Trawl survey data from the Jabuka Pit area (central-eastern Adriatic Sea, Mediterranean) collected between 1956 and 1971

OBIS and EurOBIS

Between October 1956 and January 1971, the Institute of Oceanography and Fisheries (IOF, Croatia) performed a series of trawl-surveys in the Croatian coastal waters between Split and Šibenik (central-eastern Adriatic, Mediterranean) in the area of the Jabuka Pit with two motorboats, “Bios” (300 HP; LOA = 26 m) and “Predvodnik” (200 HP; LOA = 19 m).
447 hauls were carried out at 26 fixed stations. Three different bottom otter-trawl nets were used. A cotton bottom otter-trawl net (wing mesh-size: 55 mm; cod-end mesh-size: 20 mm; foot-rope length: 36.3 m; head-rope length: 29.1 m) was towed by the motorboat “Bios”, while a cotton bottom otter-trawl net (wing mesh-size: 55 mm; cod-end mesh-size: 20 mm; foot-rope length: 46.1 m; head-rope length: 34.1 m) was towed by the motorboat “Predvodnik”. In 1971, a synthetic bottom otter-trawl net (wing mesh-size: 50 mm; cod-end mesh-size: 20 mm; foot-rope length: 40 m; head-rope length: 37 m) was towed by the motorboat “Bios”. Tow duration was one hour for all hauls. The average tow speed was 3 knots. CPUE (n/h and kg/h) indexes were derived for 129 demersal species (19,756 records). Species synonymies were updated according to the modern nomenclature referring to the World Register of Marine Species (WoRMS). Some species are grouped into multispecies categories that group taxonomically similar species, i.e. species of the same genus or family (e.g. Raja spp., Triglidae). Information on the sediment type at each station was also recorded using an echo sounder. The depth of each station was extracted from the EMODnet Digital Bathymetry.

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/a6f8db9e-2794-4260-b7f6-66febc029002
Data Provider's dataset page:
http://ipt.vliz.be/eurobis/resource?r=bios_predvodnik_2_trawl_survey_1956_1971

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)