Macroinvertebrate species occupancy frequency distribution patterns in eutrophic lakes

Metacommunity models describe species occupancy frequency distribution (hereinafter 'SOFD'). Our goal is to present how the differences in eight macroinvertebrate orders dispersal ability affect SOFD patterns. A total of 293 species from eight macroinvertebrate orders were observed in 14 eutrophic lakes in southern Finland. Species occupancy ranged from 1 to 14. About 30% (89 out of 293) of the species were found in only one lake, yielding a surprisingly high number of rare species. So, there were few widely distributed common species and numerous rare species with a restricted distribution. Combined data from eight macroinvertebrate orders supported the bimodal truncated SOFD pattern. Similarly, the low dispersal ability orders, watermites and mayflies, fitted the bimodal truncated SOFD pattern. However, bimodal symmetric SOFD pattern also fitted relatively well to the dragonflies and damselflies with high dispersal ability. It seems that differences in dispersal ability among different macroinvertebrate orders may partly explain observed differences. Moreover, our results supported slightly more a niche-based model rather than a metapopulation dynamics model in eutrophic lakes littoral macroinvertebrate metacommunities. Our results highlight that the dispersal ability is important trait for species conservation in patchily distributed habitat.</p

Raspodjela lindana u vodi, sedimentu i ribama iz rijeke Warri (Delta Nigera, Nigerija)

This paper is the first attempt to quantify the levels and the distribution pattern of lindane in the surface water, sediment and fish (Chrysichthys furcatus and Tilapia zilli). The samples were collected from three stations (Ovwian, Ekakpamre, and Ovu) of the Warri River in the western Niger Delta of Nigeria in 2006: during the dry (January-April) and wet seasons (May-August). The analysis included a total of 96 samples made up of 24 samples each for water, sediment, and fish. The pesticide levels were analysed using high performance liquid chromatography to elucidate its distribution in various environmental compartments. Residue levels in the matrices ranged from below the detection limit (BDL) to 1.37µg L-1 in water, BDL to 12.66 µg g-1 dry weight (dw) in sediment, BDL to 16.67 µg g-1dw in Chrysichthys furcatus, and BDL to 0.15 µg g-1dw in Tilapia zilli .The observed values were above the ecological benchmarks (0.01 µg L-1) recommended by the Nigerian Environmental Protection Agency and European Union. They were also relatively higher than in previous studies on the Nigerian environment, which calls for regular monitoring of the Niger Delta water bodies.Istražene su pojava i raspodjela lindana u površinskoj vodi, sedimentu i dvije vrste riba Chrysichthys furcatus i Tilapia zilli iz rijeke Warri u zapadnom dijelu delte Nigera (Nigerija). Uzorci su skupljeni 2006. godine na tri postaje (Ovwian, Ekakpamre i Ovu) tijekom sušne (siječanj - travanj) i vlažne sezone (svibanj - kolovoz). Analizirano je ukupno 96 uzoraka: po 24 uzorka vode, sedimenta i riba. Razine pesticida odre|ene su primjenom tekućinske kromatografije visoke djelotvornosti (HPLC) te je utvr|ivana njihova raspodjela u različitim dijelovima okoliša. Koncentracije rezidua u uzorcima vode bile su u rasponu: ispod granice detekcije (BDL) do 1,37 µg L-1, u sedimentu: BDL do 12,66 µg g-1 suhe tvari, u ribama Chrysichthys furcatus: BDL do 16,67 µg g-1 suhe tvari te Tilapia zilli: BDL do 0,15 µg g-1 suhe tvari. Određene vrijednosti bile su ispod graničnih vrijednosti (0,01 µg L-1) propisanih od Nigerijske uprave za zaštitu okoliša i Europske unije. Kako su dobivene vrijednosti bile relativno više u odnosu na podatke iz ranijih istraživanja okoliša u Nigeriji, istaknuta je potreba trajnog monitoringa vodotoka u delti Nigera

A molecular-based identification resource for the arthropods of Finland

Publisher Copyright: © 2021 The Authors. Molecular Ecology Resources published by John Wiley & Sons Ltd.To associate specimens identified by molecular characters to other biological knowledge, we need reference sequences annotated by Linnaean taxonomy. In this study, we (1) report the creation of a comprehensive reference library of DNA barcodes for the arthropods of an entire country (Finland), (2) publish this library, and (3) deliver a new identification tool for insects and spiders, as based on this resource. The reference library contains mtDNA COI barcodes for 11,275 (43%) of 26,437 arthropod species known from Finland, including 10,811 (45%) of 23,956 insect species. To quantify the improvement in identification accuracy enabled by the current reference library, we ran 1000 Finnish insect and spider species through the Barcode of Life Data system (BOLD) identification engine. Of these, 91% were correctly assigned to a unique species when compared to the new reference library alone, 85% were correctly identified when compared to BOLD with the new material included, and 75% with the new material excluded. To capitalize on this resource, we used the new reference material to train a probabilistic taxonomic assignment tool, FinPROTAX, scoring high success. For the full-length barcode region, the accuracy of taxonomic assignments at the level of classes, orders, families, subfamilies, tribes, genera, and species reached 99.9%, 99.9%, 99.8%, 99.7%, 99.4%, 96.8%, and 88.5%, respectively. The FinBOL arthropod reference library and FinPROTAX are available through the Finnish Biodiversity Information Facility (www.laji.fi) at https://laji.fi/en/theme/protax. Overall, the FinBOL investment represents a massive capacity-transfer from the taxonomic community of Finland to all sectors of society.Peer reviewe

A molecular-based identification resource for the arthropods of Finland

To associate specimens identified by molecular characters to other biological knowledge, we need reference sequences annotated by Linnaean taxonomy. In this study, we (1) report the creation of a comprehensive reference library of DNA barcodes for the arthropods of an entire country (Finland), (2) publish this library, and (3) deliver a new identification tool for insects and spiders, as based on this resource. The reference library contains mtDNA COI barcodes for 11,275 (43%) of 26,437 arthropod species known from Finland, including 10,811 (45%) of 23,956 insect species. To quantify the improvement in identification accuracy enabled by the current reference library, we ran 1000 Finnish insect and spider species through the Barcode of Life Data system (BOLD) identification engine. Of these, 91% were correctly assigned to a unique species when compared to the new reference library alone, 85% were correctly identified when compared to BOLD with the new material included, and 75% with the new material excluded. To capitalize on this resource, we used the new reference material to train a probabilistic taxonomic assignment tool, FinPROTAX, scoring high success. For the full-length barcode region, the accuracy of taxonomic assignments at the level of classes, orders, families, subfamilies, tribes, genera, and species reached 99.9%, 99.9%, 99.8%, 99.7%, 99.4%, 96.8%, and 88.5%, respectively. The FinBOL arthropod reference library and FinPROTAX are available through the Finnish Biodiversity Information Facility (www.laji.fi) at https://laji.fi/en/theme/protax. Overall, the FinBOL investment represents a massive capacity-transfer from the taxonomic community of Finland to all sectors of society.</p

Chemical reactivity and long-range transport potential of polycyclic aromatic hydrocarbons – a review

Polycyclic aromatic hydrocarbons (PAHs) are of considerable concern due to their well-recognised toxicity and especially due to the carcinogenic hazard which they present. PAHs are semi-volatile and therefore partition between vapour and condensed phases in the atmosphere and both the vapour and particulate forms undergo chemical reactions. This article briefly reviews the current understanding of vapour-particle partitioning of PAHs and the PAH deposition processes, and in greater detail, their chemical reactions. PAHs are reactive towards a number of atmospheric oxidants, most notably the hydroxyl radical, ozone, the nitrate radical (NO3) and nitrogen dioxide. Rate coefficient data are reviewed for reactions of lower molecular weight PAH vapour with these species as well as for heterogeneous reactions of higher molecular weight compounds. Whereas the data for reactions of the 2-3-ring PAH vapour are quite extensive and generally consistent, such data are mostly lacking for the 4-ring PAHs and the heterogeneous rate data (5 and more rings), which are dependent on the substrate type and reaction conditions, are less comprehensive. The atmospheric reactions of PAH lead to the formation of oxy and nitro derivatives, reviewed here, too. Finally, the capacity of PAHs for long range transport and the results of numerical model studies are described. Research needs are identified