scholarly journals Creating genetic reference datasets: Indirect sampling of target species using terrestrial leeches as sample “collectors”

2021 ◽  
Author(s):  
Andreas Wilting ◽  
Thanh V. Nguyen ◽  
Jan Axtner ◽  
An Nguyen ◽  
Anke Schmidt ◽  
...  
Keyword(s):  
Target Species ◽  
Indirect Sampling

Challenges of Aircraft and Drone Spray Applications

2020 ◽  
Vol 31 (2) ◽  
pp. 83-88 ◽  
Author(s):  
Fernando K. Carvalho ◽  
Rodolfo G. Chechetto ◽  
Alisson A. B. Mota ◽  
Ulisses R. Antuniassi
Keyword(s):  
Smallholder Farmers ◽  
Crop Protection ◽  
Crop Canopy ◽  
Target Species ◽  
Buffer Zones ◽  
Correct Dose ◽  
Knapsack Sprayer ◽  
Water Courses ◽  
Low Toxicity ◽  
Heavy Loads

Crop protection on major crops is now required to follow the principles of integrated pest management so the timing and accuracy of any application of a pesticide or biopesticide has to be more precise to minimize adverse effects on non-target species. The development of UAVs (unmanned aerial vehicles) provides a means of providing a more targeted application of the correct dose, especially by using formulations that are more persistent, thus minimizing loss of spray in areas subject to rain. Avoiding use of too high a dosage allows greater survival of natural enemies and reduces the selection pressure for pests becoming resistant to specific modes of action. The downward flow of air from a UAV should also provide better distribution and impaction of droplets within a crop canopy, reduce soil impaction caused by taking heavy loads of spray applied with 200 l ha–1 of water, and allow treatments when fields are too wet to access with ground equipment. In Asia, many smallholder farmers are using a drone in preference to using a knapsack sprayer. According to Matthews, it has been shown that ULV spraying can be effective, but it needs a narrow droplet spectrum with the droplets remaining stable and not shrinking to become too small. Formulation research can reduce the volatility of the spray, hence the success of oil-based sprays. However, instead of petroleum-based oils, there is a chance to develop vegetable oil carriers with micro-sized particle suspensions to deliver low toxicity pesticides in droplets that can be deposited within the crop and not drift beyond the crop boundary. Oil deposits will be less prone to loss after rain so less should be lost in neighbouring ditches and water courses, especially as rainfall patterns are forecast to change. More studies are needed to evaluate the swath for deposition, buffer zones, formulation, nozzle selection, to guide future specific legislation for UAV applications.

scholarly journals Environmental DNA preserved in marine sediment for detecting jellyfish blooms after a tsunami

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Mizuki Ogata ◽  
Reiji Masuda ◽  
Hiroya Harino ◽  
Masayuki K. Sakata ◽  
Makoto Hatakeyama ◽  
...  
Keyword(s):  
Marine Sediment ◽  
Oil Spills ◽  
Sediment Cores ◽  
Environmental Dna ◽  
Target Species ◽  
Tank Experiment ◽  
Polycyclic Aromatic ◽  
Flow Through ◽  
High Concentrations ◽  
One Year

AbstractEnvironmental DNA (eDNA) can be a powerful tool for detecting the distribution and abundance of target species. This study aimed to test the longevity of eDNA in marine sediment through a tank experiment and to use this information to reconstruct past faunal occurrence. In the tank experiment, juvenile jack mackerel (Trachurus japonicus) were kept in flow-through tanks with marine sediment for two weeks. Water and sediment samples from the tanks were collected after the removal of fish. In the field trial, sediment cores were collected in Moune Bay, northeast Japan, where unusual blooms of jellyfish (Aurelia sp.) occurred after a tsunami. The samples were analyzed by layers to detect the eDNA of jellyfish. The tank experiment revealed that after fish were removed, eDNA was not present in the water the next day, or subsequently, whereas eDNA was detectable in the sediment for 12 months. In the sediment core samples, jellyfish eDNA was detected at high concentrations above the layer with the highest content of polycyclic aromatic hydrocarbons, reflecting tsunami-induced oil spills. Thus, marine sediment eDNA preserves a record of target species for at least one year and can be used to reconstruct past faunal occurrence.

scholarly journals Pots as alternative and sustainable fishing gears in the Mediterranean Sea: an overview

2021 ◽  
Author(s):  
Andrea Petetta ◽  
Massimo Virgili ◽  
Stefano Guicciardi ◽  
Alessandro Lucchetti
Keyword(s):  
Mediterranean Sea ◽  
Early Stage ◽  
Spiny Lobster ◽  
Mesh Size ◽  
Octopus Vulgaris ◽  
Target Species ◽  
Factors Affecting ◽  
Fishing Gears ◽  
Pros And Cons ◽  
The Mediterranean

AbstractStock overexploitation, bycatch, discards and gear impacts on the environment are outstanding issues for Mediterranean fisheries. The adoption of alternative fishing gears is an appealing solution to ensure a more sustainable exploitation of resources. We discuss the pros and cons of pots as alternative gears by reviewing their main designs, spatial distribution and target species in the Mediterranean basin. We assessed the technical factors affecting the catch efficiency of the different pot designs for four target species: spiny lobster, Palinurus elephas; Norway lobster, Nephrops norvegicus; common octopus, Octopus vulgaris and pandalid shrimps, Plesionika spp. We found that pot volume is important to catch Octopus; mesh size to catch Nephrops and Plesionika; entrance surface to catch Octopus, Nephrops and Plesionika; pot shape/colour and entrance shape/position to catch Octopus and Plesionika; and bait type to catch Octopus and Nephrops. The literature review shows that pot fisheries have several considerable advantages over conventional gears, especially in terms of discards, bycatch, seabed impacts (particularly compared with bottom trawls and passive set nets), size and species selectivity, gear depredation, catch quality and gear cost, besides saving time and labour. Disadvantages hampering their wider diffusion include ghost fishing, a low catch of finfish species, the narrow range of species targeted by each pot design and the current early stage of research. These data make a clear case for using pots as alternative gears to traditional ones in the Mediterranean Sea in some areas and seasons to catch certain target species.

scholarly journals Piscine Orthoreovirus (PRV)-3, but Not PRV-2, Cross-Protects against PRV-1 and Heart and Skeletal Muscle Inflammation in Atlantic Salmon

Vaccines ◽  
2021 ◽  
Vol 9 (3) ◽  
pp. 230
Author(s):  
Muhammad Salman Malik ◽  
Lena H. Teige ◽  
Stine Braaen ◽  
Anne Berit Olsen ◽  
Monica Nordberg ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Atlantic Salmon ◽  
Host Species ◽  
Coho Salmon ◽  
Common Disease ◽  
Target Species ◽  
Viral Kinetics ◽  
Live Attenuated Vaccine ◽  
Muscle Inflammation ◽  
Heart Pathology

Heart and skeletal muscle inflammation (HSMI), caused by infection with Piscine orthoreovirus-1 (PRV-1), is a common disease in farmed Atlantic salmon (Salmo salar). Both an inactivated whole virus vaccine and a DNA vaccine have previously been tested experimentally against HSMI and demonstrated to give partial but not full protection. To understand the mechanisms involved in protection against HSMI and evaluate the potential of live attenuated vaccine strategies, we set up a cross-protection experiment using PRV genotypes not associated with disease development in Atlantic salmon. The three known genotypes of PRV differ in their preference of salmonid host species. The main target species for PRV-1 is Atlantic salmon. Coho salmon (Oncorhynchus kisutch) is the target species for PRV-2, where the infection may induce erythrocytic inclusion body syndrome (EIBS). PRV-3 is associated with heart pathology and anemia in rainbow trout, but brown trout (S. trutta) is the likely natural main host species. Here, we tested if primary infection with PRV-2 or PRV-3 in Atlantic salmon could induce protection against secondary PRV-1 infection, in comparison with an adjuvanted, inactivated PRV-1 vaccine. Viral kinetics, production of cross-reactive antibodies, and protection against HSMI were studied. PRV-3, and to a low extent PRV-2, induced antibodies cross-reacting with the PRV-1 σ1 protein, whereas no specific antibodies were detected after vaccination with inactivated PRV-1. Ten weeks after immunization, the fish were challenged through cohabitation with PRV-1-infected shedder fish. A primary PRV-3 infection completely blocked PRV-1 infection, while PRV-2 only reduced PRV-1 infection levels and the severity of HSMI pathology in a few individuals. This study indicates that infection with non-pathogenic, replicating PRV could be a future strategy to protect farmed salmon from HSMI.

Potential impacts of poison baiting for introduced house mice on native animals on islands in Jurien Bay, Western Australia

2016 ◽  
Vol 43 (1) ◽  
pp. 61 ◽  
Author(s):  
Clifford Bennison ◽  
J. Anthony Friend ◽  
Timothy Button ◽  
Harriet Mills ◽  
Cathy Lambert ◽  
...  
Keyword(s):  
Western Australia ◽  
Rhodamine B ◽  
Native Species ◽  
House Mice ◽  
Mus Domesticus ◽  
Target Species ◽  
Island Populations ◽  
Delivery Technique ◽  
Poison Baiting ◽  
Competition For Resources

Context House mice (Mus domesticus) are present on Boullanger and Whitlock islands, Western Australia, and could potentially threaten populations of the dibbler (Parantechinus apicalis) and grey-bellied dunnart (Sminthopsis griseoventer) through competition for resources. A workshop in 2007 recommended a study to assess the feasibility of eradicating house mice from the islands by using poison baits and of the risk posed to non-target native species. Aim We aimed to assess the risk to non-target native species if poison baiting was used to eradicate house mice on Boullanger and Whitlock islands. Methods Non-toxic baits containing the bait marker rhodamine B were distributed on Boullanger Island and on the mouse free Escape Island to determine the potential for primary poisoning. Acceptance of baits by mammals was measured through sampling and analysis of whiskers, and by reptiles through observations of dye in faeces. To determine the potential for secondary exposure to poison, the response of dibblers to mouse carcasses was observed using motion-activated cameras. Bait acceptance was compared using two methods of delivery, namely, scattering in the open and delivery in polyvinyl chloride (PVC) tubes. A cafeteria experiment of bait consumption by dibblers was also undertaken using captive animals held at the Perth Zoo. Ten dibblers were offered non-toxic baits containing rhodamine B in addition to their normal meals; consumption of bait and the presence of dye in whiskers were measured. Key results Bait acceptance on the islands was high for house mice (92% of individuals) and dibblers (48%) and it was independent of bait-delivery technique. There was no evidence of bait acceptance by grey-bellied dunnarts. Dibblers may consume mice carcasses if available; however, no direct consumption of mice carcasses was observed with movement sensor cameras but one dibbler was observed removing a mouse carcass and taking it away. During the cafeteria experiment, 9 of 10 captive dibblers consumed baits. Conclusions This investigation demonstrated that dibblers consume baits readily and island populations would experience high mortality if exposed to poison baits. Poison baiting could effectively eradicate mice from Boullanger and Whitlock islands but not without mortality for dibblers. Implications Toxic baits could be used to eradicate mice from Boullanger and Whitlock islands, provided that non-target species such as dibblers were temporarily removed from the islands before the application of baits.

Sign in / Sign up

Export Citation Format

Share Document