Types of Commercial Fishing Methods
Fishing is as old as hunting and gathering. In fact, whereas livestock breeding has replaced hunting, and gathering has evolved into agriculture, fishing is still, in great part, the last endeavor undertaken to capture wild animals for food. Furthermore, the basic components of fishing i.e., lines, hooks, nets, and traps are still in common use. Over time, great improvements in fishing gear, vessels and fish finding electronics have been made, but the basic elements remain the same. People still must climb aboard a boat, sail away from home, find, capture, and transport their catch back to port, often with great peril and at risk of their lives.
Fish are the last wild thing we eat, and there’s something special about that.
At Fulton Fish Market, customers often ask “How are my fish caught?” I think most people would be surprised to know the many ways there are to catch fish.
First, fishing boats are functional and not all are created equal. Each one is designed and constructed based on their intended use. The depth of the water, the size of the fish they’re after, the length of their trips, weather, the size of the crew and what kind of fishing gear will be used all go hand in hand with design and functionality. Different fisheries have their own preferred methods and these differences in intended purpose and targets bring about a variety of fishing methods all around the world.
We turn it over to our Head of Quality Control, Robert DiGregorio, as he presents you with some of the most common methods of catching fish and shellfish.
A common kind of trawler is the otter trawler. These trawlers have two otter boards called “doors” attached to either side of the net. These doors can weigh several hundred pounds and when towed behind the boat, flare out and keep the net open. The mouth of the net is typically 30 feet to 100+ feet, depending on the size of the vessel and the fishery. Fish taken this way include porgies, whiting, butterfish, any small schooling fish that swim in the mid-water column. These boats typically fish for one day at a time and can catch hundreds, even thousands of pounds of fish. In Alaska, huge trawlers can catch tons of Alaskan pollock in one tow, and over one million tons are taken this way every year.
Another kind of trawler is the bottom trawl. A bottom trawler is the same idea as the otter trawler, but with weights added to keep the net on or near the seabed. These nets are then dragged along catching “ground fish” such as cod, haddock, and pollock. Flatfish such as flounder, dab, and grey sole are also targeted by bottom trawlers.
The shrimp fishery has a different take on trawling. They typically use a setup called outrigger trawlers. The net is pulled by booms usually fastened to the mast and extended out over the sides of the vessel when shrimping.
Beam trawling is still used to some extent in the US but is more common in Europe. A beam trawler employs a trawl net held open by a horizontal transverse beam. Rigged this way, doors aren’t needed.
Another kind of old-fashioned way to rig for trawling was the side trawler. The net was dragged alongside the boat with gallows rigged fore and aft. This was very common until the 1960s when they were slowly replaced by stern trawlers which drag the net behind the boat.
A different manner of trawling employed worldwide is pair trawling. This has certain advantages, for instance, two boats can tow a larger net and theoretically catch more fish. The two vessels towing the net don’t need doors to keep the net open because the lateral pull by the boats does that; also, less fuel per vessel is used and they can usually tow faster if they want to. Pair trawlers targeting cod off the New England coast reported catches up to six times what the average single trawler records.
Let’s get off the trawlers now and get on a gill netter.
A set gillnet employs floats and weights like we described but is fastened to poles, making it stationary. The net is set out between the poles forming a wall in the water for the fish to become trapped in. This kind of fishing, and gill netting in general, is very regulated. How and where they can deploy their nets, how close to shore, how deep in the water the net is set at, the mesh size, etc. are some of the many ways this fishery is managed.
A different kind of gillnet is the drifting gillnet. Drift gillnets are not fastened to stakes or poles but are allowed to drift with the current. The ratio of floats on top and weights on the bottom control the depth the net stays at and keeps it vertical in the water.
I remember years ago in the spring, when shad season would come to the Hudson River, only stake nets (stationary gillnets) were permitted up by the George Washington Bridge, but further up in the Poughkeepsie area, only drift nets were allowed. Think of the skill these fishermen had to have to keep their nets at the right depth and in the right current of the river so it didn’t drift into the shipping lanes. Knowing where they would be, day and night, finding them, pulling them, retrieving the fish and redeploying them, often at night, often in bad weather. Very hard work and requiring a lot of skill. Knowledge of the river, the tides, the moon, the movement of the fish, the coming weather, so many things to consider. In between sets, they were packing fish, transporting fish, repairing nets, and trying to sleep. During shad season, these men lived in shacks by their wharves because they were basically working night and day. I spent some time in these camps and I can tell you fishing is a tough life, definitely not for everybody. And nothing is guaranteed! You never know if the nets are coming in empty or full.
Drift nets are not only used on rivers. Huge ocean drift nets were used until 2002 when the United Nations General Assembly established a moratorium prohibiting their use in international waters. Miles long and up to 35 meters high, these nets were indiscriminate and many marine mammals were inadvertently being trapped as bycatch. Many countries have also passed legislation banning their use. Gillnets, when used responsibly, produce very little bycatch and have minimal effect on marine environments.
Seine NetsTrawlers and gillnets aren’t the only catch methods that use nets. There are also seiners. A seine is a net used to surround a school of fish. It hangs vertically like a gillnet but the ends are drawn together to surround the school. Small seine nets can be used by boats right off the beach while large seiners can catch tons of fish at one time.
A type of large seiner is a purse seiner. These are large vessels and the net, the purse seine, is deployed by one or more smaller craft to surround a large school of fish. The bottom of the net has rings with a line running through them. At the right time, the “purse string” is pulled, drawing the bottom of the net closed, like a purse. Herring, sardines, anchovies, even certain kinds of tuna are caught this way.
Pound NetsPound nets produce some of the best fish you can buy. They are not really nets, per se, but more like a corral. There is a fence leader that is placed where a school of fish are known to pass. These leaders and nets are anchored to the bottom and are set in near shore areas. The fish are led into a mesh funnel that ends in an enclosed pound or trap. The fish are concentrated in this pound and are then removed with dip nets and packed up. These fish used to be packed in barrels with ice brine when I started, but these days more are packed in boxes. Because the fish are packed and shipped out so fast, they arrive still in rigor and super fresh. Depending on where you are, different fish are caught like this, such as butterfish, porgies, croakers, and weakfish.
Bully NetsThe bully net is a hand held scoop net attached to a pole with a line attached to the back of the net. Usually during the daylight hours, spiny lobsters hide in crevices in 10 to 15 feet of water. The only way to get them was with lobster pots or scuba diving. But at night the lobsters come in close, in 1 to 4 feet of water, and they’re much more active. They walk around looking for food, feeling safe in the dark water. That’s where the bully net comes in. With the water illuminated by the lights from the boat, the lobster is spotted on the bottom. You position the net just above the lobster and then quickly plunge it straight down, trapping it. At the same time, the line is dropped and the net is released, surrounding the lobster. Then you drag the net backwards toward the handle causing the lobster to swim into the back of the net, and it’s caught. The whole procedure takes seconds once the lobster is spotted.
Hand LinesHandlining is a very simple way of fishing that is still used today. This is a real old school method of catch. No nets here, just a baited hook and a line, sometimes with branch lines, not attached to a rod or pole of any kind, but rather held in the hands. When the fish strikes, the line is pulled in, hand over hand, until the fish is landed. A mechanized reel is used on some boats if available. Don’t think only small fish can be caught this way. Huge swordfish and tuna are fished this way in certain parts of the world. In General Santos City, in the Philippines, I stood and watched the tuna fleet return with literally hundreds of large 100+ lb yellowfin tuna, all caught by handliners. I was pretty amazed.
Pole & LineStill used in many parts of the world, including the US, pole and line fishing is also a simple technique in that it doesn’t require sophisticated or elaborate equipment. A rigid pole, these days usually made of fiberglass and around 6-9 feet, some strong line and a feathered lure with a barbless hook is all it takes. Targeting skipjack and other small tuna such as albacore or juvenile yellowfin, the fish are first lured to the boat by using bait and/or by spraying the water with a hose. The spraying of hose water gives the illusion the water is alive with small, jumping fish driving the tuna into a feeding frenzy. The fish begin to gather and the fishermen position themselves all along the rail, depending where the fish are, and throw their lines in. When the fish strike, they are heaved aboard, not reeled in, but heaved on deck where the fish release themselves from the barbless hook. Several tons of tuna can be taken this way in just a few hours. Interestingly though, during this hectic activity, if a tuna falls back into the water, something happens and the whole school might run away. The fishing can end as quickly as it began.
LonglineAnother very productive kind of fishing involving lines is longline fishing. These kinds of boats use a very long main line with branch lines spaced out. These branch lines have hooks baited with mackerel or squid, with sometimes thousands of them spread out on a line 20 to 30 miles long. Every 12 to 24 hours the line is mechanically retrieved, fish taken off, re-baited and reset. Longliners are used around the world, and longliners from this area routinely fish for tuna and swordfish and, when rigged as bottom longliners, catch tilefish. Longline fish are usually very high quality and their efforts are very efficient, but in the past there was a bycatch problem. Changes have been made to some of the gear to correct this, namely circle hooks. Circle hooks make it harder for sea turtles to bite and swallow the hook, greatly reducing turtle mortality. The use of weights to sink the lines faster, special gear to scare away birds, and making sets only at night, along with other actions, have greatly decreased incidental catch.
Hook & LineWhile broadly speaking, the hook and line fishing method can define all ways a fish is taken by a hook attached to a line and discussed earlier under such headings as “Longline” and “Handline” here we’re referring to more specific ways. All kinds of fish may be taken commercially using hook and line, like red snapper, pompano, vermilion snapper, king mackerel, and black sea bass to name a few. Some boats use rods and reels. They might have 5 or 6 lines in the water at once rigged with 2 hooks on separate branch lines. When the fish hit, it can be pretty hectic, reeling them in, taking them off the hook, re-baiting, meanwhile another two lines have fish on them. This is very fast paced fishing.
Other boats may have what looks like a long fiberglass arm, and from that arm a line is set out with 20 or more baited hooks. After a set time, a big electric or hydraulic reel brings the line in with, hopefully, fish on every hook. In the Gulf of Mexico, fishermen use the oil rigs as FADs (fish aggregating devices) and fish their lines right next to them, practically in their shadow.
TrollAnother catch method is trolling. Fishing lines, either baited or with lures, are drawn through the water behind the boat. One advantage of this kind of fishing is it can be used to catch faster swimmers like albacore and salmon. The boat moves at a speed and the lines are set at a depth appropriate for the species. Downriggers, long poles with several lines attached, are used to keep the lines spread out. There are different ways to catch salmon, but during wild king salmon season “troll kings” are considered the best.
TrotlinesA trotline is a heavy fishing line with shorter lines branching off of it. These shorter lines, called snoods, are attached to the main line by small swivels. Typically set in rivers and streams, the line with all its baited hooks can be set along the shoreline or can be strung across the width of the river, if legally permitted. Weights are used to hold the line at the desired depth in the water. When setting the trotline it’s important to consider undergrowth, currents and river traffic. Trout are sometimes caught this way, which leads people to mispronounce the term and call it a “troutline.” But trout aren’t the only fish taken by this method. Hackleback sturgeon, the last wild sturgeon still fished commercially in the US, are still taken this way.
Just as there are many ways to catch fish, there are also many different ways to harvest shellfish. Location, the specific species, the depth of the water and local fishing regulations all lend to determine which method is used. There are many nuances to all of them as well, and every commercial digger or bayman has their own time-tested secrets. Here are some descriptions to help you understand these methods a little better.
Traps, or pots (the terms are interchangeable) are usually made of wood, wire netting or plastic. They can be square, circular or rectangular, and the size varies from a large suitcase to huge king crab traps big enough to stand in. The size and shape may vary depending on the targeted species, but they all work pretty much the same way. There is a cone shaped entrance that the crab or lobster can easily navigate, but it’s nearly impossible to get out. To help ensure that undersized animals are not also captured, there is a small opening in the mesh called a cull ring to let the small guys out. These traps are usually laid out in strings, with several traps attached to buoys. When the boat comes back to haul them in, it captures the buoy line, attaches it to the winch and brings them up. They are then emptied, re-baited and set again. This is the preferred way to fish for crabs and lobsters, but some species of fish are targeted this way as well, such as black sea bass, blackfish, and eels.
Recently, there has been an interesting development from the UK. They have been experimenting using traps with disco-like LED lights to catch scallops. They were originally targeting crabs, but found that scallops were irresistibly drawn to the lights. Marine scientists say it’s like a scallop disco! Light up the traps and they can’t wait to get in! In studies, 901 traps without lights caught 2 scallops, but 985 traps with lights caught 518 scallops. This has the potential to start a whole new fishery, and also has great environmental implications. Whereas traditional scallop dredges can disturb the bottom quite a bit, this has absolutely no adverse effect on the marine environment.
Wrinkle DragA wrinkle drag is a very small, lightweight net, 6 feet or less, used behind a boat in shallow water to catch periwinkles. This, and gathering by hand, are probably the most common ways to do so. Periwinkle gathering, or “wrinkling” is pretty unregulated, the only requirement in most places is a valid commercial fishing license.
Suripera FishingSuripera fishing is a very unique method of shrimping that has existed in certain parts of Mexico for decades. It involves a small boat, called a panga, with a billowing sail rigged to a central mast. Behind the boat, the fishermen release several nets with small openings specifically constructed to catch shrimp. These nets are designed to catch only one kind of animal and to prevent the capture of non-targeted species. This is “selective fishing gear” at its best. Each net has three compartments, and as the nets are towed, the shrimp enter the large, broad chamber and are funneled into the smaller compartments at the back of the net. These smaller compartments are enclosed and capture the shrimp. A good tow can produce 500-800 pounds of shrimp. This is a very innovative approach to fishing. It is environmentally friendly, responsible, and a very sustainable fishing method.
DiversScuba divers enter the water with either a spear gun and/or a basket. This is the way to harvest sea urchins. This is an environmentally safe method with no damage to kelp forests or the ocean floor. While keeping an eye out for predators, divers swim up to the urchins and pick them like flowers, being sure not to take ones that are too small and leaving enough to spawn for next season.
Rock lobsters are also taken this way by some lobstermen instead of using traps, again being sure to not take any that are undersized or with roe.
Ever see “Diver Scallops” on a menu? These are inshore scallops actually harvested by hand. Depending where they’re diving, the scallops are usually in the 20-30 range, although I’ve seen larger ones from Maine.
TongsTongs are used for digging clams. They are long poles with sharp, toothed baskets attached to each pole. The poles are typically 10 to 12 feet long and operate similar to scissors. When you open your hands, the baskets open; when you close your hands, the baskets close. With the baskets open, you work them into the bottom and wriggle them around some. Then you close the baskets and shimmy them up on deck and dump your clams. I can tell you from personal experience this is tough work. You stand there, for hours on end doing this over and over until you’ve had enough for the day. In nice weather you think, “This is a great way to make money!” But in the freezing cold, sweltering heat, rain or wind other thoughts about digging clams come to mind.
Hand Dug/Hand HarvestedSoft shell clams, such as steamer clams, are hand harvested with short, handheld rakes or forks. They kind of look like a gardening tool, and at low tide you go out on the flats, stoop over and start carefully digging.You look for a little hole in the sand and dig 3 to 8 inches, being careful because their shells are so fragile. If the sand or mud is soft enough, you can dig by hand. This is backbreaking work as you are stooped over the entire time you are working.
SaltRazor clams are hand dug like other soft shell clams, but these require a little ingenuity. First, because they have extremely fragile shells, and secondly because they can dig so fast you might not be able to catch them! Studies have shown razor clams can dig 24 inches in a minute. You can use a shovel to dig for them, but an easier, more efficient way is to use salt. A lot of diggers use a salt gun that injects a salty solution into the holes to help harvest razor clams. Typically within a minute or two of injecting the salty solution, the razor clam will lift itself almost out of the hole and all that’s left to do is pluck them out of the sand.
Post Hole DiggerOn the West Coast, a common method is to use something that looks like a post hole digger. You find where you want to dig, (look for the dimples in the sand), and wriggle the post in, twisting a little as you do it. When it’s extracted, a tube of sand comes with it, and inside that core of sand are the clams.
A dredge is a metal framed out rectangle, about 14 feet across, depending on local regulations. Attached to this frame is a large, metal mesh "bag" that looks similar to a chain link fence with 4 inch links to keep out the undersized fish and shellfish. There is an open mouth in the front of the frame and mesh bag. The boats can be rigged to drag from the sides or from the stern. The dredge is dragged along the bottom and everything that gets stirred up ends up in the bag. It is hauled back on board, emptied and deployed again. Scallops are typically fished this way.
Huge hydraulic dredges are used to target shellfish, like sea clams, which are found at depths up to 120 feet. Modern technology has made working on these boats a lot easier than it used to be. The dredge is set on the bottom alongside the boat and usually the tow is about 10 minutes long. These dredges have water lines to jet water along the bottom to make it faster and easier to tow.
Mussel CultivationOnce upon a time most Americans didn’t know or care about mussels and wouldn’t touch them with a ten-foot pole. Back then mussels were found all clumped together on rocks or pilings and were sold barely cleaned, most with barnacles and beards and replete with little crabs. People just didn’t want to bother with them. In the 1970s mussels began to be cultivated which made a huge difference. They now come to market clean, meaning no barnacles, no beards, and no crabs. Mussels' popularity has soared as a result of this. The big reason for their rise in popularity is the way they’re grown out. During spawning season, wild mussel seed is collected by suspending fibrous lines in the water and hatchery seed is collected from mussels spawning in the hatchery tanks. These seeds are then put into long “socks” and hung from rafts. Grown out like this, they are safe from predators and barnacles and all the other problems that wild mussels have. After 12 to 15 months, they are harvested and brought to the processing plant where they get washed, graded and bagged.
Another way to cultivate mussels is on the bottom of the ocean like wild mussels. They can get clumpy, with beards and everything, but this way has advantages. The mussels grow heartier and larger, with thicker shells and plumper meats.
Keep in mind that oyster cultivation is different from fish farming in several important ways. Oysters don’t have to be fed, as they filter their food the same way wild oysters do. They eat only what they would in the wild. They are not vaccinated or given antibiotics or medically looked after in any way. They are actually more alike than different from purely wild oysters.
One popular way of cultivating oysters is bottom or beach culturing. The spat is spread on the bottom and, while they don’t adhere to rocks or each other like wild oysters do, they grow and develop the same as wild oysters. Bottom culturing produces very hearty oysters, with thick shells and lots of meat. However, they are vulnerable to predators.
Cage culture is one way cultivators employ off-bottom methods to avoid danger from predators. These are large cages that house grow-out mesh bags full of baby oysters and keep them safe. Some farms use this method exclusively, while others may take the oysters out of the bags and bottom culture them to finish their growing.
Another oyster cultivation method is rack-and-bag culture. The oysters are placed in grow-out bags and tied to steel racks. The oysters are safe from predators and have plenty of room to grow. They don’t have to filter as much sand and silt as bottom cultured oysters do, and therefore grow faster with a deep cup.
Tray culture is a lot like using grow-out bags, but instead the oysters are placed in large trays. The trays function and serve the same purpose as the bags. An advantage to using trays is that they can be stacked to save space.
Another off-bottom culture method is suspended culture. Here the oysters are in grow-out bags and tied to lines with buoys that float on the surface. The bags are suspended vertically and rise and fall with the tides. Some suspended culture methods use cages or trays attached to a long line that is hauled in to tend to the oysters. Either way, the oysters are constantly flipped around, moved up and down, get plenty of nutrients and tumble naturally.
Surface Culture/Floating Culture
Different gear can be used, but whether it’s bags or floats, essentially all surface gear is allowed to just float on the surface of the water. These oysters are never dry, get great wave action, and get tumbled naturally.
Longline Suspension Systems
Longline suspension systems are a variation of off-bottom oyster culturing. In this procedure long ropes with seedling oysters are attached and suspended in the water. They are usually suspended horizontally and staked one to two feet off the bottom. Sometimes in deeper water they may be suspended vertically. Either way, growing out this way they have more interaction with the environment and develop sturdier shells and firmer meats. These oysters get a lot of wave action and rise and fall with the tides. It takes a stronger oyster to remain attached to the line during all this agitation than it does to lie in a tray, as in suspended tray methods.
There are many variations of the catch methods listed above depending on what part of the world you’re fishing and what you’re fishing for. Whether it’s a small-scale artisanal fishery or a large industrial factory ship, every fisherman has their own fishing secrets, their own methods and their own techniques. Their own finesse for getting it done. They all contribute to our nutrition and to our health, both today and in the future.