Thursday, May 18, 2017

"The Atlantic Sturgeon"

Sydney M. Williams
swtotd.blogspot.com

Essays from Essex
“The Atlantic Sturgeon”
May 18, 2017

Atlantic sturgeon didn’t make it for 70 million years without being resilient.
                                                                       Ted Williams
                                                                       “Yale Environment 360”
                                                                        Published by Yale School of Forestry and Environmental Studies
                                                                        February 12, 2015

A recent talk: “A Connecticut River Mystery Revealed,” given by Kimberly Damon-Randall, a naturalist and administrator with NOAA (National Oceanic and Atmospheric Administration), at Essex Meadows. The subject: the Atlantic sturgeon, an ancient fish recently returned to the Connecticut River. The meeting was sponsored by the Roger Tory Peterson Estuary Center (RTPEC), on whose board I serve.

An old saying has it that they can kill you, but they can’t eat you. Of course, a fish that is killed is usually eaten. The Atlantic Sturgeon is desired, especially, for its eggs (caviar, or black gold, as they are known). The species is still with us, but man’s rapacity over the past century severely limited its numbers. Fortunately, the fish was added to the Endangered Species Act in 2012, and is now making a come-back. However, as Ted Williams wrote in the article quoted above, the Atlantic sturgeon has been around for tens of millions of years, joining an exclusive club comprised of species like the Horseshoe Crab and the Jelly Fish. It has learned to adapt. It survived the intense heat of the Dinosaur age, when temperatures averaged 20% above today’s, and higher. They made it through the ice age, which covered most of North America, Europe and Asia with several hundred feet of ice. They survived the six-mile-wide Chicxulub asteroid, which hit the Yucatan Peninsula about sixty million years ago. Could man, with the advantages of a brain that reasons and a mind that creates, have survived such devastation and extreme temperature changes? Given the dynamic earth on which we live, someday we will surely find out. Nevertheless, the Atlantic sturgeon adapted, when most other animals, with whom they lived during the Mesozoic Era, did not.

The Atlantic sturgeon is primitive looking. Instead of having scales, it has five rows of bony plates, known as scutes. Its life-span is about sixty years. At maturity, which is achieved between fifteen and twenty years, a female can weigh up to 800 pounds and be fifteen feet in length, an unusual sight in the estuary of the Connecticut River. The fish is anadromous, which means it migrates from salt water to spawn in fresh water, as do salmon, shad and striped bass. The Atlantic sturgeon has an elongated snout, which differentiates it from its smaller, (and more common) cousin, the Snub Nose sturgeon. They are toothless, benthic omnivores. With a tube-like mouth located on the underside of the head, which extends several inches when feeding, it vacuums up insects, worms, clams and mussels from sea and river beds. Four barbels, which could be mistaken for fangs, but are in fact taste buds, dangle from their upper lip. Like many of nature’s creatures, they are camouflaged. Seen from above their brown coloring blends with the sea or river bottom, while their white belly, when viewed from below merges into the sky.

In early North America, Atlantic sturgeon were seen, as a nuisance as their rough skin would rip open fishing nets; but soon they became profitable – one of the first “cash crops” to be harvested in Jamestown, Virginia. Their exterior was used in clothing, bookbinding and as isinglass. By the late 19th Century, they were heavily fished for their eggs and flesh. Up to seven million pounds of sturgeon meat were exported annually in the last decade of the 19th Century. But, overfishing caused a sharp decline; exports declined to 22,000 pounds in 1920.

Their decline was precipitous; only gradually have they made a come-back. According to the NMFS (National Marine Fisheries Service), in the late 19th Century 180,000 “ripe” females entered the Delaware River (then known as the caviar capital of North America). Today, the agency estimates there are less than a hundred. Females reach sexual maturity about age sixteen and lay eggs every three to five years, so populations will rebound, albeit slowly.

Humans almost eradicated these fish a hundred years ago, and now humans are leading conservation efforts to restore them. It is their return to the Connecticut River that I find exciting. Three years ago, the remains of a seven-foot, 100-pound immature female was found about five miles up the River, near the entrance to Hamburg Cove. In the same year (2014), a few pre-migratory juvenile specimens (estimated to have been hatched in 2013) were collected. DNA testing suggested that a small number of families – perhaps eleven – produced the off-spring. The fish found in 2014, according to the Connecticut Department of Energy and Environmental (DEEP), were too small to have emigrated from other systems, so scientists felt certain they were hatched in the Connecticut River. It had been decades since such findings had been confirmed. Acoustic transmitters were implanted into a few larger fish, so their movements can be tracked.

Spawning occurs in flowing waters, just beyond where the salt front, the leading edge of seawater, and the fall line of large, fresh-water rivers come together – often near where dams have been built. A female can lay between 400,000 and eight million eggs. Maximum fertility is reached at around 30 years of age. As a father of three children, that seems like a lot of kids, but, keep in mind, only a small percentage make it to adulthood. Eggs are easily destroyed and the young serve as food for other species. As they get larger, and less appetizing to natural predators, survival probabilities increase. Besides man, not only as a fisherman but as a dredger and blaster of rock ledge, the natural prey to mature Atlantic sturgeons include killer whales, sharks and seals.

Generally, man operates in his own self-interest. In bygone times, and in primitive societies today, man did what he must to survive. Some of what he did was antithetical to modern concepts of conservation. However, we must keep in mind that conservation is a consequence of education and wealth. The first allows us to better know, understand and appreciate our environment, while the second provides the funds necessary to preserve and conserve what we have inherited. (In terms of education, the RTPEC now instructs over 800 school children in our region on the basics of environmental stewardship.) We have come a long way in the past 150 years. Rivers are cleaner than they were, as is the air. About 85 million acres (3.5% of our land mass) is in national parks, with another 15 million acres protected in land trusts. There remains work to be done, but we must balance the needs of myriad segments of our society, so that the path we travel permits economic growth and conservation. Taken under our wings, to mix my metaphors, the Atlantic sturgeon should survive. I hope so, for it gives our children and grandchildren the opportunity to witness a species that lived during the time of the dinosaurs, a fascinating fact and indicative of a remarkable resiliency. There is much we can learn from its adaptability to changing environmental conditions over many millennia.



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