Porbeagle Shark (Lamna nasus) 

Porbeagle sharks (fig. 1) are close relatives of Great White sharks, sometimes being mistaken for great whites based on their similar (but smaller) appearance (The Wildlife Trusts, n.d.). They are a species of mackerel shark (OSPAR, n.d.) and can grow up to 3.5m in length (Scottish Government, 2020). In Scotland, they are considered rare, but are found throughout our waters (Scottish Government, 2020). 

Niche and Distribution: 
Porbeagle habitat can range from shallow continental shelves to deep open oceans, reaching depths of 1,800m (Rigby et al 2019). They favour bony fish and cephalopods (e.g. squids, octopus) as their prey  (OSPAR, n.d.).                                                                                                                                                                                                                                                                                              The porbeagle population is split between the Northern Atlantic, and the Southern Hemisphere (fig. 2), forming two distinct subpopulations (Rigby et al, 2019). The Southern hemisphere population has a longer lifespan at 60 years, compared to 26 years for the Northern Atlantic group (Rigby et al, 2019).

Fishing:
While protected in much of the EU, porbeagle fishing still takes place in other parts of the world (Scottish Government, 2011), with their fins, liver oil and meat in high demand (Rigby et al, 2019). 

Breeding:
As with most Shark, Skate and Ray species, the porbeagle reproductive process is slow. An ovoviviparous species, they produce only about 4 pups per litter (Oceana, n.d.) after taking between 13-16.5 years for females to mature (Rigby et al, 2019). Due to this slow reproduction, OSPAR estimates that without any mortality from fishing, recovery of stock to a sustainable level would take between 15 and 34 years (OSPAR Commission, 2010). 

Abundance in Scotland: 
Currently Porbeagles numbers are unknown. They are known to have gone through a period of severe population decline (OSPAR Assessment Portal, 2021), with the time post 1930 seeing a reduction in landings of between 85-99% (OSPAR Commission, 2010). Globally, they are considered vulnerable, but are critically endangered in the NE Atlantic (Scottish Government, 2011). As a result, they are protected under a ‘zero Total Allowable Catch’ order in the EU, in place for the last 14 years (Scottish Government, 2011). 

Threats:
OSPAR suggests the main threat to porbeagles remains targeted fishing, be that commercial or personal hobby fishing, in addition to unintentional bycatching in fishing operations. Porbeagle prey stocks remain healthy, so this is not likely to be a problem for the species. (OSPAR Commission, 2010).