Sharks are underappreciated for their positive impact on fishery health

Sharks play an integral role in maintaining marine ecosystem health, and yet their numerous contributions often go unnoticed. Shark attacks on humans, despite their rarity, garner far more attention than the species’ daily actions that help to balance food chains and preserve fisheries. As we celebrate Shark Week, let’s remember that in spite of their sometimes unwelcoming appearance, sharks are incredibly important to our oceans and we must act to prevent further population declines.

 

 

The past several decades have proven not the kindest to several of the world’s fisheries. Remarkable declines in fishery health should concern all of us, not just the 41 million people who hold jobs in the fishing industry. Productive fisheries help to improve global food security, promote economic growth, and ensure environmental health.

 

This downward trend in fishery stability is attributable to a number of sources, but corresponding declines in shark populations are of utmost concern. A combination of overfishing and unsustainable catch techniques has resulted in the loss of millions of sharks each year.

 

An absence of healthy shark populations significantly disrupts the trophic balance of marine ecosystems. As apex predators, sharks play a crucial role in stabilizing populations throughout the food chain, with effects on species ranging from primary producers such as coral to barracuda and other upper level predators.

 

Without the stable presence and influence of sharks, the herbivorous fish that we see as commercially valuable–such as crustaceans and shellfish–experience significant population decline. When sharks are removed from coral reef ecosystems, other tertiary predators thrive and subsequently decimate these critical primary species. The depletion of herbivore populations leads to exacerbated algal growth, and we end up with quickly diminishing coral health, thereby transforming once colorful landscapes into nitrified disasters.

 

The presence of sharks may impact the physical characteristics of other species in addition to altering their population levels, too. A recent study found that fish in areas with lower shark populations exhibited smaller eyes and tails. Given that sharks often target prey that are weak or sick, they clearly assist in the maintenance of healthy gene pools and promote natural selection. The findings of this study are not surprising.  

 

A number of solutions are available to aid in the reversal of the devastating trend of shark population decline. Exploring alternatives to harmful tools like drift gillnets–fishing instruments that attract excessive levels of bycatch–would help in facilitating recoveries in shark populations and fisheries as a whole.  

 

Sharks, primarily known for their massive size and impressive strength, are seldom recognized for their critical contributions to preserving fisheries. Few are aware of the severity of shark population decline and the vast environmental and economic ramifications that will arise should the current trends continue. Together, we can (and must) save sharks–and global fish populations–by promoting sustainable fishing practices and educating individuals on the importance of this issue. If we don’t, the ocean of the future may look vastly different than the one we know and love today.

Ronnie Thompson