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Coastwatch Spring 2012
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|A sign of spring at the Cypress Grill in Jamesville in March. Photo Credit: Arthur Lewis
But the signs, like the fish, are not as common these days. The great river herring runs, or spawning migrations, into Tar Heel rivers and creeks are things of the past. The herring on dinner plates now come from the ocean or out-of-state waters. Measures enacted in recent years regulate river herring fishing to protect populations that have drastically dropped from historical levels.
Fish that once came by the millions could not overcome changes in natal, or native, waters. Dams and development blocked access to traditional spawning grounds, and pollution degraded habitat. Fishing pressure and predation by striped bass — a species that rebounded after harvest limits were imposed — likely took a heavy toll as well.
Some researchers believe river herring may be harbingers of something more ominous. They compare the herring to the proverbial canary in the coal mine that, by succumbing to unseen peril, provides a warning for other species. Marc Turano, North Carolina Sea Grant extension specialist, says river herring are very susceptible to changes in habitat, so they can serve as an "indicator species" for other fish.
Scientists are stumped by the inability of river herring to rebound the way striped bass did after management agencies restricted harvests.
Ongoing research on herring habitat and behavior may help determine if the fish will eventually die out or endure. Projects funded by the state's Fishery Resource Grant Program — or FRG — administered by Sea Grant, and also by Sea Grant's core research program have provided insight on a new way to determine which waters the fish prefer, estimate the size of fish populations and evaluate the availability of food the herring need.
Alewife (Alosa pseudoharengus) and blueback herring (A.aestivalis), known collectively as river herring, have been fished for more than 350 years, making the fishery one of the oldest in the country. According to the National Marine Fisheries Service, it was exclusively an inshore operation until the late 1960s when foreign fleets began fishing for river herring off the mid-Atlantic coast. Commercial landings peaked in the late 1950s at nearly 75 million pounds before declining to less than 8.8 million pounds in the late 1970s.
|The range of sizes for juvenile alewife caught in this study indicates differences in habitat quality. Photo Credit: Dan Zapf|
In North Carolina, commercial harvests of river herring averaged 286,171 pounds worth $120,545 between 1996 and 2006, according to the N.C. Division of Marine Fisheries, or DMF. The commercial value peaked in 1985 when fishermen caught 11.6 million pounds worth $846,000. Its value fell to $67,000 in 1993 when landings totaled 916,235 pounds.
In 2006, the N.C. Wildlife Resources Commission enacted a rule that prohibited the taking or possession of adult herring in inland waters. The following year, the N.C. Marine Fisheries Commission approved a harvest moratorium. Under the current regulations, a harvest of 7,500 pounds of river herring is permitted for research.
Currently, the National Oceanic and Atmospheric Administration is considering a petition by the Natural Resources Defense Council to protect river herring under the federal Endangered Species Act. NOAA agreed that the petition warranted further review and is compiling information nationwide on river herring population status and trends. A decision is expected later this year on whether the agency should designate river herring as threatened or endangered, or take no action.
However, research on river herring continues. East Carolina University biologist Roger Rulifson, commercial fisheman Willy Phillips, and graduate student Daniel Zapf are conducting a study, supported by the FRG program, to assess herring nursery habitat in tributaries of Albemarle Sound. The study looks at which locations support growth of juvenile river herring and survival of adults.
To do so, they study the inner ear bones of fish, called otoliths, which contain chemical elements from waters where the fish live. The technique, which has been used on shad and striped bass, examines otoliths to determine if adult blueback herring are returning to natal streams to spawn and which streams are producing the largest proportion of spawning adults.
|The line on the otolith shows where it has been scanned with a laser. Photo courtesy of University of Manitoba
|This otolith is from a four-year-old blueback herring from the Scuppernong River. Photo Credit: Dan Zapf
An otolith holds information much like growth rings on a tree, Rulifson explains. Each day, it incorporates minerals from the water, forming tiny rings that indicate the fish's age and the chemical composition of the water the fish has lived in at different times.
DMF provided the fish for the study. Zapf measured and weighed each fish, and then removed otoliths that in juvenile fish are smaller than a sesame seed. The tiny specimens were sent to the University of Manitoba in Winnipeg, Canada, where specialized equipment was used to remove thin sections of the otolith with a laser and analyze the elements in each layer.
The scientists used a two-fold approach to evaluate habitat. First, juvenile herring were collected from tributaries and western portions of Albemarle Sound in the summer of 2010. Better nursery areas yielded larger and healthier fish with higher growth rates.
Second, adult river herring were collected from the Chowan, Perquimans and Scuppernong rivers during the 2010 spawning run. Rivers that produced high percentages of adult fish were considered good nursery areas.
Of 11 habitats studied, the Alligator, Chowan and Roanoke rivers, along with nonriverine areas on western Albemarle Sound, seemed to offer high-quality nursery habitat for river herring.
However, the Perquimans and Scuppernong rivers appeared to be poor habitats, possibly caused by decreased water quality, shoreline development or impediments restricting access to spawning locations. River herring moving into the Scuppernong River might not be able to access historical spawning grounds in Phelps Lake because of obstructions and low water levels, the report says.
The study highlights the need to restore degraded habitat. It also demonstrates the importance of good habitat in the Alligator, Chowan and Roanoke rivers, and the western portion of Albemarle Sound. It's possible that spawning populations could be re-established with habitat improvements in degraded watersheds, the researchers note. "Conversely, degradation to quality habitats could drastically decrease Albemarle Sound river herring populations."
Rulifson and Zapf are still analyzing the results, but they have found some fascinating migration patterns so far. For example, the results suggest that the fish seek out better waters for their habitat, and prefer non-riverine to riverine waters. They found high-quality juvenile alewife and juvenile blueback herring populations in some overlapping areas — northwest and southwest Albemarle Sound.
In addition, results suggest that river herring have low rates of natal homing. Rulifson says the finding that only 50 percent of the adult river herring in the Chowan originated there indicates that there is significant wandering from the fish's natal stream. However, he notes that it is difficult to pinpoint a particular tributary where the fish originated because herring are broadcast spawners that release eggs into the water column.
Tracking Fish Populations
One side effect of the moratorium on fishing for river herring was a lack of information from fishermen about where and how many fish were in coastal waters. Warren Mitchell, now a fisheries biologist with the NOAA Laboratory in Beaufort, says information on herring stocks used to be available from landings data. When he was with North Carolina State University's Center for Marine Sciences and Technology, Mitchell worked with other researchers and commercial fisherman Terry Pratt on an FRG-funded study that determined sonar technology could be used to estimate blueback herring populations.
The researchers transmitted high-frequency sound waves through the water to detect fish.
They analyzed the returning echoes for the density and average fish size for a particular study area. Then they caught fish in the same area to determine the types of fish, and the abundance and the size range of herring.
|Researchers found that the Chowan River was one of the most important nursery habitats for juvenile river herring. Photo Credit: Dan Zapf
The technique had not been attempted before in the southeast. One problem with the approach in North Carolina, Mitchell notes, is that there were many other kinds of fish in the same area so the researchers had to figure out what proportion were herring.
The study, completed in 2009, combined sonar technology and gillnet surveys to assess migratory herring in western Albemarle Sound and the lower Chowan River. The researchers estimated the 2008 population of blueback herring at about 6.2 million, and 6.3 million in 2009, down from an estimated 90 million in the early 1970s, according to a DMF report. Mitchell says his numbers were within the range of stock estimates in previous state assessments that relied on landing data.
The results highlighted the need for additional studies to better document migration patterns of herring through Albemarle Sound, and to determine when fish are staging or continuously migrating.
Mitchell, a former Sea Grant-DMF fisheries fellow, is fascinated that herring hatch in a backwater creek, make their way downstream, swim through inlets to the ocean and later reverse the journey. "It's amazing that they do that kind of distance travel," he says.
Kathy Rawls, DMF manager for the northern district, says the state acquires information on herring from a survey of fishermen who catch the fish as bycatch in pound nets. The division will consider the possibility of using hydroacoustics to track fish as part of an update of the state's river herring fishery management plan, she says.
Plenty of Food
In a Sea Grant-funded core research project, researchers examined the amount of food available to river herring to see if that might be a cause of poor recruitment and survival.
ECU fisheries ecologist Anthony Overton and then-graduate student Samantha Binion studied the availability of food for herring and shad after they emerge from eggs in the Roanoke River and part of Albemarle Sound. The study analyzed the abundance of plankton, microscopic plants and animals the fish eat. They also evaluated mouth gape or opening of the tiny fish's mouth to see if that affected what the fish could eat.
|Coley Hughes and Joey Smith collect water samples for analysis in the Perquimans River. Photo Credit: Dan Zapf
|Joey Smith and Jeff Dobbs sample in the Scuppernong River. Photo Credit: Dan Zapf
Overton summed up the research thus: "There's still plenty of food out there."
Researchers took weekly samples from 19 sites on the Roanoke River between March and June in 2008 and 2009. The study examined river habitat; delta areas described as the transitional area where the Roanoke, Middle and Cashie rivers converge at the N.C. 45 Bridge; and in the Bachelor Bay area of Albemarle Sound. They noted environmental conditions, and caught tiny fish and microscopic creatures called zooplankton.
Researchers concluded that reasons for declining recruitment of river herring in Albemarle Sound remain unclear, but food is not a limiting factor. "Recruitment failure may be related to the demographics of the spawning populations or other factors operating on multiple scales," the report says. Overton and Rulifson say that additional research is needed to determine what is preventing river herring from rebounding.
Rulifson notes that stocks have not recovered despite restrictions on harvesting. "If there are enough adults spawning," he says, "there has to be another factor that is short-circuiting the life history of those fish."
It could be related to physiology of the fish or something in the habitat, he speculates. Overton does not believe predation by striped bass is a key factor, as some people have suggested. Striped bass may have more effect than in the past because herring populations are smaller, but they likely are not causing the low river herring population.
Nor does he blame commercial fishing, citing landings data that noted a sharp drop in populations. "It's not commercial fishing that caused the fish to decline that quickly," he notes.
Willy Phillips, a commercial fisherman and seafood dealer in Columbia, assisted Rulifson in studies by catching herring in pound nets for research. He says the fish were important food sources in Eastern North Carolina many years ago and he would like to see the fishery return. "It has been an integral part of the culture of Eastern North Carolina for a long, long time," he says.
Holding on to a Way of Life
While researchers continue to probe the mystery, others try to hold onto the cultural significance of the fishery that once enlivened the region every spring. Many communities already have had to adapt to the loss of traditional activities tied to herring runs.
The aroma of fried herring wafted over the fire department in the Pitt County community of Pactolus one March evening as the Ruritan Club held its annual spring fish fry. The fish fry, which offers heaping plates of herring or trout, is a tradition that goes back at least 50 years, says club president Junior Mizell.
|Sam Bowers prepared herring at Pactolus Puritan Club fish fry in March. Photo Credit: Jerry Allegood
Club members used to catch all the herring they needed in area streams. Now they buy the fish from a Chowan County dealer who gets them from another state. Herring weren't available last year, Mizell says, so the club relied on white perch. He adds that many people travel 30 or 40 miles for the yearly feast, which raises money for scholarships, the local fire department and rescue squad, and community projects. This year they dished out about 700 pounds of fish and netted about $4,000.
In the past, similar fish fries fed countless families and made money for schools and churches. In his book Herring Fishermen: Images of an Eastern North Carolina Tradition, Frank Stephenson describes extensive fishing operations that shut down years ago and never reopened. "It's a way of life and culture that's gone," he says. "It's a terrible loss."
Stephenson, a Murfreesboro resident, recalls when river herring were so thick in area creeks it looked like you could walk on them. Commercial fishermen caught tons of herring each year in long seine nets strung out in waterways or in pound nets anchored with poles. Many people simply scooped up fish in hand-held dip nets, cast nets, plastic laundry baskets, shallow pans and, Stephenson says, even old straw hats.
These days, herring still come up area waterways but many of the colorful activities associated with the runs have died out. "It would be nice to see it come back," he says.
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