Modeling Problems in Conservation Genetics Using Captive Drosophila Populations: Consequences of Equalization of Family Sizes

Equalization of family sizes is recommended for use in captive breeding programs, as it is predicted to double effective population sizes, reduce inbreeding, and slow the loss of genetic variation. The effects of maintaining small captive populations with equalization of family sizes versus random choice of parents on levels of inbreeding genetic variation, reproductive fitness, and effective population sizes ( N _e) were evaluated in 10 lines of each treatment maintained with four pairs of parents per generation. The mean inbreeding coefficient ( F ) increased at a significantly slower rate with equalization than with random choice (means of 0.35 and 0.44 at generation 10). Average heterozygosities at generation 10, based on six polymorphic enzyme loci, were significantly higher with equalization (0.149) than with random choice (0.085), compared to the generation 0 level of 0.188. The competitive index measure of reproductive fitness at generation 11 was more than twice as high with equalization as with random choice, both being much lower than in the outbred base population. There was considerable variation among replicate lines within treatments in all the above measures and considerable overlap between lines from the two treatments. Estimates of N _e for equalization were greater than those for random choice, whether estimated from changes in average heterozygosities or from changes in F. Equalization of family sizes can be unequivocally recommended for use in the genetic management of captive populations.     

Ecological implications of fecal pellets produced by the Antarctic krill Euphausia superba in the Antarctic Ocean

Organic analyses and electron microscopic observations on fecal pellets produced by the Antarctic krill Euphausia superba Dana showed that krill fed on choanoflagellates, the abundant heterotrophic flagellate in the Antarctic Ocean. Two new pathways of organic materials in the Antarctic ecosystem are proposed: (1) a new food chain including non-living particulate and dissolved organics, and bacteria-choanoflagellate-krill-vertebrate, which coexists with the traditional diatom-krill-vertebrate food chain; (2) non-phytoplanktonic organic materials in surface waters are transferred into choanoflagellates and are transported to deep water as fecal pellets which are still useful as nutrition for other organisms there.     

Citizen science on speed? Realising the triple objective of scientific rigour,policy influence and deep citizen engagement in a large-scale citizen science project on ambient air quality in Antwerp

Citizen science projects are increasingly recognised as catalyst for triggering behaviour change and building social capital around environmental issues. However, overview studies observe recurrent challenges in many citizen science projects in terms of combining high levels of data quality with deep citizen engagement and policy influence. This paper reports on the findings of the CurieuzeNeuzen project (www.CurieuzeNeuzen.eu), a large-scale citizen science project on air quality in Antwerp, delivering results in the three areas described above. Through CurieuzeNeuzen, 2,000 citizens studied the air quality levels in and around Antwerp in 2016 and were intensively deliberating on possible causes and solutions. Surveys were conducted at the start and towards the end of the project, with participants stating that their participation resulted in changed views and behaviour towards air pollution, mobility solutions, and city planning. The findings were picked-up academically and contributed to policy debates on air quality at city and regional level.