Shining a light on the composition and distribution patterns of mesophotic and subphotic fish communities in Hawai‘i

As agencies shift from single-species management to ecosystem-based fisheries management, ecosystem models are gaining interest for understanding species dynamics in relation to oceanographic and ecological processes and human marine uses. However, information on community structure or distribution of many species that occupy deep (>30 m) waters is largely unavailable. We amassed a total of 24 686 fish observations of 523 species/taxa for the 30−410 m depth areas surrounding the main Hawaiian Islands (MHI). We also obtained estimates of geomorphological variables, including substrate type, slope, rugosity, and ridge-like features. Using these 2 data sources, we (1) identified distinct fish communities along the 30−410 m depth gradient, and (2) generated relative biomass maps for fish functional groups. We showed that the mesophotic zone ranges between 30 and 129 m, with a fish faunal break at 60 m. Beyond this zone, 4 subphotic zones were identified: upper rariphotic (130−169 m), mid-rariphotic (170−239 m), lower rariphotic (240−319 m), and upper bathyal (320−410 m). We assigned fish species to functional groups partly based on identified depth ranges and fitted general additive models (GAMs) integrating geomorphological covariates to the functional group relative biomass estimates to determine the environmental variables that best predict the probability of encounter and relative biomass of each fish functional group. Finally, GAM predictions were employed to map functional group relative biomass distributions. These distribution maps showed a high relative biomass of many groups in the center of the MHI chain. This study contributes to a better understanding of fish community structure around the MHI and will inform ecosystem model parameterization

The relative efficiency of automatic and discretionary regional aid

For the last two decades, the primary instruments for UK regional policy have been discretionary subsidies. Such aid is targeted at "additional" projects - projects that would not have been implemented without the subsidy - and the subsidy should be the minimum necessary for the project to proceed. Discretionary subsidies are thought to be more efficient than automatic subsidies, where many of the aided projects are non-additional and all projects receive the same subsidy rate. The present paper builds on Swales (1995) and Wren (2007a) to compare three subsidy schemes: an automatic scheme and two types of discretionary scheme, one with accurate appraisal and the other with appraisal error. These schemes are assessed on their expected welfare impacts. The particular focus is the reduction in welfare gain imposed by the interaction of appraisal error and the requirements for accountability. This is substantial and difficult to detect with conventional evaluation techniques

Political cycles in Greece's municipal employment

We consider the politically motivated fluctuations in Greece’s municipal employment, constructing a data-set from primary data and focusing on the composition of municipal employment in terms of employment relationship forms. Our analysis produces strong evidence of pre-electoral manipulation through increases in the number of contract employees. Considering a number of control variables and robustness checks does not affect the key results. Such variables include whether mayors run for reelection, incumbents’ political alignment with central government, partisan shifts, general elections, mayors’ turnover rate, and timing patterns. Our evidence provides insights into Greece’s political economy in the run-up to the current economic crisis

The First Aysnchronous Microprocessor: The Test Results

No abstract available

Can ecosystem-based deep-sea fishing be sustained?

Can there ever be a truly sustainable deep-sea fishery and if so, where and under what conditions? Ecosystembased fisheries management requires that this question be addressed such that habitat, bycatch species, and targeted fish populations are considered together within an ecosystem context. To this end, we convened the first workshop to develop an ecosystem approach to deep-sea fisheries and to ask whether deep-sea species could be fished sustainably. The workshop participants were able to integrate bycatch information into their framework but found it more difficult to integrate other ecosystem indicators such as habitat characteristics. (First two paragraphs from the Executive Summary

A taste of the deep-sea: The roles of gustatory and tactile searching behaviour in the grenadier fish <i>Coryphaenoides armatus</i>

The deep-sea grenadier fishes (Coryphaenoides spp.) are among the dominant predators and scavengers in the ocean basins that cover much of Earth's surface. Baited camera experiments were used to study the behaviour of these fishes. Despite the apparent advantages of rapidly consuming food, grenadiers attracted to bait spend a large proportion of their time in prolonged periods of non-feeding activity. Video analysis revealed that fish often adopted a head-down swimming attitude (mean of 21.3 degrees between the fish and seafloor), with swimming velocity negatively related to attitude. The fish also swam around and along vertical and horizontal structures of the lander with their head immediately adjacent to the structure. We initially hypothesised that this behaviour was associated with the use of the short chin barbel in foraging. Barbel histology showed numerous taste buds in the skin, and a barbel nerve with about 20,000 axons in adult fish. A tracing experiment in one undamaged animal revealed the termination fields of the barbel neurons in the trigeminal and rhombencephalic regions, indicating both a mechanoreceptory and a gustatory role for the barbel. Our conclusion was that olfactory foraging becomes ineffective at close ranges and is followed by a search phase using tactile and gustatory sensing by the barbel. The development of this sensory method probably co-evolved alongside behavioural changes in swimming mechanics to allow postural stability at low swimming speeds

What have transgenic and knockout animals taught us about respiratory disease?

Over the past decade there has been a significant shift to the use of murine models for investigations into the molecular basis of respiratory diseases, including asthma and chronic obstructive pulmonary disease. These models offer the exciting prospect of dissecting the complex interaction between cytokines, chemokines and growth related peptides in disease pathogenesis. Furthermore, the receptors and the intracellular signalling pathways that are subsequently activated are amenable for study because of the availability of monoclonal antibodies and techniques for targeted gene disruption and gene incorporation for individual mediators, receptors and proteins. However, it is clear that extrapolation from these models to the human condition is not straightforward, as reflected by some recent clinical disappointments. This is not necessarily a problem with the use of mice itself, but results from our continued ignorance of the disease process and how to improve the modelling of complex interactions between different inflammatory mediators that underlie clinical pathology. This review highlights some of the strengths and weaknesses of murine models of respiratory disease