DFO Maritimes Research Vessel Trawl Surveys Fish Observations

OBIS and OBIS Canada

This is the OBIS-formatted view of the Canadian Department of Fisheries and Oceans (DFO) Maritimes Research Vessel Trawl Surveys. This data is created using a Structured Query Language (SQL) program run against the DFO production database. Refer to the project section for more information about the surveys.

This OBIS product reports the abundance and weight of demersal fish species captured by a variety of trawl gear and vessels. Catch data appear in the "individualcount" and "observedweight" OBIS fields (DwC dynamic properties field)and have been normalised for distance towed. The swept area of each tow can be found in the "samplesize" field of the OBIS schema (DwC dynamic properties field). Care should be taken when using multiple types of gear since the catchability of different fish species varies from gear to gear. The OBIS field "locality" contains the DFO stratum number where each tow was conducted. The OBIS field "collectioncode" identifies which survey series each data record comes from.
Strata statistics required to derive stratified random estimates of catch abundance and biomass can be found on the OBISCanada website http://obiscanada.marinebiodiversity.ca/database/dfo-maritimes-survey-strata-statistics).

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/3d922162-062c-4ad2-bf4a-f2493bd3a95d
Data Provider's dataset page:
http://ipt.iobis.org/obiscanada/resource?r=dfogfsdbfish

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)