The Gulf Stream

The Gulf Stream

If you happen to catch a daybreak ride over the Bonner Bridge that spans across Oregon Inlet, or a North Carolina Ferry at sunrise that skims across Hatteras or Ocracoke Inlets, chances are you will encounter a fleet of charter boats, single file, making their way west into the ocean. These charter boats have the same destination and goal in mind - the Gulf Stream - for some of the best deep sea fishing along the East Coast.

The coast of North Carolina is one of the best launching points for Gulf Stream access, located just 12-15 miles off the beaches of the Outer Banks, and the prospect of reeling in the big one attracts countless fishermen year after year.

But what is the Gulf Stream and why are its waters so significantly different from the cool breakers just off the beach? Why is it a harbor for countless species of fish and ocean life that would otherwise have no business being located off the coast of North Carolina?

The Gulf Stream is, essentially, a 40-50 mile wide current that runs through the Atlantic Ocean, but its breadth and speed can categorize it more accurately as a river. Like all other currents throughout the world, the Gulf Stream is formed by the sun, the wind, and the water.

Light and heat beams from the sun and hits the earth more directly at the equator than at the poles. Naturally, this means the air temperature along the equator is significantly higher.

Because heat moves from warmer to cooler bodies, this hot tropical air moves towards the poles in large currents that force the cold air at the poles back towards the equator. The process also causes winds, which blow across vast areas of ocean and pull the surface water in the same direction, especially where waves increase the friction between wind and water. The Earth rotates from west to east and moves under the atmosphere at the same time the warm air moves north and south towards the poles.

This makes the pole-heading currents appear to curve to their right in the Northern Hemisphere and to their left in the Southern Hemisphere. Off the eastern coast of the United States, warm winds and water sweep up from the equator toward the pole, curves to the right, and moves into a clockwise circular pattern over the Atlantic Ocean in its journey to bring cool polar air back to the equator. This warm rushing current is the Gulf Stream.

The Gulf Stream begins off the Coast of Africa where the river of ocean water, called the North Equatorial Current, flows west to the coast of South America. Once there, the shape of the continent forces the North Equatorial Current to fork into two branches: one passes into the Caribbean, while the other flows northeast towards the West Indies. Eventually, the two separate "rivers" rejoin and flow through the Straights of Florida at an incredibly fast pace.

The Mississippi River and the Amazon River move water at roughly 0.6 million cubic meters per second. By comparison, the Gulf Stream, as it flows and forms off of Florida, moves at approximately 30 million cubic meters per second.

From this starting point, the Gulf Stream flows parallel to the East Coast of the United States, increasing speed and picking up more water as it approaches the Carolinas. Off the coast of Cape Hatteras, the Gulf Stream reaches an estimated 80 million cubic meters per second. An east-blowing wind separates the Gulf Stream from the continental margin at Cape Hatteras. Here the Gulf Stream creates a countercurrent that flows south and west, but the main part of the Gulf Stream current continues north and slightly east, passes near the Grand Banks (internationally known fishing waters,) goes south of Newfoundland, and continues onward towards the British Isles.

Carrying the original tropical waters the Gulf Stream begins with, the current loses temperature as it moves north, picking up cooler water and encountering colder air temperature and wind, but it still maintains a relatively high temperature. The initial Gulf Stream water is 75 degrees Fahrenheit off the coast of Florida. By the time the Gulf Stream has moved about 1800 miles north up the U.S. coast to Newfoundland, its temperature has only dropped to 64 degrees. This is why when viewing the Atlantic Ocean with an infrared screen to identify warmer and cooler waters, the Gulf Stream stands out as a wide line that borders the East Coast.

The Gulf Stream is unique in and of itself as the largest and fastest warm water current to span the Atlantic Ocean, but it's also unique as its very nature makes it a home for countless species of fish and wildlife, specifically off of Cape Hatteras and the surrounding waters of the Carolina Coast.

Migration plays a large role in attracting varying species to the Gulf Stream. Many species use the quickly paced waters as taxis from one feeding source to another, or to different locations throughout the globe, depending on the time of year. Because of this constant movement, while many species will pass through the Gulf Stream, not all of them will stay there permanently.

A remarkable example of this migration at work, and an example that can be found on the North Carolina Coast's own backyard, is the journey of the sea turtle. In early summer, dozens of mature sea turtles hoist themselves onto the beach, where they pick a perfect spot to lay eggs, leaving them behind as they return to the ocean.

Take a long walk along the beaches of the Outer Banks in the peak of summer, and it's a safe bet that you'll encounter one of these turtle nests, protectively marked off by the National Park Service.

By late summer and fall, the eggs will hatch, typically at night, and the hatchlings will make a mad dash to the ocean, following the lights coming from the moon and sky's reflection on the water. Once they have hit the ocean, theses 2"-3" turtles will swim 12-15 miles, living on a small sack of sustenance that's leftover from their egg, until they frantically reach the safety of the Gulf Stream. In the Gulf Stream, they can hide themselves in a patch of sea grass, which provides ample food as well as protection and cover from predators, as they begin to grow.

Another aspect of the Gulf Stream that attracts fish and other ocean species is the presence and formation of eddies. Eddies are sections of moving water that swirl off from the main Gulf Stream current and loop back on themselves, forming large whirlpool-like bodies of water.

Eddies form and consist of water that is a different temperature than the waters surrounding it. The Gulf Stream and the border of colder water around it provides ample breeding grounds for eddies, as does colder water mingling with the warmer water of the Sargasso Sea, a large warm body of water in the middle of the Atlantic Ocean. The area off of Cape Hatteras, where a portion of the current meanders away from the Gulf Stream, is especially conducive to forming eddies.

On the surface, eddies are usually about 100-300 kilometers in diameter. However, they are not just surface features. They are large cylinders of water that can reach to depths of almost 4,000 meters. Eddies travel very slowly, often towards the equator, and can last anywhere from a few months to several years.

With the mixing of warmer and cooler waters, eddies attract a variety of wildlife. The plankton and grass that linger along the edges of the eddies, usually a token from warmer water bodies like the Sargasso Sea, is home to a multitude of baitfish. These baitfish attract larger species, which in turn attract predators of their own. In addition, because of the depth of the eddies, they can easily accommodate larger deep sea species.

The vast range of species, particularly larger fish, attracts charter boats and fishermen from all over the world, chugging out into the Gulf Stream in search of the big one. And while these charter boats target a multitude of different "meat" and "sport" fish, including yellowfin tuna, grouper, rockfish, snapper, or mahi mahi, there are a few varieties in particular that stand out as true trophies of the Gulf Stream fisherman. One of the most popular species for the sport fisherman is the blue marlin.

The blue marlin, though not abundant, can be found off the coast of North Carolina in large numbers, and is one of the most prized fish in the Gulf Stream. Many marinas, charter boats, museums and cultural centers don the blue marlin's image, or a cast replica of a marlin that was once fished out of the Gulf Stream. For example, the Hatteras Village Public Library on the Outer Banks showcases a blue marlin in a glass case on the outside of the building for all passer-bys to admire. This particular marlin shattered the world record in 1962, and helped earn Hatteras Village the nickname of "Blue Marlin Fishing Capital of the World."

The marlin is a long, angular fish with the upper jaw pointed in the shape of a spear, similar to a swordfish. A long pectoral fin runs along the top of the marlin, and the top half of the blue marlin is a shimmery cobalt blue, while the underside is silver. The male blue marlins are typically around 300 pounds, while the female marlins can weight well over 1,000 pounds.

Spawning for blue marlins typically begins in warmer tropical waters with a number remaining in these waters year-round. Marlins, like many other species, use the Gulf Stream primarily for migration purposes to take advantage of different feeding opportunities during warmer and cooler seasons.The marlins are not picky and can feed on a variety of fish, especially tuna, squid and mackerel. They tend to attack schools of fish or invertebrates near the surface of the water, swimming through the schools at high speeds, slashing at fish with their bills, and then coming back to eat the dead or stunned ones.

The most popular method of catching blue marlins is via charter boat, with large shiny lures topping off larger bait fish, such as mullets, that can splash in the water and attract a lot of attention.

Another popular catch in the Gulf Stream, one that fishermen tend to keep an eye out for, is the dolphin fish. The dolphin fish, or mahi mahi, (Hawaiian for "strong-strong,") is similar to the blue marlin in that it's a very unique and unusual looking species. Beautifully colored with an iridescent blue and gold body, yellow fins, and forked tail, the average size of a dolphin is 3-6 pounds, but they can be as large as 5 feet and reach 70 pounds. The most distinguishing feature of a dolphin, besides the bright color, is the head. The male's head is rounded, while the female's slopes down to the mouth, appearing almost flat. This makes the dolphin fish an unmistakable catch for even the most novice fisherman.

Like the blue marlin, the dolphin like to stick to tropical waters and use the Gulf Stream for feeding and migration, namely on smaller fish and invertebrates that are tangled in the sea grass.

Unlike the blue marlin, which is primarily caught for its status as a prize sporting fish, the dolphin is one of the tastiest fish to traverse the Gulf Stream. Visitors who aren't interested in catching their own meal can often find dolphin at local restaurants and fish markets, particularly in the summer months of June, July and August when the dolphin frequents the waters off the North Carolina Coast.

The modern fishermen and scientists who study and revere the Gulf Stream are not the first people to notice this unusual ecosystem, and the Gulf Stream, as a warm current that hugs the coast, has effectively been recognized for hundreds of years.

Before the colonization of North America, early explorers and sailors were aware of the Gulf Stream and documented the unusual warm current that they encountered, starting with Ponce De Leon in 1513. Credited with discovering the Gulf Stream, Ponce De Leon noted that while traveling through the Atlantic, they were pushed along, backwards, by a current that was more powerful than the wind. By 1516, the existence of the Gulf Stream was widely known and accepted as past of the Atlantic navigational routes.

The Gulf Stream became instrumental in the exploration, colonization and later trade with the Americas. The clockwise current that drifted up the coast and eventually towards Europe was used in most all navigational plans and trips to the New World.

This is not to say that the current always provided a smooth course home. The use of the Gulf Stream resulted in many ships traveling along the Florida Keys to wreck along its reefs or run into storms and shoals further north in the Graveyard of the Atlantic off of Cape Hatteras. The indigenous Indians were the first to take advantage of these unfortunate shipwrecks, salvaging treasure and goods that would wash upon the shores. The practice of "wrecking," or salvaging goods from wrecked ships, became a popular endeavor, with many entrepreneurs flocking to Florida's southern coast to await shipwrecks and the treasures they brought.

Along the North Carolina coast, many locals still tell stories about centuries of salvaging, resulting from numerous shipwrecks off the coast. Old homes along Hatteras Island, dating back to the early 1900s, tell their own story as well with foundations made out of mismatched salvaged wood blended in with typical builder's planks.

But despite the dark prospect of shipwrecks, the current remained a fixture of fascination and the most popular method of travel.

In 1769, Benjamin Franklin, the US Deputy Postmaster, decided to investigate complaints that mail from Europe to America took weeks longer than the eastbound mail from America to Europe. After talking with a Nantucket sailor named of Timothy Folger, Franklin learned the English ships had to travel against the Gulf Stream.

There are a few early charts of the Gulf Stream, the earliest known chart being published in 1665, but Benjamin Franklin and Timothy Folger arguably produced the first real map of the Gulf Stream in 1769-1770.

Franklin accomplished this by taking water temperature measurements on three North Atlantic crossings, and recording the readings. The differences in water temperature indicated whether the ship was in or out of the warm current. Franklin theorized that, "This Stream is probably generated by the accumulation of water on the eastern coast of America between the tropics, by the trade winds that constantly blow there ..."

For this observation, Franklin is generally given credit for identifying the cause of the Gulf Stream, even though corrections were made throughout the years to take into account ocean bottom changes, surface winds, and other factors. Along with the maps and theory of its origin, Franklin also gave the warm current the name of "The Gulf Stream."

In modern times, ships still use the Gulf Stream to conserve fuel, although the lack of definitive and ever changing borders of the stream can make it difficult to navigate.

The Gulf Stream is more than just a single current that attracts an exotic range of fish, and provides quick shortcuts to traveling ships. In fact, its very existence continuously changes the scope of an entire continent's weather patterns and climates.

Locally, particularly off the coast of North Carolina, the Gulf Stream can affect water temperatures, providing warmer ocean waters and balmy days, even in the height of fall and winter.

In addition, the Gulf Stream can affect local storm systems that form or meander off the coast. As the currents of eddies often flow in the same direction as winds, the weather systems can intensify, feeding off the warmer water below it.

For this reason, the Gulf Stream current also has a remarkable albeit dangerous ability to feed and intensify hurricanes and tropical storms which gain strength when passing over warmer waters. This is a phenomenon seen several times along North Carolina's coast, the most recent being Hurricane Alex in 2004, which approached the coast as a moderate tropical storm. After encountering the warmer waters surrounding Hatteras Island, it made landfall as a category 1 Hurricane, intensifying just miles away from Cape Hatteras.

In terms of overall climate, coastal North Carolina enjoys moderate temperatures, ranging typically from 50 degrees on average in January to 80 degrees on average in July, and a portion of this is attributed to the consistent warmer waters of the Gulf Stream.

The Gulf Stream is especially influential on the climate of the east coast of Florida, particularly southeast Florida where the current meets and begins its path up the coast, helping to keep temperatures warmer than in the rest of the southeastern United States during the winter. In fact, because of the Gulf Stream's proximity, many coastal towns along the eastern United States, particularly from Florida to North Carolina where the Gulf Stream begins to veer east, enjoy temperate climates that are less volatile and warmer than their inland counterparts.

This also allows a variety of plans and wildlife to thrive along coastal areas: wildlife that otherwise wouldn't be found at said area's particular latitude, were it not close to the Gulf Stream.

On the other side of the world, the Gulf Stream's flow of tropical air has a significant impact on Europe, particularly England and the British Isles. Britain and Ireland have balmy climates that are also moderate and don't fluxuate dramatically, thanks to the warm once-tropic waters brought in from the Gulf Stream. Like the American East Coast, this brings a host of wildlife and plants that doesn't belong in a location so far north. For example, palm trees can thrive in the middle of winter in Cork, Ireland, even though it's located much farther north than Montreal, Canada. Essentially, if the Gulf Stream did not exist, the climate in Britain would be similar to that found in Siberia.

Because of the Gulf Stream's phenomenal and far reaching impact on global climates, oceanographers and meteorologists pay particular attention to any suspicious changes in its condition or temperature, particularly in recent years when the affect of global warming has come to international attention.

The slightest disruption in the Gulf Stream, whether it's a change in direction or a change in strength, can have unusual consequences in a variety of regions.

In 2006, fishermen off the coast of Rhode Island started noticing abnormally large numbers of tropical fish being caught in their nets. The Gulf Stream, on occasion, does bring several species of tropical fish off the coast of New England, but in this instance, tropical fish were being spotted in record numbers. Among the fish observed were juvenile orange filefish, snowy grouper and lookdowns. A local lobsterman even pulled up a large trigger fish in one of his traps. These are species that normally stick to the southern states, and typically do not venture much farther than the coast of Virginia and North Carolina.

Scientists concluded that the reason for these accidental species flooding the coast of Rhode Island was a change in the pattern of the Gulf Stream. The northeast turn that brings the Gulf Stream towards Europe had moved a little more north, bringing warmer water and consequently more tropical fish further up the coast.

Small changes like these, though harmless on the surface, cause scientists to worry about more catastrophic, long term affects.

And, unfortunately, observations made in the past several years have given scientists plenty of reasons to be concerned.

In 2005, the National Oceanography Centre in Southampton determined that there was reason to believe that Europe's central heating system, the Gulf Stream, was breaking down under the impact of global warming.

A consequence of the theory of global warming is that the polar ice caps will melt, and scientists postulated that this would have a dramatic affect on the Gulf Stream.

With global warming, extra freshwater from the melting ice caps and glaciers reduces the salinity of the Arctic waters, stopping it from sinking, and breaking the circuit of the Gulf Stream.

Scientists have always predicted that the melting of the ice caps could disrupt the Gulf Stream, but new research suggests this process is already in play. In fact, they have concluded that the strength of the Gulf Stream has weakened by 30 percent in just the past 12 years.

Furthermore, these studies point to a cooling of 1C (1.8F) over the next decade or two for Britain's climate, with an even deeper freeze predicted if the Gulf Stream system were to shut down completely.

Though most oceanographers think it is very unlikely that the Gulf Stream will stop altogether, if it did happen, it could reduce average temperatures by between 4C (7.2F) and 6C (10.8F) in as little as 20 years, far outweighing any increase in temperatures predicted across the globe as a result of global warming. Essentially, as the rest of the world heats up, Britain and the British Isles would get much colder.

Over the same period of time, the flow of warm water that branches off the Gulf Stream near the North Carolina coast and heads east towards Africa has increased significantly, contributing in the decline of warm waters being carried to Europe.

A project is currently underway to determine if these findings were an indication of a long term, progressing problem for the Gulf Stream, or simply a disruption that may change seasonally or annually. The currents of the Gulf Stream will be monitored continuously for a four year period to find the answer to this question.

It's remarkable how much of the global climate relies and is attributed to the Gulf Stream. Countries and entire continents all over the world are dependent on this Atlantic current for their mild temperatures, their plant and animal life, as well as their food source. The Gulf Stream makes species of fish that would otherwise be inaccessible to northern areas available and plentiful for commercial fishermen and recreational fishermen alike.

Here in North Carolina, the effects of the Gulf Stream on our environment can be seen every day, from the sea turtles that hoist themselves onto the beaches to give their eggs a running start towards their trek into the ocean, to the blue marlin and meat fish that are reeled in off the coast of the Outer Banks by enthusiastic sport fishermen from across the country. Even the local population relies on the Gulf Stream for the popular charter boat businesses that flourish when the big game fish are running. In addition, the small local fish houses reel in the day's catch for local seafood restaurants and markets to the delight of North Carolina visitors.

Not to mention North Carolina also has the unusual distinction of being one of the closest areas to the Gulf Stream's current, just an estimated 15 miles off the coast.

And as the currents change due to universal conditions, such as global warming, the attention of North Carolina residents and frequent visitors alike will be fixed upon the affects of a shift in the strength or path of this river in the middle of the Atlantic Ocean, hoping that precautionary measures will be taken to protect its' course, and the Gulf Stream will remain undisrupted.

In the meantime, however, the charter boats will continue to run every morning, and the big fish will always be around, simply lurking in the turquoise waters hugging the Carolina coast, and just waiting to be reeled in by a lucky Gulf Stream fisherman.