SAFETY MONITORING by Canaries, Crayfish, and Brook Trout
Dr. James J. S. Johnson
Canary “recruited” for Mining Safety (U.K. gov’t/public domain)
Son of man, I have made thee a watchman unto the house of Israel: therefore hear the word at my mouth, and give them warning from me. (Ezekiel 3:17)
It’s good to have warning devices – like smoke detectors — that monitor environmental conditions, to give us an alarm if a deadly danger is imminent. However, long before humans invented mechanical safety monitoring devices, God had installed creatures all over the planet, with traits that equip them to serve us a safety monitors who can alarm us humans regarding environmental hazards.
ISLAND CANARY photo credit: HBW Alive
CANARIES, AS AIR QUALITY MONITORS
The Canary (Serinus canaria, a/k/a the “Island Canary” or “Wild Canary”) is an amazingly valuable finch. For generations it has been commonly known, at least within the mining community, that canaries are good safety indicators — serving as caged air quality monitors – if the air is becoming dangerous, the Canary provides the alarm, signaling (by its distress) that it’s time to evacuate(!).
BIRDS AS DANGER SIGNALS – Until 1992 miners used to take a caged canary underground to warn them of dangerous gases [such as carbon monoxide] in the mine. The bird would react to poisons in the air before miners became aware of them. … Canaries were used to rescue teams in coal mines to detect poisonous carbon monoxide gas. Reacting more rapidly than humans, their fluttering and other [behavioral] signs of distress gave warning when [dangerous] gas was present. Oxygen was also carried to help birds recover. No detecting apparatus was so reliable and canaries were used until 1992 when new electronic equipment, which can also meter the concentration of gas, was introduced.
[Quoting Colin Harrison & Howard Loxton, THE BIRD: MASTER OF FLIGHT (Hauppauge, NY: Barron’s Educational Series, 1993), page 277.] Perhaps we should not be surprised that canaries have been used as “watchdogs”, in mines, to give warning of dangers – the word “canary” points to the historic discovery of that species of yellow-and-brown finches, in the Canary Islands (and Madeira and the Azores), by Spanish conquistadores. The term “Canary Islands” means “dog islands”, i.e., canine islands, so it makes sense, philologically speaking, that canaries have been harnessed to serve humans as air quality “watchdogs”.
On 1478, when the Spanish invaded the Canaries, they started to export these birds throughout Europe. There followed intensive rearing in captivity, giving rise to the remarkable varieties of forms with their great varieties of forms with their great variety of plumage coloration.
[Quoting Gionfranco Bologna, SIMON & SCHUSTER’S GUIDE TO BIRDS OF THE WORLD (London: Fireside Books, 1990; edited by John Bull), page 365-366.]
Yellow Canary (Crithagra flaviventris) Male ©WikiC
But what is a Canary? Do we see them – or their cousins – in America?
The original Canary (Serinus canaria) is a small yellow and brown species of finch with a lively manner and a cheerful song. The familiar yellow bird of today is the result of controlled breeding [i.e., real “selection” of phenotype-coded genotypes, by human breeders] usually suppressing the dark pigments in the plumage. Breeding has also produced a wide range of color in shades and mixtures of white, red (which needs a carotene-rich diet to maintain the color) green and brown, tufted headcaps and variations in body shape. Birds produced by crossbreeding with Red Hooded Siskins (to produce red) and Mules (hybrids with other finches such as the Goldfinch and Linnet), are not taxonomically true canaries but are exhibited as such. The Roller, Malinois and Spanish Timbrado are considered the most musical breeds.
[Quoting Colin Harrison & Howard Loxton, THE BIRD: MASTER OF FLIGHT (Hauppauge, NY: Barron’s Educational Series, 1993), page 236.] Thus, within the extended “family” of finches, the American Goldfinch (Carduelis tristis) is a cousin to the wild Canary (Serinus canaria) of the Canary Islands.
CRAYFISH crawling out of drainage ditch water photo credit: Aaron LeSieur
CRAYFISH, AS WATER QUALITY MONITORS
While caged Canaries can monitor the underground air quality, Crayfish (e.g., Procambus, Orconectes, Cambarus, Fallicambarus, & Faxonella species) serve as water quality monitors. (This is a service that I especially appreciate, having previously served the Texas Natural Resource Conservation Commission and the Trinity River Authority of Texas, as a Certified Water Quality Monitor, and having taught a course in Environmental Limnology at Dallas Christian College, back in the AD1990s.)
Just as canaries are sensitive to airborne poisons, crayfish (called “crawfish” by Louisiana Cajuns, as well as “mudbugs”) serve as indicators of lotic freshwater quality, as well as indicating the freshwater quality of lacustrine margins and muddy-water bayous.
[C]rawfishes have proved to be good indicators of the health of streams and other aquatic ecosystems [such as drainage ditches] and are of great interest to environmental biologists. Because the lives of these creatures are tied so closely to water, pollution and lowered water quality often lead to loss of crawfish populations over both small and large areas. Some studies suggest tha talmsot half the species of eastern American crawfishes suffer from increasingly poor water quality and rapid loss of their aquatic habitats to agriculture or human housing development. A few species in other states appear to have become extinct [i.e., locally or regionally extirpated], and several others – including some in Louisiana – could disappear within the next few decades.
[Quoting Jerry G. Walls, CRAWFISHES OF LOUISIANA (Baton Rouge: Louisiana State University Press, 2009), page 1.] For further (and very comprehensive) details, on the need for relatively pure freshwater, for successful crayfish habitats, see Walls’ book (CRAWFISHES OF LOUISIANA), at pages 34-37 & 52-54.
As a youth, I learned to observe and appreciate (and catch) crayfish, in rural Baltimore County (rural Maryland), as reported elsewhere — see “Catching Crayfish, a Lesson in Over-Reacting”. These wetland-loving decapods are truly shellfish, creative constructions of crustacean beauty, exhibiting God’s bioengineering brilliance.
So America’s Crayfish, which come in a variety of species, are water quality monitors, indicating by their presence (or absence) whether the freshwaters in streams and drainage ditches are relatively healthy.
Consequently, in recent years, I have been glad to see the mud chimneys of crayfish, on the sides of a drainage ditch that runs runoff rainwater alongside my front yard, in the shadow of my mailbox. Even gladder, I was, when I saw active crayfish, darting here and there in the pooled up rainwater-runoff water that accumulates in that drainage ditch. In other words, the crayfish in my front yard’s drainage ditch are (by their very lives!) signaling me that the drainage ditch has fairly “healthy” freshwater quality! As a former Certified Water Quality Monitor, I was happy for the crayfish’s monitoring “report”.
BROOK TROUT ( photo credit: troutster.com )
BROOK TROUT, AS WATER QUALITY MONITORS
Of course, the Crayfish is not the only indicator of freshwater quality. Another example is the Brook Trout (Salvelinus fontinalis – a/k/a “brook charr”, “speckled trout”, “mud trout”, etc.), a salmonid famous for inhabiting freshwater streams, as its name suggests. It prefers ponds and streams with clean, clear, cold waters.
The importance of Brook Trout, to mankind, is illustrated by the fact that it is the official fish of 9 states: Michigan (where a potamodromous [fish that migrate only within contiguous freshwaters] population in Lake Superior is called “coaster trout”), New Hampshire, New Jersey, New York, North Carolina, Pennsylvania, Vermont, Virginia, and West Virginia – plus it is Nova Scotia’s official “provincial fish”.
Since the Brook Trout thrives only in clean freshwater, it too is an indicator – a water quality monitor of sorts – whose presence exhibits that its home-waters are relatively healthy, i.e., unpolluted.
The brook trout (Salvelinus fontinalis) is a small, brilliantly colored freshwater fish native to clear, cold streams and rivers in the headwaters of the [Chesapeake] Bay watershed. … There fish thrive in clear, silt-free, well-shaded freshwater streams with numerous pools and a substrate made of mixed gravel, cobble and sand. Because brook trout are not tolerant of water temperatures above 75 degrees Fahrenheit, they are rarely found in developed areas. . . .
In addition to being noted for their recreational value [as a “prized game fish”], brook trout are also very significant biologically [i.e., ecologically]. Because they require pristine, stable habitat with high water quality conditions, brook trout are viewed as indicators of the biological integrity of streams. As the water quality in headwater streams has declined so have brook trout populations.
[Quoting Kathy Reshetiloff, “Got Brook Trout? Then You’ve Also Got a Healthy Stream”, CHESAPEAKE BAY JOURNAL, 26(8):40 (November 2016). For further (and more comprehensive) details regarding how urban, agricultural, and/or industrial development routinely reduces water quality in affected stream-waters, review Kathy Reshetiloff’s article (cited above), regarding streamside vegetation impacts, sedimentation, rate changes to waterflow, water temperature impacts, acidic runoff, erosion impacts, etc.
In sum, if your stream-water hosts healthy Brook Trout, the stream-water itself is healthy! Like a water quality monitoring device, these salmonids detect and report (by their populational successes or failures) lotic freshwater quality.
It’s good to have an “early warning” system, a safety monitor who provides a timely alarm of approaching danger. And yet we who have God’s Gospel, the Gospel of Christ’s redemptive grace, are obligated to warn others about the realities of eternity – woe to whoever shuts his or her ears to the good news of Christ the Redeemer. The time to secure one’s relationship to God is now: today is the day of salvation!
He heard the sound of the trumpet, and took not warning; his blood shall be upon him; but he who takes warning shall deliver his soul. (Ezekiel 33:5)
Whom [i.e., Christ] we preach, warning every man, and teaching every man in all wisdom, that we may present every man perfect in Christ Jesus. (Colossians 1:28)
For He saith, I have heard thee in a time accepted, and in the day of salvation have I helped thee: behold, now is the accepted time; behold, now is the day of salvation. (2nd Corinthians 6:2)
Catching Crayfish, a Lesson in Over-Reacting