Report of the expert meeting on food safety for seaweed – Current status and future perspectives

The world production of marine macroalgae, or seaweed, has more than tripled since the turn of the millennium, increasing from 10.6 million tonnes in 2000 to 32.4 million tonnes in 2018. Increased cultivation and utilization of seaweed are expected to be important pillars of sustainable food security and a robust aquatic economy in the coming years. It is important, therefore, to consider the food safety implications of (increased) seaweed use for food. Many factors can affect the presence of hazards in seaweed, including: the type of seaweed, its physiology, the season in which it is produced, production waters, harvesting methods and processing. Several hazards such as heavy metals and marine biotoxins have been reported to be (potentially) associated with seaweed. However, legislation and guidance documents on the production and utilization of seaweed are generally still lacking. FAO and the World Health Organization (WHO) have therefore developed this report to identify food safety hazards (microbiological, chemical and physical) linked to the consumption of seaweed and aquatic plants. The present analysis could therefore provide a basis for undertaking further work in this area. Moreover, both FAO and WHO believe that there would be a value in developing relevant Codex guidance on this subject.publishedVersio

Report of the expert meeting on food safety for seaweed – Current status and future perspectives

The world production of marine macroalgae, or seaweed, has more than tripled since the turn of the millennium, increasing from 10.6 million tonnes in 2000 to 32.4 million tonnes in 2018. Increased cultivation and utilization of seaweed are expected to be important pillars of sustainable food security and a robust aquatic economy in the coming years. It is important, therefore, to consider the food safety implications of (increased) seaweed use for food. Many factors can affect the presence of hazards in seaweed, including: the type of seaweed, its physiology, the season in which it is produced, production waters, harvesting methods and processing. Several hazards such as heavy metals and marine biotoxins have been reported to be (potentially) associated with seaweed. However, legislation and guidance documents on the production and utilization of seaweed are generally still lacking. FAO and the World Health Organization (WHO) have therefore developed this report to identify food safety hazards (microbiological, chemical and physical) linked to the consumption of seaweed and aquatic plants. The present analysis could therefore provide a basis for undertaking further work in this area. Moreover, both FAO and WHO believe that there would be a value in developing relevant Codex guidance on this subject

Outcomes of Brood Parasite–Host Interactions Mediated by Egg Matching: Common Cuckoos Cuculus canorus versus Fringilla Finches

Antagonistic species often interact via matching of phenotypes, and interactions between brood parasitic common cuckoos (Cuculus canorus) and their hosts constitute classic examples. The outcome of a parasitic event is often determined by the match between host and cuckoo eggs, giving rise to potentially strong associations between fitness and egg phenotype. Yet, empirical efforts aiming to document and understand the resulting evolutionary outcomes are in short supply.We used avian color space models to analyze patterns of egg color variation within and between the cuckoo and two closely related hosts, the nomadic brambling (Fringilla montifringilla) and the site fidelic chaffinch (F. coelebs). We found that there is pronounced opportunity for disruptive selection on brambling egg coloration. The corresponding cuckoo host race has evolved egg colors that maximize fitness in both sympatric and allopatric brambling populations. By contrast, the chaffinch has a more bimodal egg color distribution consistent with the evolutionary direction predicted for the brambling. Whereas the brambling and its cuckoo host race show little geographical variation in their egg color distributions, the chaffinch's distribution becomes increasingly dissimilar to the brambling's distribution towards the core area of the brambling cuckoo host race.High rates of brambling gene flow is likely to cool down coevolutionary hot spots by cancelling out the selection imposed by a patchily distributed cuckoo host race, thereby promoting a matching equilibrium. By contrast, the site fidelic chaffinch is more likely to respond to selection from adapting cuckoos, resulting in a markedly more bimodal egg color distribution. The geographic variation in the chaffinch's egg color distribution could reflect a historical gradient in parasitism pressure. Finally, marked cuckoo egg polymorphisms are unlikely to evolve in these systems unless the hosts evolve even more exquisite egg recognition capabilities than currently possessed

Sex-specific effects of the local social environment on juvenile post-fledging dispersal in great tits

An individual’s decision to disperse from the natal habitat can affect its future fitness prospects. Especially in species with sex-biased dispersal, we expect the cost–benefit balance for dispersal to vary according to the social environment (e.g., local sex ratio and density). However, little is known about the social factors affecting dispersal decisions and about the temporal and spatial patterns of the dispersal process. In our study, we investigated experimentally the effects of the social environment on post-fledging dispersal of juvenile great tits by simultaneously manipulating the density and sex ratio of fledglings within forest plots. We expected young females in the post-fledging period mainly to compete for resources related to food and, as they are subordinate to males, we predicted higher female dispersal from male-biased plots. Juvenile males compete for vacant territories already in late summer and autumn; thus, we predicted increased male dispersal from high density and male-biased plots. We found that juvenile females had a higher probability to leave male-biased plots and had dispersed further from male-biased plots in the later post-fledging phase when juvenile males start to become territorial and more aggressive. Juvenile males were least likely to leave male-biased plots and had smallest dispersal distances from female-biased plots early after fledging. The results suggest that the social environment differentially affected the costs and benefits of philopatry for male and female juveniles. The local sex ratio of individuals is thus an important social trait to be considered for understanding sex-specific dispersal processes

Flock composition, agonistic behaviour and body condition of wintering Bullfinches Pyrrhula pyrrhula

During October-April of 1989-2003 I made observations on size and sexual composition of Bullfinch Pyrrhula pyrrhula flocks (ringed and unringed birds), recorded interactions between members and estimated the body condition of birds observed in a mixed forest in central Norway. The flock size did not change with ambient temperature and ranged from two to seven with a mean of 4.1 in October-January and 2.3 in February-April. During March-April, 28 of 29 flocks consisted of one male and one female. Seventeen flocks fol- lowed over 6-17 days in November-December did not change in size or sexual composi- tion. The adult sex ratio was equal. In flocks consisting of two, four or six birds, 88-97% consisted of equal numbers of males and females. Few birds stayed in the area throughout the winter. One colour-ringed mated pair breeding in the area was observed during two winters. Two ringed females, each observed in the company of an unringed male, were re- peatedly observed during two subsequent winters. Females were socially dominant over males. Adult and juvenile females had a better body condition (body mass to wing length ratio) than juvenile males, but not better than that of adult males. The body condition of the birds increased with decreasing ambient temperature