New Zealand chironomids as proxies for human-induced and natural environmental change: Transfer functionsfor temperature and lake production (chlorophyll a)

The analysis of chironomid taxa and environmental datasets from 46 New Zealand lakes identified temperature (February mean air temperature) and lake production (chlorophyll a (Chl a)) as the main drivers of chironomid distribution. Temperature was the strongest driver of chironomid distribution and consequently produced the most robust inference models. We present two possible temperature transfer functions from this dataset. The most robust model (weighted averaging-partial least squares (WA-PLS), n = 36) was based on a dataset with the most productive (Chl a > 10 µg l−1) lakes removed. This model produced a coefficient of determination ($$r^{2}_{\rm jack}$$) of 0.77, and a root mean squared error of prediction (RMSEPjack) of 1.31°C. The Chl a transfer function (partial least squares (PLS), n = 37) was far less reliable, with an $$r^{2}_{\rm jack}$$ of 0.49 and an RMSEPjack of 0.46 Log10µg l−1. Both of these transfer functions could be improved by a revision of the taxonomy for the New Zealand chironomid taxa, particularly the genus Chironomus. The Chironomus morphotype was common in high altitude, cool, oligotrophic lakes and lowland, warm, eutrophic lakes. This could reflect the widespread distribution of one eurythermic species, or the collective distribution of a number of different Chironomus species with more limited tolerances. The Chl a transfer function could also be improved by inputting mean Chl a values into the inference model rather than the spot measurements that were available for this study

First record of the freshwater jellyfish Craspedacusta sowerbii Lankester, 1880 in Greece suggests distinct European invasion events

This contribution presents the first record of the freshwater jellyfish Craspedacusta sowerbii Lankester, 1880 in Greece. The species was found in a water transfer canal adjacent to Lake Marathon, 45 km northeast of Athens; this is the southernmost record of this invasive alien medusa in the Balkan Peninsula and Europe. A review of recently published records shows that this species has expanded its range in Europe and the Mediterranean countries. Genetic analysis of the Greek specimen suggests that the phylogeny of C. sowerbii needs further evaluation since we are probably dealing with a distinct species within the genus Craspedacusta, and that the Greek population represents a distinct invasion event from that previously recorded in central Europe. However, due to a lack of molecular information on the native and invasive ranges, further phylogenetic studies are necessary to clarify this issue.info:eu-repo/semantics/publishedVersio