Are great white sharks endangered? The white shark was listed as an endangered species in Canada in 2006, and is estimated to have declined in population close to 80% in North America over the past 14 years.
Did you know that a female white shark takes approximately 35 years to reach sexual maturity and a male 25 years? And when they finally reach this stage, they give birth to only 2-10 pups every two to three years.
Well, now we can imagine how vulnerable this slow development makes their population numbers, and the long road these creatures have towards success as a shark species.
Now imagine their situation again considering human activity in the oceans.
White sharks had been doing very well before humans brought large scale commercial fishing to their habitats, massive tourism on beaches complete with underwater protection nets, pollution, poaching, and especially illegal fishing. There could be only a few thousand remainings, but this is not an easy figure to estimate when researchers still aren’t even sure where they mate and reproduce. In fact, conservationists in some countries have spotted more sharks off the coastline, but they are not sure of the fraction they are really seeing- it could be ten, twenty or up to fifty per cent.
Many locations have documented an increase in marine mammal attacks, but this does not correlate directly to an increasing white shark population. No decreased attacks in other locations have been recorded, so conservationists infer that there could reasonably be more white sharks feeding on these mammals in some areas.
White Shark protection has been reduced
As the world faces the current pandemic, some activities have been drastically reduced- one such area is the patrol and protection of marine resources. Fishing vessels could be taking advantage of this to illegally fish inside protected areas. We have seen news coming from the Galapagos Islands in July reporting vessels poaching, harvesting, fishing illegally, and eliminating sharks within a protected area. We are afraid that this could be happening at Guadalupe Island as well. Most of the protection from illegal vessels comes from ecotourism, conservationists, and yachts visiting the island and now none of these vessels are in the ocean due to park closures.
The ocean’s natural balance is kept in check by vulnerable and endangered sharks and other apex predators. This is so important in maintaining our oceans healthy, sustainable and profitable, not only for ecotourism but for regulated fishing companies that can harvest approved amounts of fish without disturbing nature’s equilibrium.
If an apex predator like a great white shark disappears
If at some point there is a species made extinct, we will see changes in the ocean’s balance in response. For example, if an apex predator like a great white shark disappear from an ecosystem, there would likely be an overpopulation of seals, which were formerly hunted by the sharks. This could then lead to some fish species being wiped out as seals are known to overeat, bringing down the supply of fish on the market and increasing the price of fish. In Cape Cod in the 1970’s, the seal population was culled as they were seen as competition for fisherman. White sharks nearly disappeared from the area until seal killing was banned and they began to reproduce in higher numbers in the 21st century. White sharks have since returned, and there is a large community of sharks off of Cape Cod today.
White sharks are widely dispersed around the world, with some areas such as Australia, South Africa and North America being especially well known for their presence. Every shark belongs to a particular community and they tend not to mix among population groups, even if they are capable of traveling long distances such as from South Africa to Mozambique or from Madagascar to Australia.
In South Africa, white shark populations have not done well even though they have been under protection since 1991. On the coast of Durban and Kwazulu-Natal, a 320km coastal protected area saw shark nets killing more than 33,000 sharks of a variety of species, including the white shark. Most shark nets installed to protect swimmers tend to catch different species, not only their target.
In Australia, the white shark has been protected since the 1990’s, but the population hasn’t seen a significant recovery following their drastic reduction in population in previous decades, from 1950-1990.
White Shark Population
The white shark was listed as an endangered species in Canada in 2006, and is estimated to have declined in population close to 80% in North America over the past 14 years.
Off the California coast, juvenile white shark populations seem to be increasing over the past decade based on commercial fishery data which shows an increased incidental catch of white sharks in gill nets. Regulatory protections introduced in the 1990’s which prohibited white shark fishing and imposed regulations on gill net gear could have contributed to this apparent increase in white shark population.
On Farallon Island in the northeast Pacific, there is evidence of an increase in numbers of adult white sharks. Researchers have been comparing data on elephant seal and other marine mammal attacks in the area, and increasing seal populations seem to be bringing more white sharks to the island. A similar effect is seen at nearby San Miguel Island, where more attacks on pinnipeds have been observed, and carcasses with shark bites have been found in the area.
Guadalupe Island was designated as a Biosphere Reserve by the Mexican government in 2005, and since has since an increase in white shark population. We can attribute this to protection efforts from conservationists and the ecotourism industry increasing education and changing attitudes towards this important predator. One living shark is much more valuable over time that one dead shark.
So, Are great white sharks endangered?
Yes, White sharks are a vulnerable species that need to continue under protection. While many countries have banned white shark fishing, others continue to harvest them from the oceans. If we don’t do more to change human behaviour, this species could be at risk of extinction within a century.
Divemaster Martin Ferruggiaro