The Asian Carp Invasion

On my walks around Landen Lake this week (a small suburban lake north of Cincinnati), I have been repeatedly reminded that the Asian carp invasion is a significant problem throughout the Mississippi River watershed.  Introduced in the 1970s to control aquatic vegetation and to filter sewage water, they escaped containment areas during floods and have spread throughout most of the U.S.  Favoring shallow, sluggish waters, they often attract our attention as they thrash about, their dorsal and tail fins breaking the surface.

Represented by four species (grass, black, silver and bighead carp) these large fish are very prolific and soon dominate the aquatic ecosystems that they colonize; black carp, which feed on mollusks, threaten native snail, mussel and clam populations while the others reduce the availability of plankton and vegetation vital to native fish, amphibians and aquatic reptiles.  As video enthusiasts know, silver carp also pose a threat to boaters, jumping into the air (and into boats) in response to the sound of outboard motors.

Concerned that Asian carp will enter the Great Lakes and disrupt the ecology of their fisheries, efforts have been made to block carp migration along canals that connect those Lakes with streams of the Mississippi watershed; "electric fences" have been used with some success but carp also spread as eggs or fingerlings on boat hulls, via the use of live bait, during floods and perhaps even on the legs of wading birds.  Taking advantage of the carp bonanza, some companies are culling them to produce pet food or fertilizer; vultures also partake of the bounty, feasting on dead carp that were stranded by shrinking lakes or rivers.

Eulachon

Eulachon are small marine fish (8-9 inches in length) that feed on plankton in the eastern Pacific, from Alaska to northern California.  In late winter, they move into estuaries and coastal rivers to spawn; most adults die after this process.  Fertilized eggs, which sink to the gravel beds, hatch in a month and the fry head to sea; there they will live in offshore waters for 3-5 years before returning to spawn.

Heavily laden with fat, the spawning eulachon are known as candlefish (since dried specimens can be lit like candles) and were called "salvation fish" by Native Americans of the Pacific Northwest since their calorie-rich bodies provided vital nutrition during the leans months of late winter and early spring.  Of course, Steller's sea lions, dolphins and sea birds also welcome their spawning runs.

Unfortunately, eulachon have all but disappeared from the coastal rivers of northern California, Oregon and Washington and their numbers have decreased significantly farther north.  Global warming, overfishing, water pollution and altered river sediments (due to hydroelectric dams) are all thought to be playing a role in the population decline of this smelt.

Tragedy at the Zoo

Throughout my formative years, I was enamored with animals of every kind and visited zoos on a regular basis; in my mind, despite their use of restrictive cages, zoos played an important role in public education and wildlife conservation.  The increasing use of "naturalized enclosures" allayed some of my concerns and I planned to pursue veterinary medicine long before I opted for medical school.

The zoo of my youth was the Cincinnati Zoo, where yesterday's tragedy unfolded; a four-year old boy somehow gained access to the gorilla exhibit and fell into the moat.  This caught the attention of a 17 year-old male gorilla who grabbed the child (perhaps with protective rather than hostile intent), forcing staff members to kill him.  While the cause of this tragedy is under investigation, inadequate fencing and inattentive parenting both surely played a role.

In a larger sense, this tragic event highlights both the potential risks and ethical dilemmas of caging intelligent creatures (primates, elephants, cetaceans, etc.) for our own entertainment, even if a certain degree of education and research is achieved.  The concept of rescuing endangered species for captive breeding and reintroduction to the wild has been unsuccessful in most cases (California condors and black-footed ferrets are two exceptions) and "naturalized exhibits" can never match the freedom and benefits of native habitat.  Though tragedies such as occurred yesterday are rare, the greater tragedy of human-imposed captivity has long been a cherished practice in our culture.  Perhaps, as human enlightenment progresses, we will come to reject the imprisonment of intelligent animals.

Assault on Yosemite

As we left Oakdale, California, this morning and headed east on Route 120, the high peaks of the Sierra Nevada shimmered across the eastern horizon, partly obscured by clouds.  Leaving the flat landscape of the Central Valley, we climbed through hills of grass and oak savanna before ascending more steeply into the Sierra foothills.  Charred forest, damaged by wildfire, was soon encountered along the road, extending into western portions of Yosemite National Park.

When we eventually rounded a curve and Half Dome appeared in the distance, I knew that my dream of visiting Yosemite was finally realized.  Indeed, the Park's spectacular glacial valley, lined by the granite cliffs of El Capitan, Half Dome, North Dome and other well-known summits, drained by the beautiful Merced River and adorned by Bridal Veil Falls, Yosemite Falls and other magnificent cascades, is one of the more inspiring sites on our planet.

Arriving on a Monday morning in mid May, we hoped to escape the summer crowds that descend on Yosemite and many other National Parks.  Alas, the crowds were already there, parked along the roadways, congregating at overlooks and clogging popular trails; we, of course, contributed to the human assault.  One wonders if our population has expanded beyond the point where landscapes as grand as Yosemite National Park cannot withstand the onslaught.  It seems we must significantly curtail access if we are to protect these natural gems (or even to make them worth visiting).

Joining eBird

An avid birder for 40 years, I have generally shunned the traditional habit of creating life or regional lists to document my success; rather, I simply record the date and site of "first sightings" in my field guides; of course, various posts in this blog also document many of my encounters.  And though I regularly participate in seasonal songbird and waterfall counts, sponsored by local nature centers or national conservation organizations, I have not personally contributed to the collection of data on avian populations.

Having become familiar with eBird, based at Cornell University, I have decided to join their effort to compile information on bird populations across the globe.  Taking in data from birding groups and individual birders, they are monitoring the health and range of each species, thereby documenting the effects of human activity and helping to determine what conservation policies might be most effective.

My plan is to focus on three birding hotspots that I visit on a regular basis:  South Platte Park in Littleton, Colorado, Eagle Bluffs Conservation Area near Columbia, Missouri, and Longboat Key off Sarasota, Florida.  Having established an account with eBird, I will file a bird sighting report after each visit to these sites.  Those interested in this program, which also provides records of rare bird sightings and report filings from across the globe, are encouraged to visit https://ebird.org

Humboldt the Ecologist

In the course of reading The Invention of Nature, by Andrea Wulf (see Getting to know Humboldt), I have come to learn the important role that Alexander von Humboldt played in the field of ecology, theretofore an unacknowledged science.  Famous for his intrepid exploration of the tropics in Venezuela and the Andes of Colombia and Peru, Humboldt's major gift to humanity may have been his insights regarding the unity of nature, the interdependence of ecosystems and the effects of human civilization on the health of our natural environment.

Energetic, enthusiastic and inquisitive, he made detailed records of his discoveries and, in the course of that process, took note of similar ecosystems across the globe, related by latitude and/or elevation.  Indeed, to my knowledge, he was the first explorer to develop the concept of life zones, thereby emphasizing the effects of climate on the resident plants and animals.  He also observed and reported on the negative effects that human societies have on the environment, including those produced by deforestation, stream diversion and over-hunting.

Completing his excursion through South and Central America just as Lewis and Clark were beginning their exploration of the American West, Humboldt clearly had far more interest in the ecology of the landscapes through which he traveled.  Based on my readings (see Up River with Lewis and Clark and subsequent posts), the famous American explorers were focused primarily on finding a route to the Pacific; while their description of the landscape and wildlife is fascinating and their journey was no less courageous, they made little reference to the natural science of Western ecosystems.

Politics, Science & the Environment

As the field of Republican Presidential candidates continues to dwindle, those left are courting the Right Wing of their Party, hoping to garner their support.  Of course, this means that they must ridicule global warming, oppose environmental regulations and promise to reduce federal funding for science, including space exploration and medical research.

Were it up to that segment of the American populace, we would eliminate the Department of Education and the Environmental Protection Agency, would defund Planned Parenthood and stem cell research and would repeal subsidies for clean energy technology.  Opposed to most environmental regulations, they would curtail (if not repeal) legislation devoted to reducing air and water pollution, protecting wilderness areas and limiting human impact on vital ecosystems.

Fortunately, young voters seem inclined to adopt lifestyles that foster human health and protect the welfare of our environment.  Hopefully, they will use the power of the ballot to elect individuals who share their commitments.  After all, it is their future that is most threatened by the anti-science rhetoric and pro-industry policies of Right Wing Conservatives.

Banded Knots on Longboat Key

This afternoon, while walking along the beach on Longboat Key, Florida, I came across a flock of thirteen red knots; on closer inspection, I discovered that three of them had multiple leg bands of various shapes and colors.

Over the past few decades, ornithologists and conservation organizations have been banding certain species of shorebirds, attempting to document their seasonal ranges and migration patterns.  Participating countries along the Atlantic flyway have been assigned specific band colors and banding site codes have been used to clarify the movement of the birds.  Unfortunately, the latter codes (printed or engraved on the bands) are often difficult to read unless a spotting scope is available or, of course, the bird is dead.

Once I documented the color and type of bands on the red knots (only one of which contained a code), I submitted the report to www.bandedbirds.org; in addition, I established a profile with that organization, hoping to submit additional sightings over the coming years.  After all, most conservation organizations depend on both financial and active support from the public and those of us who care about the welfare of threatened species and endangered ecosystems relish the opportunity to participate in their vital work.

Nature Gifts for Children

In this digital era, when many children are reluctant to stray too far from their video screens, nature related gifts may entice them into the great outdoors.  Telescopes, binoculars, bird feeders (ignore my post on 12-2-15), field guides and snowshoes are just a few examples.

While it may be a challenge to compete with computer games and streaming movies, an enthused parent or grandparent can provide the mentorship to get children interested in rocks, plants, local wildlife or the night sky.  In many cases, that introduction will unleash their natural curiosity and allow their innate connection to nature to surface.  Unfortunately, that connection has been suppressed by a number of factors in our modern world (see: Children & Nature, a Lost Connection); hopefully, the right nature gift will ignite a deep-seated attraction to our natural environment.

Those of us who enjoy the many wonders of nature recall persons and incidents from our childhood that were instrumental in triggering that enthusiasm.  It is now imperative that we "pass it forward."  After all, the future welfare of Earth's ecosystems will depend on the commitment of today's children.

No Drone Zones

Advancing drone technology has led to the increasing use of these unmanned craft by the military, security agencies, agriculture, engineering firms and other industries.  Of course, they have also become very popular among want-to-be pilots.

This explosive growth of aerial drones has led to a variety of concerns, including infringement on privacy rights, augmentation of noise pollution and threats to public safety.  For those of us who relish the sanctuary of nature preserves, the prospect of drones zooming overhead is a development we prefer to avoid.

Hopefully, before the domain of drones begins to encroach on sensitive natural habitats, the Department of the Interior will forbid their use in Wilderness Areas, National Parks, National Wildlife Refuges and other fragile ecosystems.  After all, ATVs, snowmobiles and dirt bikes already disturb the tranquility and threaten the welfare of many State and National preserves.