Weird and Wonderful Water

Water is the stuff of life. We can't live without it, and neither can the rest of the food chain. The search for extraterrestrial life hinges on whether or not a planet or moon contains liquid water, but that assumes that any life off Earth is the same as Earth-based life. This week we'll take a look about what makes water so special and how it keeps all of us alive.

Water, the most abundant substance on Earth.
Unless air is more abundant.

Water is unique among all chemicals (yes, it's a chemical) because it is the only one found in solid, liquid, and gas states naturally on Earth. While ice and water vapor aren't basic requirements for life, they are key components of the water cycle. Water stored as snow and ice in the mountains is slowly released during the dry summers in the American west, meaning a steady flow in rivers throughout the year. Clouds made of water vapor transport precipitation over long distances. On top of that, ice and steam make modern life more convenient- think food storage and electricity generation.

Winter snow waiting for the spring melt, March 2016

Typically, solids are more dense than liquids, which in turn are more dense than gases. Water flips this around, as ice is less dense than liquid water. If you freeze a container of water, you'll notice that the ice fills more of the container than the water did. This is why your frozen pipes burst in winter. The expansion of water as it freezes is a visual of the density decreasing. Because ice is less dense than water, it floats. Because ice floats, it forms on the surface of lakes and other bodies. This allows aquatic life to survive. If water froze from the bottom up, everything would either freeze in place, or eventually be exposed on the surface.

Molecular structure of liquid water and ice (Mountain Empire CC)

Water has adhesive and cohesive properties. Water molecules stick to each other (cohesion) and other substances (adhesion). Adhesion causes capillary action. This is the movement that is responsible for plants being able to absorb water in the ground through their roots, up the stem, and to the highest leaves. Cohesion also contributes to surface tension. Water molecules on the surface are more tightly packed and can resist pressure from outside forces. This allows objects to float. Water striders can stand on the surface because of surface tension.

Water strider striding water (National Wildlife Federation)

Water has a high specific heat. Specific heat is the amount of energy needed to raise the temperature of a gram of water by one degree Celsius. Because it takes a lot of energy (1 calorie per gram) to heat water, it takes a lot of heat to boil water. Ocean life appreciates not being boiled. Water also holds onto heat it absorbs and releases it slowly, moderating Earth's temperature and making the seasonal changes gradual.

Water dissolves more substances than any other. The polar structure of the water molecule. The positive hydrogen end will attract negative ions, while the negative oxygen ends attract positive ions. Water's solvency is important for plants and animals to absorb nutrients, and for animals to flush waste from their bodies. Nonpolar substances like fats do not dissolve. That's where the saying "Oil and water don't mix" comes from. Less dense fats will float on top of water, and with some skill they can be separated.

Next time you take a drink, raise a glass in appreciation of water. Without it, your drink wouldn't be here and neither would you. This week's information comes from USGS and Mountain Empire Community College.

Pros and Cons of Hydroelectric

Hydroelectric power generates the most electricity of all renewable energy sources in the US, about
7% of the total production. It is a truly renewable source as the same water can flow through a series of dams on a single river, and it is renewable. It is also “clean”, producing no carbon emissions outside of those during the dam building process. 

Water held back by a dam goes through an intake pipe and turns turbines as it passes through the dam.
Faster flowing water will produce more power. Hydroelectric power is about 90% efficient, making it a
great source of power. Due to controls at the dam, the flow of water can be adjusted to meet peak
demands much more quickly than at a nuclear or coal-fired plant. Some dams are equipped with a
pump and can pump water to a higher level during times of low energy usage. The water is then
released back through the dam at peak times to generate additional power.

Not all dams are generating stations, but hydroelectric dams often serve other purposes such as flood
control, irrigation, drinking water supply, and recreation. Because the water is naturally occurring and
free, hydroelectric power is among the cheapest on the market, less than a penny per kilowatt hour on
average. An electric utility can earn additional income through recreational fees, keeping utility rates
low.

Hydroelectric dam in Arizona (USGS)

Although hydroelectric power is “clean”, it is not completely “green”. Like the fossil fuels, it also has
negative environmental impacts. Dams affect fish migration, hydrology, and sediment and nutrient
movement. Flooding a reservoir also causes terrestrial habitat loss, which is traded for aquatic habitat.

Fish ladders can be built to aid anadromous fish in passing around a dam. These fish hatch in
freshwater, live as adults at sea, and return to their native streams to spawn. The journey through
natural aquatic habit frequently involves jumping over small waterfalls, which fish ladders mimic.
Different species of fish move at different speeds and therefore have different needs. Fish ladders come
in many different designs, and some even look like a natural stream rather than a flooded staircase.
Intake screens covering the intake pipes can successfully keep most fish from getting sucked into the
turbines, which can kill them.

Fish ladder (Army Corps of Engineers)

Terrestrial habitat is lost at the expense of aquatic habitat gain. However, the reservoir behind the dam
is of lower quality than a natural lake and alters downstream hydrology. Reservoir water stagnates
since there is no outlet and sediments and nutrients from upstream collect behind the dam rather than
enriching downstream areas. Downstream ecosystems can also suffer if not enough water is released
from the dam.

Sediment deposits after a dam removal in Washington (NPS)

This week's information comes from US Bureau of Reclamation, Michigan DNR, and
Union of Concerned Scientists.

Spring Shorebird Migration

I spent a day along the Jersey Shore (Delaware Bay side, away from the beachgoers) in search of migratory shorebirds making their way north. In particular, I was after the rare and elusive red knot. I failed to find any, but they were at the first beach I visited just hours before I arrived. Instead, I saw sandpipers, terns, laughing gulls, some oystercatchers, and even a few ruddy turnstones. Some of these birds nest and breed in New Jersey, while others are taking advantage of the horseshoe crab spawning as an opportunity to fatten up after flying nonstop from South America on their way to other areas. I also strolled around inland and found some egrets, osprey, purple martins, swans, geese, ducks, and songbirds. There were non-birds running around too: a muskrat, snake, deer, and of course lots of bugs. The sightings kept coming after I left. I spotted a great blue heron flying overhead, and a turkey flew across the road ahead of me as I made my way back home.

Unidentified sandpipers jumping for joy

Those sandpipers have friends

Here, we see hundred of birds flying over Delaware Bay

This beach had maybe a thousand laughing gulls.
Not pictured: the noise 

Species of the Month

Wherever you live, fishing season is in full swing. This month we'll profile one of the most common game fishes, the rainbow trout. They can be found in lakes and streams almost everywhere around the world, though introduced to many of them.

Rainbow trout (State Department)

Scientific name: Oncorhynchus mykiss

Kingdom: Animalia (animals)

Class: Actinopterygii (ray-finned fishes)
Order: Salmoniformes 

Range: Pacific coast of North America from Alaska to Mexico

Habitat: Aquatic, some also have a marine phase

Lifespan: 6-8 years average, up to 11 years
Diet: Insects, insect larvae, crustaceans, small fish, algae
Predators: Lampreys, eagles, osprey, herons, mergansers, bears, mink, river otters, seals, sea lions, other fish, humans

Fish on! (NPS)

Conservation Status: No special protection for freshwater only fish; nine populations of steelhead are listed as threatened or endangered

Steelhead (NOAA Fisheries)

Other information: Rainbow trout get their name from a colorful iridescent streak along the sides of its body. State fish and game agencies around the country raise them to stock streams and lakes for fishing season. Stocked trout remain in freshwater; some native trout along the west coast are anadromous (have a saltwater phase) and return to their birthplace to spawn and die. The anadromous trout are called steelhead. Females lay eggs in a gravel nest called a redd. Fertilized eggs hatch after a few weeks, and the hatchling remains attached to the yolk sack as a food source before leaving the redd for the wider world. Young trout tend to stick to slower, shallow water. Young steelhead remain in the stream for up to three years before heading out to sea. Due to habitat degradation and loss, several western steelhead species are listed as threatened or endangered under the Endangered Species Act. Meanwhile, introduced trout are becoming a problem in some areas. They eat and/or outcompete native fishes such as cutthroat and brook trout. They threaten genetic integrity by hybridizing with native species. They also carry a parasite responsible for whirling disease, which causes deformities that make a fish easier prey.

Steelhead (NOAA Fisheries)

This week's information comes from University of Michigan's Animal Diversity Web and the US State Department, of all places.

Pond Life

Having spent three seasons doing amphibian egg mass surveys, I can tell you that there are two kinds of people: those who look at a pond from the outside and just see a pond, and those of us who have been in a pond and have seen little world contained within.

Northwest salamander egg mass

Just getting close to the pond changes your view of it. Driving by, you can easily define the shoreline. Walk up to the shoreline and you aren't so sure anymore when the ground gets softer and wetter.
The most obvious pond life is visible before you get to spongy edges. Ducks and geese are patrolling like an avian navy, while a great blue heron flies overhead. Lily pads dot the surface and the whole northern and eastern sides are cloaked in rushes and reeds. If you are still, you might hear the bullfrogs and Pacific tree frogs.

Pacific tree frog

Mallard duck

Put on your waders and step into another world. Look into the water and you'll see insects and their larvae on and below the surface: mosquitoes, craneflies, dobsonflies, and more. Tadpoles and the occasional small fish dart by. A squeak and a splash reveals a startled river otter. Attached to the plant life, you'll find frog, toad, salamander, and newt eggs. Some are below the surface, covered in algae. Some are on the surface, anchored to the stem of emergent vegetation.

Caddisfly larvae

Scoop up a water sample to look at under a microscope. In addition to the floating dirt and plant material, there are tiny shrimp-like critters a quarter inch long. Even tinier are the microscopic algae, protozoa, and bacteria.

Freshwater shrimp- either an isopod or a copepod

If it's a rainy day you won't see much below the surface, but the raindrops take on a totally different sound when they are falling all around you and only landing on more water.
I hope you enjoyed today's aquahike. Ponds are full of life, even if hidden in plain sight. It's a fragile ecosystem, so be kind to your local ponds.

Caution: beavers working

More Winter Adaptations

The dead of winter is nigh upon us. It had been relatively mild where I am, despite a colder fall than usual. Unlike this time last year, we are having some temperatures above freezing. I deal with the cold by putting on this flannel,

but how are some more of out animal friends coping?
The wood frog survives by going into suspended animation while buried in mud or leaf litter. For all intents and purposes, it is dead. It survives the cold (and insect-free) winter because it produces a natural antifreeze that keep the water in its cells from freezing and bursting.

Wood frog (MN Dept. of Natural Resources)

Deciduous trees also have to work around internal ice causing cells to burst. In late summer they prepare for winter by shedding their leaves, which reduces the surface area that snow and ice can accumulate on. That protects branches from breaking. They also drastically reduce water consumption. It won't be needed without photosynthesis happening, and less water stores in the trunk is less risk of water freezing and causing a rupture.

Leafless trees that gave up drinking

Snapping turtles survive by spending the winter underwater. Lucky for them, water freezes from the top down rather than from the bottom up. The cold water and lack of oxygen may seem less than ideal living conditions but somehow the turtles survive by changing their blood chemistry to compensate for increasing levels of acid.

Snapping Turtle (Missouri Dept. of Conservation)

Insects also are able to adapt to winter conditions. I always assumed they flew south ahead of the birds or just did when I was younger. Some use the same antifreeze method as the wood frog. Others allow themselves to freeze without becoming ice, a process known as supercooling. Supercooled fluids remain liquid at temperatures below freezing. But the risk is always there that a single particle could allow ice crystals to form. Once that happens it's game over.  The fluid instantly iced over, killing the insect.

Supercooled stonefly (Scientific American)

While you are enjoying the snow from inside your cozy house, just be thankful you don't have to rely on chemistry or dehydration to make it through the winter. And next time you need a snack, it probably won't be your last for a few months.
This week's information comes from the Minnesota Department of Natural Resources and Bernd Heinrich's book "Winter World".

Daffy Ducks

This week, let’s have a look at one of my favorite critters, ducks. Mallards are probably one of the most common birds in North America. There have always been a lot of them near me, whether I was living in Pennsylvania or Washington. Many species are migratory, but my mallards are year-round residents. Growing up, I could always count on a few in the back yard, as we had a small stream separating us from the town park.

A pair of ducks swimming in a stream

There are two kinds of ducks- diving ducks and dabbling ducks. Diving ducks, as the name implies, dive underwater for food. Dabbling ducks like the mallard flip their butts in the air and their heads in the water to find food, but remain afloat. Different species have different food needs, but as a group they feed on fish, insects, worms, mollusks, and plants.

A mallard (a dabbling duck) goes bottoms up for food

A Barrow's goldeneye (a diving duck) beginning a dive

Females lay eggs in a nest, then lead their hatchlings to water. One year, a mallard nested in a tree in my parents’ yard. It’s a common practice among wood ducks, but at the time such behavior was unknown to me or anyone else in town. City workers came and got the ducks out of the tree. They didn’t believe it until they saw it. Ducks with tree nests usually nest right above a body of water. After hatching, the babies will plop out of the nest into the water, following mom’s lead.

Wood duck hatchlings leaving the nest (Pintrest)

One thing I’ve been guilty of in the past is feeding the ducks. Since they were frequent visitors, and because no one likes the end piece of bread, I would tear it into little pieces and toss it to the ducks. Bread isn’t part of a duck’s natural diet and can lead to health issues down the road. It’s better to let wildlife be wild and not count on people for food, but if you must feed the ducks, give them grape halves.

Mother mallard and babies

Ducks are known for their stereotypical quacking, but that sound belongs to the female mallard alone. She seems to be especially noisy in a large group of ducks. Probably the best duck sound is the mutter. I notice this if I’m on a bridge or at the water’s edge and a duck swims by. They sound to me like they’re muttering something under their breath at me. My favorite duck behavior occurs during mating season. On many occasions, I’ve seen half a dozen or more males chasing a female around the back yard. There’s nothing like a bunch little footballs with heads waddling around as quickly as possible.

Maybe you see a lot of ducks in your area too. Are they so common as to become almost invisible? Slow down and take the time to watch them.

Desert Life

This time of year, there’s usually no place in America that’s hotter than the desert Southwest. The region is known for its striking red sandstone formations, deep canyons, and ancient ruins. While the desert may seem like a barren wasteland to the casual observer, it is full of life. If you know where to look. The critters of the desert have evolved with special adaptations that allow them to survive in a harsh environment. Let’s have a look at some.

Extreme heat and scarce water are two hardships of the desert. Because of the second problem, sweating is an impractical solution to the first problem. As a workaround, the jackrabbit has large ears which are full of blood vessels. The blood vessels bring warmer blood away from the body core to cool. The large surface area of the ears also helps the cooling process (National Geographic).

Black-tailed jack rabbit (NPS)

The kangaroo rat has adapted to life without beverages. It can go an extended period without water, absorbing what it needs from its plant-based diet. Too keep cool, it lives underground and is nocturnal (Arizona-Sonora Desert Museum).

Stephen's kangaroo rat (Arizona-Sonora Desert Museum)

The various cactus species have evolved to avoid water loss. All plants lose water through their leaves in a process called transpiration. Cactus plants minimize the loss by having long, thin needles in place of the leaves we’re familiar with on trees and other leafy plants. They also have an extensive root system for maximizing water collection potential and a wide, hollow stem for water storage (BBC).

Saguaro cactus (US Forest Service)

Other desert plants have adapted as well. Shrubs and non-woody flowers survive by growing deep roots that can reach down into the water table. They have hardy seeds that can last for years before germinating. When the rare shower falls, these plants simultaneously burst to life in a brief but spectacular desert bloom (Science News for Kids).

Superbloom (National Park Service)

The Great Basin spadefoot toad has a cool adaptation for surviving in the desert. They burrow underground and remain in a state of suspended animation for years until rainfall brings it to the surface for mating and feeding. Mating pairs will lay and fertilize eggs anywhere water collects, then the race is on for the eggs to hatch and tadpoles to develop before the water evaporates. The tadpoles are cannibalistic, which might be an incentive to hurry up and grow (The Nature Conservancy).

Great Basin spadefoot toad (Idaho Fish and Game)

You probably don’t think of shrimp living in the desert. The fairy shrimp’s habitat is ephemeral (seasonal) pools that form in depressions in rock. They are tough little buggers, able to withstand extreme heat. Their eggs can survive desiccation for decades, using sugars instead of water inside the egg. The eggs can remain in place until rain activates it and it hatches, or they can be carried on the wind to a new location and hatch there when rain comes (National Park Service).

Fairy shrimp (National Park Service)

Next time you happen to be in the desert, look around for these and other fascinating critters. The desert is alive, if you look hard enough to see the life all around you.

Dead Zones

This week we’re taking a look at a problematic summer tradition: hypoxic dead zones. These are marine or aquatic areas that don’t have enough oxygen to support life. The most famous is probably the dead zone in the Gulf of Mexico. Let’s look at dead zones, how they form, and what you can do to help prevent them.

The most common cause of dead zones is excessive nutrient runoff. Nutrients in this case are nitrogen and phosphorus, nutrients from plants. The main source of this nutrient runoff is agriculture, but it can also come from detergents, animal waste, and untreated sewage.

Gulf of Mexico dead zone (Digital Journal)

The nutrient overload leads to a sudden population boom in the local algae community. It seems paradoxical that algae, which produces oxygen, leads to an area without oxygen. First, when a large mat of algae covers the water’s surface it prevents oxygenation at the water/air interface. Then, when the algae dies and decomposes, that is where the oxygen disappears to. Mobile critters like fish can move to more oxygenated areas to survive, but something that can’t move or is very slow like a starfish or sea urchin will suffocate unless the situation clears up.

How a dead zone forms (Gulf Hypoxia)

Sometimes the algae bloom is of a type that produces toxins. Sometimes the toxins cause fish kills. Shellfish can absorb the toxins through filter feeding and pass them on to predators and people. Algae toxins can even threaten public drinking water.

A closer look at an algae bloom (NOAA)

How can you help? Trying to stop non-point pollution seems hopeless, but if everyone ups their game a little bit it adds up and makes a difference. Simple steps you can take at home include limiting the amount of fertilizer you use for your lawn and garden, cleaning up after your pup, and washing your car in the grass rather than the driveway or street. Reducing fertilizer use reduces the amount of excess nitrogen and phosphorus washing into the storm drain and out to sea. If you’re already doing that, buy organic produce which doesn’t use any fertilizer or pesticide. Picking up your dog poop keeps the nitrogen and phosphorus from that source out of the system as well. Washing your car in the yard lets the phosphorus in the detergent soak into the yard rather than washing into the storm drain. Every little bit helps.

This week's information comes from the EPA.

Salamanders and Newts

As promised, our species comparison series returns to the world of herps. A few weeks ago we looked at turtles, tortoises, and terrapins, which are all reptiles. This week we’ll explore the differences between salamanders and newts, which are both amphibians.

Before going into the differences between salamanders and newts, let’s have a look at the differences between reptiles and amphibians. Both are cold blooded and can spend time on land or in water. Reptiles, however, spend more time on land generally. They breathe exclusively with lungs (some turtles are the exception, because nature hates following a hard rule). Amphibians spend more time in the water, generally, and can breathe air on the surface or below water, using their smooth, moist skin to exchange gases in many cases. Reptiles have dry, scaly skin that doesn’t breathe. Reptiles lay soft eggs on land, while amphibians prefer to lay their eggs in the water, usually in a gelatinous mass.

Rough-skinned newt

 Just as tortoises and terrapins are turtles but not all turtles are tortoises or terrapins, all newts are salamanders but not all salamanders are newts. Newts are a type of salamanders that prefer to spend most of their time living on land. Some lay eggs in the water, some on land. Some go through stages of development from larva to adult, some are just miniature versions of adults. Some salamanders have lungs, some have gills, some have both, and some have neither. There is much variety in the salamander’s order, so spotting the differences between salamanders and newts is difficult. A general rule is to look at the skin. Frog-like skin, which is smooth and wet, is a salamander. Toad-like skin, dry and warty, is a newt.

Northwestern salamander (USFWS)

A third critter thrown into the mix, also a member of the salamander order, is the siren. It looks and behaves like the salamander and newt, but instead of having four legs it only has two. Sirens have flat tails that they use for swimming, moving it from side to side like a fish does.

Greater siren (University of Georgia)

Are you confused by all this? Don’t worry about. I’m learning right along with you. Fortunately for you, all these technical terms and differences are merely to satisfy your curiosity; for me it’s a career choice. We’ll wrap up this series next week and leave the natural world for the labs and halls of scholarly debate. This week’s information comes from the SanDiego Zoo.

Mr. Frog and Mr. Toad

Part 4 of a continuing series on differences in similar critters brings us the frog and the toad. If you’re new to the show, or have a bad memory, you’ll recall that last year (and the previous two seasons) I was slogging through a pond looking for eggs belonging to frogs and toads (as well as newts and salamanders). They are out laying their eggs as we speak, so this week’s is a timely topic even if it has nothing to do with egg laying.

Frogs and toads are both amphibians, meaning they can breathe on land or in the water, and have similar body shapes. So how can you be sure which critter you’re looking at? Here are a few differences to help you figure it out.

Frogs are generally more aquatic than toads, although there is variation of aquaticness among both frogs and toads. Frogs have smoother skin, a taller and narrower body, and buggier eyes. When moving on land, frogs are magnificent jumpers. The hind legs are long and powerful.

Bullfrog with smooth skin and bugeyes

Cascades frog- note the long legs

Toads are famous for their warty skin, which will not give you warts. The body is wider and flatter than a frog’s. Toads don’t jump much; rather they walk or take small hops. The hind legs are shorter than a frog’s. Their eyes aren’t nearly as bulging as a frog’s. A frog is more likely to be near water, while a frog feels more comfortable straying from the water.

Western toad with bumpy skin and squat little body

Wyoming toad- note the shorter legs and less bulgy eyes
(USFWS)

If you ever encounter one of these critters in the wild, or even just your back yard, hopefully this helps identify what you’re looking at. Info this week comes from Kidzone. Next week we take a break from comparing similar species but the series will resume in April.

The Shell Game

Ever wonder what the difference is between a turtle and a tortoise? They’re both shelled reptiles so is it all just a name? Not exactly. All tortoises are turtles, but not all turtles are tortoises.

Desert tortoise (NPS)

A tortoise is a turtle that lives exclusively on land, while most (but not all, remember there’s always an exception) turtles spend most of their time in the water. Because of the lifestyle differences, turtles have webbed feet and tortoises don’t. And of course sea turtles, who only come on land to lay eggs, have flippers instead of legs. Tortoise shells are generally taller, while turtles have a flatter, more aquadynamic shell design.

Box turtle (NPS)

Loggerhead sea turtle (USFWS)

Now that you have that down, let’s introduce the terrapin. Terrapins are mix of the landlubbing tortoise and seafaring turtle. They spend half their time on land, half in the water. They have a more streamlined shell than a tortoise, yet it’s taller and rounder than a turtle’s. 

Diamondback terrapin (USFWS)

This week's compare and contrast is from the National Marine Life Center.