Infant mortality and social environment in Georgia: an application of hotspot detection and prioritization

Recent years have witnessed the growth of new information technologies and their applications to various disciplines. The goal of this paper is to demonstrate how the two innovative methods, upper level set scan (ULS) hotspot detection and the multicriteria prioritization scheme, facilitate population health and break new ground in public health surveillance. It is believed that the social environment (i.e. social conditions and social capital) is one of the determinants of human health. Using infant health data and 10 additional indicators of social environment in the 159 counties of Georgia, ULS identified 52 counties that are in double jeopardy (high infant mortality and a high rate of low infant birth weight). The multicriteria ranking scheme suggested that there was no conspicuous spatial cluster of ranking orders, which improved the traditional decision making by visual geographic cluster. Both hotspot detection and ranking methods provided an empirical basis for re-allocating limited resources and several policy implications could be drawn from these analytic results.     

Comparing macroalgal food and habitat choice in sympatric, tube-building amphipods, Ampithoe lacertosa and Peramphithoe humeralis

For small tube-building amphipods that live on the algae they consume, food and habitat are tightly linked. This study compared two closely related amphipods to determine whether the species’ algal preferences are based on the food value of the algae or on some other aspect of their algal habitat. Ampithoe lacertosa and Peramphithoe humeralis are both abundant on Shannon Point beach (Anacortes, Washington, USA; 48°30.542′ N, 122°41.070′ W) but specialize on different algae. In observations and laboratory experiments conducted July–September 1997, 2007, and 2008, the two species exhibited markedly different choices of food and habitat when offered six common macroalgae. Ampithoe lacertosa ate all algae offered, but preferentially built tubes on the green alga Ulva lactuca. Survival was relatively low among juveniles maintained on single species diets, except when they were fed Mazzaella splendens. Conversely, P. humeralis consumed primarily the brown kelp Saccharina latissima, Alaria marginata, and Desmarestia ligulata and preferred those species for tube building. Juvenile P. humeralis could not survive on a diet of U. lactuca or M. splendens. While A. lacertosa builds simple, temporary tubes and relocates frequently, P. humeralis is a highly thigmotactic species that builds long-term, complex tubes on the alga it prefers to eat. Feeding and habitat preferences of the two species were not clearly linked to nitrogen content of the algae, C:N ratio, or toughness of the algal tissue. Instead, preferences of the species may be related to their mobility and the permanence of the tubes they build. Ampithoe lacertosa and P. humeralis also use different feeding strategies; the former appears to mix algae to produce a high-quality diet, while the latter is more selective and has a capacity for compensatory feeding. The species are abundant on the same protected rocky shores, but specialize on different algae for habitat and food. Results suggest that the nutritional requirements of these sympatric mesograzers differ considerably and even closely related species can exhibit divergent behavioral strategies.     

On the relationship between regional and local species richness: a test of saturation theory

What are the local community consequences of changes in regional species richness and composition? To answer this question we followed the assembly of microarthropod communities in defaunated areas of moss, embedded in a larger moss "region." Regions were created by combining moss from spatially distinct sites, resulting in regional species pools that differed in both microarthropod richness and composition, but not area. Regional effects were less important than seasonality for local richness. Initial differences in regional richness had no direct effect on local species richness at any time along a successional gradient of 0.5-16 months. The structure of the regional pool affected both local richness and local composition, but these effects were seasonally dependent. Local species richness differed substantially between dates along the successional gradient and continued to increase 16 months after assembly began. To the best of our knowledge, this is the first critical test of saturation theory that experimentally manipulates regional richness. Further, our results failed to support the most important mechanisms proposed to explain the local richness-regional richness relationship. The results demonstrate that complicated interactions between assembly time, seasonality, and regional species pools contribute to structuring local species richness and composition in this community.     

Restoring piscivorous fish populations in the Laurentian Great Lakes causes seabird dietary change

Ecosystem change often affects the structure of aquatic communities thereby regulating how much and by what pathways energy and critical nutrients flow through food webs. The availability of energy and essential nutrients to top predators such as seabirds that rely on resources near the water's surface will be affected by changes in pelagic prey abundance. Here, we present results from analysis of a 25-year data set documenting dietary change in a predatory seabird from the Laurentian Great Lakes. We reveal significant declines in trophic position and alterations in energy and nutrient flow over time. Temporal changes in seabird diet tracked decreases in pelagic prey fish abundance. As pelagic prey abundance declined, birds consumed less aquatic prey and more terrestrial food. This pattern was consistent across all five large lake ecosystems. Declines in prey fish abundance may have primarily been the result of predation by stocked piscivorous fishes, but other lake-specific factors were likely also important. Natural resource management activities can have unintended consequences for nontarget ecosystem components. Reductions in pelagic prey abundance have reduced the capacity of the Great Lakes to support the energetic requirements of surface-feeding seabirds. In an environment characterized by increasingly limited pelagic fish resources, they are being offered a Hobsonian choice: switch to less nutritious terrestrial prey or go hungry.     

Incorporating catastrophic risk assessments into setting conservation goals for threatened Pacific salmon

Catastrophic die-offs can have important consequences for vertebrate population growth and biodiversity, but catastrophic risks are not commonly incorporated into endangered-species recovery planning. Natural (e.g., landslides, floods) and anthropogenic (e.g., toxic leaks and spills) catastrophes pose a challenge for evolutionarily significant units (ESUs) of Pacific salmon listed under the Endangered Species Act and teetering at precariously low population levels. To spread risks among Puget Sound chinook salmon populations, recovery strategies for ESU-wide viability recommend at least two viable populations of historical life-history types in each of five geographic regions. We explored the likelihood of Puget Sound chinook salmon ESU persistence by examining spatial patterns of catastrophic risk and testing ESU viability recommendations for 22 populations of the threatened Puget Sound chinook salmon ESU. We combined geospatial information about catastrophic risks and chinook salmon distribution in Puget Sound watersheds to categorize relative catastrophic risks for each population. We then analyzed similarities in risk scores among regions and compared risk distributions among strategies: (1) population groups selected using the ESU viability recommendations of having populations spread out geographically and including historical life-history diversity, and (2) population groups selected at random. Risks from individual catastrophes varied among populations, but overall risk from catastrophes was similar within geographic regions. Recovery strategies that called for two viable populations in each of five geographic regions had lower risk than random strategies; strategies that included life-history diversity had even lower risks. Geographically distributed populations have varying catastrophic-risks profiles, thus identifying and reinforcing the spatial and life-history diversity critical for populations to respond to environmental change or needed to rescue severely depleted or extirpated populations. Recovery planning can promote viability of Pacific salmon ESUs across the landscape by incorporating catastrophic risk assessments.     

Risk Assessment and Management of Contamination of Eels (Anguilla Spp.) By Persistent Xenobiotic Organochlorine Compounds

Contaimination of anguillid eels by organochlorine pesticides and PCBs is reviewed using a risk assessment-management approach. Quantitative structure-activity relationships, biomonitoring of body residues and field and laboratory studies demonstrate hazards and risks of persistence; organic carbon binding, sediment transport and sinks; volatility, aerial transport and deposition; hydrophobicity/lipophilicity, bioaccumulation, bioconcentration and dietary biomangification. Risks of acute narcotic toxicity are generally lower than those of chornic effects. Cause-effect relationships and critical loadings are, however, unclear. Critical environmental and body residue levels to protect eels and animal and humans consumption must be formulated and interpreted with caution. Risks for eels at different life-stages and in different habitats are compared with respect to routes of uptake, elimination, bioaccumulation and biomagnification. It is concluded that organochlorine contamination has not been a major cause of recent declines in eel recruitment. the use of eels in biomonitoring and biomarker studies are recommended. Appropriate methodologies and uses in risk assessment and management are discussed.     

Effects on the structure of Arctic ecosystems in the short- and long-term perspectives

Species individualistic responses to warming and increased UV-B radiation are moderated by the responses of neighbors within communities, and trophic interactions within ecosystems. All of these responses lead to changes in ecosystem structure. Experimental manipulation of environmental factors expected to change at high latitudes showed that summer warming of tundra vegetation has generally led to smaller changes than fertilizer addition. Some of the factors manipulated have strong effects on the structure of Arctic ecosystems but the effects vary regionally, with the greatest response of plant and invertebrate communities being observed at the coldest locations. Arctic invertebrate communities are very likely to respond rapidly to warming whereas microbial biomass and nutrient stocks are more stable. Experimentally enhanced UV-B radiation altered the community composition of gram-negative bacteria and fungi, but not that of plants. Increased plant productivity due to warmer summers may dominate food-web dynamics. Trophic interactions of tundra and sub-Arctic forest plant-based food webs are centered on a few dominant animal species which often have cyclic population fluctuations that lead to extremely high peak abundances in some years. Population cycles of small rodents and insect defoliators such as the autumn moth affect the structure and diversity of tundra and forest-tundra vegetation and the viability of a number of specialist predators and parasites. Ice crusting in warmer winters is likely to reduce the accessibility of plant food to lemmings, while deep snow may protect them from snow-surface predators. In Fennoscandia, there is evidence already for a pronounced shift in small rodent community structure and dynamics that have resulted in a decline of predators that specialize in feeding on small rodents. Climate is also likely to alter the role of insect pests in the birch forest system: warmer winters may increase survival of eggs and expand the range of the insects. Insects that harass reindeer in the summer are also likely to become more widespread, abundant and active during warmer summers while refuges for reindeer/caribou on glaciers and late snow patches will probably disappear.     

Phosphorus fractionation in manure from swine fed traditional and low-phytate corn diets

Traditional corn (Zea mays L.) (TC), the primary grain used in swine (Sus scrofa) diets, stores a majority of its P as phytate, which is largely unavailable for digestion by nonruminant animals. Low-phytate corn (LPC) contains similar amounts of total P but a smaller percentage of P as phytate. When fed to swine, LPC increases P utilization and reduces P content of manure. While differences in P content between manure from animals fed TC and LPC diets have been documented, solubility and lability of manure P have not been compared. Manure P was characterized in manure from swine fed either LPC or TC diets in 2000 and 2001. Total P was lower (20 vs. 34 g kg(-1)) and N to P ratio was higher (4.5 vs. 3.3) in LPC manure than in TC manure. Manures were sequentially extracted with deionized water, 0.5 M NaHCO3, 0.1 M NaOH, and 1.0 M HCl. Extracts were analyzed for inorganic and total P. Most P (approximately 80%) in the extracts was in the inorganic form. Concentration of P in the water-extractable fraction was lower for LPC manure (10.2 g kg(-1) in 2000 and 9.7 g kg(-1) in 2001) than for TC manure (13.6 g kg(-1) in 2000 and 17.0 g kg(-1) in 2001). Percentage of total P in each extract was in the order of: H2O (60%), HCl (22%), NaHCO3 (12%), NaOH (8%), and residue (<1%). Total P and distribution of P in extracts indicates swine are able to utilize more P contained in LPC feed but the composition of P excreted in LPC manure is similar to TC manure. Solubility, crop availability, and lability of P in LPC manure should be similar to that of TC manure.     

Occupant restraint use in Canada

Legislation regarding seat belt use in Canada is a provincial/territorial responsibility. Each of the 13 jurisdictions has enacted legislation and set the penalties regarding non-use of seat belts and appropriate child restraint systems. The federal government regulates occupant restraint systems and child restraints. In addition, Transport Canada (TC) gathers annual survey data on the use of seat belts and child restraints on Canadian roads and provides research support. National coordination toward the Canadian Road Safety Vision 2010 goal of a 40% reduction in fatalities and serious injuries related to non-belt/child restraint use and a 95% restraint usage rate is provided by the Canadian Council of Motor Transport Administrators' (CCMTA) National Occupant Restraint Program (NORP). The paper examines the history of legislation, provincial/territorial penalties, NORP, and TC involvement in promoting the use of occupant restraints.