Infestation rates of lice Lepeophtheirus salmonis and Caligus elongatus on Atlantic salmon in fixed and towed sentinel cages.

Sea lice are a key limitation to sustainable salmon aquaculture, and effective monitoring strategies are critical for the management of these parasites. Sentinel cages are an established means of assessing infestation pressure at fixed locations, but as smolts move through systems they will be exposed to varying lice densities. As a means of assessing infestation pressure along trajectories, we describe the development and application of towed sentinel cages (TSCs) in a Scottish sea loch containing salmonid aquaculture. Trial deployments took place over 3 yr (2016-2018), and levels of sea lice infestation were compared between methodologies. Oceanographic data was collected alongside TSCs to put the results into the environmental context that smolts and sea lice experienced during the tows. The sea lice infestation rates found from TSCs were comparable to those on contemporaneously deployed fixed sentinel cages. Thus, due to their practicability and consistency with other surveillance methods, TSCs could be used to improve the assessment of exposure risk along wild salmonid smolt migration trajectories, where these are known.

The Transpolar Drift conveys methane from the Siberian Shelf to the central Arctic Ocean.

Methane sources and sinks in the Arctic are poorly quantified. In particular, methane emissions from the Arctic Ocean and the potential sink capacity are still under debate. In this context sea ice impact on and the intense cycling of methane between sea ice and Polar surface water (PSW) becomes pivotal. We report on methane super- and under-saturation in PSW in the Eurasian Basin (EB), strongly linked to sea ice-ocean interactions. In the southern EB under-saturation in PSW is caused by both inflow of warm Atlantic water and short-time contact with sea ice. By comparison in the northern EB long-time sea ice-PSW contact triggered by freezing and melting events induces a methane excess. We reveal the Ttranspolar Drift Stream as crucial for methane transport and show that inter-annual shifts in sea ice drift patterns generate inter-annually patchy methane excess in PSW. Using backward trajectories combined with δ18O signatures of sea ice cores we determine the sea ice source regions to be in the Laptev Sea Polynyas and the off shelf regime in 2011 and 2015, respectively. We denote the Transpolar Drift regime as decisive for the fate of methane released on the Siberian shelves.

Using biological-physical modelling for informing sea lice dispersal in Loch Linnhe, Scotland.

Sea lice are a constraint on the sustainable growth of Scottish marine salmonid aquaculture. As part of an integrated pest management approach, farms coordinate procedures within spatial units. We present observations of copepodids being at relatively greater density than nauplii in upper waters, which informs the development of surface layer sea lice transmission modelling of Loch Linnhe, Scotland, for informing farm parasite management. A hydrodynamic model is coupled with a biological particle-tracking model, with characteristics of plankton sea lice. Simulations are undertaken for May and October 2011-2013, forced by local wind data collected for those periods. Particles are continually released from positions representing farm locations, weighted by relative farm counts, over a 2-week period and tracked for a further 5 days. A comparison is made between modelled relative concentrations against physical and biological surveys to provide confidence in model outputs. Connectivity between farm locations is determined in order to propose potential coordination areas. Generally, connectivity depends on flow patterns in the loch and decreases with increased farm separation. The connectivity indices are used to estimate the origins of the sea lice population composition at each site, which may influence medicinal regimens to avoid loss of efficacy.

Simulated environmental transport distances of Lepeophtheirus salmonis in Loch Linnhe, Scotland, for informing aquaculture area management structures.

In the majority of salmon farming countries, production occurs in zones where practices are coordinated to manage disease agents such as Lepeophtheirus salmonis. To inform the structure of zones in specific systems, models have been developed accounting for parasite biology and system hydrodynamics. These models provide individual system farm relationships, and as such, it may be beneficial to produce more generalized principles for informing structures. Here, we use six different forcing scenarios to provide simulations from a previously described model of the Loch Linnhe system, Scotland, to assess the maximum dispersal distance of lice particles released from 12 sites transported over 19 day. Results indicate that the median distance travelled is 6.1 km from release site with <2.5% transported beyond 15 km, which occurs from particles originating from half of the release sites, with an absolute simulated distance of 36 km observed. This provides information suggesting that the disease management areas developed for infectious salmon anaemia control may also have properties appropriate for salmon lice management in Scottish coastal waters. Additionally, general numerical descriptors of the simulated relative lice abundance reduction with increased distance from release location are proposed.

Development and assessment of a biophysical dispersal model for sea lice.

Salmon aquaculture in Scotland continues to increase; however, one of the potential limitations to its further sustainable growth is the ectoparasitic sea louse Lepeophtheirus salmonis. The industry in Scotland undertakes coordinated management procedures to control the levels of sea lice on farms in designated production areas. We developed a biophysical sea lice dispersal model for Loch Linnhe, one of the largest fjords on the west coast of Scotland, to provide further information to help establish more effective farm management areas. We successfully extend modelling principles previously applied to a small Scottish fjordic system. Modelling scenarios demonstrate heterogeneity in the distribution of sea lice within the system and simulations, suggesting that lice could be transmitted up to 30 km. The scenarios are assessed by comparing model predictions against lice sampled by both planktonic trawls and settlement on sentinel caged fish. The model predicts the ranked abundance of both planktonic and settled lice assuming that the lice input to the system is relative to host biomass. Data collection is ongoing for undertaking and assessing additional scenarios.

Body mass index of the elderly derived from height and from armspan.

The body mass index (BMI) has been promoted as a useful indicator for chronic energy deficiency, and to a lesser extent to indicate obesity. For the growing sector of elderly in developing countries, such as Indonesia, both issues are taking on public health relevance. The aging process leads to a progressive loss of height, and questions have been raised as to the appropriate value to include in the denominator of the BMI formula, WT(kg)/HT(m2), when applied in this age-group. The armspan has been advanced as a surrogate for height, correcting for the lifelong loss of stature. In a data-set from 69 elderly in Indonesia, 36 women and 33 men, aged 60 to 69 y, we have examined the interrelationships of height and armspan. The correlation coefficient for the regression of the two measures were r = 0.83 and r = 0.81 (p < 0.001), for women and men, respectively. Substituting the armspan term in the denominator to compose a Body Mass using Armspan (BMA) Index, we observe for this population a 32% increase in estimates for Chronic Energy Deficiency (CED) for women and 24% increase in estimates of CED for men. Corresponding estimates for obesity rates declined by 45% and 81% respectively. The senescent changes in stature raise important questions for our capacity to estimate prevalences of body composition disorders in the older population.

When siting works, Canada-style.

Hazardous waste management poses increasing problems for Canadian provinces and American states, given the vast quantities and types of wastes generated and the virtual inability to open new storage, treatment, or disposal facilities. The Canadian experience is very similar to the American one in many respects, except for the fact that three provinces (Alberta, Manitoba, and Quebec) have devised alternative approaches to siting that appear successful in moving beyond the political gridlock so common on this issue. In each of these cases, traditional, top-down approaches to siting have been eschewed in favor of a more comprehensive approach that includes extensive public participation, economic and social compensation packages, formal partnerships between public and private organizations, and direct links between siting proposals and other aspects of waste management, including waste reduction, recycling, and export/import control.

Licit and illicit drug policies: a typology.

To foster comparison of policy interventions across the various categories of licit and illicit drugs, we develop a typology of policies intended to address drug abuse problems. The principal dimensions of the typology are policy type and intervention channel. While the typology has important limitations, as a mechanism to organize information and stimulate thought it holds the potential to improve understanding of commonalities and distinctions among policies applying to widely discrepant drug problems, both within and across cultures. As such, it could contribute to the development of more effective approaches to grappling with a diverse set of drug policy issues.

Legislative incapacity: the congressional role in environmental policy-making and the case of Superfund.

Congress plays a central role in national environmental policy formation but appears ill equipped to set policy priorities and devise integrative legislation. Fragmentation of authority among a multiplicity of committees and subcommittees, especially in the House, contributes to these problems. This pattern is evident in the evolution of Superfund, the national program to clean up abandoned hazardous waste sites. The prolonged process of reauthorization in the 1980s contributed to serious program delay and failed to resolve a number of fundamental questions concerning the national cleanup effort. Institutional reforms could contribute to a more effective congressional role in future environmental policy deliberations.

Geograpehic variation and episodic evolution in an ordovician trilobite.

A single lineage of the trilobite Flexicalymene shows two evolutionary "punctuated equilibria" within a 2-million-year, 1000-square-kilometer stratigraphic interval. The 2 x 10(5)-year-long "punctuation" may represent parapatric speciation. Commonness of depth-related clines before, during and after this event suggests that short-term adjustment to local conditions was important in long-term evolution.