spp. life history, and population recovery for these species in community-based conservation programs elsewhere in South America, we recommend community-managed captive breeding of faster-maturing P. unifilis and P. vogli to satisfy turtle consumption needs. These measures, along with improved nesting-beach protection, may allow recovery of populations of P. expansa and make possible their legal subsistence harvest in the future.
The Environmental Forum
Ryan Kelly and Meg Caldwell
A rising tide of acidity is overwhelming the global ocean. Estuaries and near-shore waters fall under the jurisdiction of states and the federal government, mandating treatment under the Clean Water Act (CWA), but criteria for action are uncertain and unclear. The acidity of the marine environment has increased by roughly a third since 1750, changing chemical processes vital to life, including shell and coral formation and the growth of bony structures in fish. This massive change in ocean chemistry is a growing water quality problem that focuses attention on the surprisingly difficult business of determining whether and how a particular water quality standard has been violated. Such attention brings with it a larger question of whether water quality criteria are legally sufficient under the CWA if they are difficult or impossible to test as a practical matter, and highlights the changing role of the act as it is used to combat a new class of water pollution.
Metagenomic profiling of microbial composition and antibiotic resistance determinants in Puget Sound
Jesse A. Port, James C. Wallace, William C. Griffith, and Elaine M. Faustman.
Human-health relevant impacts on marine ecosystems are increasing on both spatial and temporal scales. Traditional indicators for environmental health monitoring and microbial risk assessment have relied primarily on single species analyses and have provided only limited spatial and temporal information. More high-throughput, broad-scale approaches to evaluate these impacts are therefore needed to provide a platform for informing public health. This study is the first comparative metagenomic survey of Puget Sound and provides baseline data for further assessments of community composition and antibiotic resistance determinants in the environment using next generation sequencing technologies. In addition, these genomic signals of potential human impact can be used to guide initial public health monitoring as well as more targeted and functionally-based investigations.
Sea level along most of California’s coast is rising and the best science available suggests it will continue to rise at an increasing rate in the future. In addition, climate change will bring higher air and water temperatures, changes in precipitation and runoff, thus changes in water supplies and quality, and more extreme tides and storm surges that will aggravate coastal flooding and erosion. While uncertainty remains as to how these changes will unfold in any one place along the coasts and embayments of California, further change is assured.
Are coastal professionals preparing for these changes? This report presents results of a survey of California coastal managers that shows that neither the state nor coastal communities are standing by until science and policy questions are settled. Communities along both the open ocean coast and along bay and estuarine shorelines are beginning to plan for climate change impacts. Despite scientific uncertainties and the economic challenges of recent years, they are rising to the challenge of coastal climate change. In light of already experienced changes, and the scientifically robust projections of additional and accelerating impacts of climate change in the future, this survey aimed to assess coastal professionals’ concerns with climate change impacts, their activities to date to plan and prepare for them, and the needs and barriers they encounter in planning for climate change.
Why Ocean Acidification Matters to California, and What California Can Do About It: A Report on the Power of California's State Government to Address Ocean Acidification in State Waters
California’s ocean is becoming more acidic as a result of increased atmospheric carbon dioxide (CO2) and other pollutants. This fundamental change is likely to have substantial ecological and economic consequences for California and worldwide.
This document is intended to be a toolbox for understanding and addressing the drivers of an acidifying ocean. We first provide an overview of the relevant science, highlighting known causes of chemical change in the coastal ocean. We then feature a wide variety of legal and policy tools that California’s government agencies can use to mitigate the problem.
The State has ample legal authority to address the causes of ocean acidification; what remains is to implement that authority to safeguard California’s iconic coastal resources.
Rod Fujita, Alexander C. Markham, Julio E. Diaz Diaz, Julia Rosa Martinez Garcia, Courtney Scarborough, Patrick Greenfield, Peter Black, Stacy E. Aguilera
Increasing concerns regarding oil spills, air pollution, and climate change associated with fossil fuel use have increased the urgency of the search for renewable, clean sources of energy. This assessment describes the potential of Ocean Thermal Energy Conversion (OTEC) to produce not only clean energy but also potable water, refrigeration, and aquaculture products. Higher oil prices and recent technical advances have improved the economic and technical viability of OTEC, perhaps making this technology more attractive and feasible than in the past. Relatively high capital costs associated with OTEC may require the integration of energy, food, and water production security in small island developing states (SIDSs) to improve cost-effectiveness. Successful implementation of OTEC at scale will require the application of insights and analytical methods from economics, technology, materials engineering, marine ecology, and other disciplines as well as a subsidized demonstration plant to provide operational data at near-commercial scales.