Background

Scientific name (Carcharhinus longimanus)

Kingdom Animalia

Phylum Chordata

Class Chondrichthyes

Order Carcharhiniformes

Family Carcharhinidae

Genus Carcharhinus

Species longimanus

(NOAA Fisheries, 2020) 

Oceanic whitetip sharks (OWT) are large predatory fish reaching lengths up to 11ft. They have large rounded dorsal and pectoral fins that help them glide through the water. Commonly grey/bronze with white mottling along their ventral side and distinctive white-tipped fins which gives them their name (Bonfil et al., 2009). 

The oceanic whitetip shark is a pelagic species that primarily lives within the top 200 meters of the water column but has been reported to depths up to 1,082m.  Whitetips can be found in tropical and subtropical waters across the globe. Commonly found in deep open water they also have been found on continental shelves and Islands near deep water. Oceanic whitetips undergo long migrations but very little research has been done to determine the extent of the patterns (Young & Carlson, 2020). 

Once considered to be the most abundant pelagic shark species oceanic whitetip populations have declined significantly within the past 70 years. There is currently no global population size assessment, however, the global population has been estimated to have declined by up to 90%. Estimates are based on regional fishing and scientific data, with areas showing declines between 70-99%. One of the most drastically impacted regions is the Gulf of Mexico with an estimated 99.5% population decline within a 50-year period (Young & Carlson, 2020).

Oceanic whitetip sharks' life history traits are not well understood with little research having been done. Like many other shark species whitetips can have long life spans and reach maturity at a late age. It is estimated that OWTs have a lifespan of 25 plus years becoming mature between 6-9 yrs. Whitetips are a viviparous species which means they give birth to live pups. Reproduction cycles are thought to occur in alternate years, the gestation period ranges from 10-12 months with  1-14 pups per litter (Bonfil et al., 2009) . Females are commonly larger than males, and studies have shown there is a strong correlation between the size of the female and the number of pups born with larger females often giving birth to more pups (Young & Carlson, 2020). 

Oceanic Whitetip sharks are vital pelagic apex predators, feeding at the highest trophic level with little to no natural predators. Whitetips feed primarily on large bony fish such as tuna, barracuda, marlin, dolphin fish, and cephalopods (squid). OWTs have also been found to feed on sea turtles, marine mammal carrion, seabirds, and garbage. Open ocean environments are often difficult to hunt for food in due to the vast area for prey to disperse into. Oceanic whitetips have a curious nature allowing them to investigate possible food sources, which helps them to thrive in this difficult environment.   Whitetips' inquisitive behavior can cause them harm with increasing fishing pressures and ingesting harmful materials like garbage (Young & Carlson, 2020). OWTs are commonly solitary but have been shown to aggregate to abundant food sources. Such as at Cat Island in the Bahamas, where they have been found in high concentrations during high prey abundance (Madigan et al., 2015) .