Macalester College marine mammal sightings around Grenada, West Indies 1999

Aldemaro Romero, Macalester College

To document the Grenadian marine mammal fauna and its distribution in the eastern Caribbean, we conducted field and archival studies in that country. All records of sirenians and cetaceans for Grenada were assembled and analyzed. The total number of confirmed marine mammal species for this part of the world is 11. The humpback whale (Megaptera novaeangliae) was the most commonly reported mysticete species while a variety of odontocetes seem to be equally frequent in those waters. The manatee (Trichechus manatus) has been extinct from those waters for at least 300 years. Comparison with the marine mammal fauna of adjacent regions (Venezuela, Trinidad, and St. Vincent and the Grenadines), leads us to believe that at least seven additional species of cetaceans may be present in Grenadian waters, probably as occasional visitors.

There are three indications that the marine mammal fauna of Grenada may be much more abundant and diverse than ever reported. Therefore, we decided to investigate the nature of the marine mammal fauna for that country. To that end, we combined information for three major sources: data from published or unpublished (archival) documents, accounts from reliable observers, and our own field observations. As a result, we have been able to increase the number of confirmed records from three to 11.

Sightings from the field observations are a subset of the entire dataset, presented here on OBIS-SEAMAP.

For records that did not have time of observation available, "00:00:00" was used and noted in the [Notes] field.

For records that originally sighted a range for the number of individuals observed, the median number was used to be conservative, and noted in the [Notes] field.

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.
Only minimum required attributes are visible and downloadable online. Other attributes may be obtained upon provider's permission.

Attributes in dataset

Attribute (table column)	Description
oid	Unique ID (created by OBIS-SEAMAP)
recnum	Record number (by spreadsheet)
latitude	Latitude (decimal degrees)
longitude	Longitude (decimal degrees)
latdeg	Latitude (degree)
latmin	Latitude (minute)
longdeg	Longitude (degree)
longmin	Longitude (minute)
landref	Land reference (distance in m)
depth	Depth (m)
obs_time	Time of observation
duration	Duration of observation (minutes:seconds)
numind	Number of individuals
obs_count	Number of animals sighted
sp_obs	Species observed
obs_date	Date of observation
sp_tsn	Species ITIS TSN
notes	Notes for when time was not available or when abundance was originally a range and a median was used (created by OBIS-SEAMAP)
geom	Geometry field added by OBIS-SEAMAP