A coffin for cod? The downward spiral of the fish that built New England

While we don’t always see eye-to-eye with the Pew Foundation on fishery management, particularly where reef species or marine refuges are concerned, this column on the decline of New England cod is well worth reading. Editor
from The Fishing Wire

by Lee Crockett of The Pew Charitable Trusts

Landing a Cod

When Mike Anderson arrived in Cape Cod in the 1960s as a young man with dreams of adventures at sea, many people shared the same warning: “You won’t get rich in the fishing business; it’s just a way of life.”

But Anderson, undeterred, embraced that lifestyle, fishing his way through decades of long, sometimes treacherous days at sea in the sun, wind, fog, and ice. His hands toughened like leather as he baited hooks late into the night in anticipation of the next day’s bounty. He relished the challenge of each day, the camaraderie among tough-as-nails fishermen, and the exhilarating adventure of it all.

Anderson, now 72, was part of the glory days of thriving New England fishing towns, when fishermen followed their fathers into the business and old-timers spoke, only half-jokingly, of cod so plentiful one could practically walk across the water on their backs. Back then, despite early signs of decline, people still thought the fish were limitless. Most people, that is, except for Anderson.

He believed trawlers that dragged nets along the ocean bottom, scooping up vast amounts of cod, were capturing too many fish and damaging the seafloor. He stubbornly stuck to hook-and-line fishing, even as nets started sweeping up cod in numbers he’d never seen before. In due time, his two-man crew—which once pulled in thousands of pounds of cod a day and regularly caught fish weighing 40 to 50 pounds—began to see both its catch and the size of the fish decline. By the 1990s, the cod were so sparse and small that Anderson gave up and moved on to other species.

Anderson feels he witnessed the decimation of one of the greatest concentrations of marine life on Earth.

Drying Cod

“The fish never really had a chance,” says Anderson, who still fishes every day, both for the joy of it and to make ends meet. “It was greed, shortsightedness, and naiveté. People misunderstood how many fish there were. The world is finite, and we haven’t got the right to diminish the world.”

A recent study determined that the 2014 cod population on Georges Bank, located off Cape Cod in the easternmost side of the Gulf of Maine, was the lowest ever recorded—roughly 1 percent of what scientists would consider a healthy population. That’s down from the 7 percent reported for 2011. In other waters off Cape Cod, the species is also in dire straits. For the fish that built New England, it’s been a long downward spiral.

Because other species in the region also are in decline, the U.S. Department of Commerce declared a fishery disaster in New England in September 2012, the second such declaration for the region in 20 years. As fish populations have plummeted, fishery managers have shown a consistent pattern of failing to heed warnings from scientists, sufficiently limit catch, promptly pursue corrective actions, and otherwise do what’s needed to help fish populations recover, including protecting the habitat and bait fish that cod rely upon.

It’s high time to finally get it right. We at Pew are urging the New England Fishery Management Council—which sets fishing policies in federal waters (from three to 200 miles offshore), from Maine to Connecticut—to address these critical issues:

First, the council must enact and enforce realistic science-based catch levels. Current methods of setting catch amounts are too permissive. It’s wrong to let people keep fishing for the average amounts they’ve caught in the past when fish numbers are dropping and other environmental factors, such as warming waters, may be putting the fish populations at risk of extinction.

School of Cod

Second, many cod die because they are caught incidentally as fishermen target other species. Fishery managers still don’t have a good handle on the extent of the problem. It’s hard to set safe catch amounts when it’s unclear how many fish are being taken from the water. Add to that the issues created when some fishermen misreport the areas from which they are taking fish or the size of the fish they take, or underreport their catch, and it’s nearly impossible to see the big picture. Fishery managers have been too slow to ramp up their force of at-sea observers and dockside inspectors to better monitor and resolve these problems.

Third, it’s unproductive for the council to consider lifting protections for important cod habitat when the fish need them most. Decades ago, in response to the fisheries crisis of the early 1990s, the federal government curtailed fishing in 8,887 square miles of New England waters where fish live and spawn, including 26 percent of Georges Bank.

But now, fishery managers propose reducing the protected areas substantially, including a drastic rollback of 81 percent of the protected parts of Georges Bank. Cod used to be spread throughout the Cape; but as the fish grew more scarce, scientists believed they took refuge in limited prime habitat areas within their former range. Fishermen in the past knew these spots and targeted them, further decimating the species. Why would anyone let that happen again?

Mike Anderson

Lastly, researchers know cod and other fish are much smaller today than they were decades ago. Although the cause is uncertain, scientists theorize that overfishing and warming waters are playing a role. Researchers are also baffled about what is happening to young fish. Experts know that eggs are hatching and fish are growing for several years, but then they are disappearing. These mysteries are worrisome and deserve more study.

This uncertainty makes it all the more urgent for officials to take a comprehensive view of the ecosystem when setting fishing policies—for example, by weighing habitat, food sources, warming waters, and other factors when making decisions about how to manage a species. Pew is advocating that this approach, called ecosystem-based fisheries management, be incorporated into federal law as Congress renews the Magnuson-Stevens Fishery Conservation and Management Act. You can read more about it in our blog series here.

As for Anderson, he isn’t involved or weighing in on these current-day debates. Rather, the philosopher’s son and English major is penning stories about his life at sea and telling cautionary tales on the fishing docks as part of efforts by the Cape Cod Commercial Fishermen’s Alliance to educate the public about the history and future of the Cape’s small boat fishing industry.

He wants current and future generations to learn from past mistakes. And he hopes New England’s legendary fishing towns can spawn new stories of adventure and plentiful catch, instead of just relying on the memories the old-timers leave behind.

Little things turn out to be big deals in Chesapeake Bay predators’ diets

Today’s feature comes to us from Karl Blankenship, long-time editor of Bay Journal, detailing a topic that is beginning to be understood as critical to gamefish populations everywhere—the forage the fish eat.

Analysis finds invertebrates, tiny anchovies are critical in Chesapeake food web

By Karl Blankenship, Editor
Bay Journal; www.bayjournal.com.

Menhaden are caught in a purse seine net

After all, menhaden — dubbed by some as the “most important fish in the sea” would also be the “most important” fish in the Bay, right?

Apparently not. That honor, were one species to be singled out, might belong to the tiny bay anchovy — a fish that rarely grows more than 3–4 inches in length and typically doesn’t live longer than a year.

“They’re the most abundant fish in the Bay,” said Ed Houde, a fisheries scientist with the University of Maryland Center for Environmental Science, who helped organize the workshop. “They’re really important in the Bay’s food web.”

An analysis of 12 years of Baywide diet information for five major predators prepared for the workshop found that bay anchovy was a significant portion of the diet for four of those species. Menhaden was important for only one, striped bass, and even for them, bay anchovy were more important.

“Menhaden came out not as high on the list as people thought it was going to be,” Houde said. “It was an important prey, but it certainly wasn’t in the top three or four.”

Even more significantly, the analysis showed that the Bay’s food web is less of a fish-eat-fish world than popularly thought, even among many scientists. A host of unheralded species, from worms to clams to crustaceans, are major food sources for the Chesapeake’s predatory fish.

Those were some of the findings that came out of the workshop conducted by the Bay Program’s Scientific and Technical Advisory Committee late last year. The workshop focused on the question of whether the Bay produces enough food, or “forage,” to adequately support its predator population. The workshop stemmed from a commitment in the 2014 Chesapeake Bay Watershed Agreement that called for assessing the “forage fish base.”

It’s a question conservation groups, scientists and fishery managers are increasingly asking for oceans and coastal areas around the globe: Are there enough herring, anchovies, menhaden and similar species to feed predatory fish, marine mammals, fish-eating birds and, in many cases, to support major fisheries?

It was once thought those small schooling fish were so abundant that they could not be overfished. Around the world, they account for about a third of all fish harvested, after which they are processed for oils, fish meal, livestock feed and other products. A 2012 report by the Lenfest Forage Fish Task Force, prepared by scientists around the world, including Houde, called for global harvests to be cut in half to protect both forage species and the many predators that depend upon them.

Similar questions about the forage base have been raised around the Bay. Anglers have complained for years that striped bass were underfed because of a lack of menhaden, and watermen have contended that large numbers of striped bass and other fish looking for food ate too many blue crabs.

Fishery management over the years has sought to maximize the production of predators like striped bass. Other predators have been introduced, sometimes accidentally, such as snakeheads, at other times deliberately, to give anglers new pursuits, such as blue catfish and flathead catfish.

Populations of many fish-eating birds, including bald eagles, osprey, great blue herons and cormorants are at or near record highs, at least compared with recent decades. Meanwhile, some prey thought to have been important historically, such as river herrings and American shad, are at historic lows.

Invertebrates ‘key’ food source

The forage workshop, which followed the new Bay agreement commitment by a few months, was aimed at reviewing what data were available about forage in the Bay and identifying new information that might be needed to guide future forage fish management — and to ensure high and sustainable production of their predators.

But along the way, workshop organizers began to realize that in the Chesapeake, the emphasis just on “forage fish” might be less important than it is for some other areas.

That stemmed from an analysis done for the workshop that examined the diets of five predators thought to be good indicators of predator food demand in different areas around the Bay. The predators in the analysis included striped bass, summer flounder, Atlantic croaker, clearnose skate and white perch.

The analysis drew on 12 years of data from the Chesapeake Bay Multispecies Monitoring and Assessment Program (ChesMMAP), conducted by the Virginia Institute of Marine Science, which collects fish at locations from the mouth of the Bay to near Baltimore five times a year.

Since 2002, the survey has captured 391,000 fish, and measured 285,000. Biologists have examined the stomach contents of more than 35,000 fish, representing 94 species, to determine what the fish had been eating.

A type of forage was considered “important” if it accounted for more than 5 percent of the food in any predator species in at least one survey. It was “key” if it accounted for 5 percent in more than one predator.

More than half of the 20 forage groups identified as “key” or “important” turned out to be invertebrates such as mollusks, worms and crustaceans.

For instance, mysids, a small shrimp-like crustacean, was the most common food consumed by summer flounder, measured by weight, the second most common consumed by striped bass, and the third most common prey of Atlantic croaker. Polychaete worms were the most common prey of Atlantic croaker and white perch, and the third most important for striped bass.

In other coastal areas, “the invertebrates are not the big issue — it is the small schooling herring and anchovies or what have you,” said Tom Ihde, an ecosystem modeler with the National Oceanic and Atmospheric Administration Chesapeake Bay Office, who helped organize the workshop.

Forage fish vs. forage base

Bay Anchovy

Ihde and Houde said much of the previous work concerning forage has focused on predators in ocean fisheries. Those fish are often larger, and primarily consume small fish. Also, much of that focus has been in places such as the West Coast, which lack large estuarine feeding grounds like the Chesapeake Bay.

In the Chesapeake, the predators are often smaller — the largest striped bass generally are here only a few weeks of the year to spawn — and much of the food of the smaller, resident striped bass consists of a variety of bottom-dwelling organisms. As a result, what started out as a discussion aimed at addressing forage fish turned into one focused on the entire forage base.

In fact, the importance of soft-bodied organisms like worms is likely understated when fish stomach contents are examined, Ihde said. “Some of these invertebrates are digested quickly and are probably even more important than our analysis would show because they very quickly turn into unidentifiable goo,” he said.

That said, workshop participants said in their recently released report that menhaden should still be considered a key forage species because the species is important to large striped bass for whom the Bay is a critical spawning area, even if they are only here part of the year. Menhaden are also considered important prey for larger individuals of other large predatory fish such as weakfish and bluefish. And menhaden are likely important for other species, such as fish-eating birds, workshop participants said.

“There’s a general perception that it is all about menhaden,” Ihde said. “They are important. But we can’t forget about all these other things that in some cases are more important to our current system.”

And those other things add to the complexity of understanding, and ultimately trying to manage, the Bay’s food web.

Some organisms not typically thought of as forage turned out to be important in the Bay, such as the young of croaker, weakfish and spot — adults of which are generally considered predators.

“It was a big surprise to me to see something like young-of-the-year weakfish show up as one of the more important prey in the diets of predators,” said Houde, who has participated in several forage fish studies in recent years.

Scant data for tributaries

But the total picture is far from complete. The ChesMMAP surveys only cover the mainstem of the Chesapeake. There is little information available about tidal tributaries.

Those areas are important nurseries for many fish — and are also home to a rapidly growing population of predatory blue catfish. Although some studies are under way to better understand the diet of blue catfish, much less is known about the forage base and food demand by predators in those areas.

Because of those limitations, workshop participants suggested the data from ChesMMAP may under-represent the importance of some forage species such as American shad, river herrings, mummichog, killifishes, gizzard shad, silversides and some small bivalves, which tend to be found in low-salinity areas.

Even less is known about shallow water of less than 2 meters, especially in habitats such as underwater grass beds and marshes, which biologists think may be particularly important for forage production, and where survey boats have a hard time operating.

And the ChesMMAP data have their own limitations. It is a trawl survey, so it collects fish mainly from the bottom, and collections from its gear under-represents both the largest and smallest fish.

The survey is being modified in coming years to collect more samples from higher in the water column and from the benthic invertebrate communities at its collection sites.

While that should refine its information, it is not likely to dramatically change overall conclusions, as other — albeit smaller — surveys examined in the workshop analysis found similar results.

“Our hope is it will lead to a much better understanding of the ecosystem,” said Chris Bonzek, the VIMS scientist who oversees the ChesMMAP survey and who prepared the forage analysis for the workshop. “But we are not going to all of a sudden see that bluefin tuna are the most important predator in the Bay.”

A more complete picture

Because predators are eating so many types of prey — many of which are poorly studied — it’s difficult to characterize the current status of the Bay’s forage base. But, with support from the Bay Program’s Sustainable Fisheries Goal Implementation Team, Houde and several colleagues are reviewing existing information to start piecing together a more complete picture of forage abundance and predator demand.

With information gleaned from the ChesMMAP analysis and other sources, they are assessing the relative abundance of different forage groups in regions of the Bay to see if there are trends in the overall amount and availability of prey, or in the relative abundance of the different types of forage.

In addition, they are looking at stomach content data from major predator fish species to begin to estimate the amount and kinds of forage they are consuming.

That information will start addressing the fundamental questions of how much forage is consumed by predators, what type of forage is most important in different regions of the Bay and how much change has taken place over the years. Ultimately, it will help answer the question of how much food is needed to support the Bay’s predators, both now, and in the future.

“While we are not close to getting that answer, it is the direction we are heading in,” Houde said. “Providing estimates of consumption and forage demand is something we would like to be able to deliver to managers in the next decade.”

A ‘balanced’ ecosystem

Figuring out how to use that information to maintain a “balanced” ecosystem will be a challenge for managers as populations of many forage species vary widely. For instance, the numbers of bay anchovy can fluctuate tenfold from year-to-year — they can live up to three years, but most are eaten by predators within a year — so the relative success of annual reproduction drives their overall abundance. Likewise, the numbers of young croaker, weakfish and spot available to be eaten depend on year-to-year reproduction success.

When the issue moves beyond fish to the broader forage base, the level of complexity increases. Many bottom-dwelling species can be sensitive to extended periods of low oxygen, so a large seasonal “dead zone” can reduce overall abundance, and even eliminate species, from some areas. “If it is a bad hypoxia year, the benthic invertebrates cannot get up and swim away like the fishes,” Ihde said.

The loss of underwater grass beds, coastal marshes and oyster reefs have reduced the amount of habitat available for many forage species. The hardening of shorelines, development of land adjacent to the Bay and its tributaries, sea-level rise and climate change will likely cause continued habitat losses, the workshop report said.

At the same time, predator populations are constantly changing — and not just the fish.

Around the Bay, the populations of fish-eating birds such as eagles, osprey and blue herons are large — and growing. The Bay’s population of double-crested cormorants, which was almost nonexistent four decades ago, is nearly 5,000 today. That’s enough cormorants to consume 300 tons of fish annually, according to the workshop report.

Overall, the fish demand of birds around the Bay is largely unknown, Houde said. Birds, though, could be one of the first indicators of stress if there were a problem with the Bay’s forage base. Houde noted that research in other areas has shown that when forage fish populations decline by a third of unfished levels, the populations of fish-eating birds may drop precipitously.

Protecting forage fish

Other than menhaden, most of the forage species in the Bay are not actively managed fishery species. Menhaden have been increasingly regulated in recent years by the Atlantic States Marine Fisheries Commission, which manages migratory fish along the coast. The commission is working to establish new harvest goals in the next several years that recognize the role of menhaden as prey for predators.

The abundance of other forage can be influenced by a range of actions aimed at improving environmental conditions and protecting habitat, the workshop report said.

For instance, reducing nutrient pollution could reduce the size and duration of dead zones — Bay water quality standards were written to promote a greater diversity of benthic creatures as well as larger, longer-lived species.

Other actions can help protect habitat important for forage species, the report said, such as limiting the use of bulkheads and other hardened shorelines that degrade local habitats, and controlling development near the shore, which is increasingly linked to the lost or reduced production of benthic species.

Forage could also be protected by reducing some predator fish populations, such as snakeheads or blue catfish, but managers have little control over other predators, such as birds.

But the emerging information could offer other opportunities for management. The recognition that the little bay anchovy plays a relatively big role in the Bay food chain could promote efforts to better understand it, Houde said.

“The anchovy is so tiny that most people have discounted it as the target of a directed fishery,” he said, “but there have been proposals for bay anchovy fisheries in other areas along the Atlantic coast.”

Although he said such a proposal is unlikely for the Bay, fishery managers might want to consider policies to prohibit a future fishery in recognition of the bay anchovy’s importance to other species.

“Sometimes,” he said, “in the case of a forage fish, it is easier to develop and implement management policies before there is a fishery.”

The workshop report, “Assessing the Chesapeake Bay Forage Base: Existing Data and Research Priorities,” is found at the Scientific and Technical Advisory Committee website, chesapeake.org/stac/; click on “publications.”

The Bay Program’s management strategy for its forage fish outcome is found at chesapeakebay.net/chesapeakebaywatershedagreement/goal/sustainable_fisheries.

What’s on the menu for Bay’s predators

Drawing on information from the Scientific and Technical Advisory Committee’s workshop report, the Management Strategy for the Chesapeake Bay Watershed Agreement’s Forage Fish outcome preliminarily identified these as the Bay’s key forage species and groups for a wide variety of predators:

Bay Anchovy
Polychaetes
Mysids
Amphipods
Isopods
Mantis Shrimp
Young Spot
Young Weakfish
Sand Shrimp
Young Atlantic Croaker
Razor Clams
Atlantic Menhaden

These species were recognized as potentially important forage groups or species, but were not identified as the top contributors to the diets of predatory fish by information presented at the workshop:

American Shad
River Herring
Atlantic Rock Crab
Atlantic Silverside
Blackcheek Tonguefish
Blue Crab
Flounders
Gizzard Shad
Kingfish
Lady Crab
Macoma Clams
Mud Crab
Mummichog
Killifishes
Small Bivalves

Carl Blankenship

Read more about Chesapeake Bay at www.bayjournal.com.

Times Changing for Giant Grouper

By Rodney Smith, www.rodneysmithmedia.com.

Landing a giant grouper

It might as well have been the Loch Ness monster I stood over, except there was nothing either anecdotal or mystical about this giant sea monster; it was real! The rotting carcass of what was then called a jewfish, estimated to weigh over six-hundred pounds, lay before me in the wet Gulf of Mexico sands near the base of the Pier Kahiki, which was part of a Hawaiian-themed complex at Indian Rocks Beach. The high tide had dumped the decaying beast there after fishermen had caught it using a hand gaff-sized steel hook baited with a football-sized black drum. The hook was attached to a short 3/8″ steel chain, which was tied to a sturdy hemp rope they had secured to the pier’s railing.

Once I was up and on the pier’s deck, I overheard the crusty dock manager, Joe, chuckling and talking through the cigar permanently clenched in his broad, crooked mouth to a couple of tourists. “It took six of them men to pull it to shore” he was telling them. Later, when I asked Joe why they wasted such a giant fish, he followed his normal method of operation, spitting his words in my direction. “Boy, them big fish ain’t any good; anyway, they took the cheek meat with’em.”

It was the late Sixties, a time of ignorant bliss, well before most fishermen understood our oceans’ bounties were not finite. Less than a decade later, I believe it was the summer of 1975, during one of my first surfing trips to Sebastian Inlet State Park, I saw three Volkswagen Bug- sized grouper swimming along the bottom of the inlet’s main channel. Their size was amazing and unbelievable. This was the last time I saw any truly giant jewfish.

Looking back at how drastically fisheries management has changed, it might as well have been a hundred years ago. Today jewfish have been officially renamed goliath grouper. Since 1990, these remarkable fish have been fully protected in the U.S.A as a “no take” fish, and their numbers continue to grow. In fact, goliath grouper have rebounded to the point that segments of the angler population find them to be quite the nuisance.

Acting like protected California seals, goliath grouper hang out at places where they know they can steal angler’s catches. Their thieving habits alone have partially fueled a push to remove a couple of layers of Federal and State regulations protecting these endangered fish. Less restrictive rules could give fisheries managers several keen opportunities to raise research money and fisheries datum, or find ways to better protect habitat and build artificial reefs.

States like Florida could sell goliath grouper kill-tags, much like special hunting permits. They could open up a couple of goliath grouper short seasons and help the recreational sports fishing industry raise revenue. This strategy could pump major bucks into coastal fishing communities around the Sunshine State and help researchers and scientist collect valuable data. It could be a “win/win” for everybody!

However, there are serious obstacles standing in the way of this idea. Fisheries biologists understand the complexities of protecting the sustainability of these potentially huge, but slow- growing fish better than most of us. They will tell you we must protect the biggest goliath groupers or they will never return to their historical size and range.

There are two things I’ve learned about fisheries management as a member of the South Atlantic Fishery Management Council’s Snapper/Grouper Advisory Panel. Management of our fisheries and other marine resources is most often driven by money and greed, and secondly, I now understand why the following statement is true. Fisheries management isn’t rocket science, it’s worse!

To read more like this, visit www.rodneysmithmedia.com.

“The Five Best Reasons To Pass The Gulf States Plan”

by Jeff Angers
from The Fishing Wire

Red Snapper

I’m speaking of the five fish and wildlife management agencies of the Gulf states. I’ve spent the last 20-plus years working with the individuals who lead and work in these departments, and I have found them all to be impressively competent professionals — serious and passionate about sustaining the stocks of fish and game under their management.

In my own state of Louisiana, we are justly proud of our Department of Wildlife and Fisheries, which has developed a state-of-the-art creel survey for offshore anglers (“LA Creel”).

Now in its third year, the innovative LA Creel survey is providing pinpoint-precise, real-time estimates of fisheries populations and harvest levels.

This is exactly the kind of data that fisheries managers need to protect red snapper — but only if they have the authority to act.

Once Washington gets out of the way, the five state fisheries managers can respond with flexible approaches that reflect the real state of affairs in the Gulf; they will be able to preserve the species for the enjoyment of all sectors, with no group excluded. Today, federal fisheries managers are left to guess — and to play favorites.

It was this kind of advanced knowledge that led Louisiana’s DWF to realize that the recreational red snapper catch during the regular season was short of its quota by at least 88,823 pounds, making possible an extended season that just began November 20. (The extended season will be subject to a daily bag limit of two snapper per person of 16-inch minimum length; Louisiana’s regular state-waters red snapper season ended September 8).

LA Creel is featured in a new video that also introduces us to representatives from all five Gulf state fishery management agencies. It ought to be “Exhibit A” in the case for adopting the five Gulf States’ plan. I urge recreational fishing advocates to watch the video and share it widely on social media.

Louisiana isn’t alone: each of the five Gulf States has been at the forefront of advanced fisheries science.

It was their devotion to the sustainability of the red snapper that drove the five states’ fisheries directors to put aside regional, political and personal differences and take the historic step of coming together to develop the five states’ plan.

They were doing what we ask all leaders to do: when confronted with a serious problem like federal mismanagement of the red snapper fishery, real leaders set aside distractions, utilize the most advanced scientific tools and information at their disposal and then act in the best interests of future generations.

It wasn’t just a matter of joining together to fill the vacuum left by the federal government’s mismanagement. The five directors then went further, each of them becoming personally involved in advocating for the plan, both in their own state capitals and in the halls of Congress.

Over the last year, testimony advocating state management from Nick Wiley, the executive director of the Florida Fish and Wildlife Conservation Commission; Chris Blankenship, the director of the Marine Resources Division of the Alabama Department of Conservation and Natural Resources, and Robert Barham, Secretary of the Louisiana Department of Wildlife and Fisheries, before the U.S. House of Representatives has been especially compelling and persuasive.

The state directors traveled to Washington to move the ball forward on their historic agreement. Once H.R.3094 is enacted, their words will be remembered as watershed moments in saving the fish and the fishery.

As those of us who live here know, the Gulf is a very special place, unique in every way. These are the men and women who know it better than anyone else — certainly better than a distant bureaucrat in Washington, D.C., however well intentioned.

Plugging Into the Gulf Stream?
Can the Gulf Stream be used to generate power? Should it?

by Kip Tabb, Coastal Review
www.coastalreview.org
from The Fishing Wire

MANTEO — The Gulf Stream passes at times just 12 miles from Cape Hatteras. The amount of water it carries past our coast is massive. In fact, if it were a river, the Gulf Stream would be the greatest river that ever existed on this planet.

“”By the time the Gulf Stream gets off Cape Hatteras (it’s greater than) the flow of all the rivers of earth . . . 45 times greater the entire flow of every river on earth (at flood stage) is what we have off Cape Hatteras,” Mike Muglia of the Coastal Studies Institute said.

A team of researchers and scientists from the institute, N.C. State University and the Institute of Marine Sciences in Morehead City has been studying for the last two years whether all that water could be put to use to create electricity.

Gulf Stream hugging the Southeast coast

It is still too early to tell, but there are characteristics of the Gulf Stream as it passes the Outer Banks that may make better suited for energy production. As it flows north past the Outer Banks, the Gulf Stream is constrained from changing position by the edge of the continental shelf on its west side, Muglia explained. It veers east into deeper water at The Point, an undersea geologic structure about 40 miles off Hatteras Island, and its course can meander.

“The key point is that off of Hatteras, the variability in available energy at a specific location is due primarily to the variability in the Gulf Stream location,” he said.

The Gulf Stream gains three times the amount of flow as it moves north up the Southeast coast. Its flow is measured in svedrups, or Sv — named for the late Harald Sverdrup, a pioneering oceanographer and an early director of the Scripps Institution of Oceanography in California. Off the south Florida coast, the stream’s flow is 33 Sv, or 33 million cubic meters per second; by the time the current reaches Cape Hatteras it’s flow has increased to 90 Sv.

However, with no banks to constrain its flow, the location of the Gulf Stream is not a constant, nor is the force of the current the same at all times. Because it varies in place and flow as much as it does, if the Gulf Stream is to be developed as an energy resource accurate predictions of its fluctuations will be needed, the researchers noted.

Ruoying He, an oceanographer at N.C. State, develops models of coastal circulation currents. It is the modeling that his group has created that is being used to predict where the Gulf Stream will be and the force of the current as it moves past the Outer Banks.

“I got involved in this project because my team at NC State develops a high resolution computer model to predict ocean circulation off the East Coast of U.S.,” He wrote in an email in response to a question. “Similar to the weather forecast, our model provides time and space continuous ocean state . . . predictions. They are quite useful to fill observational gaps and help understand Gulf Stream variability measured by (the) limited suite of observational assets we deployed . . .”

The models He’s team have developed have been remarkably accurate, according to Muglia. “We’ve compared (our) measurements to the model and the model does an extremely good job of capturing the average speed over a long time period,” he said.

He notes there is more work to be done. The model has done a good job of predicting the amount of flow in the Gulf Stream and giving a good idea how it fluctuates. However, if the resource is going to be developed, better information is needed.

“A major research area in my team is to further improve the accuracy of our ocean prediction model,” He wrote. “The model is doing a decent job in predicting the Gulf Stream variability. We hope, through further model refinements and data assimilation, we can perform accurate real-time . . . forecasts of the Gulf Stream to support (and) optimize offshore surveys and energy harvesting efforts.”

Whether the Gulf Stream can be utilized as an energy resource is still very much up in the air. Muglia notes there are a number of hurdles that must be crossed before energy will surge from the waters of the Atlantic Ocean.

“Is it a viable resource in terms of permitting? Is it a viable resource in terms of economics? Engineering?” he asked.

Those questions, especially the topic of engineering, are being addressed by John Bane at the Institute of Marine Sciences. He points out that the studies that are being done are comparable to almost any study looking at a potential energy resource. “The observations that Mike has made shows very clearly that it (the Gulf Stream) fluctuates. It’s very similar to studies of wind energy,” he said.

Expanding on that, Bane talked about other energy resources. “If you were out in West Texas and wanted to drill for oil, you would examine and explore where oil might most likely be. This is a resource assessment. That’s what we’re doing.”

The assessments are ongoing and expanding. Initially the instruments used to measure what was happening with the currents were coastal radars, ongoing measurements taken from instrument in the sea and onsite observations. Instrumentation is being increased to look at a broader cross section of the Gulf Stream, giving the scientists a better picture of the energy closer to shore where it may be more accessible and farther out to sea where there may be more potential energy but the cost of engineering would become higher.

The first biological assessments are also being done. The role of the bottom arrays that are used to assess current and flow is being expanded.

“These now have hydrophones on them. We’re passively listening and seeing what kind of critters we have out there,” Muglia said. “We’ve certainly observed clicks and marine animals. Some of them seem pretty curious. We have one where it sounds like he comes right up to the instrument.”

A place of verdant sea life, the Gulf Stream has been a remarkable asset for the Outer Banks for as long as the islands have been populated. Whether it will be a part of the energy assets of North Carolina is still an unanswered question.

“We really are just trying to understand what the resource is and whether it’s a viable resource,” Muglia said.