Syed Muhammad Khan is a Biologist, a teacher and history enthusiast.
“In the past overfishing has been the major threat to sturgeons. The value of their products inspired the merciless persecution of these helpless beings. The year 1977 witnessed the peak of sturgeon catch: 32,000 tons…"
For more than 200 million years, sturgeons have been swimming peacefully in the waters of the northern hemisphere. They witnessed the age of dinosaurs, the cretaceous mass extinction, the dawn of mammals, the ice ages, the great American interchange, the appearance and disappearance of the Bering Bridge, and they lived on, undisturbed. This was until we showed up. Their scale-less bodies, covered with laterally running bony plates and their shark-like heterocercal tail (despite sharing no ancestry with sharks), all make the sturgeons very unusual animals. Evolution has been so slow that it is as if they were transferred here via time travel, intact in their primitive form. In their extraordinary lifespan of about 100 years, their body sizes cap at around eight metres and their weight reaches a metric tonne. They are easily among the largest fish present in freshwater bodies and may as well have inspired famous legends like that of the Loch Ness monster and many other long-feared underwater behemoths. But sturgeons are far from being dangerous, they are our victims and us, their assailants.
"With 23 out of 27 sturgeon species on the brink of extinction, they are the most critically endangered animal group according to the International Union for Conservation of Nature (IUCN)"
With 23 out of 27 sturgeon species on the brink of extinction, they are the most critically endangered animal group according to the International Union for Conservation of Nature (IUCN). These beings thrived for millions of years, until now. From time immemorial, sturgeons were prized for their rarity and elusiveness. Their meat was considered a luxury food, to be consumed on special occasions, by special people. But there is something else that has brought upon them the wrath of humankind – their roe.
Roe is the internal unfertilized egg-mass of fish. Most notably Beluga sturgeons are raised for their caviar, a prized luxury food. Initially a peasant’s diet, roe is now one of the most expensive edibles on the planet. Its nicknames, “black pearls” and “black gold”, fail to do justice with its actual price, which is far more in comparison, a whopping €10,000 per kg! A single lucky catch transformed the lives of fishermen, from poverty-stricken anonymity to one of comfort and joy. But this came at a price for the sturgeons.
Sturgeons are rare and elusive for a reason. Their longevity necessitates a slow procreation rate, otherwise, the water would be teeming with them. They mature very slowly; females can take up to 20 years to reach the reproductive age; males, too, require around 15 years before they produce viable gametes. Moreover, females don’t mate every year and mating usually resumes three to five years after the previous mating season. This is primarily the reason why overexploitation causes irreparable damage to sturgeon populations.
In the past overfishing has been the major threat to sturgeons. The value of their products inspired the merciless persecution of these hapless beings. The year 1977 witnessed the peak of sturgeon catch: 32,000 tonnes, the number was never matched again and has dropped steeply by 99 per cent. With the enforcement of protection laws securing sturgeons against human exploitation, the direct risk has largely been averted. But poaching and indiscriminate fishing practices such as using nets continue to haunt the fish even to this day.
Even though they may inhabit coastal waters and inner seas, sturgeons still have to migrate up rivers to spawn; other river-dwelling species also swim upstream to lay eggs. They travel thousands of kilometres for this purpose, but this voyage poses threats of its own. Infrastructure and dams constructed along the length of rivers interrupt their migrations, keeping them from reproducing. Predictable migratory patterns also put them at risk of poaching.
Sturgeons are also generally very sensitive to water pollution; they act as bio-indicators of pollution. Silt is especially destructive for their eggs. Sturgeon eggs are sticky and remain so for 30 minutes after being laid, which allows them to adhere to surfaces. With silt, however, this becomes impossible and the eggs are often wasted and drift away due to water currents. Similarly, the influx of saltwater, as a result of anthropogenic activities, is detrimental for the eggs. The heavy presence of motorboats is also a potential risk; impact with boat propellers is usually fatal and always painful. For the first time in over 200 million years of their existence, sturgeons face the risk of extinction.
These highly-prized beings deserve our attention and require our help to ensure their survival. Habitat restoration and a switch to sustainable development are a decent start, but a sense of responsibility is desperately needed for the general public. Sturgeon products ought to be boycotted to root out the problem. Water pollution, a consequence of unsustainable industrialization, must also be checked in time before it becomes a more serious problem than it already is. Fishermen must be trained to practice better fishing techniques, targeted towards readily available species, leaving endangered varieties in peace. Ex-situ conservation efforts are also underway in protecting these species from extinction. One fortunate thing is that they do lay a lot of eggs, so effective nourishment of the fry will allow us to reimburse the natural population for the losses they have sustained, once the natural environment has been made safe again. Care must be taken not to introduce another competitive species in the habitat of another species.
Most sturgeons are capable of breeding with members of other species from their order. If a mixture of sturgeon species coexists in an area, the possibility arises that members of both species might prefer to breed interspecifically (between species) rather than intraspecifically (within species). Different genotypes, or genetic variants of the same species, can shift the population gene pool towards a lower survival state. Genes tend to be modelled by environmental stresses, so any adulteration in this regard will have far-reaching consequences on the fate of the population. In the midst of all the gloom, there is also hope.
The WWF network has been working for the conservation of sturgeons actively with not only communities but scientists, civil society organizations and law and enforcement agencies to save and protect this extraordinary fish. They introduced a sturgeon policy in 2017 which mentions that by 2025 and beyond the level of exploitation of wild sturgeons should be reduced to a point where it no longer poses a threat to the populations through different initiatives but not limited to market transformation, traceability, developing incentives for fishing communities to reduce poaching/bycatch etc. The organization is also working on short and long term strategies for the conservation of sturgeons by partnering with TRAFFIC and fighting black markets in key countries by collecting evidence of illegal caviar trade, raising public awareness and advocating stronger enforcement of policies. Sturgeons, despite their remarkable adaptations and excellent survival history, have finally met their biggest threat ever - humans.
We are responsible for putting them in this condition and it is up to us to help them out of it. Experts claim that we may already have started the sixth mass extinction event in our planet’s history. If we keep on losing species at this alarming rate, life as we know it may cease to exist. Shakespeare’s resonating words: “like flies to wanton boys we are to these gods, they kill us for pleasure”, have been rendered ironic by recent events in the history of our planet. Nature is now like those flies and we are the wanton boys.