New sightings records of marine mammals and seabirds off French Guiana

Abstract

French Guiana region is one of the most productive in the world and hosts a wide variety of marine vertebrates. In the same time, anthropogenic activities are a growing concern in French Guiana, both in coastal and offshore areas. However, few studies are published on marine mammals, seabirds and potential interactions. Twenty-three marine mammal species are known to occur in the Exclusive Economic Zone (EEZ) and important seabird breeding sites are located in the area. Most of the existing literature relates to breeding birds and coastal cetaceans, but the continental slope appears to be an essential habitat for marine mammals and seabirds. Between October 22 and November 23, 2017, an oceanographic survey was conducted on the Guiana slope to study the quality of sediments and water. Three marine fauna observers (MFOs) were onboard to record sightings of marine mammals and seabirds opportunistically. During 462 h of visual effort in good sighting conditions, 313 sightings (824 individuals) were recorded: 61 marine mammals (501 individuals) and 252 seabirds (323 individuals). Seven seabird families were observed: Laridae (42%), Fregatidae (26%), Procellariidae (12%), Stercorariidae (10%), Hydrobatidae (4%), Sulidae (2%) and Phaethontidae (1%). 3% concerned wader species. The most frequently observed seabird species was the magnificent frigatebird (Fregata magnificens), as well as the common tern (Sterna hirundo), Cory's shearwater (Calonectris diomedea) and the pomarine jaeger (Stercorarius pomarinus). Many Delphinidae species were observed (Stenella longirostris, Stenella attenuata, Stenella frontalis, Delphinus delphis, Tursiops truncatus) in addition to sperm whales (Physeter macrocephalus) and humpback whales (Megaptera novaeangliae). Only a few sightings of humpback whales have been previously recorded in this area. Sighted individuals were mainly mother-calf pairs suggesting that the area may be an extended part of a calving ground for humpback whales.

Cetacean community off French Guiana

“…During de Boer's (2015) campaign, a high proportion of sperm whale sightings was recorded (12% of sighted groups and 3% of individuals). During our study, only two groups of sperm whales were sighted in bad weather conditions and during previous campaigns sperm whales made from 2% to 4%1,2 (Mannocci et al, 2013;Martinez et al, 2019) of the sightings. In Suriname, de Boer (2015) highlighted that sperm whales were most frequently seen in the vicinity of the Demerara Plateau.…”

“…The humpback whale (Megaptera novaeangliae) was sighted for the first time during these surveys: a mother and calf pair was observed at the end of 2009 2 and seven sightings, including three mother-calf pairs were collected from August to November 2012 1 . In October and November 2017, Martinez et al (2019) opportunistically collected cetacean sightings during an oceanographic survey conducted on the continental slope. Seven species were identified, including the humpback whale, the sperm whale, and five delphinids.…”

Recent occurrence of marine mammals and sea turtles off Angola and first report of right whales since the whaling era

“…This marine megafauna survey was part of an Environmental Baseline Study (EBS) focused on characterizing the benthic and planktonic communities and the biological and physio-chemical characteristics of the sediment and seawater prior to commencement of drilling operations in a deep-water site off Angola. The integration of knowledge about regional biodiversity within oil and gas exploration activities is part of an approach focused on integrated environmental management (Chaineau et al ., 2010; Martinez et al ., 2019). Few systematic studies of marine megafauna have been conducted in deep waters off Angola.…”