Effort and potential efficiencies for aquatic non-native species early detection

2011 ◽  
Vol 68 (12) ◽  
pp. 2064-2079 ◽  
Author(s):  
Joel C. Hoffman ◽  
John R. Kelly ◽  
Anett S. Trebitz ◽  
Greg S. Peterson ◽  
Corlis W. West

Our objective was to determine the effort required for high-probability early detection of non-native zooplankton, benthic invertebrates, and fish using Duluth–Superior Harbor — a Great Lakes port under intense non-native species introduction pressure — as a case study. Initially, we allocated samples using a spatially balanced random design. We then resampled the harbor, but allocated samples to a few targeted areas. We detected 21 non-native invertebrate and 10 non-native fish species; however, many rare zooplankton and benthic invertebrates were likely missed. The two designs did not have significantly different species accumulation curves, but the targeted area design samples had higher species richness and detected non-native species with a significantly higher probability. It was possible to reduce the effort required to detect established non-native species. In contrast, the effort required to detect an ultra-rare, newly arrived species remained large. Based on statistical estimation theory, the effort required to detect 95% or more of species present could exceed enumerating 750 zooplankton samples (~500 000 individuals, ~90 species), 150 benthic invertebrate samples (~100 000 individuals, ~250 species), and 100 fish samples (~75 000 individuals, ~40 species).

2016 ◽  
Vol 75 (s2) ◽  
Author(s):  
Norman D. Yan ◽  
John Bailey ◽  
James C. McGeer ◽  
Marina M. Manca ◽  
Wendel (Bill) Keller ◽  
...  

<p>The recovery of lakes from severe, historical acid and metal pollution requires that colonists of extirpated species arrive, survive and subsequently thrive.  We employed 40 year records from weekly to monthly crustacean zooplankton samples from Middle and Clearwater lakes near Sudbury, Canada, to identify the main mechanistic bottlenecks in this recovery process. While both lakes now have circum-neutral pH, acidity decreased more rapidly in Middle Lake because of past liming interventions, while Clearwater Lake, being larger and supporting more housing, likely receives more zooplankton colonists than Middle Lake. Community richness increased much faster in Middle Lake than in Clearwater Lake, at 1.6 <em>vs</em> 0.9 species decade<sup>-1</sup>, respectively. Richness has recovered in Middle Lake, when assessed against a target of 9-16 species collection<sup>-1</sup> determined from regional reference lakes, but it has not yet recovered in Clearwater Lake. Species accumulation curves and a metric of annual persistence show that this difference is a product not of greater rates of species introduction into Middle Lake, but rather to their greater annual persistence once introduced.  Greater annual persistence was associated with better habitat quality (<em>i.e</em>., lower acid and metal toxicity) in Middle Lake, particularly early in the record, and lower planktivore abundance, more recently. These results support a growing consensus that ecological recovery of zooplankton from acidification and metal pollution does not depend strongly on propagule introduction rates which are adequate, but rather on propagule persistence, in lake-rich, suburban landscapes such as those near Sudbury. </p>


Author(s):  
Joel Hoffman ◽  
Christy Meredith ◽  
Erik Pilgrim ◽  
Anett S Trebitz ◽  
Chelsea Hatzenbuhler ◽  
...  

When first introduced, invasive species typically evade detection; DNA barcoding coupled with high-throughput sequencing (HTS) may be more sensitive and accurate than morphology-based taxonomy, and thereby improve invasive (or rare) species detection. We quantified the relative error of species detection between morphology-based and HTS-based taxonomic identification of ichthyoplankton collections from the Port of Duluth, Minnesota, an aquatic non-native species introduction ‘hot-spot’ in the Laurentian Great Lakes. We found HTS-based taxonomy identified 28 species and morphology-based taxonomy 30 species, of which 27 were common to both. Among samples, 76% of family-level taxonomic assignments agreed; however, only 42% of species assignments agreed. Most errors were attributed to morphology-based taxonomy, whereas HTS-based taxonomy error was low. For this study system, for most non-native fishes, the detection probability by randomized survey for larvae was similar to that by a survey that is optimized for non-native species early detection of juveniles and adults. We conclude that classifying taxonomic errors by comparing HTS results against morphology-based taxonomy is an important step toward incorporating HTS-based taxonomy into biodiversity surveys.


2019 ◽  
Vol 3 (1) ◽  
pp. 1-9
Author(s):  
Robert M. Anderson ◽  
Amy M. Lambert

The island marble butterfly (Euchloe ausonides insulanus), thought to be extinct throughout the 20th century until re-discovered on a single remote island in Puget Sound in 1998, has become the focus of a concerted protection effort to prevent its extinction. However, efforts to “restore” island marble habitat conflict with efforts to “restore” the prairie ecosystem where it lives, because of the butterfly’s use of a non-native “weedy” host plant. Through a case study of the island marble project, we examine the practice of ecological restoration as the enactment of particular norms that define which species are understood to belong in the place being restored. We contextualize this case study within ongoing debates over the value of “native” species, indicative of deep-seated uncertainties and anxieties about the role of human intervention to alter or manage landscapes and ecosystems, in the time commonly described as the “Anthropocene.” We interpret the question of “what plants and animals belong in a particular place?” as not a question of scientific truth, but a value-laden construct of environmental management in practice, and we argue for deeper reflexivity on the part of environmental scientists and managers about the social values that inform ecological restoration.


Insects ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 462
Author(s):  
Enrico Ruzzier ◽  
Andrea Galli ◽  
Luciano Bani

Detecting and monitoring exotic and invasive Coleoptera is a complex activity to implement, and citizen science projects can provide significant contributions to such plans. Bottle traps are successfully used in wildlife surveys and can also be adapted for monitoring alien species; however, a sustainable, large scale trapping plan must take into account the collateral catches of native species and thus minimize its impact on local fauna. In the present paper, we tested the use of bottles baited with standard food products that can be purchased in every supermarket and immediately used (apple cider vinegar, red wine, and 80% ethyl alcohol) in capturing exotic and invasive beetles in the area surrounding Malpensa Airport (Italy). In particular, we reduced the exposition type of the traps in each sampling round to three days in order to minimize native species collecting. We found a significant effect of the environmental covariates (trap placement, temperature, humidity, and forest type) in affecting the efficiency in catching target beetles. Nearly all invasive Nitidulidae and Scarabaeidae known to be present in the area were captured in the traps, with apple cider vinegar usually being the most effective attractant, especially for the invasive Popillia japonica.


Author(s):  
Alexenko T. ◽  
Shevchenko I.

For the first time, systematic studies of the structural and functional properties of macrozoobenthos of Lake Zakіtne were conducted. A taxonomic list of macroinvertebrates with their zoogeographical characteristics is given. According to the results of research, 3 types of benthic invertebrate groups were identified and described, of which Oligochaeta-Chironomidae type were the most widespread. Only two species were common to all found groups: Einfeldia longipes and Glyptotendipes glaucus of Chiromonidae family. The calculated biotic indices indicate a fairly high degree of use of existing biotopes by macroinvertebrates, as well as the predominance of species characteristic of the α-β-mesosaprobic zone.The variety of ways and mechanisms of feeding of benthic invertebrates is shown. Collectors, scraper collectors, sedimentators, filter feeders, shredders, predators, as well as macroinvertebrates with an indeterminate feeding type were identified in the trophic structure by the predominant type of feeding. The number of species, as well as their representation in trophic groups, varied in different years, yet 54-73% of them were nonpredatory forms.According to the obtained data, the components of the energy balance for macroinvertebrates were calculated. The active participation in the production of organic matter of Chironomidae larvae (from 29 to 62% of the total production of nonpredatory and predatory forms) is indicated. In some years, Ephemeroptera and Mollusca were actively involved in production. The largest flow of energy passed through insects (Ephemeroptera, Trichoptera) and leeches. Attention is drawn to the role of predators, which can significantly reduce the production of groups. High production and food ration of predators do not allow to ignore them when calculating the production of the entire zoocenosis.In average, during the vegetation season, the total production of nonpredatory and predatory benthic invertebrates was 77,89 kJ/m2, and the predator's food ration was 61,80 kJ/m2.Key words:macroinvertebrates, taxonomic structure, trophic structure, community, production, food ration, energy balance. Вперше проведено систематичні дослідження структурно-функціональних властивостей макрозообентосу озера Закітне. Наведено таксономічний список макробезхребетних з їх зоогеографічною характеристикою. За результатами досліджень виявлено та описано 3 типи угруповань донних безхребетних, з яких найбільшепоширення отримали олігохетно-хірономідні комплекси. Лише двавиди виявилися спільними для всіх знайдених угруповань: Einfeldia longipes і Glyptotendipes glaucus (родина Chironomidae).Розраховані біотичні індекси свідчать про достатньо високий ступень використання існуючих біотопів макробезхребетними, а також про переважання видів, що характерні для α-β-мезосапробної зони.Показанарізноманітність способів і механізмів живлення донних безхребетних. У трофічній структурі угруповань за переважаючим способомживлення було виділено збирачів, збирачів-шкребачів, седиментаторів, фільтраторів, подрібнювачів, хижаків, а також макробезхребетних із невизначеним типом живлення. Кількість видів, а також їх представленість утрофічних групах в різні роки була неоднакова, але на 54–73% це були мирні форми.За отриманими даними було розраховано складові енергетичного балансу за макробезхребетними. Вказано на активну участь упродукуванні органічної речовини личинок родини Chironomidae, яким належить від 29 до 62% від сумарної продукції мирних і хижих форм. В окремі роки в продукування активно включалися одноденки та молюски. Найбільший потік енергії проходив через комах (Ephemeroptera, Trichoptera) і п’явок. Звернуто увагу на роль хижаків, які можуть суттєво знижувати продукцію угруповань. Високапродукція і раціон хижаків не дозволяють нехтувати ними при розрахунку продукції всього ценозу.Підраховано, що в середньому за вегетаційний період сумарна продукція мирних і хижих донних безхребетних дорівнювала 77,89 кДж/м2, а раціон хижаків складав 61,80 кДж/м2.Ключові слова: макробезхребетні, таксономічна структура, трофічна структура, угруповання, продукція, раціон, енергетичний баланс.


2017 ◽  
Vol 1 (2) ◽  
Author(s):  
Khalid BENAMOR ◽  
Wissam ABAI ◽  
Lamdjed BOUZIDI

Despite positive results quantitative variables have had in predicting the future of companies alongside their predictive ability of companies’ financial position, the remarkable increase in bankruptcies of companies without any early detection and the consequent damage to the economy in general and to companies in particular, highlighted the need to make up for quantitative variables luck in terms of predictive significance in the process of predicting companies’ financial position, which made studies interested in this field react by emphasizing variables of descriptive nature. The aim of this study is to appreciate aspects of variables of descriptive nature and the extent of their contribution to the prediction of financial position of Algerian companies, using as a case study descriptive variables data of the risk scoring technique with application on a sample data of 15 companies operating in Algiers. This study concluded that descriptive variables contribute significantly to the prediction of the financial position of Algerian companies.


2007 ◽  
Vol 13 ◽  
pp. 69-73
Author(s):  
Sánchez Márquez ◽  
G.F. Bills ◽  
I. Zabalgogeazcoa

Morphological and molecular methods were used to identify the endophytic mycobiota of the grass Dactylis glomerata. Fungal endophytes belonging to 109 different species were isolated from asymptomatic plants sampled in different ecosystems in Spain. Species accumulation curves showed that most species commonly infecting this grass have been identified, but the number of singleton species occasionally infecting the plants is likely to increase with more sampling effort. A large endophytic assemblage consisting of fungi with diverse ecological roles, and potentially unknown species was found in a small number of plants. Keywords: endophytes, Dactylis glomerata, diversity, abundance


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