Saving Seafood

Learning About Menhaden: A Journey to Reedville

January 27, 2017 — The following is excerpted from an article by Emily Liljestrand, a master’s student in the University System of Maryland’s Marine Estuarine Environmental Sciences program. It was published Tuesday by Maryland Sea Grant:

Atlantic menhaden, though completely unpalatable to all but the most desperate diners, can be found in many commercial products. They are processed into omega-3, fatty-acid-rich nutritional supplements as well as aquaculture feed and fertilizer. People have utilized them for hundreds of years. The name “menhaden” even comes from the Native American word “munnawhatteaug,” which means “that which fertilizes.”

To get from this one-foot-long, oily, bug-eyed creature to the myriad of products we use them for requires several steps of fishing and processing. Most of which we got to witness first-hand on our trip to Reedville.

We were welcomed by the Omega Protein staff who guided us to a cozy conference room where we watched a video that demonstrated the fishing operation. Delightful as it might have been, having nine students and faculty go out on a fishing vessel that can often spend days offshore is a bit impractical.

But in the video we got to see the whole fishing process. Spotter planes take off across the Chesapeake Bay and nearshore Atlantic waters, looking for the telltale sign of a menhaden school – darkened bubbling waters where menhaden were being targeted by predatory fish and sea birds. Pilots can estimate with a high degree of accuracy not only the size of a school but also the average size of menhaden within that school.

The fishing vessel charges onto the scene and once in position, deploys two smaller seine boats that together use a single net to rope up as much of the school as they can. Once the bottom “purse string” gets pulled, it’s only a matter of hauling everything up onto the larger vessel and/or vacuuming menhaden into the hold. If done efficiently, the whole process may take no longer than half an hour.

Our guided tour around the on-shore facility in Reedville showed us how the processing continues onshore. The school of menhaden (or multiple schools, collected over several days) are deposited into a large holding vat and cooked at extreme temperatures. This procedure breaks down the fish and creates a sort of menhaden “slurry.” Through a series of heating, cooling, and further chemical processing, the lighter liquid oil gets separated from the harder, denser meal.

Omega Protein told us about its efforts to make its processing operations sustainable. It uses recycled/reclaimed water extracted from the menhaden themselves as a cooling agent, which has saved about 18 million gallons of water annually, and safely disposes of nitrogen byproducts. Omega’s fossil fuel consumption has dropped by 80 percent since 2012 thanks to several plant renovations.

Read the full story at Maryland Sea Grant

This forecasting tool aims to keep ships and blue whales from colliding

January 16, 2017 — A new forecasting tool will help scientists predict blue whale traffic, as the ocean behemoths make their annual migration.

The tool allows researchers to post online maps showing likely “hot spots” for blue whales that will help ship captains avoid collisions with the animals.

“We can both see where they go and when they go,” said Elliot Hazen, a research ecologist with the National Marine Fisheries Service, who developed the forecasting program. “We can take their movements and combine that with remotely sensed oceanographic data, to find out not only where they go, but also some of the oceanographic conditions that trigger that.”

When the whales travel up the California coast, they navigate a marine highway of shipping vessels, fishing boats and cruise liners. There are several reported ship strikes per year, but there may be many more than that, said Helen Bailey, a research associate professor at University of Maryland, Center for Environmental Science, who coordinated the forecasting process.

“We’re probably underestimating the number that have been hit by ships, because they sink and don’t float,” Bailey said.

Blue whales are the largest creatures ever to live on the planet, with silvery bodies that can grow more than 80 feet and up to 165 tons. But there are just under 2,000 of them, and their numbers aren’t growing, Bailey said.

Read the full story at The San Diego Union-Tribune

Biologists alarmed over lack of young Atlantic sturgeon in surveys

August 16, 2016 — Biologists have been surprised in recent years about how many big Atlantic sturgeon they are finding around the Chesapeake Bay. But rather than celebrating, they have become increasingly alarmed about what they are not seeing: a new generation of young sturgeon.

While finding more adults is certainly good news, biologists say they have seen little evidence those sturgeon have successfully produced significant numbers of offspring in recent years that would be critical if the endangered species is to make a comeback in the Chesapeake.

“To get any kind of recovery, the best thing you can do is to increase that first year of survival,” said Dave Secor, a fisheries biologist with the University of Maryland Center for Environmental Science. If young fish survive, he said, “you can actually realize very rapid recovery, even for a species like sturgeon.”

That’s something that biologists working with sturgeon around the Bay say they haven’t seen, perhaps for a decade or more. Many blame the absence of young sturgeon on a rampant population of introduced blue catfish, which they say could be consuming eggs and newly hatched fry, or outcompeting them for habitat.

But researchers who study the catfish dispute that, and even sturgeon specialists acknowledge they lack concrete evidence.

Read the full story at the Bay Journal

Chesapeake Bay health improves in 2015

May 18, 2016 — The overall health of Chesapeake Bay improved in 2015, according to scientists at the University of Maryland Center for Environmental Science. The largest estuary in the nation scored a C (53%) in 2015, one of the three highest scores since 1986. Only 1992 and 2002 scored as high or higher, both years of major sustained droughts.

“We’d expect to see improvements after a drought year because nutrients aren’t being washed into the Bay, fueling algae blooms and poor water quality,” said Bill Dennison, Vice President for Science Applications at the University of Maryland Center for Environmental Science. “However, in 2015 stream flow was below normal, but nowhere near the drought conditions in 1992 and 2002. Thus, the high score for 2015 indicates that we’re making progress reducing what’s coming off the land.”

The overall score for the Chesapeake Bay Health Index for 2015 was 53%, compared with 50% in 2014 and 45% in 2013. There were strong improvements in many regions throughout the Bay, such as the Choptank River, Upper Eastern Shore, Lower Western Shore, and the Rappahannock River. There were no regions that had lower scores in 2015 compared to 2014. Improvements could be related to a number of factors, including several years of moderate weather, sewage treatment upgrades, use of winter cover crops by farmers, and reductions in atmospheric nitrogen deposition.

Read the full story at Science Daily

MARYLAND: Oyster study bill advances despite watermen objections

April 5, 2016 — State fisheries managers use science-backed information to determine how many striped bass, blue crabs and menhaden can be caught each season without damaging the overall health of each species.

But not the Chesapeake Bay’s oysters.

A bill passed by the Maryland Senate and pending before the House would require University of Maryland scientists to establish harvest limits that ensure a sustainable catch for years to come. Representatives of the seafood industry are branding the measure as costly and unnecessary.

The bill’s supporters, however, say Maryland’s oyster population is being overfished, pointing to estimates that it is 1 percent of its historic size.

“We’ve learned the hard way that nature, especially with these oysters, is not inexhaustible,” said Bill Goldsborough, a fisheries scientist for the Chesapeake Bay Foundation. “So this attitude, this disregard for science, led to the depletion of this valuable resource and the unstable boom-and-bust pattern of fishery that we see today.”

Maryland’s oyster haul plummeted from an all-time high of 15 million bushels in the 1880s to 26,000 bushels in 2004. After surpassing 100,000 for several years, the total harvest rocketed above 300,000 in 2013 and 2014. Researchers attribute the jump to hearty reproduction in 2010 and 2012.

The size of oyster catch this season, which officially ended Thursday, is expected to be lower again, reflecting poorer reproduction in subsequent years.

Read the full story at Delmarva Now

Bay anchovies appear to be more important than menhaden in predators’ diets

December 7, 2015 — The Chesapeake Bay may be the best-studied estuary in the world, but a group of scientists attending a recent workshop were surprised about how little they knew about what predatory fish eat.

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.

Read the full story at Bay Journal