Biological impacts of ocean acidification: a postgraduate perspective on research priorities

Research into the effects of ocean acidification (OA) on marine organisms has greatly increased during the past decade, as realization of the potential dramatic impacts has grown. Studies have revealed the multifarious responses of organisms to OA conditions, indicating a high level of intra- and interspecific variation in species’ ability to accommodate these alterations. If we are to provide policy makers with sound, scientific input regarding the expected consequences of OA, we need a broader understanding of these predicted changes. As a group of 20 multi-disciplinary postgraduate students from around the globe, with a study focus on OA, we are a strong representation of ‘next generation’ scientists in this field. In this unique cumulative paper, we review knowledge gaps in terms of assessing the biological impacts of OA, outlining directions for future research.     

Eliciting expert knowledge in conservation science

Expert knowledge is used widely in the science and practice of conservation because of the complexity of problems, relative lack of data, and the imminent nature of many conservation decisions. Expert knowledge is substantive information on a particular topic that is not widely known by others. An expert is someone who holds this knowledge and who is often deferred to in its interpretation. We refer to predictions by experts of what may happen in a particular context as expert judgments. In general, an expert-elicitation approach consists of five steps: deciding how information will be used, determining what to elicit, designing the elicitation process, performing the elicitation, and translating the elicited information into quantitative statements that can be used in a model or directly to make decisions. This last step is known as encoding. Some of the considerations in eliciting expert knowledge include determining how to work with multiple experts and how to combine multiple judgments, minimizing bias in the elicited information, and verifying the accuracy of expert information. We highlight structured elicitation techniques that, if adopted, will improve the accuracy and information content of expert judgment and ensure uncertainty is captured accurately. We suggest four aspects of an expert elicitation exercise be examined to determine its comprehensiveness and effectiveness: study design and context, elicitation design, elicitation method, and elicitation output. Just as the reliability of empirical data depends on the rigor with which it was acquired so too does that of expert knowledge.     

Can Local Voluntary Environmental Programs “Work”? An Examination of Fort Collins’ (Colorado) Climate Wise Program

Previous research on voluntary environmental programs (VEPs) frequently assesses the effectiveness of federal, state, and third party programs and why organizations seek to join such programs. Yet, research has yet to evaluate the effectiveness or firm motivation relative to local VEPs. Recognizing this gap, our paper examines the structure and organization of Fort Collins’ Climate Wise program, a local VEP. Using a variety of sources, we find that the program has successfully met both short- and long-term goals by persistently self-evaluating and seeking outside financial support. Findings from this analysis can aid in understanding and developing local VEPs elsewhere. Specifically, this initial research suggests that local VEPs need to consider local context and available resources when implementing such programs. Furthermore, it is possible for local VEPs to attract a diverse variety of participating firms by avoiding one-size-fits-all participation levels and by establishing a sense of ownership among partners.     

Toxicity tests aiming to protect Brazilian aquatic systems: current status and implications for management

The current status of toxicological tests performed with Brazilian native species was evaluated through a survey of the scientific data available in the literature. The information gathered was processed and an electronic toxicology database (http://www.inct-ta.furg.br/bd_toxicologico.php) was generated. This database provides valuable information for researchers to select sensitive and tolerant aquatic species to a large variety of aquatic pollutants. Furthermore, the toxicology database allows researchers to select species representative of an ecosystem of interest. Analysis of the toxicology database showed that ecotoxicological assays have significantly improved in Brazil over the last decade, in spite of the still relatively low number of tests performed and the restricted number of native species tested. This is because most of the research is developed in a few laboratories concentrated in certain regions of Brazil, especially in Southern and Southeast regions. Considering the extremely rich biodiversity and the large variety of aquatic ecosystems in Brazil, this finding points to the urgent need for the development of ecotoxicological studies with other groups of aquatic animals, such as insects, foraminifera, cnidarians, worms, amphibians, among others. This would help to derive more realistic water quality criteria (WQC) values, which would better protect the different aquatic ecosystems in Brazil. Finally, the toxicology database generated presents solid and science based information, which can encourage and drive the Environmental Regulatory Agencies in Brazil to derive WQC based on native species. In this context, the present paper discusses the historical evolution of ecotoxicological studies in Brazil, and how they have contributed to the improvement of the Brazilian Federal and Regional regulations for environment.     

Environment as the Stage for Economic Actors

The relative importance of economics and environment in debate may soon be reversed due to the influence of three fac- tors. Firstly, in the global economy it is hard to hide the unwanted products of economic processes. Secondly, huge advances in sci- ence will reduce the imperfect knowledge of markets, making some monitoring and analyzing tools show the design of sensible and equitable livelihood in communities, which is more important than the motivation of maximising profits for some individuals or firms. Thirdly, China, as the last major player on the planet to take on economic growth, comes from traditions fundamentally differ- ent from those economies that have experienced the Industrial Revolution previously. Its challenges with sustainability and en- vironmental conservation predate Western economics by millennia, and it is implementing policies domestically and starting to work on the world stage that acknowledges that the surroundings are the host for any economic and socio-political system.     

Optimizing carbon sequestration in commercial forests by integrating carbon management objectives in wood supply modeling

This paper provides a methodology for generating forest management plans, which explicitly maximize carbon (C) sequestration at the forest-landscape level. This paper takes advantage of concepts first presented in a paper by Meng et al. (2003; Mitigation Adaptation Strategies Global Change 8:371–403) by integrating C-sequestration objective functions in existing wood supply models. Carbon-stock calculations performed in Woodstock^TM (RemSoft Inc.) are based on C yields generated from volume table data obtained from local Forest Development Survey plots and a series of wood volume-to-C content conversion factors specified in von Mirbach (2000). The approach is used to investigate the impact of three demonstration forest-management scenarios on the C budget in a 110,000 ha forest in south-central New Brunswick, Canada. Explicit demonstration scenarios addressed include (1) maximizing timber extraction either by clearcut or selection harvesting for greatest revenue generation, (2) maximizing total C storage in the forest landscape and in wood products generated from harvesting, and (3) maximizing C storage together with revenue generation. The level of clearcut harvesting was greatest for scenario 1 (≥15 × 10⁴ m³ of wood and ≥943 ha of land per harvesting period), and least for scenario 2 (=0 m³ per harvesting period) where selection harvesting dominated. Because softwood saw logs were worth more than pulpwood ($60 m⁻³ vs. $40 m⁻³) and were strategic to the long-term storage of C, the production of softwood saw logs exceeded the production of pulpwood in all scenarios. Selection harvesting was generally the preferred harvesting method across scenarios. Only in scenario 1 did levels of clearcut harvesting occasionally exceed those of selection harvesting, mainly in the removal of old, dilapidated stands early in the simulation (i.e., during periods 1 through 3). Scenario 2 provided the greatest total C-storage increase over 80 years (i.e., 14 × 10⁶ Mg C, or roughly 264 Mg ha⁻¹) at a cost of $111 per Mg C due to lost revenues. Scenarios 3 and 1 produced reduced storage rates of roughly 9 × 10⁶ Mg C and 3 × 10⁶ Mg C, respectively; about 64% and 22% of the total, 80-year C storage calculated in scenario 2. The bulk of the C in scenario 2 was stored in the forest, amounting to about 76% of the total C sequestered.     

Competition,fluctuating asymmetry and sperm transfer in male gryllid crickets (<Emphasis Type="Italic">Gryllus bimaculatus</Emphasis> and <Emphasis Type="Italic">Gryllodes sigillatus</Emphasis>)

Sperm competition theory predicts that ejaculate expenditure by males should increase with the risk of competition from rivals. The tendency to modulate expenditure, however, may reflect various constraints acting on different individuals. We test this idea here by looking at the effects of competition and fluctuating asymmetry (FA) in two species of gryllid cricket. Male Gryllus bimaculatus and Gryllodes sigillatus modulated the sperm content of their spermatophores in relation to both apparent competition and FA in limb size. Males of both species increased the amount of sperm transferred when an apparent male competitor was present, sperm number increasing regardless of the species of apparent competitor in G. bimaculatus, but significantly more with a conspecific competitor in G. sigillatus. In addition, the relative size of the spermatophylax in G. sigillatus increased in the presence of apparent competition, while spermatophore transfer time decreased in G. bimaculatus. Sperm number showed opposite relationships with limb asymmetry in the two species, decreasing with increasing asymmetry in males in G. sigillatus, but increasing with asymmetry in both males and females in G. bimaculatus. G. bimaculatus, but not G. sigillatus, also transferred more sperm when paired with a larger female. Relationships between reproductive measures and limb asymmetry were significant only when competitors were present in G. bimaculatus, but were significant regardless of competition in G. sigillatus. The differences may reflect the additional burden of producing a spermatophylax in G. sigillatus.     

The effect of two applications of atrazine on the water quality of freshwater enclosures

To simulate runoff from agricultural lands, atrazine was applied to aquatic enclosures (112 m(3)) on 1 June 1983 at a concentration of 0.1 mg litre(-1). Thirty-five days later the nominal concentration was increased to 0.155 mg litre(-1). Treated enclosures became clearer with Secchi disc readings of 3.6 m compared to non-treated controls (2.9 m). Less than 5% of the first atrazine addition disappeared during the first 35 days and little effect on biological activity was observed. However, with the second enrichment the rate of loss of atrazine was rapid (t(1/2) = 150 days), ammonium, calcium, dissolved inorganic carbon and nitrate levels were higher, while oxygen, chlorophyll, dissolved organic carbon and particulate organic carbon concentrations were lower in the treated enclosures. These water quality changes cannot be explained by herbicide-water chemistry interactions alone, thereby suggesting an indirect effect as a consequence of atrazine inhibition on photosynthesis and possibly other microbial processes.     

Concentrations of dioxin-like PCB congeners in unweathered Aroclors by HRGC/HRMS using EPA Method 1668A

We have determined the congener compositions of nine commercial Aroclor products of polychlorinated biphenyls (PCBs) to the sub-part-per-million level using high-resolution gas chromatography combined with high-resolution mass spectrometry according to US Environmental Protection Agency (EPA) Method 1668A. These Aroclor composition data should allow improved characterization and risk assessment of PCB contamination at hazardous waste sites, particularly for dioxin-like PCB congeners. By combining the data on the concentrations of each dioxin-like congener with its World Health Organization toxicity equivalency factor, we have established dioxin toxic equivalent concentrations for each pure Aroclor product.