Scallop Abundance Data

SUMMARY:

The scallops data frame is a spatial data set listing the catch of scallops from a 1990 National Marine Fisheries Service trawl survey in the Atlantic Ocean. The survey area runs from the Delmarva Peninsula off the coast of Virginia and Maryland up to the George Banks.

DATA DESCRIPTION:

This data frame contains the following columns:

ARGUMENTS:

strata
a factor indicating the National Marine Fisheries Service (NMFS) 4 digit strata designator in which the sample was taken.
sample
sample number per year ranging from 1 to approximately 450.
lat
location in terms of latitude of each sample in the Atlantic Ocean.
long
location in terms of negative longitude of each sample in the Atlantic Ocean.
tcatch
total number of scallops caught at the ith sample location. This is prerec + recruits.
prerec
number of scallops whose shell length is smaller than 70 millimeters.
recruits
number of scallops whose shell length is 70 millimeters or larger.

SOURCE:

From Ecker and Heltshe (1994) who present a geostatistical analysis of the data.

REFERENCES:

Ecker, Mark D. and Heltshe, James F. (1994) Geostatistical estimates of scallop abundance. In Case Studies in Biometry. Nicholas Lange, Louise Ryan, Lynne Billard, David Brillinger, Loveday Conquest, and Joel Greenhouse, eds. New York: Wiley, pp. 107-124.