Fish and Aquatic Conservation

Law of Nature

The Endangered Species Act and Forty Years of Fisheries Conservation
By Ben Ikenson

Apache trout are on the rebound in eastern Arizona, thanks to the work of the Arizona Fish and
Wildlife Conservation Office and Alchesay-Williams Creek National Fish Hatchery. Jeremy Voeltz/USFWS
photo of Apache trout

Previous generations of White Mountain Apache believed that to eat the brilliant gold fish flecked with black spots that was once so abundant in their streams was to risk getting spots on their faces. While the fish played no role in its traditional diet, the tribe in a prescient act was compelled to start protecting it in the 1940s. White settlers who fished for the trout had decimated its population; streams were subsequently stocked with non-native trout, which further displaced the native fish. By the late 1960s, its range had been reduced from some six hundred miles of mountain streams in southeastern Arizona to less than 40. In 1973, the Apache trout became the first fish listed as an endangered species.

“I remember even when I was a kid, the tribe had closed off a lot of areas to fishing,” says Daniel Parker, a White Mountain Apache who worked as a fishery technician at the U.S. Fish and Wildlife Service’s Arizona Fish and Wildlife Conservation Office in the early 1970s. “The tribe had been working early on in partnership with the Fish and Wildlife Service for the Apache trout.”

Fortunately, the cooperative efforts helped reverse the decline of Apache trout, whose status was upgraded to “threatened” in 1975. Today, the prognosis is good: the first fish listed may well be among the first to be removed from the endangered species list altogether, thanks largely to the protections afforded by the historic legislation passed on December 28, 1973.

The Endangered Species Act has not only helped Apache trout and many others by devoting resources to the cause of preventing extinction. It introduced the now ubiquitous phrase “endangered species” into the modern lexicon, raising collective conscience. Along with other environmental laws, the Act ushered in a new era of formal—if often contentious—natural resources management. It also significantly broadened the mission of the U.S. Fish and Wildlife Service, endowing an agency once focused largely on waterfowl and sport fish with new regulatory powers, broad oversight responsibilities, and expansive international assignments.

Of course, the law spawned a number of worthy aquatic species conservation efforts.

Biological Pearls of Wisdom: Freshwater Mussels

Freshwater mussels, for example, stand to gain by the protections of the ESA. With names like little spectaclecase, sculptured pigtoe, and shine-rayed pocketbook, mussels make an interesting testament to the imaginations of those who coined the terms, primarily fishermen who overharvested them for a thriving pearl button industry. But even after the advent of plastic buttons in the 1950s, mussels have been declining, especially over the last 40 years, because they can’t tolerate changes in water quality resulting from pollution or sediment from dredging and soil erosion. They also suffer from the introduction of non-native species, the effects of siltation, and even remnants of pharmaceutical drugs that end up in wastewater that reaches streams. Of the 300 different mussel species in the United States, more than 60 are listed as endangered and eight are listed as threatened.

It is well known that mussels are filter feeders that help keep water sources clean. But “little is known about the life history and the reproductive biology of the majority of freshwater mussel species,” says Carlos Echevarria, manager of Warm Springs National Fish Hatchery, in Georgia. The hatchery has been studying the decline of mussels in the Apalachicola-Chattahoochee-Flint River Basin, which drains nearly 32,000 square miles in western Georgia, eastern Alabama, and the Florida panhandle and supports one of the most diverse freshwater mollusk assemblages in the Southeast.

“Historically, we had at least 14 genera and 33 species—with six being unique to the basin,” says Echevarria. “Over the past decade, surveys concluded that only 29 native mussels currently exist here. Of these, four are listed as endangered and two are listed as threatened.”

Echevarria points to the both natural and human factors, including sixteen dams on the Chattahoochee and Flint rivers. Many species, he says, will require population management and manipulation to prevent extinction and maintain genetic flow between isolated populations.

Since 2000, Warm Springs NFH has been conducting successful mussel propagation studies.  Currently, biologists are working with common, unlisted mussel species in order to refine their methods with hatchery-reared listed mussel species and, ultimately, the wild populations in decline.

The San Marco Salamander benefits from the work of scientists at
the San Marco Aquatic Resources Center. Joe Fries/USFWS
San Marcos Salamander photo

In the Hill Country: San Marcos Salamander

Similarly vulnerable to water quality degradation—a liability exacerbated by slow reproduction rates and limited distribution—is the San Marcos salamander, which was listed as threatened in 1980. The translucent reddish-brown amphibian, typically between one to three inches long, inhabits Spring Lake and the very upper reaches of the San Marcos River in south central Texas, where reduced water flows represent its greatest threat, followed by pollution, sediment buildup and the introduction of exotic organisms.

There is, however, hope, with the development of a comprehensive partnership aimed at reconciling the longstanding conflict between the federal mandate to protect threatened and endangered species associated with the Edwards Aquifer and the region's dependence on the same aquifer as its primary water resource. The Service’s recent approval of the Edwards Aquifer Recovery Implementation Program Habitat Conservation Plan and its implementation by various signatories could provide much needed protection for the salamander and other species while simultaneously serving the region’s growing population with more efficient use of aquifer water.

In the meantime, biologists at the San Marcos Aquatic Resources Center actively maintain a salamander refugia and remove exotic plants and animals in the river itself. One such plant species, the water trumpet once invaded and occupied miles of habitat. Over the last decade, the Center’s SCUBA dive team has been surveying the river and removing this aggressive plant.  “This last year was the first time no plants were observed,” says Kenneth Ostrand, Deputy Center Director.

list of stations that provide refugia for adult fishes

Additionally, biologists are continually involved in field and lab studies. One such study is focused on producing San Marcos salamander offspring. “Aquaculture often relies upon mimicking and altering environmental cues, such as water temperature and day length, that tell a species it is time to produce young,” Ostrand explains. “Conversely, San Marcos salamander reproduction appears to be triggered by behavioral cues. Intuitively this makes sense given that they have evolved in a spring-fed system with relatively constant water temperatures and chemistry.”

But biologists here believe they have figured out how to get salamanders ‘in the mood,’ in lab conditions. When together naturally, the female picks up the sperm packet dropped by the male.   Biologists have observed that, in a tank, if the male remains within close proximity, she tends not to go for that precious packet and consequently won’t release her eggs. But if the male is removed, egg releases ultimately take place. Love me and leave me alone. This discovery is helping foster consistent reproduction that will maintain the species in refugia.

Resurrecting a Dinosaur: Pallid Sturgeon

Pallid sturgeon, so-named for their pale skin, get the
attention of biologists from Montana to Louisiana. USFWS

Artificial propagation is an important component of recovery as well for the pallid sturgeon. With its long, flat snout, a few rows of bony scales, and a growth potential of seven feet, the pallid sturgeon—sometimes called the “dinosaur of the Missouri River”—certainly looks prehistoric. And in fact, the species descends from fish that inhabited the Missouri and Mississippi rivers 70 million years ago. But the river is certainly not the same one its ancient ancestors inhabited, and most changes have occurred only within the last 100 years as a result of flood control, navigation, and hydropower operations. Today, biologists are struggling to keep the fish, listed as endangered in 1990, from going the way of the dinosaurs.

“Since 1992, we’ve been involved in stocking more than 135,000 pallid sturgeon in the lower Missouri River,” says Colby Wrasse, a biologist at Columbia Fish and Wildlife Conservation Office. “We contribute to the cause largely through our broodstock collection efforts. Since 2007, we’ve fished the lower Missouri River with trotlines and gill nets, capturing large pallid sturgeon to utilize in propagation.”

But Wrasse notes, catching the right fish can be challenging: any potential broodstock specimen must be an adult; must be a “wild” fish (one not previously stocked); and must be reproductively ready since pallid sturgeon may spawn only once every three to five years. “The combination of these three factors rule out many of the pallid sturgeon we capture,” he says. Last year, for instance, staff caught 65 pallid sturgeon; only three met the criteria.

And catching pallid sturgeon is but the first step in a very coordinated process that involves transportation to hatcheries, genetic testing, and ultrasound and endoscopic testing to determine sex and reproductive readiness.

“If a pallid sturgeon is genetically determined to be a good candidate for propagation and it is reproductively ready, then biologists will work their magic and attempt to spawn the fish,” says Wrasse. Baby pallid sturgeon produced from artificial propagation typically spend about a year at the hatchery before being tagged and stocked in the lower Missouri River. “With the ability to freeze milt, the broodstock fish we collected this year could also be used in future years to increase the number and genetic diversity of the species,” says Wrasse.

Troubled Waters: Atlantic Salmon

Atlantic Salmon. Bob Hines/USFWS

Casting an enormous shadow over so many species conservation efforts, however, is the specter of global warming. Case in point: Atlantic salmon.

“Recent research shows that the combination of climate change and carbon deposition in the oceans is leading to a whole suite of challenges for sea-run fish, marine life and their environment, primarily driven by the increased acidification of the oceans,” says Peter Lamothe, Program Manager for the Fish and Wildlife Service’s Maine Fisheries Complex.

Historically, Atlantic salmon ranged from waters off the shores of Connecticut north to Ungava Bay, Canada, and from Portugal to Russia's White Sea. Today the last stronghold for the species is in the Gulf of Maine, where, in 2000, it was listed as an endangered “distinct population segment”—the smallest division of a taxonomic species that can qualify for protections of the ESA. Here, the fish contend with dams and culverts that block access to spawning habitat; diminished water quantity and quality; disease and predation; a historic commercial fishery; and climate change, which is not only causing acidification of the sea but also leading to increased temperatures in both the Gulf of Maine and Maine's rivers.

information about the National Fish Passage Program

“Temperature shifts can work both ways,” adds Lamothe. “Since salmon growth is tied to water temperature, seasonal timely increases in temperature can lead to increased growth that provides benefits such as predator avoidance and increased mobility. Unfortunately, what more commonly occurs are increases at the wrong times of year that lead to low oxygen and warmer water in the streams in Maine.”

While the Service, the National Oceanic and Atmospheric Administration and other partners  have enjoyed significant successes over the years—limitations on the commercial harvest of salmon off the coast of Greenland; removal of dams in the Kennebec and Penobscot rivers; establishment of conservation hatcheries—recent adult estimates of the Gulf of Maine Atlantic salmon are near historic lows: “Currently, only five percent of salmon habitat in freshwater is considered suitable and accessible,” says Lamothe. “The combination of a shift in marine survival and creation of accessible and suitable freshwater habitat offers the best opportunity to recover the species.”


The next generation of conservationists may be inspired by the technological advances, comprehensive research, and efficient partnerships that have become hallmarks of these, and many other efforts established by the Endangered Species Act. But as the historic legislation that has helped conserve so many species enters its fifth decade, the future for so many species, including our own, looks daunting. Even if the Apache trout is ultimately removed from the endangered species list before long, an increasingly complex set of environmental challenges will demand even greater innovation and resolve.

There’s no time for resting on laurels.

Last updated: September 17, 2014