Sunday, November 27, 2011

You are what you eat – the colour version

A flamingo from a local butterfly garden
Every kid knows that a flamingo is pink because of what it eats. They filter water through their beak to catch brine shrimp and algae. The beta carotene in their food is converted to the pink pigments in their feathers, without this pigment source the bird would be white. Unfortunately, flamingos aren't found on my Pacific island except in captivity. But, we do have critters using the same pigment trick.

Recently, I met up with the local Natural History Society (I'm a member) for a beach seine at night because that was when the best low tide was this time of year. Based on the wind storms recently, we were lucky the wind had dropped off and it wasn't raining. The surf was manageable with the net for people wearing hip-waders and dry-suits – so not me as I don't own either. Two people took the net out into the surf. The first seine was over sand resulting in hardly any fish. So, the net was taken out and hauled in a second time over eelgrass. All sorts of interesting intertidal creatures were pulled up.

Everyone gathered around to check out the fishes, crabs and shrimps. The fish catch included: walleye pollock, English sole, stary flounder, sharpnose sculpin, sailfin sculpin, sandlance, roselip sculpin, tubesnout, high cockscomb, a type surf perch, Pacific spiny lumpsucker (the cutest fish ever) and a penpoint gunnel. Each type was put into a clear ziplock bag along with plenty of water and passed around. By holding the bags up to my headlamp, I got a good look at each critter.

The penpoint gunnel intrigued me because it was neon green – a tropical water colour in our temperate zone. A picture can be found here, the fish looks like an eel, but isn't. This guy hangs around in eelgrass or sea lettuce beds waiting to ambush little crustaceans and mollusks. The bright green colour of the one we found would allow it to blend in almost perfectly (they also come in other colours to match other seaweeds). Like the flamingo, the penpoint gunnel gets it's colour through what it eats. The green comes from the sea lettuce.

Few of the fish and invertebrates were held on to for a local museum's tide pool, the rest were released. As we packed up our gear, another beach seine group arrived. In the darkness, all we could see of them was dark shapes and headlamps – it was like looking at ourselves a couple hours in the past.
As a tangent, my trips to the beach seem to coincide with when my rubber boots are muddy. Once again they are clean.

Friday, November 18, 2011

Swamp Water

Home for many microbes
On a whim, I did an internet search on 'swamp water'. What came up included alcoholic drink concoctions and a 1941 movie based on an earlier book which looked like more of a drama than the potential horror promised in the title. No search result came up for swamp water as the random mixing of soda pops (which always came out brown for me because of the necessity of root beer). When I was a kid, I looked forward to any opportunity to mix pops and called it 'swamp water'. I did an informal survey of friends, and I'm not the only one who made swamp water, in fact, a few friends admitted they still do it, especially with slurpees. It even turns out some kids today are still making swamp water.

Speaking of kids and swamp water, I ran a group activity for kids last week on microbes (specifically the oceanic variety, although discussions didn't go that way). I borrowed a microscope and brought in water wrung out of my aquarium's filter, otherwise known as my in-house swamp water. The whole activity reminded me of when I was kid and my science-teacher father brought home a microscope from work for me to use. All the little critters out of my aquarium's filter became visible to me.

We haven't always known about microbes. Anton van Leeuwenhoek (I have no idea how to pronounce his name) discovered these tiny life forms everywhere in 1675. For his discovery, he used a microscope of his own design – one of the earliest microscopes. By definition microbes are simply creatures you need a microscope to see, and they typically form the base of an ecosystem. According to Wikipedia, many blame the failure of Biosphere II on an improper balance of microbes. Microbes are incredibly useful: they are required for brewing, wine making, baking, pickling and fermentation; they play a role in decomposition of organic matter; and they aid our own digestion by synthesizing vitamins and fermenting complex carbohydrates into digestible form. Microbes aren't all beneficial, in fact, many infectious diseases can be attributed to them.

My favourite of the aquarium-filter microbes are amoeba, partly because I can identify them and partly because they lack a definable shape. They are moving blobs that use their blobiness to envelope their prey. Amoeba were discovered by August von Rosenhof (another name I can't pronounce) in 1757, a surprisingly long time after the discovery of microbes especially considering how ubiquitous they are (in every aquarium I've ever had amoebas have flourished).

With the exception of amoeba, I can't identify specific microbes. They are hugely diverse: there are ones that swim like snakes, ones shaped like tiny ovals zooming around, and ones formed as large blobs that change shape as they move – plus many more. And this is just in my aquarium (which was originally seeded from local pond water). What would I find in my soil? Under the oak leaves in the park nearby? In a tidal pool? How about in my kitchen sink's drain? I'm always amazed by the diversity of critters right under our noses (or even in our noses). We live in a wild place.

Wednesday, November 2, 2011

Down on the beach

Breaking waves on a sandy beach
I took a group of students down to a local beach last week – it turned out to be the only day that week that poured rain (I often have that kind of luck). As the students were doing their work, I walked up and down the beach to check on them. Since I was dressed for the rain I didn't mind the weather, in fact I found it pleasant to be away from my computer for a few hours. In addition to my rain jacket, I wore my rubber boots so I could walk through the shallowest waves and feel their strength tugging at my ankles. Okay, the real reason I wore my rubber boots was because they were dirty and I hoped the wave action would clean them.

Most of the beach was cobble, that is, composed of golfball to baseball sized smooth stones. With each step shifting rocks allowed my foot to sink in a bit, it almost felt like I was wading. Off shore, breaking waves (less than 1 metre) formed perfect curls along their tops before crashing down. Beneath the crashing waves, rocks tumbled with the moving water adding their own sound to that of the waves. Constant wave action was moving the rocky beach, in fact, all beaches exist in a constant state of change. At different time of year a beach may look completely different. In summer, gentle waves bring more sand on shore while in the winter, larger waves can remove the sand entirely.

Beaches are made from loose sediments like rock and sand or even ground up hardened lava (Hawaii has beaches like this) that are deposited. A sheltered place in between headlands is ideal as the headlands will take the brunt of wave energy. Beach sediments can originate from a far off river or from right close by. The cliffs overlooking the beach I was on provided all the sediments needed for the beach to form.

As a tangent – my rubber boots are now nice and clean.