Last month’s article on bottled juvenile sharks for sale as souvenirs touched on the disclaimer put forth by those selling them that they are merely bycatch from legitimate fishing operations. Fact aside that the shark pups cannot be bycatch of commercial deep water fisheries because they are found in shallow waters along coasts and estuaries; the term bycatch conjures up yet another serious threat to our oceans and marine life.
Bycatch is an innocuous sounding term until we delve deeper. Commercial fishers would have us believe that bycatch is nothing more than a few worthless, pesky critters who become tangled in nets or hook themselves on long lines.
In reality, while bycatch has not, historically, been documented by most fishers, studies by innumerable conservation and scientific organizations have proven that approximately 25% or more of all marine life hauled onboard by commercial fishers is considered bycatch. Defined by the fishers themselves, bycatch is undesired or unmarketable species. As they haul in their nets and long lines the bycatch, if not already dead from suffocation or drowning, is quickly dispatched and thrown dead or dying back into the sea.
So, what constitutes bycatch? Porpoise, whales, sea turtles, swordfish, the batoids (rays and skates), sharks, sea birds, seals, sea horses, invertebrates and fish that aren’t the targeted species suffer the fate of bycatch every day around the world.
How many are killed? Scientists with the United Nations estimate roughly 25% of all take by commercial fisheries is bycatch that is thrown back into the sea, dead, dying, and wasted. Based on tonnage in the holds, that 25% calculates to some 27 million tons of bycatch thrown back into the sea annually, never to reproduce their species.
Blue sharks in the North Atlantic were once prolific but researchers now have difficulty finding even a few. Thousands upon thousands of Blues were killed and thrown back as bycatch in long line fisheries. Many other shark species around the world have suffered and continue to suffer the same fate by the millions.
Porpoise die as bycatch. Since the Yellowfin tuna fishery began in the Pacific, evidence, both scientific and anecdotal, leads scientists to the conclusion that some 6,000,000 dolphin died as bycatch in the Pacific alone.
Observers of shrimp fisheries have noted time and again that for every 1 pound of shrimp hauled aboard, 2-10 pounds of bycatch come up in the nets. This bycatch contains sea horses, living shellfish, corals, anemones, and bottom dwelling fish.
As I was researching this article I received word that 5 porpoises drowned in nets just a few weeks ago off the coast of England during the annual sea bass fisheries. Their carcasses were found floating at the surface.Deep lacerations on their bodies indicated they struggled futilely to free themselves from standard trawl nets as researchers from St. Andrews University continue to test grid trawl nets.In 2003 during grid net trials consisting of 82 hauls the grid nets brought up only 2 dolphins compared with 28 dead dolphins in 49 hauls with standard nets.
In the spring of 2003 the World Wildlife Foundation issued a promising report on the success of new tuna fishing practices in the Pacific.Nets similar to the grid trawl nets had reduced dolphin bycatch deaths from 100,000 in 1986 alone to 1,500 per year using the new nets and modified hauling tactics.
While 1,500 remain far too many, advancements in nets and fishing practices are on the horizon. Countries with foresight are signing on to the new practices, realizing that upsetting the balance of life in the seas leads only to environmental and economic tragedy.