Cetacean sightings in Ghana and Ivorycoast
Marijke de Boer

Dataset credit

Marijke N. de Boer

Contacts

RoleNameOrganization 
Primary contact Marijke de Boer Wageningen Marine Research, University of Wageningen
Data entry Ei Fujioka Duke University

Citation

Abstract

Within the Gulf of Guinea the information on the cetacean abundance and distribution is scarce. A cetacean survey took place during geophysical surveys (2013–2014) along the coasts of Ghana and Côte d’Ivoire. Due to large group-sizes, melon-headed whales were the most abundant (0.34 animals
km−1) followed by Fraser’s dolphins and short-finned pilot whales. Range state records were confirmed for melon-headed whale and Fraser’s dolphin in Ivoirian waters and ten further species represented first at-sea sightings. Fraser’s dolphins, melon-headed whales, pantropical spotted dolphins, bottlenose dolphins, and pilot whales were recorded in areas with the highest fishing densities. Melon-headed whales, pilot whales, and rough-toothed dolphins were observed in vicinity of trawlers; bottlenose dolphins, pantropical spotted dolphins, and pilot whales in vicinity of canoes. The poor knowledge on population trends of cetaceans in this unique upwelling region, together with a high demand for cetacean products for human consumption (as “marine bushmeat”) may lead to a potential decline of some species that may go unnoticed. These new insights can provide a foundation for the urgently required risk assessments of cetacean mortality in fisheries within the northern Gulf of Guinea.

Purpose

The objective of this study was to gather new information on the poorly monitored local cetacean populations in order to understand the threat posed by interactions with fisheries either due to unintended bycatch (entanglement) or direct capture. The information presented provides a valuable insight into the occurrence, relative abundance, and at-sea distribution of cetaceans and an indication as to which cetacean species appear to be under the greatest fishing pressure. As such, these findings provide new directions for future assessments of fishing pressure on cetaceans through incidental catches and directed takes.

Supplemental information

Information regarding location of fishing vessels is available upon request

References

Attributes

Overview

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

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 in dataset provided

Attribute (table column)Description
oidUnique ID number (generated by OBIS-SEAMAP)
sighting_noSighting Number
date_timeDate and time at local time zone
datetime_utcDate and time at UTC
observerThe name of the observer who first sighted the animal
latitudeLatitude in decimal degrees
longitudeLongitude in decimal degrees
depthWater depth (metres)
speciesSpecies name
latin_nameLatin name
sp_tsnTaxonomic Serial Number added by OBIS-SEAMAP
certaintyCertainty
bearingBearing to animal
range_of_animalRange of animal (metres)
total_numberTotal number of animals sighted
num_adultsNumber of adults
num_juvenilesNumber of juveniles
num_calvesNumber of calves (visual sightings only)
photoPhoto (yes/no)
behaviourBehaviour
direction_relativeDirection of travel (relative to ship)
direction_compassDirection of travel (compass points)
sea_stateSea state
swellSwell
visibilityVisibility
glareGlare
precipationPrecipation
sstSST in celsius
timezone_hTime zone added by OBIS-SEAMAP
geomGeometry field added by OBIS-SEAMAP
OBIS-SEAMAP ID2018
Seabirds0
Marine mammals315
Sea turtles0
Rays and sharks0
Other species0
Non spatial0
Non species0
Total315
Date, Begin2013-04-18
Date, End2014-05-24
Temporal prec.111110
Latitude3.60 - 4.87
Longitude-3.44 - -1.85
Coord. prec.5 decimal digits
PlatformBoat
Data typeAnimal sighting
EffortN/A
Registered2019-10-03
Updated2019-10-14
StatusPublished
Sharing policy CC-BY-NC (Minimum)
Also availalbe from iOBIS
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