NEFSC Harbor Porpoise 1991

National Marine Fisheries Service

The ship survey was performed from 22 July 1991 to 30 August 1991 to estimate the abundance and spatial distribution of harbor porpoises.
The study area, covering approximately 13,300 nm , was from Port Clyde, ME to 2
St. John, New Brunswick over to the Nova Scotian coast, up to Liverpool, Nova Scotia.

PRIMARY OBJECTIVES
1) Estimate the abundance of harbor porpoises in the Gulf of Maine - Bay of Fundy - Nova Scotia area.
2) Investigate if there are any spatial distribution patterns of the harbor porpoises, and if those patterns are correlated with water depth or harbor porpoise group
size.

SECONDARY OBJECTIVES
1) Estimate the abundance and spatial distribution of other cetaceans.
2) Determine if harbor porpoise avoid this ship, and if so, at what distance.
3) Determine if there is a spatial distribution pattern of mother-calf pairs of harbor porpoise.
4) Compare the abundance estimate and spatial distribution of harbor porpoise as seen this year with that seen in previous years.
5) Investigate if inland bays can be surveyed using a rigidhull inflatable boat as the observation platform in a line transect survey.
6) Determine if Buckland's sighting procedure (1991), which is a line transect survey using both a primary and marking team, is a feasible procedure to estimate the abundance of harbor porpoise in the Bay of Fundy area.

In addition to the sighting data, effort data was recorded every half hour or whenever conditions change.
This dataset, therefore, should be used with the effort data.

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.
All attributes are included in the downloadable file (CSV or ESRI File Geodatabase) for "Complete Set of Dataset".

Attributes in dataset

Attribute (table column)	Description
dataset	Dataset ID
lineno	Line number
cruise	Cruise ID
date	Date of the observation
time	Time of the observation (local time)
latitude	Latitude in decimal degrees
longitude	Longitude in decimal degrees
species	Species name
common	Common name
tsn	ITIS Taxonomic Serial Number added by OBIS-SEAMAP
scientific	Scientific name
group_	Group size
rank	Taxonomic rank
herdsize	Group size
transect	Transect No
leg	Leg No
excluded	For internal use
geom	Geometry field added by OBIS-SEAMAP
oid	Unique ID number (generated by OBIS-SEAMAP)