To the Beach

July 9, 2018 / Robinne Weiss / 1 Comment

While all you folks in the Northern Hemisphere are flocking to be beach for a swim and some sun and sand, we are shivering down here in the dark days of winter. But that doesn’t mean we don’t go to the beach.

Research from England has found that people living by the coast have better physical and mental health than those living inland. I can certainly understand that.

Growing up three hours’ drive from the beach, I visited the ocean about once a year. My husband, raised in the midwestern US, doesn’t remember seeing the ocean until age twelve or thirteen.

Today, we live a mere four kilometres from the beach. When the wind is calm, we can hear the surf. When the wind is high, we can smell the sea. Even without research to back us up, we’ve learned to head to the beach when we’re stressed.

Our beach isn’t a white-sand swimming beach—it’s made of cobbles, and the waves pound viciously on the shore. It’s not a place to swim, nor really a place to sit for very long (those rocks get uncomfortable fast). It’s a place to walk. A place to search for wave-polished rocks in glittering colours. A place to watch sea birds, dolphins, and the occasional seal. A place to leave all the stress of daily life behind (I challenge anyone to remain stressed while watching dolphins cavorting in the waves).

Researchers point to the calming blue colour, the hypnotic sound of waves, and the cultural context of the beach to explain its calming effect. But for me its influence is more profound. Our beach is usually free of other people—on a busy day you might see four others. From the beach, it is difficult to see any sign of humans at all—the odd bit of flotsam, but not even much of that. On our beach, the world is reduced to sky, water, and rock, shared only with wildlife. It’s easy to imagine the world is in better shape than it is. It’s easy to believe the vast ocean will endure, in spite of human stupidity. It’s easy to think those rare Hector’s dolphins, which we see nearly every time we visit the beach, are actually common. For the space of time we inhabit the beach, all is right in the world.

It doesn’t last, of course, but it’s good to have that escape so close at hand.

Beautiful Brawny Barnacles

July 4, 2018 / Robinne Weiss / Leave a comment

My daughter and I went for a walk on the beach after school yesterday. It was chilly, but calm, with a clear mid-winter sky and dolphins in the surf.

Washed up on the beach was a large tree stump crusted with barnacles whose colours mirrored the evening sky. The size and profusion of barnacles indicate the tree was lodged in the water for a long time before it was hurled onto our beach.

Barnacles are strange creatures. They’re crustaceans—kin to crabs, shrimp, and lobsters—but they don’t look anything like their relatives. Barnacles have given up the ability to move on their own (after a brief mobile larval stage), and instead settle down in places where the water moves around them—intertidal zones, the backs of whales and the bottoms of ships are popular barnacle real estate. Instead of having to wander in search of food, moving water carries lunch to the barnacles, and they filter it out of the water with feathery appendages called cirri.

Staying put in places where waves pound day in and day out isn’t easy. Barnacles produce a ‘glue’ that’s one of the strongest natural adhesives around. With a tensile strength of 35 N/mm²(5000 psi), it rivals the best commercial epoxies. In a strange quirk of biology, the glue is produced by a gland at the base of the barnacle’s antennae, and so the animal is glued head-first to the substrate. Once glued to its home, the barnacle forms a ring of plates around its body to protect it (this is all that is left of the barnacles pictured here—the animals themselves have died).

There are costs to gluing oneself in place. Unlike other sessile animals like corals who release their eggs and sperm into the water for fertilisation, most barnacles rely on internal fertilisation. To reach their neighbours and manage this feat, the hermaphroditic (both male and female) animals have penises that can be 8 times the length of their bodies. Until recently, researchers thought this was the only way barnacles could reproduce, but in 2013, a study found that at least one species of barnacle (with a particularly short penis) can capture sperm from the water if it’s too far from its neighbours.

Barnacles are of human importance. They encrust ships, leading to increased drag and fuel costs. But their habit of attaching themselves to all sorts of debris can also be used forensically to track marine wildlife like whales and turtles, items from shipwrecks and airplane crashes, and marine debris. Additionally, barnacles are considered culinary delicacies in Spain, Portugal and Chile.

Beautiful and brawny, weird and wonderful, barnacles always make me smile.

Backyard Biodiversity

June 25, 2018 / Robinne Weiss / Leave a comment

Craterium minutum

I know it’s been a good weekend when I arrive in my office Monday morning to find my microscope in the middle of the desk, and dirt and bits of plant material strewn about.

It means I’ve been outdoors, seeing cool stuff, identifying plants, insects, or other organisms.

Once you start looking at and identifying what lives around you, the variety is astounding. A glance at the citizen science website iNaturalist shows a pile-up of dozens of observations at our address—and those are only the species we’ve bothered to upload. I’ve identified 58 species of weeds in the vegetable garden alone. We have half a dozen slime moulds, dozens of fungi and lichens, who knows how many insects and other invertebrates. Then, of course, there are the birds, rats, mice, stoats and other vertebrates. I’ve never bothered to make lists of anything beyond the weeds.

So here in the dark depths of winter, I’ve decided to start a comprehensive list of the biodiversity on our little acre and a half. It will take time. It will require my microscope and many Monday mornings brushing dirt off my desk. But wouldn’t it be cool to know exactly how many other species we share this patch with?

And though many of the species I’ll put on my list are ones I’ve noted many times before, I’m sure some will be new and surprising, like the beautiful slime mould, Craterium minutum my daughter found last week.

Because, the truth is, we needn’t travel far to find natural wonders. We merely need to look closely and have a sense of wonder.

Here Comes the Sun

June 20, 2018 / Robinne Weiss / Leave a comment

After weeks of grey, unending drizzle, we’re finally seeing a bit of sun. Mushrooms abound in the yard, revelling in the dank mist we’ve been swimming through for a fortnight. We are all eagerly awaiting passing of the solstice and the lengthening of the days.

Though it is still pretty dark and drear, and the days will still be short for some time, there are signs of the spring to come.

Lambing has started. This is the time of year when the neighbours grow noisy, with lambs and ewes calling to one another day and night.

The preying mantids are gone, but their egg cases are dotted around the yard, promising a healthy population of my favourite predators come spring.

The daffodils and snowdrops are coming up, and I’ve even seen them blooming in other people’s yards.

And tomorrow is the solstice. Friday, the sun will remain above the horizon fractionally longer than it did the previous day. We’ll be on the upswing.

Beautiful Basket Fungus

June 2, 2018 / Robinne Weiss / Leave a comment

Mature fruiting body

One of my favourite fungi is Ileodictyon cibarium, the basket fungus, native to Australia, New Zealand and Chile. We have been treated this year to an amazing display of these fungi in our recently wood-chipped pond garden. Usually we don’t notice them until the fruiting bodies are fully formed, but because there are so many this year, we’ve been able to watch their whole emergence, from egg-like volva to lacy soccer ball.

Aside from their striking look, there’s nothing particularly lovely about these fungi. The basket fungus is in the family Phallaceae, also known as the stinkhorn fungi. Members of this family—you guessed it—have a foul odour (and many are phallus-shaped). The carrion or dung-smelling fruiting bodies attract flies to disperse the spores. Supposedly, the young fruiting bodies are edible … but not very tasty, as you can imagine.

Immature volvae

In spite of their smell, basket fungi have a certain celebrity status, owing to their remarkable structure. In fact, in Hagley Park in Christchurch there used to be a play structure in the shape of a giant basket fungus. I’m not sure if it’s still there—my kids don’t frequent playgrounds anymore—but it was always a favourite with my kids.

Geek 1: Fear 0

May 9, 2018 / Robinne Weiss / Leave a comment

I was in Christchurch for an all-day workshop on Saturday. The closest all-day parking was in the Art Gallery carpark. I resisted the idea of parking there. I never liked basement carparks, even before the 2010-2011 earthquakes, and I like them even less now.

Stupid, I thought. Time to get over this fear. Thousands of people park in multi-storey and basement carparks every day in this city. I can do it for one day.

I dove into the carpark, leapt out of my car, and practically sprinted to the exit. I was dismayed to find the pedestrian exit was through a couple of doors, down a corridor, and up a flight of stairs.

But just as I was about to climb the stairs, I noticed one of the seismic base isolators the building is equipped with. The geek in me overrode the scaredy cat, and I had to stop to snap a photo.

These isolation units are a cool piece of technology. They essentially decouple the building from the ground, so that when the earth shakes, the building stays still. In a quake, the top and bottom plates of the unit slide contrary to one another—the building’s inertia keeps the top plate relatively still while the lower plate jiggles around.

The isolation units were retrofitted to the art gallery (along with lots of other repairs) after the 2010-2011 earthquakes.

According to the manufacturer’s website, the Triple Pendulum Bearings like those installed in the Art Gallery are designed to dampen the wide range of lateral vibrations from small, medium, and large quakes. They don’t make the building completely quake-proof, but they did make me more comfortable leaving my car there for the day.

Ode to a Fern

April 26, 2018 / Robinne Weiss / Leave a comment

I could have posted a blog yesterday, but only from here, where there was cellphone reception. You’ll excuse me if I decided to enjoy the view instead of write a blog post.

It’s not that I didn’t write. My daughter and I, out for two days of hiking, stopped a couple of times on our way to sit and write. Sometimes I gave us a challenge, sometimes we just wrote.

I can’t say that anything I penned in the past two days is great literature, but I did smile as I wrote this Ode to a Fern, which was our first challenge. True to our writing styles, my daughter’s poem was deep and insightful, mine silly doggerel. Here it is, to lighten your day …

O filmy fern
All wet with dew
With fronds so thin
They are see-through.

You could adorn
A lady’s hat
A leafy veil
Fine to look at.

Or perhaps a curtain
You could be
Your gauzy fronds
Flapping free.

O filmy fern
These aren’t for you
To your wild self
You must be true.

Inhabit damp footpaths
Dimly lit
The forest floor
Is where you fit.

Pigeon Bay Walkway

April 23, 2018 / Robinne Weiss / Leave a comment

View from the head toward Christchurch.

Yesterday was a beautiful autumnal day. We headed out to the Banks Peninsula and did the Pigeon Bay Walkway.

It has been over a decade since we’ve been to Pigeon Bay. Last time we went, the kids were preschoolers. Then, we’d hoped for some sort of beach where the kids could play in the water, but Pigeon Bay is rocky. The shoreline is covered in cobble-sized rocks teeming with life. Lift any rock and a dozen crabs scuttle away. A decade ago, the pursuit of crabs delighted the kids. Still does. Yesterday, we also noted starfish, chitons, limpets and snails under the rocks.

But the main activity for yesterday was the walkway. It’s rated as a five hour return walk, but is mostly on a well-graded farm track. It’s easy going, and we did it in four hours, including a lunch break.

The track runs all the way to the head of the bay. It’s not exactly a wilderness experience—the land is a beef and sheep farm—but the views are spectacular. It’s one of the few places on the Banks Peninsula where you can get right out to the tip of the headland.

Out on the head, the cliffs are quite spectacular, and you can see the layers of volcanic deposits, well-spattered with poo from the shag colonies there. In the clear air yesterday, we could see all the way to the Kaikoura ranges.

The best part of the walk for me was looking down on a small pod of Hector’s dolphins feeding in the bay below. The dolphins were clearly circling and corralling fish, and there was a trio of gulls shadowing them in the air, picking off the fish the dolphins missed.

A lovely walk. Hard to believe it took us this long to get around to doing it.

Nursery web spiders

April 14, 2018 / Robinne Weiss / Leave a comment

The nursery web spider (Dolomedes minor) is one of New Zealand’s larger spiders, in spite of it’s species name. At this time of the year, it’s also one of the more visible spiders, or at least its webs are.

Nursery web spiders don’t use webs to catch food. Instead, they use their silk to create shelters for their eggs and newly-hatched young. These shelters are visible in late summer and autumn on the tips of shrubby plants, especially gorse.

The female spider can sometimes be seen hanging around the web during the day. In fact, if she’s nearby, its hard to miss her, with a body nearly two centimetres long, and a leg span reaching six centimetres.

The nursery web isn’t the only care the nursery web spider gives her young. Until the spiderlings are near to hatching, she carries the egg sac with her to protect it. The young hatch out inside the nursery web, staying within the web’s protection for about a week.

The spiderlings disperse by ballooning—they let out a strand of silk until the force of the wind blowing on it is greater than their own weight, and then they float away on the end of the thread to a new home.

Like other members of the genus Dolomedes, the nursery web spider is an ambush hunter, chasing down its prey on foot. But most other Dolomedes do this exclusively on or in water, whereas the nursery web spider hunts on land as well as water, eating a wide range of invertebrates.