Effects of sex change on the implications of marine reserves for fisheries

Marine reserves have become widely used in biodiversity conservation and are increasingly proposed as fisheries management tools. Previous modeling studies have found that reserves may increase or decrease yields, depending on local environmental conditions and on the specific life-history traits of the fishery species. Sex-changing (female-to-male) fish are targets of some of the most important commercial and recreational fisheries in the world. The potential for disproportionate removal of the larger, older sex of such species requires new theory to facilitate our understanding of how reserves will affect the yields of surrounding fisheries, relative to fishes with separate sexes. We investigated this question by modeling the effects of marine reserves on a non-sex-changing and a sex-changing population. We used demographic parameter estimates for the common coral trout as a baseline, and we conducted extensive sensitivity analyses to determine how sustainable yields of sex-changing species are likely to be affected by reserves across a broad range of life-history parameters. Our findings indicate that fisheries for sex-changing species are unlikely to receive the same yield-enhancing benefit that non-sex-changing fisheries enjoy from marine reserves, and that often reserves tend to reduce sustainable yields for a given overall population size. Specifically, the increased egg production and high fertilization success within reserves is more than offset by the reduced egg production and fertilization success in the fished areas, relative to a system in which fishing mortality is distributed more evenly over the entire system. A key reason for this appears to be that fertilization success is reduced, on average, when males are unevenly distributed among subpopulations, as is the case when reserves are present. These findings suggests that, for sex-changing populations, reserves are more suited to rebuilding overfished populations and sustaining fishery viability, rather than enhancing fishery yields. These results are robust over a range of sex-change regimes, stock-recruitment relationships, adult mortality rates, individual growth strategies, and fertilization-success functions. Our findings highlight the importance of considering the different contributions of males and females to population growth and fishery yields when evaluating the efficacy of marine reserves for enhancement of fished species.     

Relating characteristics of global biodiversity targets to reported progress

To inform governmental discussions on the nature of a revised Strategic Plan for Biodiversity of the Convention on Biological Diversity (CBD), we reviewed the relevant literature and assessed the framing of the 20 Aichi Biodiversity Targets in the current strategic plan. We asked international experts from nongovernmental organizations, academia, government agencies, international organizations, research institutes, and the CBD to score the Aichi Targets and their constituent elements against a set of specific, measurable, ambitious, realistic, unambiguous, scalable, and comprehensive criteria (SMART based, excluding time bound because all targets are bound to 2015 or 2020). We then investigated the relationship between these expert scores and reported progress toward the target elements by using the findings from 2 global progress assessments (Global Biodiversity Outlook and the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services). We analyzed the data with ordinal logistic regressions. We found significant positive relationships (p < 0.05) between progress and the extent to which the target elements were perceived to be measurable, realistic, unambiguous, and scalable. There was some evidence of a relationship between progress and specificity of the target elements, but no relationship between progress and ambition. We are the first to show associations between progress and the extent to which the Aichi Targets meet certain SMART criteria. As negotiations around the post-2020 biodiversity framework proceed, decision makers should strive to ensure that new or revised targets are effectively structured and clearly worded to allow the translation of targets into actionable policies that can be successfully implemented nationally, regionally, and globally.     

INTEGRATED WATER RESOURCES MANAGEMENT WHO SHOULD LEAD,WHO SHOULD PAY?1

ABSTRACT: Improving water management to meet future global needs will certainly require technical advances, but the main challenge is to integrate the viewpoints of diverse societal interests into decisions about allocation of water resources. The integration cannot be done solely by the market because it requires a balancing among interests which do not respond well to market forces, nor by the state alone because of institutional problems. The concept of “integrated water resources management” has been developed to provide the framework for the required balancing of interests, and, like similar concepts in industries other than water, it has a dual purpose - to link stakeholders and apply best practices to management actions. To clarify the process of integrated water management, the paper focuses on two questions: who should lead integrated water resources management and who should pay for it? Several examples are given to illustrate a range of situations. The paper concludes with a call to improve paradigms of integrated water management, a proposition that water organizations should accept and budget for their external responsibilities as well as their direct missions, affirmation of the need for state and federal agencies to be involved with local interests, a call for better scientific and public information, and identification of the need for continued work to improve the process of integrated water management.     

Filter light attenuation as a surrogate for elemental carbon

Light attenuation (b(att)) measured from filter light transmission is compared with elemental carbon (EC) measurements for more than 180,000 collocated PM2.5 (particulate matter [PM] < or = 2.5 microm in aerodynamic diameter) and PM10 (PM < or = 10 microm in aerodynamic diameter) samples from nearly 200 U.S. locations during the past 2 decades. Although there are theoretical reasons for expecting highly variable relationships between b(att) and EC (such as the effects of "brown carbon" and iron oxides in PM2.5), reasonable correlations are found. These correlations are not a strong function of season or location (e.g., rural vs. urban). Median EC concentrations can be predicted from filter transmittance measurements to within +/- 15-30%. Although EC predicted from b(att) shows larger uncertainties (30-60%), especially at concentrations less than 0.3 microg/m3, the consistent mass absorption efficiency (sigm(att)) derived from the regression analysis demonstrates the feasibility of using b(att) as a surrogate for EC. This study demonstrates that a constant factor of 0.1 g/m2 (equivalent to the 10 m2/g sigma(att) used in the Interagency Monitoring of Protected Visual Environments chemical extinction formula) can be used to estimate EC concentrations from b(att) through a Teflon-membrane filter sample. Greater accuracy is achieved with site-specific sigma(att) derived from a period with collocated EC measurements.     

Gaseous and particulate water-soluble organic and inorganic nitrogen in rural air in southern Scotland

Simultaneous daily measurements of water-soluble organic nitrogen (WSON), ammonium and nitrate were made between July and November 2008 at a rural location in south-east Scotland, using a ‘Cofer’ nebulizing sampler for the gas phase and collection on an open-face PTFE membrane for the particle phase. Average concentrations of NH₃ were 82 ± 17 nmol N m^?3 (error is s.d. of triplicate samples), while oxidised N concentrations in the gas phase (from trapping NO₂ and HNO₃) were smaller, at 2.6 ± 2.2 nmol N m^?3, and gas-phase WSON concentrations were 18 ± 11 nmol N m^?3. The estimated collection efficiency of the nebulizing samplers for the gas phase was 88 (±8) % for NH₃, 37 (±16) % for NO₂ and 57 (±7) % for WSON; reported average concentrations have not been corrected for sampling efficiency. Concentrations in the particle phase were smaller, except for nitrate, at 21 ± 9, 10 ± 6 and 8 ± 9 nmol N m^?3, respectively. The absence of correlation in either phase between WSON and either (NH₃ + NH₄⁺) or NO₃^? concentrations suggests atmospheric WSON has diverse sources. During wet days, concentrations of gas and particle-phase inorganic N were lower than on dry days, whereas the converse was true for WSON. These data represent the first reports of simultaneous measurements of gas and particle phase water-soluble nitrogen compounds in rural air on a daily basis, and show that WSON occurs in both phases, contributing 20–25% of the total water-soluble nitrogen in air, in good agreement with earlier data on the contribution of WSON to total dissolved N in rainfall in the UK.     

Sediment-associated aliphatic and aromatic hydrocarbons in coastal British Columbia, Canada: concentrations, composition, and associated risks to protected sea otters

Sediment-associated hydrocarbons can pose a risk to wildlife that rely on benthic marine food webs. We measured hydrocarbons in sediments from the habitat of protected sea otters in coastal British Columbia, Canada. Alkane concentrations were dominated by higher odd-chain n-alkanes at all sites, indicating terrestrial plant inputs. While remote sites were dominated by petrogenic polycyclic aromatic hydrocarbons (PAHs), small harbour sites within sea otter habitat and sites from an urban reference area reflected weathered petroleum and biomass and fossil fuel combustion. The partitioning of hydrocarbons between sediments and adjacent food webs provides an important exposure route for sea otters, as they consume ∼25% of their body weight per day in benthic invertebrates. Thus, exceedences of PAH sediment quality guidelines designed to protect aquatic biota at 20% of the sites in sea otter habitat suggest that sea otters are vulnerable to hydrocarbon contamination even in the absence of catastrophic oil spills.     

Estimating Remediation Costs at Contaminated Sites With Varying Amounts of Available Information

Environmental professionals are often tasked with projecting the cost to bring a contaminated site or portfolio of sites to regulatory closure. Fortunately, there are a number of useful guidance documents and industry publications available to assist in such cost projections. However, the usefulness of such tools is limited when adequate costing information is lacking, such as (a) the nature and extent of contamination; (b) regulatory requirements; (c) the remedial approach to be implemented; and/or (d) the duration of operation, maintenance, and monitoring activities. Despite the lack of such information, cost‐to‐closure estimates are nevertheless routinely needed and generated for internal assessments or audits, regulatory disclosures, property acquisitions, insurance claims, litigation, and other business transactions. Cost estimates are also often needed in bankruptcy proceedings where the trier of fact must estimate the total future costs associated with an environmental legacy portfolio to determine the overall value (or solvency in the case of evaluating the potential bankruptcy) of a company. This article presents a solution for developing cleanup costs for single sites or a portfolio of sites using a comprehensive, three‐tiered method that is effective over a wide range of site information. Real‐world examples of the successful application of this method are then provided, based on detailed environmental analyses that were completed for a recent bankruptcy proceeding and a case in which an estimated cleanup cost was needed in a legal proceeding. © 2013 Wiley Periodicals, Inc.     

Extreme Values in TSP Distribution Functions

The highest values in annual TSP distributions fall below the best-fit, log-normal straight line more than one would expect from ordinary sampling statistics but not dramatically so. The lowest values in annual TSP distributions overwhelmingly fall below the best-fit, log-normal straight line. The most highly improbable high values above the best-fit line in such distributions are very questionable and probably do not represent true air quality values. The most improbable cases of highest values falling below the best-fit, log-normal line are the result of data artifacts at the opposite end of the data distribution. They do not represent low probabilities and probably do represent true air quality values. The most improbable low values are all of highly doubtful validity.