Longline Fishing Leads to Drop in Sea Life Populations

Our oceans are vast and largely unexplored with marine life we have yet to discover; populations of fish are living completely beyond the reach of human interaction. But for the species we do know, the demand is high and the fishing industry continues to expand, developing new techniques and maintaining the traditional ones, often with a lack of regard for the environmental effects.

One such technique is longline fishing, which is like traditional hook and bait fishing, but on a much larger scale. Instead of one rod and line with one hook, longline fishing can have thousands of baited hooks on one line, stretching across miles of ocean. It’s true that if you are tasked with commercial fishing for large quantities of swordfish, tuna, halibut, and sablefish, longline fishing is effective but there’s a catch...

Longlines can be used in various ways according to where the hooks are placed in the water column. Baited hooks on branch lines, or snoods, can be attached to the main line and hang anywhere between the water’s surface or far below in depths exceeding 3,600 feet. With hooks that reach out far and deep, longline fishing puts more than the targeted fish at risk. It’s time to stop and consider the effects of accidental catches of seabirds, turtles, marine mammals, and sharks.

Seabirds are especially vulnerable as the lines are setting. The bait is often a deadly tempting source of food for endangered species such as the albatross and petrel. Hundreds of these birds die each week from longlines as they get tangled or receive serious wounds from the hooks. Some fishermen and companies have attached streamers to scare the birds away or set hooks deeper than the birds can dive. In some cases, lines are set at night to avoid birds altogether. With some diligence there may be hope in reducing the number of albatross deaths but none of these measures can protect the creatures that dwell beneath the surface.

These hooks may be baited for fish but turtles and marine mammals, such as whales and dolphins, are often attracted to the light sticks and food meant for fish. Turtles, already an endangered species, can get caught in the wire or become seriously injured by the hooks. On the bright side, other fishermen are using hooks that won’t cause as much physical damage like the traditional ‘J’ hook. Teaching fishermen how to perform live-saving operations for entangled animals can go a long way towards helping these endangered creatures.

Another creature severely affected by longlines, one of the most infamous of the seas, is the shark. Painted as toothy, evil predators in the media, sharks are creatures at the top of the food chain whose numbers are rapidly dwindling thanks to longline fishing. Their capture and their deaths can be accidental, but in too many cases, they have become the target. The shark fin industry is a booming one accompanied by unsustainable and cruel practices. Longline fishing is a highly successful technique to lure and catch sharks, and fishermen funded by companies and corrupt governments have capitalized on it, cruelly killing thousands of sharks just for their fins. Often, sharks caught on a long line are reeled in for their fins and thrown back to the sea to drown and bleed to death. In Costa Rican waters alone, scientists have seen a 60 percent decrease in the shark numbers in the last decade.

What can we do? We have to speak out. We have to reveal the ongoing ecosystem damage that takes place far away from the public eye thanks to irresponsible commercial fishing. By raising awareness and reaching out to governments to implement stricter fishing regulations, combat illegal fishing operations, and protect endangered species, we can change the future for these creatures.


Learn more about longline fishing:

The Humane Society of the United States - Longline Fishing Threatens Seabirds and Other Marine Life

NATURE’S Shark Mountain



 (Image via Blue Channel 24)


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-Written by: Inés de Sequera