Genetic structuring of <Emphasis Type="Italic">Latris lineata</Emphasis> at localized and transoceanic scales

Striped trumpeter (Latris lineata) is a demersal teleost distributed around the temperate clines of all the major oceans in the southern hemisphere. Within Tasmanian waters the species is managed as a single stock, although no studies have been performed to confirm genetic panmixia. A protracted pelagic larval phase and a recent transoceanic tag recapture of an adult fish suggest significant potential for genetic mixing between widely separated populations. Phylogenetic analysis of mitochondrial DNA control region sequences suggested no genetic mixing between Tasmania, New Zealand and St Paul/Amsterdam Islands, evidence for the first time that there is population structure at a transoceanic scale for this species. In addition, an analysis of molecular variance coupled with phylogenetic analyses suggested no significant structuring of striped trumpeter from three locations around Tasmania. The information provided in this study is useful for the design of modern fisheries management techniques such as spatially implemented marine reserves. In addition, species-by-species knowledge about population structures of marine species facilitates ecologically useful generalizations concerning their population dynamics and key issues on the broader ecology of the oceans.     

Ready or not: How do we accelerate the developmental readiness of leaders?

A theory of leader developmental readiness is examined comprised of leaders' motivation and ability to develop. Early theory-building and testing suggests leaders' motivation to develop is promoted through interest and goals, learning goal orientation, and developmental efficacy; while leaders' ability to develop is promoted through self-awareness, self-complexity, and meta-cognitive ability. Copyright © 2010 John Wiley & Sons, Ltd.     

A multi-criteria assessment of fishing gear impacts in demersal fisheries

Fishing gears have multiple impacts on the marine environment, and policies to reduce these impacts through modifying fishing gears are becoming common place. Different modifications result in different changes in the set of environmental impacts, and imply different sets of costs and benefits for different stakeholder groups. In this study, the analytic hierarchy process (AHP) is used to quantify the relative importance of the environmental impacts of fishing to different stakeholder groups. Forty eight individuals representing six different stakeholder groups (ecologists, biologists, economists, gear technologists, fishers and fisheries managers) were surveyed. As expected, fishers and gear technologists placed substantially greater importance on reducing discarding of commercial fish species than on habitat damage. Priorities of other stakeholder groups varied, but all placed greater priority on habitats than the commercial sector. The results suggest that management aimed at reducing environmental impacts of fishing broader than just discarding is appropriate, but such moves are likely to be opposed by the fishing industry. The derived weights also have a direct application to fisheries management, as they allow otherwise non-commensurate impacts to be aggregated into an overall impact to compare environmental benefits from alternative modifications of fishing gear.     

Emissions of volatile fatty acids from feed at dairy facilities

Recent studies suggest that dairy operations may be a major source of non-methane volatile organic compounds in dairy-intensive regions such as Central California, with short chain carboxylic acids (volatile fatty acids or VFAs) as the major components. Emissions of four VFAs (acetic acid, propanoic acid, butanoic acid and hexanoic acid) were measured from two feed sources (silage and total mixed rations (TMR)) at six Central California Dairies over a fifteen-month period. Measurements were made using a combination of flux chambers, solid phase micro-extraction fibers coupled to gas chromatography mass spectrometry (SPME/GC–MS) and infra-red photoaccoustic detection (IR-PAD for acetic acid only). The relationship between acetic acid emissions, source surface temperature and four sample composition factors (acetic acid content, ammonia-nitrogen content, water content and pH) was also investigated. As observed previously, acetic acid dominates the VFA emissions. Fluxes measured by IR-PAD were systematically lower than SPME/GC–MS measurements by a factor of two. High signals in field blanks prevented emissions from animal waste sources (flush lane, bedding, open lot) from being quantified. Acetic acid emissions from feed sources are positively correlated with surface temperature and acetic acid content. The measurements were used to derive a relationship between surface temperature, acetic acid content and the acetic acid flux. The equation derived from SPME/GC–MS measurements predicts estimated annual average acetic acid emissions of (0.7 + 1/?0.4) g m^?2 h^?1 from silage and (0.2 + 0.3/?0.1) g m^?2 h^?1 from TMR using annually averaged acetic acid content and meteorological data. However, during the summer months, fluxes may be several times higher than these values.     

Social network theory: new insights and issues for behavioral ecologists

Until recently, few studies have used social network theory (SNT) and metrics to examine how social network structure (SNS) might influence social behavior and social dynamics in non-human animals. Here, we present an overview of why and how the social network approach might be useful for behavioral ecology. We first note four important aspects of SNS that are commonly observed, but relatively rarely quantified: (1) that within a social group, differences among individuals in their social experiences and connections affect individual and group outcomes; (2) that indirect connections can be important (e.g., partners of your partners matter); (3) that individuals differ in their importance in the social network (some can be considered keystone individuals); and (4) that social network traits often carry over across contexts (e.g., SN position in male–male competition can influence later male mating success). We then discuss how these four points, and the social network approach in general, can yield new insights and questions for a broad range of issues in behavioral ecology including: mate choice, alternative mating tactics, male–male competition, cooperation, reciprocal altruism, eavesdropping, kin selection, dominance hierarchies, social learning, information flow, social foraging, and cooperative antipredator behavior. Finally, we suggest future directions including: (1) integrating behavioral syndromes and SNT; (2) comparing space use and SNS; (3) adaptive partner choice and SNS; (4) the dynamics and stability (or instability) of social networks, and (5) group selection shaping SNS. This contribution is part of the special issue “Social networks: new perspectives” (Guest Editors: J. Krause, D. Lusseau and R. James).