Service Description: Displays the estimated presence/absence of America Shad according to data collected by the MA Division of Marine Fisheries Resource Survey from 1978-2016

Service ItemId: 9b2ed02df84341f8909724ceba02fc5c

Has Versioned Data: false

Max Record Count: 1000

Supported query Formats: JSON

Supports applyEdits with GlobalIds: False

Supports Shared Templates: False

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Layers:

• Fall American Shad Presence (0)

Description: Data was provided by the Massachusetts Division of Marine Fisheries (DMF). Data was collected during the bi-annual (Spring and Fall) Resource Survey from 1978-2016. DMF provided the following information for every trawl: latitude, longitude, cruise number, stratum, trawling station, set dept, date of trawl, bottom temperature, number of each specie collected in net, weight of each specie. Latitude, longitude, and number of each specie collected in net data was used to create this visual. Separate data sets were made for spring data (green) and fall data (blue). Each dataset identifies the number of American Shad caught during each trawl (3781 data points in the Spring, 3450 data points in the Fall) and the location of each trawl. To effectively interpolate using Natural Neighbor and to show areas that were “Not Surveyed”, shapefile points were created along the Massachusetts border, around the Martha’s Vineyard and Nantucket border, and outside the extent of the DMF trawl. Not surveyed data points (n=311) were assigned the value, NUMi, of 0. Trawl data points where no American Shad were caught received the value of 0.1 (NUMi=0.1). All other data points where American Shad were caught kept their value as the number of American Shad caught. Natural Neighbor Interpolation Tool was then used for all these data points according to "NUMi" category. The interpolated data can be found in "Spring American Shad Presence" and "Fall American Shad Presence" Displayed interpolated categories were created by giving "Not Surveyed" (NUMi=0, 311 data points) and "Absent" American Shad (NUMi=0.1, no American Shad presence), their own category. Then, remaining data points were binned into the following categories based on the aggregation behavior of the species: Absent=0 American Shad Low=1-25 American Shad Medium=26-100 American Shad High=101-500 American Shad

Copyright Text: Amanda Davis and Dr. Michelle Staudinger of the Northeast Climate Science Center (NE CSC) and Brad Chase of Massachusetts Division of Marine Fisheries (MA DMF)

Spatial Reference: 102100 (3857)

Initial Extent:

XMin: -8002227.92228759
YMin: 5124308.5477401
XMax: -7684515.69141242
YMax: 5314302.57284817
Spatial Reference: 102100 (3857)

Full Extent:

XMin: -7917243.4209
YMin: 5030431.0286
XMax: -7769500.1928
YMax: 5292072.6322
Spatial Reference: 102100 (3857)

Units: esriMeters

Child Resources:   Info

Supported Operations:   Query   ConvertFormat   Get Estimates