scholarly journals Spatial and temporal distributions of larval sealworm, Pseudoterranova decipiens (Nematoda: Anisakinae), in Hippoglossoides platessoides (Pleuronectidae) in the Canadian Maritime Region from 1993 to 1999

2001 ◽  
Vol 3 ◽  
pp. 77
Author(s):  
G McClelland ◽  
DJ Martell
Keyword(s):  
Environmental Temperature ◽  
Gulf Of Maine ◽  
Temporal Trends ◽  
Halichoerus Grypus ◽  
Grey Seal ◽  
Spatial And Temporal Distributions ◽  
Pseudoterranova Decipiens ◽  
Infection Parameters ◽  
Spatial And Temporal Trends ◽  
Hippoglossoides Platessoides

Spatial and temporal trends of larval sealworm (Pseudoterranova decipiens) infection in eastern Canadian groundfish were monitored in an indicator host, Canadian plaice (Hippoglossoides platessoides), in the 31 to 40 cm length range. Between February 1993 and September 1999, a total of 8,482 plaice were collected from 33 locations in Canadian Maritime waters (NAFO Subdivisions 4TVWX-5ZE), and their fillets and napes were examined for sealworm. Prevalence (P) and abundance (A) of the parasite were greatest (P ranging from 95 to 100%, A from 7.48 to 15.60) in fish collected from the central Scotian shelf (4VSW) near Sable Island, site of the largest grey seal (Halichoerus grypus) colony in the northwest Atlantic, and from Jordan Basin in the northeastern Gulf of Maine (4X). The infection of greatest intensity (I=158) occurred in a fish from “The Gully” slopewaters of Banquereau (4VS), a few kilometres northeast of Sable Island. By 1995-99, sealworm prevalence and/or abundance had increased significantly in plaice from most locations where stable or declining infection parameters were observed from 1989 to 1993, but abundance of the parasite continued to decline in the Sable Island area. While spatial and temporal distributions of larval sealworm in plaice seemed largely related to the distribution and growth of grey seal populations,the influence of definitive hosts was probably mitigated by other factors such as changes in environmental temperature and parasite density limiting effects in the indicator host.

scholarly journals Surveys of larval sealworm (Pseudoterranova decipiens) infection in various fish species sampled from Nova Scotian waters between 1988 and 1996, with an assessment of examination procedures

2001 ◽  
Vol 3 ◽  
pp. 57 ◽  
Author(s):  
G McClelland ◽  
DJ Martell
Keyword(s):  
Gadus Morhua ◽  
Gulf Of Maine ◽  
New Host ◽  
Pseudoterranova Decipiens ◽  
Infection Parameters ◽  
Routine Inspection ◽  
Frozen Fish ◽  
Nova Scotian ◽  
New Host Records ◽  
Benthic Consumers

Between November 1988 and October 1996, >10,000 fish from the Breton Shelf, Sable Island Bank and the northeastern Gulf of Maine were examined for larval anisakines. Larval sealworm, Pseudoterranova decipiens, occurred in 30 of 39 species surveyed, including 8 new host records, Enchelyopus cimbrius, Lycodes reticulatus, Eumesogrammus praecisus, Lumpenus lumpretaeformis, Lumpenus maculatus, Cryptacanthodes maculatus, Artediellus atlanticus and Triglops murrayi. The parasite was most prevalent and abundant in mature demersal piscivores and benthic consumers. Sealworm densities (nr kg-1 host wt.), however, were greatest in small benthophagous fish including mature E. cimbrius, A. atlanticus, T. murrayi and Aspidophoroides monopterygius, and juvenile Hippoglossoides platessoides. ANOVA revealed that geographical disparities in sealworm prevalence and abundance were highly significant in 14 of 20 species tested, although significant disparities between samples from each of the three areas were evident only in H. platessoides. Almost invariably, infection parameters were greatest in fish from Sable Island Bank. ANOVA also indicated that sealworm prevalence and/or abundance increased significantly in Sable Island Bank populations of Gadus morhua, H. platessoides, and seven other species between 1985-1986 and 1989-1990. Routine examinations, in which host flesh was sliced and candled, proved as efficacious as digestion in warm (35° C) pepsin-HCl for detection of larval sealworm in the flesh of large frozen fish. Procedures employing fresh (iced) samples, digestion at ambient temperature and microscopy are recommended, however, for surveys of small benthic consumers. Many of the sealworm infecting the latter hosts are tiny (2 to 10 mm in length) nematodes, which escape detection by routine inspection, and may not survive in warm pepsin-HCl solution.

In vitro effect of ivermectin on Pseudoterranova decipiens survival

1989 ◽  
Vol 63 (1) ◽  
pp. 72-74 ◽  
Author(s):  
K. M. Manley ◽  
J. A. Embil
Keyword(s):  
Broad Spectrum ◽  
Developmental Stages ◽  
Culture Media ◽  
Halichoerus Grypus ◽  
Grey Seal ◽  
Larval Stages ◽  
Pseudoterranova Decipiens ◽  
Vitro Effect ◽  
Drug Vehicle

ABSTRACTThird larval stages (L3) removed from fish fillets, fourth larval stages (L4) raised in in vitro culture, and adults of Pseudoterranova decipiens, collected from grey seal (Halichoerus grypus) stomachs, were exposed to the broad spectrum anthelmintic, ivermectin. L3 and L4 parasites were exposed, in vitro, to 500, 100, 50, 20, 5 and 1 μg/ml concentrations of the drug, in culture media. Adult P. decipiens were exposed in vitro to a concentration of 500 μg/ml ivermectin, only. Controls consisted of parasites placed in culture media alone or culture media plus drug vehicle. These three developmental stages of P. decipiens were all found to be susceptible to the effects of ivermectin.

Use of the EventViewer for Visualizing and Exploring Events Extracted From Ocean Observing System Data

2011 ◽  
Vol 45 (1) ◽  
pp. 112-124
Author(s):  
Kate Beard ◽  
Jake Emerson ◽  
Heather E. Deese ◽  
Avinash Rude ◽  
Mike Scott ◽  
...  
Keyword(s):  
Time Series ◽  
Gulf Of Maine ◽  
Temporal Trends ◽  
Sensor Data ◽  
Multiple Time ◽  
Periodic Patterns ◽  
System Data ◽  
Data Collections ◽  
Spatial And Temporal Trends ◽  
Ocean Observing

AbstractRapidly expanding data collections from ocean observing systems create a need for new tools to process, to explore, and to analyze data. This article presents capabilities of the EventViewer in the context of exploring ocean observing system data. The EventViewer is a graphical user interface for visualizing and exploring patterns in events where events constitute changes of interest in a time series. The EventViewer allows users to make queries on events stored in an events database and explore various spatial, temporal, and thematic patterns in events. Once events are selected, the user can assign event spatial, temporal, and thematic categories to graphic display elements in the interface called bands, stacks, and panels. Selected events are displayed according to their associations with the user-specified categories. The spatial, temporal, and thematic categories can be directly manipulated and rearranged among the bands, stacks, and panels to change the view of events and highlight different patterns. The EventViewer supports exploration of periodic patterns, spatial and temporal trends, and event‐event relationships. The EventViewer functionality is illustrated with oceanographic events extracted from ocean observing system sensor data collected in the Gulf of Maine. Events were extracted from multiple time series variables collected at a number of locations and depths.

Utilizing next-generation sequencing to identify prey DNA in western North Atlantic grey seal Halichoerus grypus diet

2020 ◽  
Vol 655 ◽  
pp. 227-240
Author(s):  
KR Flanders ◽  
ZH Olson ◽  
KA Ono
Keyword(s):  
Next Generation Sequencing ◽  
Feeding Habits ◽  
Atlantic Menhaden ◽  
Halichoerus Grypus ◽  
Frequency Of Occurrence ◽  
Grey Seal ◽  
Next Generation ◽  
Significant Difference ◽  
Generation Sequencing ◽  
Seal Diet

Increasing grey seal Halichoerus grypus abundance in coastal New England is leading to social, political, economic, and ecological controversies. Central to these issues is the foraging ecology and diet composition of the seals. We studied grey seal feeding habits through next-generation sequencing of prey DNA using 16S amplicons from seal scat (n = 74) collected from a breeding colony on Monomoy Island in Massachusetts, USA, and report frequency of occurrence and relative read abundance. We also assigned seal sex to scat samples using a revised PCR assay. In contrast to current understanding of grey seal diet from hard parts and fatty acid analysis, we found no significant difference between male and female diet measured by alpha and beta diversity. Overall, we detected 24 prey groups, 18 of which resolved to species. Sand lance Ammodytes spp. were the most frequently consumed prey group, with a frequency of occurrence (FO) of 97.3%, consistent with previous studies, but Atlantic menhaden Brevoortia tyrannus, the second most frequently consumed species (FO = 60.8%), has not previously been documented in US grey seal diet. Our results suggest that a metabarcoding approach to seal food habits can yield important new ecological insights, but that traditional hard parts analysis does not underestimate consumption of Atlantic cod Gadus morhua (FO = 6.7%, Gadidae spp.) and salmon Salmo salar (FO = 0%), 2 particularly valuable species of concern.

Spatial and temporal trends and effects of contaminants in the Canadian Arctic marine ecosystem: a review

1999 ◽  
Vol 230 (1-3) ◽  
pp. 83-144 ◽  
Author(s):  
D Muir ◽  
B Braune ◽  
B DeMarch ◽  
R Norstrom ◽  
R Wagemann ◽  
...  
Keyword(s):  
Marine Ecosystem ◽  
Temporal Trends ◽  
Canadian Arctic ◽  
Spatial And Temporal Trends

scholarly journals Spatial Disparities of COVID-19 Cases and Fatalities in United States Counties

2021 ◽  
Vol 18 (16) ◽  
pp. 8259
Author(s):  
Sarah L. Jackson ◽  
Sahar Derakhshan ◽  
Leah Blackwood ◽  
Logan Lee ◽  
Qian Huang ◽  
...  
Keyword(s):  
United States ◽  
Great Plains ◽  
Explanatory Power ◽  
Temporal Trends ◽  
The United States ◽  
First Year ◽  
Significant Case ◽  
Urban Rural ◽  
Spatial And Temporal Trends ◽  
Mitigation Policies

This paper examines the spatial and temporal trends in county-level COVID-19 cases and fatalities in the United States during the first year of the pandemic (January 2020–January 2021). Statistical and geospatial analyses highlight greater impacts in the Great Plains, Southwestern and Southern regions based on cases and fatalities per 100,000 population. Significant case and fatality spatial clusters were most prevalent between November 2020 and January 2021. Distinct urban–rural differences in COVID-19 experiences uncovered higher rural cases and fatalities per 100,000 population and fewer government mitigation actions enacted in rural counties. High levels of social vulnerability and the absence of mitigation policies were significantly associated with higher fatalities, while existing community resilience had more influential spatial explanatory power. Using differences in percentage unemployment changes between 2019 and 2020 as a proxy for pre-emergent recovery revealed urban counties were hit harder in the early months of the pandemic, corresponding with imposed government mitigation policies. This longitudinal, place-based study confirms some early urban–rural patterns initially observed in the pandemic, as well as the disparate COVID-19 experiences among socially vulnerable populations. The results are critical in identifying geographic disparities in COVID-19 exposures and outcomes and providing the evidentiary basis for targeting pandemic recovery.

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