ME harbor and gray seals time series

NOAA Northeast Fisheries Science Center
James Gilbert, University of Maine
Wendy Dow, Duke University

Seal populations in the northwest Atlantic are thriving, yet few grant dollars go to seal projects in the northeast region. According to many researchers and managers in the region, the healthy state of stocks is exactly why we should be studying seals. Seal and human activities along the coast often result in conflicts, which will undoubtedly increase as the population and range of both seals and humans increase. The east coast of the United States lacks a management plan for seals. A problem that seriously impedes management is that managers do not know where the seals are and more specifically, where haul-out sites are. This atlas is designed to aid managers and researchers in the management and conservation of seals in the northwest Atlantic. The atlas and the data used to create the atlas can be accessed through OBIS-SEAMAP.

The purpose of this dataset and atlas is to provide data from a series of aerial surveys conducted between 1981 and 2001 of harbor and gray seal haul-out sites in Maine.

The original data were transposed so that each record represents seals abundance at a single ledge on a single day. As this dataset is a time-series, an appropriate way to represent it is to show it with time-series charts by region. Currently, OBIS-SEAMAP lets you see it on Google Earth with the charts. Not all seasons are represented in this dataset, and distributions of seals may be different in other seasons. Lack of a count for a ledge on a particular date does not necessarily mean the ledge was not observed.

Overview

This section explains attributes included in the original dataset. OBIS-SEAMAP restricts the attributes available to the public to date/time, lat/lon and species names/counts only. Should you need other attributes described here, you are encouraged to contact the data provider.

Attributes described below represent those in the original dataset provided by the provider.
Only minimum required attributes are visible and downloadable online. Other attributes may be obtained upon provider's permission.

Attributes in dataset

Attribute (table column)	Description
dataset	Dataset ID
lineno	Line number
id	ID
ledge	Ledge name
region	Ledge region
longitude	Longitude in decimal degrees
latitude	Latitude in decimal degrees
survey_id	Survey ID
notes	Notes
date	Date of the observation
spcode	Species code
common	Common name
scientific	Scientific name
tsn	ITIS Taxonomic Serial Number added by OBIS-SEAMAP
lifestage	Life stage
replicate	Replicate
count	The number of animals
excluded	For internal use
geom	Geometry field added by OBIS-SEAMAP
oid	Unique ID number (generated by OBIS-SEAMAP)