Water Closet For February 20, 2015
A friend of the Stream Team far Down East in Pembroke, Maine, has sent us his nature notes every two weeks for several years. Here is his latest on salt. If you want to see and feel lots of salt, run you finger across your car. Our DPWs will give us more before this cold snowy winter is over.
QUODDY NATURE NOTES (2/8/15)
SALT by Fred Gralenski*
[pullquote]”It wasn’t until relatively recent times that scientists found out how seabirds evolved to flourish in a salt water environment”[/pullquote]With all this dreaded(?) snow, there are some people who wish it would go away. Of course, the way the snow will go away (and it will) is to melt it, and salt can be used to hurry the process, especially on the roads. Annually, the US uses about 17 million tons of salt on the roads, and in Pembroke we use about 185 tons. Our salt in Pembroke came by way of a broker from a salt mine in Pugwash, Nova Scotia. I stopped there once and wondered if they gave tours of their salt mining operation, but the receptionist sweetly (not saltily) said that was not corporate policy. I kept my salty comments to myself.
Even though most of the earth’s surface is salt water, on land, salt is often considered a pollutant, and, depending on concentration, is generally damaging to both flora and fauna. However, some plants like asparagus, barley, wheat, and coconut benefit from a judicious amount of salt, and all green plants depend on chloride ions for photosynthesis. A study in Canada in the vicinity of Pugwash on the effects of salt solution on the local amphibians indicated that American toads were adversely affected the least; Spotted salamanders and Wood frogs were the most sensitive and Spring peepers and Green frogs were listed as intermediate. My research indicated that Bullfrogs are relatively tolerant of brackish water, and I ve found Gray Tree frog tadpoles in upper tide pools on the Acadian peninsula. Snakes and turtles can tolerate living in a somewhat salty environment better than amphibians, but must have fresh water to hydrate. Some fish are diadromous, that is, they may live part of their lives in either salt or fresh water, and these include Atlantic salmon, alewives, eels and Brook trout. Since their body chemistry stays the same in both environments, they have to do some fancy footwork (finwork?) to maintain similar blood-salt relationship. This feature can be upset by pollutants such as pesticides and leaching of detrimental chemicals from the soil by acid rain.
Farmers who raise animals, especially dairy farmers, supply their livestock with a salt lick to satisfy the needs of their animals. Similarly, wild herbivores from deer to porcupines need salt in their diet and will seek out ways to get the necessary mineral. Carnivores like foxes and bobcats get most if not all of their salt requirements from their prey. Marine mammals easily get the necessary salt from their environment, but since their blood-salt concentration is less than one-third of normal seawater, they are in danger of dehydration. Seals apparently cannot drink seawater, but get the necessary amounts of fresh water from their prey. Some references say seals occasionally drink from rainwater pools, and one stated that seals may get some freshwater from inhaling fog. Seals can live in freshwater, but the food supply is more reliable offshore. Whales can drink seawater, and their kidneys can concentrate the salt and excrete the excess as waste.
It wasn’t until relatively recent times that scientists found out how seabirds evolved to flourish in a salt water environment. Schmidt-Nielsen and his co-workers in 1957 discovered that the lateral nasal glands of seabirds, located near the eye socket, was a salt gland, that could clear excess salt from the bird’s body and excrete this salt through the nostrils of the bird. His experiments were initially done with Double-crested cormorants which have nares (nostrils) that open to the roof of the bird’s mouth. This concentrated saline solution flows towards the tip of the bird’s beak, and the bird must find the process disagreeable because it intermittently shakes its head. All seabirds, even those with regular external nostrils like seagulls, have this capability to various degrees. Think of all the money we could save if we could train seagulls to snot on our winter roads instead of pooping on our roof.
* Fred Gralenski is a crackerjack backyard naturalist in the easternmost part of the United States. His sharp eyes and clever little experiments have long delighted. He sees and studies the small creatures around us that most overlook. In ten weeks he will lead a group in his area to look and listen for signs of amphibians.
WATER RESOURCE AND CONSERVATION INFORMATION
FOR MIDDLETON, BOXFORD AND TOPSFIELD`
|Precipitation Data* for Month of:||Nov||Dec||Jan||Feb|
|30 Year Normal (1981 – 2010) Inches||4.55||4.12||3.40||3.25|
|2014 – 2015 Central Watershed Actual||4.60||8.45||3.67||6.6 as of 2/17**|
Ipswich R. Flow Rate (S. Middleton USGS Gage) in Cubic Feet/ Second (CFS):
For Feb 17, 2015 Normal . . . 61 CFS Current Rate . . . Unavailable–
*Danvers Water Filtration Plant, Lake Street, Middleton is the source for actual precipitation data thru Jan.
**Middleton Stream Team is source of actual precipitation data for Feb.
Normals data is from the National Climatic Data Center.