Linking consumer physiological status to food-web structure and prey food value in the Baltic Sea.

Declining physiological status in marine top consumers has been observed worldwide. We investigate changes in the physiological status and population/community traits of six consumer species/groups in the Baltic Sea (1993-2014), spanning four trophic levels and using metrics currently operational or proposed as indicators of food-web status. We ask whether the physiological status of consumers can be explained by food-web structure and prey food value. This was tested using partial least square regressions with status metrics for gray seal, cod, herring, sprat and the benthic predatory isopod Saduria as response variables, and abundance and food value of their prey, abundance of competitors and predators as predictors. We find evidence that the physiological status of cod, herring and sprat is influenced by competition, predation, and prey availability; herring and sprat status also by prey size. Our study highlights the need for management approaches that account for species interactions across multiple trophic levels.

Classifying grey seal behaviour in relation to environmental variability and commercial fishing activity - a multivariate hidden Markov model.

Classifying movement behaviour of marine predators in relation to anthropogenic activity and environmental conditions is important to guide marine conservation. We studied the relationship between grey seal (Halichoerus grypus) behaviour and environmental variability in the southwestern Baltic Sea where seal-fishery conflicts are increasing. We used multiple environmental covariates and proximity to active fishing nets within a multivariate hidden Markov model (HMM) to quantify changes in movement behaviour of grey seals while at sea. Dive depth, dive duration, surface duration, horizontal displacement, and turning angle were used to identify travelling, resting and foraging states. The likelihood of seals foraging increased in deeper, colder, more saline waters, which are sites with increased primary productivity and possibly prey densities. Proximity to active fishing net also had a pronounced effect on state occupancy. The probability of seals foraging was highest <5 km from active fishing nets (51%) and decreased as distance to nets increased. However, seals used sites <5 km from active fishing nets only 3% of their time at sea highlighting an important temporal dimension in seal-fishery interactions. By coupling high-resolution oceanographic, fisheries, and grey seal movement data, our study provides a scientific basis for designing management strategies that satisfy ecological and socioeconomic demands on marine ecosystems.

Complementary methods assessing short and long-term prey of a marine top predator ‒ Application to the grey seal-fishery conflict in the Baltic Sea.

The growing grey seal (Halichoerus grypus) population in the Baltic Sea has created conflicts with local fisheries, comparable to similar emerging problems worldwide. Adequate information on the foraging habits is a requirement for responsible management of the seal population. We investigated the applicability of available dietary assessment methods by comparing morphological analysis and DNA metabarcoding of gut contents (short-term diet; n = 129/125 seals, respectively), and tissue chemical markers i.e. fatty acid (FA) profiles of blubber and stable isotopes (SIs) of liver and muscle (mid- or long-term diet; n = 108 seals for the FA and SI markers). The methods provided complementary information. Short-term methods indicated prey species and revealed dietary differences between age groups and areas but for limited time period. In the central Baltic, herring was the main prey, while in the Gulf of Finland percid and cyprinid species together comprised the largest part of the diet. Perch was also an important prey in the western Baltic Proper. The DNA analysis provided firm identification of many prey species, which were neglected or identified only at species group level by morphological analysis. Liver SIs distinguished spatial foraging patterns and identified potentially migrated individuals, whereas blubber FAs distinguished individuals frequently utilizing certain types of prey. Tissue chemical markers of adult males suggested specialized feeding to certain areas and prey, which suggest that these individuals are especially prone to cause economic losses for fisheries. We recommend combined analyses of gut contents and tissue chemical markers as dietary monitoring methodology of aquatic top predators to support an optimal ecosystem-based management.

Hypoxic areas, density-dependence and food limitation drive the body condition of a heavily exploited marine fish predator.

Investigating the factors regulating fish condition is crucial in ecology and the management of exploited fish populations. The body condition of cod (Gadus morhua) in the Baltic Sea has dramatically decreased during the past two decades, with large implications for the fishery relying on this resource. Here, we statistically investigated the potential drivers of the Baltic cod condition during the past 40 years using newly compiled fishery-independent biological data and hydrological observations. We evidenced a combination of different factors operating before and after the ecological regime shift that occurred in the Baltic Sea in the early 1990s. The changes in cod condition related to feeding opportunities, driven either by density-dependence or food limitation, along the whole period investigated and to the fivefold increase in the extent of hypoxic areas in the most recent 20 years. Hypoxic areas can act on cod condition through different mechanisms related directly to species physiology, or indirectly to behaviour and trophic interactions. Our analyses found statistical evidence for an effect of the hypoxia-induced habitat compression on cod condition possibly operating via crowding and density-dependent processes. These results furnish novel insights into the population dynamics of Baltic Sea cod that can aid the management of this currently threatened population.

Si- and C-Functional Organosilicon Building Blocks for Synthesis Based on 4-Silacyclohexan-1-ones Containing the Silicon Protecting Groups MOP (4-Methoxyphenyl), DMOP (2,6-Dimethoxyphenyl), or TMOP (2,4,6-Trimethoxyphenyl).

4-Silacyclohexan-1-ones 1a-1c, 4-silacyclohexan-1-one oximes 2a-2c, 1,4-azasilepan-7-ones 3a-3c, 1,4-azasilepanes 4a-4c, and 2-bromo-4-silacyclohexan-1-ones 5a and 5b were prepared in multistep syntheses, starting from trimethoxypropylsilane. All of these compounds represent C-functional (R2C═O, R2C═N-OH, R-NH(C═O)-R, R2NH, or R3C-Br) silicon-containing heterocycles that contain Si-MOP, Si-DMOP, or Si-TMOP moieties (MOP = 4-methoxyphenyl; DMOP = 2,6-dimethoxyphenyl; TMOP = 2,4,6-trimethoxyphenyl), which can be cleaved under mild conditions by protodesilylation. As a proof of principle, compounds 3a-3c were transformed quantitatively and selectively into the chlorosilane 6 (treatment with hydrogen chloride in dichloromethane). Thus, the C- and Si-functional compounds 1a-1c, 2a-2c, 3a-3c, 4a-4c, 5a, and 5b represent versatile building blocks for synthesis.

Discovery of 9-(1-phenoxyethyl)-2-morpholino-4-oxo-pyrido[1,2-a]pyrimidine-7-carboxamides as oral PI3Kß inhibitors, useful as antiplatelet agents.

Optimization of AZD6482 (2), the first antiplatelet PI3Kß inhibitor evaluated in man, focused on improving the pharmacokinetic profile to a level compatible with once daily oral dosing as well as achieving adequate selectivity towards PI3Kα to minimize the risk for insulin resistance. Structure-based design and optimization of DMPK properties resulted in (R)-16, a novel, orally bioavailable PI3Kß inhibitor with potent in vivo anti-thrombotic effect with excellent separation to bleeding risk and insulin resistance.

Discovery of cyclopentane- and cyclohexane-trans-1,3-diamines as potent melanin-concentrating hormone receptor 1 antagonists.

We herein report the optimization of cyclopentane- and cyclohexane-1,3-diamine derivatives as novel and potent MCH-R1 antagonists. Structural modifications of the 2-amino-quinoline and thiophene moieties found in the initial lead compound served to improve its metabolic stability profile and MCH-R1 affinity, and revealed unprecedented SAR when compared to other 2-amino-quinoline-containing MCH-R1 antagonists.

Photo-identification, site fidelity, and movement of female gray seals (Halichoerus grypus) between haul-outs in the Baltic Sea.

The growing gray seal population in the Baltic Sea has led to increased conflicts with fisheries. Despite limited data on gray seal ecology, management measures, such as culling, have been implemented recently. We studied movements and site fidelity of Baltic gray seals using mark-recapture analysis based on photographic identification of individuals (photo-id). Seals were photographed at the major summer haul-out sites. Profile photographs of the head and neck were matched using purpose-written software to generate a database of capture histories from 1995-2000. The haul-outs were grouped into seven areas. Darroch's method (20) for a two-sample capture-recapture census was adapted to estimate rates of movement between the areas. The majority of seals were estimated to remain within the same area, suggesting that Baltic gray seals exhibit a high degree of site fidelity during the summer, and that fidelity to a site lasts for more than one season.