DFO Newfoundland and Labrador Region Ecosystem Trawl Surveys

OBIS and OBIS Canada

An OBIS version of the Fisheries and Oceans Canada Newfoundland and Labrador region (DFO-NL) ecosystem trawl survey data from 1977-2011. Survey data are collected by DFO stock assessment staff during stratified random seasonal (spring and fall) bottom trawl surveys. These surveys were initially designed to estimate abundance and distribution of commercial groundfish species, but since 1995 have also been regularly recording non-commercial species and invertebrates. The area surveyed has varied over time, as has the trawl gear used and the fishing methodology (tow duration) employed. Note in some years the ‘fall’ survey (usually Oct-Dec), continued January of the following calendar year.

This dataset is the OBIS version of the 'bottom trawl' dataset and only species presence information is included at this time for standard sets.

Taxonomic limitations
Due to the emphasis on commercial fish species, taxonomic classifications of non-commercial fish and invertebrates prior to 1995 were frequently limited to genus or family and sometimes order. With the introduction of the Campelen trawl came a major change in the taxonomic detail recorded and by 2008 efforts were made to identify all fish to species, when possible. However although improved, identifications of some invertebrate taxa continue to be recorded at higher taxonomic levels. Consequently the absence of records for a particular species cannot be equated with an absence of the species, particularly when higher taxonomic classifications are present.

N/A

This dataset was downloaded from OBIS (https://obis.org/). The records for only marine mammals, seabirds, sea turtles and rays and sharks were extracted. Records with no longitude/latitude or no date (eventDate) were excluded.
OBIS dataset page:
https://obis.org/dataset/f1a11336-64b8-46f4-ba10-5095d150039f
Data Provider's dataset page:
http://ipt.iobis.org/obiscanada/resource?r=dfo_nl_groundfish

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
oid	Internal ID
id	Record ID
dataset_id	Dataset ID
scientificname	Scientific name
vernacularname	Vernacular name
aphiaid	Aphia ID
taxonrank	taxononic rank
individualcount	Group size / individual count
eventdate	Event date (precision varies)
eventtime	Event time
decimallatitude	Latitude in decimal degrees
decimallongitude	Longitude in decimal degrees
coordinateprecision	Coordinate precision
catalognumber	Catalog number
collectioncode	Collection code
occurrencestatus	Occurrence status
basisofrecord	Basis of record (HumanObservation / MachineObservation)
modified	Date/time the record was modified
node_id	Node ID
occurrenceid	Occurrence ID
occurrenceremarks	Occurrence remarks
eventid	Event ID
institutioncode	Institution code
lifestage	Life stage
sex	Gender of the animal if known
species	Species by provider
datasetid	Dataset ID by provider
country	Country
locality	Location of ocean
waterbody	Details of ocean
dropped	Flag indicating the record was dropped (always false)
absence	Flag indicating the record represents the absence of the species (always false)
marine	Flag indicating the record is for marine life (always true)