In the mixed world of predictive biology—Contradiction or support

Statistical prediction is a tool and aim in ecology and wildlife management and conservation. A prediction may either be supported by or contradicted by observations of an unknown set of observations. A contradiction occurs if the prediction is not included within the range of the unknown observations, i.e. the prediction misses the cloud of observations completely. Mixed-effects models, frequently used for statistical assessment of clustered data, carry information needed for calculating the probability of such contradictions. Here we present a new versatile statistic, the probability of contradiction (P (Contra)), that describes how often we would anticipate a new cluster of observations contradicting our predictions. Some benefits of P (Contra) are: (1) easy to calculate and intuitive interpretation, (2) comparability between datasets, (3) inclusion of residual correlation, (4) summary of the multitude of information from mixed models into one statistics, and (5) applicable to local mixed-effect models.     

Towards improved understanding of injury prevention program sustainability

As policy makers and funders have become more concerned with allocating scarce resources effectively, attention to the sustainability of health intervention programs has increased. However, the empirical knowledge base about factors facilitating or working against sustainability remains at an early stage. The aim of this study was to contribute to improved understanding of the conditions under which community-based injury prevention programs are most likely to attain sustainability. Ten Swedish community-based injury prevention programs were analysed with respect to factors that contribute to or detract from program sustainability. All the programs are integrated within existing municipality structures. Data were collected by means of semi-structured telephone interviews with key informants.The results suggested that different factors are interrelated, with no one factor being either primary or by itself sufficient for program sustainability. Financial, human, and relational resources lay the groundwork for the long-term operation of a program. The “integrated” program model appears to facilitate sustainability, but program intensity is vulnerable to changes in the financial status of the municipality and the priority-setting by municipality political decision makers. Sustainability may be compromised if a program becomes too dependent on a few key individuals. In contrast to financial, human, and relational resources, structural resources (e.g., injury surveillance and goals) appeared to have limited influence on sustainability. The programs were sustained with little evidence of effectiveness, resulting in limited feedback about how to improve a program in order to achieve and maintain long-term effectiveness.     

Invasives, Introductions and Acidification: The Dynamics of a Stressed River Fish Community

We describe the development of the fish community in the acidified and limed river Litleåna in southern Norway, and describe how chemical restoration, compensatory introductions of exotics, and accidental invasion of exotics interact to influence the population of the naturally occurring brown trout (Salmo trutta). The river Litleåna is a tributary to the river Kvina in Vest-Agder County, southern Norway. During the years 1996–2004, annual mean pH was 4.9–5.0 and 6.1–6.4 above and below the liming facility, which was installed in 1994. Originally, brown trout was the only fish species in the river, but brook trout (Salvelinus fontinalis) have been intentionally introduced, whereas European minnow (Phoxinus phoxinus) was introduced by accident. Fish densities were recorded by means of electrofishing annually over the ten year period 1995–2004. Although close to extinction before liming was initiated, brown trout fry densities increased from 1995 to 1999, with subsequent varying densities. There has been a simultaneous major increase in the occurrence and density of European minnow since 1997. Our results show that both brown trout and European minnow increase after liming. Minnow densities are negatively affected by low pH episodes in the river. The growth rates of brown trout fry are negatively correlated to minnow densities, indicating competition between the species. Brook trout densities have decreased since liming started, and during the brown trout recovery.     

Sustainably Harvesting a Large Carnivore? Development of Eurasian Lynx Populations in Norway During 160 Years of Shifting Policy

The management of large carnivores in multiuse landscapes is always controversial, and managers need to balance a wide range of competing interests. Hunter harvest is often used to limit population size and distribution but is proving to be both controversialand technically challenging. Eurasian lynx (Lynx lynx) are currently managed as a game species in Norway. We describe an adaptive management approach where quota setting is based on an annual census and chart the population development through the period 1996–2008, as management has become significantly more sophisticated and better informed by the increased availability of scientific data. During this period the population has been through a period of high quotas and population decline caused by fragmented management authority and overoptimistic estimates of lynx reproduction, followed by a period of recovery due to quota reductions. The modern management regime is placed in the context of shifting policy during the last 160 years, during which management goals have moved from extermination stimulated by bounties, through a short phase of protection, and now to quota-regulated harvest. Much management authority has also been delegated from central to local levels. We conclude that adaptive management has the potential to keep the population within some bounded limits, although there will inevitably be fluctuation.     

Fungicide leaching from golf greens: effects of root zone composition and surfactant use

Soil water repellency in golf putting greens may induce preferential "finger flow," leading to enhanced leaching of surface applied fungicides. We examined the effects of root zone composition, treatment with a non-ionic surfactant, and the use of the fungicide iprodion or a combination of azoxystrobin and propiconazole on soil water repellency, soil water content distributions, fungicide leaching, and turf quality during 1 yr. Soil water repellency was measured using the water drop penetration time (WDPT) test and tension infiltrometers. Our study was made on a 3-yr-old experimental green seeded with creeping bentgrass (Agrostis stolonifera L.) 'Penn A-4' at Landvik in southeast Norway. The facility consists of 16 lysimeters with two different root zone materials: (i) straight sand (1% gravel, 96% sand, 3% silt and clay, 4 g kg(-1) organic matter) (SS) and (ii) straight sand mixed with garden compost to an organic matter content of 21 g kg(-1) (Green Mix [GM]). Surfactant treatment resulted in 96% lower average WDPTs at 1 cm depth, three times higher water infiltration rates at the soil surface, and reduced spatial variation in soil water contents. Fungicide leaching was close to zero for the GM lysimeters probably due to stronger sorption. Concentrations in the drainage water from SS lysimeters often exceeded surface water guideline values for all three fungicides, but surfactant treatment dramatically reduced fungicide leaching from these lysimeters. In autumn and winter, surfactant-treated plots were more infected with fungal diseases probably because of higher water content in the turfgrass thatch layer.     

Reconnaissance of Pharmaceuticals and Wastewater Indicators in Streambed Sediments of the Lower Columbia River Basin,Oregon and Washington

One by‐product of advances in modern chemistry is the accumulation of synthetic chemicals in the natural environment. These compounds include contaminants of emerging concern (CECs), some of which are endocrine disrupting compounds (EDCs) that can have detrimental reproductive effects. The role of sediments in accumulating these types of chemicals and acting as a source of exposure for aquatic organisms is not well understood. Here we present a small‐scale reconnaissance of CECs in bed sediments of the lower Columbia River and several tributaries and urban streams. Surficial bed sediment samples were collected from the Columbia River, the Willamette River, the Tualatin River, and several small urban creeks in Oregon. Thirty‐nine compounds were detected at concentrations ranging from <1 to >1,000 ng [g sediment]^?1 dry weight basis. Concentrations and frequencies of detection were higher in tributaries and small urban creeks than in the Columbia River mainstem, suggesting a higher risk of exposure to aquatic life in lower order streams. Ten known or suspected EDCs were detected during the study. At least one EDC was detected at 21 of 23 sites sampled; several EDCs were detected in sediment from most sites. This study is the first to document the occurrence of a large suite of CECs in the sediments of the Columbia River basin. A better understanding of the role of sediment in the fate and effects of emerging contaminants is needed.     

Effects of Liming on the Aquatic Fauna in a Norwegian Watershed: Why Do Crustaceans and Fish Respond Differently?

We studied the effects of liming on fish and crustaceans in a watershed which is in a region known to have one of the highest diversity of aquatic biota in Norway. This watershed, Enningdal, is shared between Norway (1/3) and Sweden (2/3) and includes 61 lakes  >  1.0 ha in Norway. Liming started on a large scale in the 1980s. Currently, a total of 26 of lakes (43%) are limed, covering 93% of the total lake area. The mean value ± S.D. of pH and the concentration of inorganic labile Al in these lakes is 6.62 ± 0.35 and 3 ± 4 μg l⁻¹, respectively. Historical data of fish communities have been obtained from surveys, while test-fishing and sampling of crustaceans were conducted in 24 lakes in recent years (2002–2004). The present study shows that crustaceans to a greater extent than fish has responded to improved water quality after more than 20 years of liming. Of a total of 120 fish populations, 42 (35%) have gone extinct. Only five of the lost fish populations (12%) have been re-established, all due to human re-introductions. Physical barriers are considered to be the main factor preventing fish from invading limed lakes. In contrast, crustaceans have been re-established in most limed lakes. This may be mainly due to their good spreading capacity. However, they might also have survived in refuges within the watershed, or as resting-eggs in the sediment.     

Intraguild predatory interactions between the jellyfish <Emphasis Type="Italic">Cyanea capillata</Emphasis> and <Emphasis Type="Italic">Aurelia aurita</Emphasis>

While qualitative observations of jellyfish intraguild predation abound in the literature, there are only few rate measurements of these interactions. We quantified predation rates among two common jellyfish in northern boreal waters, Cyanea capillata and its prey Aurelia aurita, both of which also feed on crustacean zooplankton and fish larvae. A series of incubation experiments using a wide range of prey concentrations (0.38–3.8 m⁻³) in large containers (2.6 m³) was carried out. By replenishing the prey continuously as they were captured we maintained a nearly constant prey concentrations. Ingestion rates increased linearly up to prey concentrations of 1.92 m⁻³, yielding maximum clearance rates of ∼2.37 ± 0.39 m³ predator⁻¹ h⁻¹ for C. capillata predators 16 ± 2.3 cm in diameter. Mean ingestion rate at saturated prey concentrations (1.92–3.85 m⁻³) was 4.01 ± 0.78 prey predator⁻¹ h⁻¹. Behavioral observations suggested that predators did not alter their swimming behavior during meals, and thus that feeding rates were generally handling limited rather than encounter limited. Predators captured more prey than needed, and semi-digested prey was often discarded when fresh prey was encountered.     

Reduction of net photosynthesis in oats after treatment with low concentrations of ozone

Oats (Avena sativa L. cv Titus) were exposed to low concentrations of O3 in an assimilation chamber system. Net photosynthesis (net CO2 uptake), measured before and after O3 fumigation, showed significantly different responses for leaves of different age. The oldest active leaf was the most sensitive to O3. Net photosynthesis was depressed after 2 h with 0.075 ppm (150 microg m(-3)) O3. For leaves exposed to 0.150 ppm (300 microg m(-3)) O3 for 2 h, net photosynthesis was reduced significantly for 4 h, after which recovery occurred, nearly reaching the preexposure level 19 h after the exposure. Dark respiration was initially more than doubled after exposure to 0.130 ppm (260 microg m(-3)) O3. There was no visible injury after any of the experiments. The results indicate that O3 may cause crop losses through effects on photosynthesis even in Scandinavia, where a typical O3 episode lasts 1 to 2 h, and the concentration seldom exceeds 0.150 ppm.