Hunting the Hunter: A Look Into the Overfishing of Sharks
Sharks and rays take a long time to reach sexual maturity, and when they finally can reproduce, they have very few offspring every 1-3 years. They do not produce millions of eggs as other fish species do, therefore they simply cannot replenish their numbers once they are hunted commercially. Generally speaking, all apex predators suffer from this biological limitation. They have evolved to hunt, not to be hunted.
Commercial fishing is devastating shark and ray populations all over the world, and still, some people doubt that the vast oceans can be depleted and that our practices are changing the natural systems. In fact, a recent study exposed that the number of sharks found in the open oceans has plunged by 71% over half a century, mainly due to overfishing. Three-quarters of the species studied are now threatened with extinction: to name a few, Thresher and Silky sharks are 72-90% reduced, and Dusky sharks off of the Atlantic coast are estimated to have plummeted by 85%. It is often argued that shark fisheries can be sustainable, but there are few to none that have proven to be that over time. Adding to the problem is illegal, unreported, and underreported fishing, destructive fishing methods and the high death toll of accidental bycatch.
It is predictable that our actions will be destroying the remaining populations of sharks and rays in a matter of years, not decades. The result is not only a loss of apex predators, but dire consequences for fish populations and coral reef health. It’s a domino effect that is far-reaching and complex, an issue that goes beyond just sharks and rays. In this article, we will go over the many facets of the commercial fishing industry that are pushing our oceans to its breaking point. If you would like to dive even deeper on this subject, please visit Shark Allies’ campaign page to end the shark fin trade and overfishing.
Industrial Fishing Methods are Destroying our Oceans
Despite some progress in US and EU regulations and recommendations by international conventions and scientists, the global devastation of our marine life and resources through large-scale commercial fishing continues. There is no escaping for marine life as millions of tons of fish and seafood are being taken by thousands of longline and purse seine vessels, bottom trawlers, factory ships and even ghost fishing gear. Commercial fishing is protected and promoted by governments and fisheries councils because it is seen as an industry that provides food and jobs. What isn’t always mentioned is the fact that in most countries it must be subsidized to continue. The problem is that this abuse is not readily seen by most of us. What happens out at sea goes on sight unseen. If we would see the devastation that happens every single day, we would be more outraged and demand a change immediately. We have technology, data and ingenuity to create better methods. What is needed is global awareness and involvement, and the political will to work in the interest of a sustainable future.
Bottom Trawling
This is by far the most destructive fishing practice, mega-sized trawling nets can catch more than 500 tons of fish in one pass. In the process destroying the sea floor by dragging heavy equipment across the ocean floor, essentially roto tilling everything in it’s path. Bottom trawling and dredging destroys 150 times more sea bottom than clear cutting destroys forests per year. That equates to 150x16,000,000 = 2,400,000,000 acres of sea bottom per year; a number so large as to be almost incomprehensible. Would you believe us if we said you can even see the sediment plumes from space? We wish it weren’t true.
According to Ibrahim Thiaw, Director General of the World Conservation Union, 80% of the catch brought up in one haul of a bottom trawl net is by-catch and thrown dead or dying back into the sea. Elias Chin, Vice-President of the Pacific island of Palau, stated recently that bottom trawling is responsible for 95% of the destruction of underwater habitats. The UN Food and Agricultural Organization’s statistics compiled over many years demonstrates that a mere 0.5% of global fish catches is contributed by bottom trawling operations yet those operations are responsible for the devastation of 2.4 billion acres of sea bottom each year.
Longline Fishing
Longline fishing is a fishing method where long fishing lines, containing thousands of baited hooks, are deployed in the open ocean to catch pelagic fish such as swordfish and tuna. They are left to drift, or “soak”, often for days, to attract fish. Unfortunately, many other animals end up getting hooked and ensnared. For example, it has been estimated that global longline fisheries kill somewhere between 160,000 and 320,000 seabirds annually. That unintended catch is called bycatch, which we will cover in more detail below.
In the longline tuna fishery approximately 5 million hooks get set each day on 100,000 miles of line. That is enough line to wrap around the entire globe four times every day. Longlines also pose a threat if they are lost or discarded at sea, where they will drift and ensnare animals sometimes for years, or until they finally degrade enough into smaller pieces, at which point they contribute to the overall plastic pollution that clogs up our ocean.
Purse Seine Fishing
Purse seine nets can be more than 1,000 feet in length. They are deployed around schooling fish, such as sardines, anchovy and tuna. When the nets are closed they scoop up everything that is within its circle. Because they are often set around floating debris or FADs (Fish Attractive Devices), where fish like to gather and juveniles find cover, the nets end up trapping and killing many oceanic species that are discarded as “incidental” or “unintended” bycatch, including dolphins, sharks, sea turtles and many undersized fish and many creatures that were using the FAD or debris pile as a habitat or for cover from other predators. Purse seine fishing is an indiscriminate way of fishing that produces a huge amount of waste, putting enormous pressure on fishing populations because it allows fisheries to take out too many fish, day after day.
Drift Gillnets
Gillnets are walls of netting that drift (“drift” gillnets) or are anchored (“set” gillnets) in the water, designed so that fish get stuck around their gills when they try to swim through. The netting can be up to two miles long and anchored hundreds of feet deep or left floating at the surface. Though researchers work to develop ways of reducing entanglement in gillnets, this gear has been banned on the high seas by the United Nations, as well as by many other countries. NOAA states, “Mesh sizes are designed to allow fish to get only their head through the netting but not their body. The fish's gills then get caught in the mesh as the fish tries to back out of the net. As the fish struggles to free itself, it becomes more and more entangled.” Gillnets inflict a lot of damage and are banned in many places. In some areas the size of the mesh is restricted to allow for smaller fish to swim through. But that does not address the many animals, anything from whales, dolphins and sharks to sea turtles and sea mammals that get trapped and killed in these curtains of death. Action Alert for Californians: support the Driftnet Modernization and Bycatch Reduction Act!
Commercial Fishing’s Wake of Destruction
‘Ropey’ photographed by Laurel Irvine in Guadalupe Island
Fisheries Management
There are many problems with the way fisheries are currently managed by government authorities. It starts with the fact that fish are categorized strictly as a resource. A bulk food that exists simply for the taking until critical levels are reached. Sustainability is judged by how fishing numbers turn out every year. Very little consideration is given to the intricate balance fish populations play in the larger oceanic system. As long as the same amount of a species can be caught every year, it is deemed a “sustainable” fishery. Fisheries scientists will oppose this point of view by saying it is an oversimplification. Clearly, there is more to the science of fisheries management than counting fish. But from the point of view of conservation, the constant argument supporting commercial take and the reluctance to protect species or whole areas from fishing always comes down to claims that there still are enough fish as evidenced by catch rates.
Fisheries management councils, in many cases, work to keep commercial fishing alive and booming. They rarely make conservation, or subsistence-level fishing a priority. Often these management councils are given the exclusive authority to make decisions on fishing policies and regulations, without there being any balancing conservation minded authorities within the government. The state of our oceans and the collapse of global fisheries is clear proof that this system is not working. Together, these mechanisms are the reason for weak regulations and a lack of enforcement. Add that to rampant illegal, unreported, and unregulated (IUU) fishing and the result is the massive over-fishing of all marine species.
Marine Protected Areas
According to the U.N.’s World Database on Protected Areas, 7.5% of the ocean is protected. But how accurate are these figures? And how protected are those areas? “MPA” has become a catch-all term for the many forms of management applied to the ocean, but it means different things to different people. The Marine Conservation Institute and its Atlas of Marine Protection, shows about 5% of the ocean managed in true MPAs. You can dive into the topic and its discrepancies here.
Ghost Nets
Galapagos Shark photographed by Stefanie Brendl
The fishing methods described above all have an additional deadly effect – their continued impact once they are intentionally discarded or lost at sea. Giants balls of line, tangled up gear and nets float for years along the ocean currents, trapping and killing animals day after day, until they get stuck on a coral reef, ensnaring plants and animals, or break down into smaller pieces that float ashore, sink to the deep or become part of the plastic soup that is polluting our oceans. We will dive into the intricacies of ghost nets and how you can help coming later this month! According to Nature.com, 46% of the plastic in the great pacific garbage patch by weight came from fishing nets. So, while tackling single-use plastics is of great importance, we simply cannot address the full plastic pollution picture without going after the outlined destructive fishing practices as well.
Subsidies
Estimates show that of the $35.4 billion of global fisheries subsidies provided in 2018, 19% went to the small-scale fishing sub-sector (SSF), including artisanal, and subsistence fisheries. Whilst more than 80% went to the large-scale (industrial) fishing sub-sector (LSF). It is time for governments to act and end harmful fishing subsidies. Stopping some payments would improve ocean health, economies, and food security worldwide. Not all subsidies are bad. Some, for instance, help countries better manage their fisheries or protect areas of the ocean that serve as fish breeding grounds. It’s critical that these subsidies remain in place. However, governments pay more than $22 billion a year in damaging types of subsidies, known as capacity-enhancing subsidies, to offset costs such as fuel, gear, and vessel construction.
More than 160 leading environmental organizations have signed on in support of ending these unsustainable funding practices and are requesting that the World Trade Organization take action. You can support the Stop Funding Overfishing campaign here. All of us need to worry about marine resources, this is not a fringe cause. It is time to ask our government agencies to acknowledge their failure and to hold them to the task of developing regulations and enforcement that works in the interest of sustainability instead of only looking out for short-term commercial profitability. As an immediate step, we must support the establishment of marine sanctuaries and protected areas around the world, which are not only a haven for marine life but also our best chance to replenish fish populations.
Bycatch & Unintended Catch of Sharks
Infographic by Greenpeace
Bycatch is not always accidental. Global bycatch may amount to 40% of the world’s catch, totaling 63 billion pounds per year. Less than 20% of existing fisheries management plans include incentives for fishermen to minimize bycatch. Mitigation methods exist, but they are not used because they may be more time-consuming, more expensive, or simply avoided because the bycatch is not quite as unintended as they would like us to believe. That is certainly the case with sharks. The excuse that all sharks are unintended catch really doesn’t hold up in many cases. But legally, as long as the sharks don’t seem to be targeted, and are on the list of permitted bycatch species, it’s essentially a no-limits shark fishery.
Long line fishers know how to fish in order to avoid sharks. They have the option to select the area and the depth the lines are set that makes it less likely to catch sharks. They can use gear that lets sharks break loose. Switching back to nylon instead of steel leaders, and the use of weak or soft hooks would ensure that sharks could get away. They can make the effort to release sharks, like they used to. Many animals would survive and recover. Because of the value of fins, sharks are kept, if not targeted. And the argument that they were “unintended” catch is used as a convenient cover that makes it legal, even if the fishery does not have licenses as a shark fishery. It is truly a free for all and no one being held accountable. While this seems like an insurmountable obstacle, what does work is to devalue the sharks by not allowing the sale of fins. If there is no money to be made, shark swill be avoided, as they are big animals that take up a lot of valuable storage space on a ship. As long as we allow shark fins to be traded because they are part of a sustainable fishery or because they were caught as so-called bycatch, we are keeping the doors wide open for sharks to be targeted.
In longline fisheries as much as 40% is wasted; on shrimp trawlers, as much as 80-90% of the catch gets thrown back overboard! Millions of tons of marine life wasted. Around 50% of the global taking of sharks from the ocean occurs from bycatch in high seas pelagic longline fisheries, that is 50 million sharks per year, echoing comparable statistics as the shark fin trade itself. Generally, most fisheries data obtained regarding elasmobranch bycatch don’t provide species-level data. Instead, mass/weight of elasmobranchs caught is obtained and estimated. Global estimates are likely underestimates, as much bycatch data is not reported at all, data on bycatch can't really be taken from all countries/fisheries.
How you can you help? Without preaching vegan-ism, think about what you eat. Generally speaking, that means eat less or smaller portions of fish, eat low on the food chain (sardines, not tuna) and eat locally, sustainably harvested (i.e. pole caught) seafood. Better yet, find a good replacement (veggies, nuts, seeds) that give you the protein and Omega-3 you need, without the toxins you get from fish these days. To read more about overfishing, fisheries subsidies and the farming of fish, check out this blog and article by Coty Perry in Shark Allies’ Oceans Knowledge Base.