A Windang Shindig

The Gong 151
#003 A Windang Shindig

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On a cool and blustery day in March, Salty, Keen Wasabi and I hiked around Lake Illawarra foreshore to the sandy arm of Windang Island. The island’s green top rises conspicuously from the lip of the lake. Anglers endure relentless plumes of spray on the seaward cliffs, each wave sending waterfalls cascading down deep flutes in the rock. Snorkelers proliferate in the summer, diving from ledges exposed at low tide, while swimmers wander up from Warilla Beach to survey the long and peaceful bay. The island is also notorious for sharks.

At 11 o’ clock the tide was at about 0.6 metres and dropping. Things that are usually submerged were becoming exposed. Keen and I dropped our nets and tanks on a rock ledge and waded out amongst the pools.

Soon we were walking on mats of Neptune’s Necklace (Hormosira banksii). This brown alga is made distinct by the string of olive-coloured beads that make up its thallus (body). Like plants, brown algae uses chlorophyll to photosynthesise and  absorb energy from the sun. Unlike plants, it also produces xanthophyll, a yellow pigment. This gives brown algae its distinct brown-green colour.

While at first it seems weird – after all, chlorophyll works perfectly well for plants – the secret of brown algae is where it exists in the ocean. Red light is bad at penetrating the ocean’s surface. Green light however penetrates deeply into the water. Because a thing’s colour is determined by the light it reflects (meaning green plants reflect green light) algae need to be differently coloured to absorb the light available to them beneath the waves. For Neptune’s Necklace, this means disguising its green chlorophyll with red pigment.

What I find fascinating about Neptune’s Necklace is just how well-equipped it is to maximise its light exposure. The alga is made up of multiple strands of beads called thalli. Each bead is made of a  spongey tissue filled with air and protected by a waxy coating. When submerged, the air makes the beads float, drawing them towards the surface, where there is more light. When the tide drops, the beads lay like a carpet across the rocks, their waxy coating preventing them from losing too much moisture.

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Shells embedded in the island’s dirt wall.

Neptune isn’t the only one who fancies his algae. As we sat by twin rock pools on the low intertidal, Keen and I counted 135 Zebra Top Snails (Austrocochlea porcata) in and around the strings of beads. Interestingly, of all the species of snail in the pools, only Zebra Tops were found on the Neptune’s Necklace. Smaller snails seemed to prefer the shelter of the algae more than the larger ones, who preferred grazing on an encrusting brown algae on the bottom of the pools.

Up until last week, I kept five Zebra Tops Snails in my laboratory aquarium. They eat the slimy brown algae that is a fact of aquarium life, and it’s fun watching a snail licking glass.

Woe betide me, this week I am down to three Zebra Tops. The reason? Clever fish. Working together, two of my fish (Holly, a Black Drummer, and Dart, a Blackspot Sergeant) repeatedly ram the Zebra Tops until they come unstuck from the glass and tumble upside-down into the sand.

Like other marine snails, Zebra Tops have a tough disc called an operculum that they can draw over the opening in their shell, like shutting a door. My fish are quite unable to get past the operculum. But, as they learned, if the snail wants to right itself, it has to push its operculum aside and stretch its soft body around the top of the shell to grab a hold of something solid. When that is done, the snail gives a quick pull and flips around upright.

Holly and Dart wait until the snail’s soft body is exposed, and attack. In just a few strikes the fish have conquered a snail as big as themselves. This bringing down of the mammoth results in tank-wide excitement, as the other drummers rush in for a nibble and the crab dances out of his cave, claws waving.

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Scary-story-snail face.

On the beach, Zebra Tops have more insidious enemies than tiny fish. Seastars prowl for young snails. You will have seen seastars sold as trinkets and jewellery. Dried and bleached, they offer poor comparison to these active hunters.

A sea star’s underside is covered in hundreds of tube feet. At the end of each arm, there is a splay of probing fingers and a rudimentary eye. A seastar can move as swiftly as a snail or abalone. It crawls over its pray, wrapping it in powerful arms. It then everts its stomach, coating its prey in digestive juices. Finally the seastar draws its stomach and its melted pray back into its body.

One such predator on Windang Island is the Eight-Armed Seastar (Meridiastra calcar.) It’s obvious when these seastars are busy eating, as their central disc will be raised into a hump, the prey engulfed beneath it. While snails are high on the menu, Eight-Armed Seastars will also graze on algae, and I have even seen them feasting on crabs’ legs and fishes’ tails.

Perhaps one reason Zebra Tops choose to hide amongst the beads of Neptune’s Necklace is that it is not readily navigated by seastars. Seastars probably also have poor vision, and cannot tell a small Zebra Top from a bead.

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Anglers enticing sharks with their juicy backsides.

“The sale of souls to gain the whole world is completely voluntary and almost unanimous…but not quite.”

As we finished counting Zebra Tops (Keen felt sorry for some and rescued them from seastars. But echinoderms need to eat too!) we noticed a huge white and grey Pelican riding thermals rising from the hot exposed rock. Wind gusted hard over the island’s top, and the Pelican would surf thermals for a minute before lowering itself into the gusts and riding in a wide crescent out over the ocean. Seeming without a care in the world, it would then coast over the island and catch another thermal.

“Do you think it’s having fun?” said Keen.

“Looks like it,” I said.

We watched the seabird, a proud example of Australian Pelican (Pelecanus conspicillatus.) Its wings wobbled as it hovered on the thermal. Then – it dropped and swooped out over the waves. In moments it was back.

“It’s not looking for food,” I said, as the seabird hung suspended in the air. “And that does look like fun.”

Keen sighed. “I wish I had wings.”

We spent a while chasing gobies in rock pools, and then we were hungry, which meant it was time to go. On the return hike to the car we walked past the mouth of Lake Illawarra. The tide was starting to rise and the foreshore was wet and dark. It also appeared to be moving.

“Hey, crabs!” I had ditched my gear and was dancing amongst crabs in a second. “Look, Keen, soldier crabs!”

All across the foreshore, an army of perhaps ten thousand soldier crabs were digging out new holes above the waterline. In amongst the waves of smaller Mictyris platycheles were large Light-Blue Soldier Crabs (Mictyris longicarpus) looking like horses amongst foot soldiers. They were oblivious to us. By the drove they kept on digging, while others processed sand through their mouthparts, restlessly surging across the boundary of surf and sand.

Salty poked his nose into a crab’s back, and watched baffled as the crab burrowed in a spiral into the wet sand. In seconds it was up again, scuttling for higher ground. From the water a Pelican watched on idly, sailing as majestically as a brilliant white yacht. Storm clouds bathed the escarpment beyond.

Keen and I finished the journey to the car in high spirits. The world can be savage, it’s true. But from the snails sampling the finest delicacies of the sea, to the pelican surveying its kingdom, it is also a world of great joy and satisfaction.

Thank you Keen and Salty for a banger of a trip out of Windang Island. Thanks to you two, I’m finally able to present the first five Gong 151 species!

 

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#001 Neptune’s Necklace (Hormosira banksii)

Length: Up to 300 mm

Zone: Low intertidal

Sighted: Day, on rocky substrate in pools and low-lying channels

Locations: Windang Island, common

 

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#027 Zebra Top Snail (Austrocochlea porcata)

Height: Up to 25mm

Zone: Low intertidal

Sighted: Day, on rocky substrate and algae fronds

Locations: Windang Island, common

 

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#078 Light-Blue Soldier Crab (Mictyris longicarpus)

Carapace width: Up to 25mm

Zone: Low intertidal (brackish water)

Sighted: Day, on border of sand and sea

Location: Windang Island (Lake Illawarra entrance), common

 

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#090 Eight-Armed Seastar (Meridiastra calcar)

Arm radius: Up to 50 mm

Zone: Low intertidal

Sighted: Day, on submerged rocks and rocky substrate

Locations: Windang Island, uncommon

 

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# 138 Australian Pelican (Pelecanus conspicillatus)

Wingspan: Up to 2.6 m

Zone: Shore

Sighted: Day, cruising on calm water or riding on thermals.

Locations: Windang Island, uncommon

 

Now it’s up to you. Get out into the Gong and meet some animals!

For the five species listed, we need to find:

  • Which locations they can be found
  • Their numbers in each location
  • Their interactions with other species
  • What they eat
  • What they do all day

You can join Salty and I for a day of discovering sea creatures on Saturday 8th April 2017 at Bellambi Beach. Some snacks will be provided. Bring a bottle of water, your camera, and let’s see what we find.

*Coming soon: Updated link to the 151 Field Guide*

The Gong 151

#001 The Gong 151

Welcome to the world of marine biology!

My name is Anneque “Dangerpus” Machelle. I’m studying to become a marine biologist. This world’s oceans are inhabited by a vast array of fascinating creatures. Some are playful, others could swallow you whole. But what we know about life in the ocean is, well, just a drop in the ocean. Some biologists think over 90% of the life in the ocean remains undiscovered!

That’s why I’ve dedicated my life to studying marine life. Together with my best buddy Salty, I’m on a mission to find 151 marine species in the Gong region. Yet we can’t do it without your help. If you’ve ever dreamed of working with marine animals, discovering new species, and learning incredible things about old ones, The Gong 151 is for you. We need your help to complete this guide and become masters of the ocean.

Each week, Salty and I will explore a new species. Come with us to swim, snorkel, dive and explore to make the ultimate guide to marine life in the Gong region.

Get ready to make amazing discoveries!

For each species, hit the beach and help us find:

  • Distribution
  • Population: common, uncommon, rare or legendary
  • Size
  • Interactions within a  species
  • Interactions with other species (including humans!)
  • And lots and lots of photos

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Links:

Species discovered so far

Area map

Submit data or suggest species

Make your own field notebook DIY

Secrets of the Rock Pools

The quest to uncover the secrets of rock pools continues…

Have you ever wondered exactly what is living in the pretty little rock pools scattering the beach? You hear the crunch of littoral snails underfoot and gaze out upon a veritable starfield of similar creatures: little blue and grey shells in hunkering packs on every available rock, others clustered like refugees at the edges of pools. Now and then you may see the silvery flash of a fish darting for cover. A crab may scuttle under a rock, or bump into another crab and simply stand there, wondering what to do. As you peer deeper, you begin to make out the long red spines of urchins, the mottled blue and green backs of sea stars, and a lonely sea hare drifting amongst pink fronds of coralline algae.

But life in the rock pools is tough. Temperatures are extreme, salinity ranges wildly from hypo to hyper in the space of a rain shower, the waves constantly hammer, hammer, hammer, throwing in new cell mates and dragging out the old, pushing in sand and cold water, offering respite and obscuring shelters in the same breath. Birds circle, and humans flounder clumsily over generations of nerites, and big crabs drive the small crabs to the lesser hunting grounds, and small crabs strip away generations of nerites that the humans couldn’t get to.

Just what are the limitations of life in this war zone? What stops a blenny from living in two inches of water? Is it the hypersalinity? The temperature? Predation from birds? Or is it simply a lack of space? Similarly, why will a green anemone attempt to take root in half a centimetre of water in the midst of a minefield of Pacific oysters?

I wanted to know. And, because no one tried to stop me, I picked 11 rock pools out on a bluff at my local beach to study with the intensity of Charles Darwin observing a barnacle. If you haven’t caught it, you can read my first post of Crab Bluff here, or what the hell, jump right in, the water is warm (-er than ambient temperature.)

High tide at Thirroul Beach averages 1.525 metres above the datum. Low tide averages 0.46 metres above the same datum. Average water level is 0.99 m, meaning anything less altitudinous than 0.99 m is inundated more often than not, and anything above 0.99 m is exposed more often than it is inundated. All pools surveyed on the Bluff remain above the waterline even during high tide.

The Pools

#1 Little Crater

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Volume: 0.24 L

Temperature: Warmer than ambient.

Exposure: This pool could be considered submerged at high tide; water constantly pushes over Big Pool into a water course encompassing Little Crater and Dry Triangle. This stream then flows across the back of the Bluff onto the beach.

As the water drops, less and less water flows over this pool, until the stream narrows and dries to isolate Little Crater. After isolation, water in this pool quickly evaporates, reducing its small volume even further.

Species:

This tiny pool is devoid of sheltering algae. What life there is clusters around the overhanging crater lip.

Molluscs:

  • Little blue periwinkles (Austrolittorina unifasciata)
  • Pyramid periwinkles (Nodilittorina pyramidalis)
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What little there is of Little Crater, with scattered little blue periwinkles.

#2 Dry Triangle

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Volume: 211 L

Temperature: Cooler than ambient up to the point of isolation. Shallow depth means it warms rapidly.

Exposure: As with Little Crater, this pool could be considered submerged at high tide. Water constantly pushes over Big Pool into a water course encompassing Dry Triangle. The pool is shallow with low walls and so the water in it is constantly changing. Outlets are to #3 Left Twin and in the tidal stream running down the back of the Bluff.

As the tide recedes, this pool still receives water, but is changed far less often. Volume is still above that of isolation. Ninety minutes from low tide, the pool is isolated from incoming water. It continues to output a small amount to #3. Eventually the pool is drained completely, and remains dry until it is restored by the rising tide.

Species:

Prone to being drained, there is no macroalgae in this pool.

Molluscs:

  • Pacific oyster (Crassostrea gigas)
  • Striped conniwink (Bembicium nanum)
  • Little blue periwinkle (Austrolittorina unifasciata)
  • Pyramid periwinkle (Nodilittorina pyramidalis)

Crustaceans:

  • Swift-footed crab (Leptograpsus variegatus)

 

#3 Left Twin

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Volume: 105 L

Temperature: Offers sustained respite from high ambient temperatures.

Exposure: At high tide this pool receives regular water from the tidal stream. #2 runs into this pool even after the tide has receded. Additional water is provided by large waves. Left Twin outputs into Right Twin, which then flows down the back of the Bluff. As the tide reaches average height, inlets and outlets to this pool stabilise, leaving it isolated.

Species:

On original observation, this pool was deep with a rocky substrate, harbouring numerous small algae. In early December a storm pushed sand into the pool, halving its volume and obscuring most of the algae. Young crabs still find it a convenient hiding spot on their hunting ventures.

Molluscs:

  • Black nerite (Nerita atramentosa or N. melanotragus … orange and black operculum suggests melanotragus)
  • Pacific oyster (Crassostrea gigas)
  • Pyramid periwinkle (Nodilittorina pyramidalis)
  • Striped conniwink (Bembicium nanum)
  • Little blue periwinkle (Austrolittorina unifasciata)

Crustaceans:

  • Swift-footed crab (Leptograpsus variegatus)

Annelids:

  • Spirorbid worms (Spirorbis sp.)
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Orange and black operculum on Nerite sp. Note cute spirorbid worm spirals on shell.

#4 Smoking Gun

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Volume: 85 L

Temperature: Warms rapidly after isolation.

Exposure: Inundated at high tide from backwash across the Bluff, this pool is otherwise relatively higher than the rest and so protected from most inlets. Still, rough wave action sees a total water change of this pool at least once per minute.

Two hours after high tide, no regular inlets remain, and there is only one small outlet to Dry Triangle.

Species:

While shallow and readily overlooked, this pool contains a good deal of encrusting and stringy algae, and supports a surprising amount of life.

Molluscs:

  • Black nerite (Nerita sp.)
  • Little blue periwinkle (Austrolittorina unifasciata)
  • Pyramid periwinkle (Nodilittorina pyramidalis)
  • Striped conniwink (Bembicium nanum)
  • Zebra winkle (Austrocochlea porcata)
  • Variegated limpet (Cellana tramoserica)
  • Flamed limpet (Notoacmea flammea)
  • Pacific oyster (Crassostrea gigas)

Crustaceans:

  • Swift-footed crab (Leptograpsus variegatus)

Annelids:

  • Spirorbid worm (Spirorbis sp.)

 

#5 High Triangle

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Volume: 99 L

Temperature: With no spray to refresh it, temps reach ambient and above.

Exposure: High Triangle is the most isolated pool tested. Its west banks are dry even at the peak of high tide; it’s a safe place to stand and not be doused. Water, even spray, does not reach is regularly. Silty sediment on the pool’s bottom and persistent crab skeletons suggest only in rough weather and rain does this pool receive new water.

Species:

Any algae in this pool is on the micro scale. A few hardy periwinkles are all that survive here. On hot days they clustered above the pool’s edges. The empty white carapaces of crabs drift along the silty bottom.

Molluscs:

  • Little blue periwinkle (Austrolittorina unifasciata)
  • Pyramid periwinkle (Nodilittorina pyramidalis)

 

#6 Big Pool

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Volume: 8998 L

Temperature: Cooler than ocean – possibly due to high evaporation levels from Big Pool.

Exposure: Hammered and inundated by violent wave action at high tide, this huge pool has outlets into the ocean on its east side and a tidal stream on its west side. Rock forms a natural funnel at this point of the Bluff and white water jets dramatically over Big Pool.

Two hours after high tide, far less is received and output. The water level remains about 5 cm above the pool’s algae line. On Big Pool’s surface, the only hint of its violent past are in the foam and shredded bladderwrack.

Species:

Big Pool is home to all sorts of interesting creatures washed in from the sea. Large amounts of coralline algae, sand and rocky crevices provide a multitude of lifestyle options, and creatures here are both visitors and regulars.

Arthropods:

  • Honeycomb barnacle (Chamaesipho tasmanica)
  • Rosy barnacle (Tesseropora rosea)

Molluscs:

  • Warrener (Turbo undulatus)
  • Mulberry whelk (Morula marginalba)
  • Black nerite (Nerita sp.)
  • Tent shell (Astralium tentoformis)
  • Zebra winkle (Austrocochlea porcata)
  • Striped conniwink (Bembicium nanum)
  • Little blue periwinkle (Austrolittorina unifasciata)
  • Variegated limpet (Cellana tramoserica)
  • Sea hare (Aplysia sp.)

Anemones:

  • Green anemone (Aulactinia veratra)
  • Shellgrit anemone (Oulactis muscosa)
  • Pacific oyster (Crassostrea gigas)

Echinoderms:

  • Tuberculate urchin (Heliocidaris tuberculata)
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Big Pool at high tide. Ride those waves!

#7 Stream Pool

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Volume: 9.6 L

Temperature: Struggles to remain cool after isolation.

Exposure: Although this pool is high above the water, waves channelled against the Bluff jet into it, changing its volume several times a minute. It outlets to Big Pool.

Two hours after high tide, Stream Pool receives far less water and is not inundated, though it still receives regular small doses from wave action.

Species:

This narrow crevice is thickly grown with Pacific oysters. A few very small urchins also hide out amongst the regular smattering of littoral snails.

Molluscs:

  • Pacific oyster (Crassostrea gigas)
  • Black nerite (Nerita sp.)
  • Zebra winkle (Austrocochlea porcata)
  • Striped conniwink (Bembicium nanum)
  • Little blue periwinkle (Austrolittorina unifasciata)
  • Variegated limpet (Cellana tramoserica)

Anemones:

  • Shellgrit anemone (Oulactis muscosa)
  • Green anemone (Aulactinia veratra)

 

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Shellgrit anemone, full of sand and grit.

#8 Elephant Pool

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Volume: 162 L

Temperature: Pool temp measured in the afternoon was cooler than the ocean temp measured in the morning. Could be due to evaporation, or cooler waters pushing onto the beach after initial ocean temperature was measured.

Exposure: Elephant Pool is the most exposed of any pool tested. It receives intense wave action during high tide, with water constantly pouring in and out of this deep pot of a pool, often violently.

Even at low tide, this pool continues to receive water, and is always at capacity. Its only outlet is the ocean.

Species:

Generous algae grows provide shelter and food for the curious inhabitants of this pool, all of whom seem to be regulars. In particular, a pair of large elephant snails hide amongst the sea grass at the bottom, while crabs and urchins tuck themselves into a deep crevice.

Anemones:

  • Green anemone (Aulactinia veratra)

Arthropods:

  • Swift-footed crab (Leptograpsus variegatus)

Molluscs:

  • Elephant snail (Scutus antipodes)
  • Zebra winkle (Austrocochlea porcata)
  • Black nerite (Nerita sp.)
  • Striped conniwink (Bembicium nanum)
  • Little blue periwinkle (Austrolittorina unifasciata)
  • Variegated limpet (Cellana tramoserica)

Echinoderms:

  • Tuberculate urchin (Heliocidaris tuberculata)

 

#9 Big Crater

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Volume: 229 L

Temperature: Is able to resist some heat from the sun after isolation. This measurement, taken at nearly low tide, suggests the pool would reach ambient temperature before regular cool spray was restored.

Exposure: Regularly sprayed in high tide, where it sits above capacity with only a small outlet draining to the ocean. This pool’s depth and sides give it some protection from wave action. Pool #10, High Half-Crater, also flows into Big Crater.

Two hours after high tide, this pool is close to its isolated volume. It receives only spray, and retains a small volume outlet to the ocean.

Species:

The deep bowl of this pool is a nursery for snail eggs. Young crabs hang out at this pool in the manner of kids at a skate park, having been pushed back from the Bluff by their old folks.

Arthropods:

  • Swift-footed crab (Leptograpsus variegatus)

Molluscs:

  • Little blue periwinkle (Austrolittorina unifasciata)
  • Black nerite (Nerita sp.)
  • Zebra winkle (Austrocochlea porcata)
  • Pacific oyster (Crassostrea gigas)
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A curious Zebra winkle.

#10 High Half-Crater

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Volume: 68 L

Temperature: Approaching ambient after isolation.

Exposure: Despite this pool’s proximity to the ocean, it is readily isolated by its height and orientation in the rocks. It receives spray only in high tides and rough weather, and more regular inlets across the Bluff from the back of #11, Neptune’s Crater. Here large waves increase #10’s volume and change its water regularly.

Two hours after high tide, the pool’s outlets to #9 Big Crater have subsided, and it receives little new water.

Species:

A small Neptune’s necklace grows here; otherwise algae is microscopic and the pool is superficially barren.

Molluscs:

  • Little blue periwinkle (Austrolittorina unifasciata)
  • Zebra winkle (Austrocochlea porcata)
  • Black nerite (Nerita sp.)

 

#11 Neptune’s Crater

11

Volume: 4 L

Temperature: While small, this pool’s proximity to the ocean keeps it cool. The shade from the many Neptune’s necklaces might also help.

Exposure: This pool rests in a wet site near the ocean edge of the Bluff, where it is doused several times a minute even in receding tides. As tide recedes, waves tend to strike the Bluff wall and then shower down on this pool. Action is intense and disruptive but not violent.

Two hours after high tide, the outlets to #10 and the ocean have subsided, and the inlets from waves are less regular; perhaps not even once a minute for a decent douse of spray.

Species:

Neptune’s necklace grows thickly here, fronds obscuring the surface of the small pool and providing plenty of cover for its inhabitants.

Anemones:

  • Green anemone (Aulactinia veratra)

Molluscs:

  • Black nerite (Nerita sp.)
  • Zebra winkle (Austrocochlea porcata)
  • Striped conniwink (Bembicium nanum)
  • Pacific oyster (Crassostrea gigas)

Crustaceans:

  • Swift-footed crab (Leptograpsus variegatus)

Arthropods:

  • Isopod ~

Annelids:

  • Spirorbid worm (Spirorbis sp.)

 

Conclusions:

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Regular inlets do a lot for a pool. Those pools receiving regular wave and spray action are closer in temperature to the ocean, while those more isolated at the back of the Bluff or higher up can be even hotter than the air temperature.

This means one, that the degree of isolation is a vital component of temperature. Two, that isolation determines what species may survive and flourish in a pool. Also interesting to note is juvenile crabs seemingly pushed back away from the edge of the Bluff, itself a wall of good hiding places, to hunt in the landward pools.

  • Are these young crabs displaced from fertile hunting grounds by larger crabs?
  • Why are larger periwinkles (Austrolittorina unifasciata and Nodilittorina pyramidalis) found in the hottest and most isolated pools – is this to prevent competition with their young?
  • What role is played by salinity and water quality in determining species variation and distribution in the pools?
  • The ocean provides a stable temperature: at night as well as day. How does pool temp behave at night? More day testing is also needed for better results.
  • A cooler daytime pool seems to provide better species diversity, as does accessibility to the ocean. Is this actually because of more stable temperatures, or due to the likelihood of creatures being pushed into the pool by waves?
  • What is the role of substrate – rock, sand, algae – in keeping a “local” population in a pool?

Join us next time for more rock pool action on Danger Ball Z!

The White Globster

It was a stormy day in early November when I happened upon the grey and battered beach. Brown lumps of bladderwrack heaped on the sand like walruses on the high tide line. Huge cups of banded fanweed nestled in the wrack. Death was in the air as dozens of sea squirts pushed one last feeble breath of water from their aorta-shaped siphons.

Then there was the Globster.

Startling white it was, with a mass of tentacles like so much upturned udon. It splayed limp yet plump on the wet sand, commanding the beach not by its size but by its sheer unknowability.

I approached with suspicion in every sodden step. Was this some monstrous anemone risen from the deep? Some nest of hideous marine worms? Or was it something altogether more sinister and strange?

Cold drizzle peppered the back of my neck as I bent over the weird lump. I found a stick and turned it over. The mass was firm and jellylike, damp, with an inner sheen. It neither quivered nor tried to escape my cautious prodding. Recalling that everything in the sea is venomous, I drew a tentacle away from the mass with the end of the stick. Each individual tentacle appeared to taper down to a fine string, woven into a net encompassing a mass of detritus. The mass had no apparent foot or mechanism of defence. I knew it had to be toxic.

The seagulls kept their distance as I wandered the short bay, overturning bladderwrack with my stick. More white masses were exposed. Two more were large, the size of an adult’s brain. Another two were not much bigger than my balled fist.

The rain drove harder. Sheets of water fell across the sea. To the west, the escarpment was cloaked in deep grey cloud. A momentary merging of sea and land. Alas, I do not have gills. In lament of a bag and gloves, I left the Globster for drier land.

 

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Artist’s rendition of author’s description.

Only to return the next day. The small masses were gone. So was the week of heavy rain and cold water pushed from beyond the continental shelf. Sun shone on the bladderwrack, baking it crusty and black. The two large white masses had survived well, one slightly dehydrated. In its greying mass were revealed paler lumps. Each tendril carried five lumps, giving them the appearance of too-many jointed fingers.

I tried to guess how many tendrils there were. A hundred, two hundred? Could it be an egg mass? Thinking of anemones, I checked the creature for a mouth. A pair of silver gulls watched from a distance. There was no mouth.

Eager now, knowing the creatures were dead (if they had ever been alive) I found the stick I’d wedged in the sand and gently peeled tendrils away from the central mass. A grey stretchy latex-like material bound the tendrils to a central net, the gatherer of debris. Twigs and stringy weeds littered the tendrils. It was impossible to tell whether the tendrils were poking through the grey latex or were part of it. I would have to dissect it to find out.

Curious now more than I was frightened, I lifted one large mass on a stick and carried it to the water’s edge. When it dropped into the foot of a wave, its tendrils bloomed out weightlessly and carried the mass back to shore. It was limp, unresponsive, even in the water. But for the first time, it was not some hideous monstrosity washed up on the sand. In the water, one could see that it was functional, even beautiful. Its shape was that of a dozen jellyfish arranged on a multi-tiered cake stand. Alien as it was, it was somehow elegant.

I picked up the mass on the stick and flung it into deeper water. Whatever it was, if it had any chance of survival, it was in the sea.

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The Globster.

Work beckoned in the afternoon, but all I had were questions about the solitary white mass left on the beach. I couldn’t tell if the thing were plant or animals. If it were dead or alive. I was unsure if it were a collective or single organisms or a strange clutch of eggs.

The home bell struck. I wandered into the workshop and picked a rubber glove from the box the mechanic keeps on his toolbox.

“I’m taking this,” I warned him. “And you won’t want it back.”

The mechanic was still shaking his head over the news that Trump looked to win presidency and didn’t deign to answer.

Well, forgiveness is easier attainted than permission, so I took my plastic bag and rubber gloves and trotted down to the beach. Right in the middle of Thirroul Beach are the big yellow buildings of the local surf lifesaving club. I ducked under the boathouse door and knocked on the tin roller. A couple of lifeguards on duty in the booth looked around.

“Come in, come in!” said the older of the pair, ushering me up the stairs to the booth. Beneath the panorama of rolling waves were clusters of tide charts and shift rosters. “What can we do for you?”
I shrugged. Regardless of the answer, I knew what I was going to do. “There’s a weird white thing washed up on the beach. I was wondering if you might know what it was?”

A brief description of the creature – like an overturned bowl of noodles – didn’t spark any fires, so I brought up a picture on my phone.

“Ew,” said the younger lifeguard. “What is that?

“Never seen anything like it here before,” said the older. “What is it?”

“No idea,” I said. “But if you don’t mind, I might collect it and take it to the University for IDing. That’s if you don’t mind.”

Both lifeguards made noises of encouragement.

“Go do it!” said the older one as I ducked back under the roller door. “Make sure you come back and tell us what it is.”

Thusly bidden, I trekked up the beach, barely able to keep from running in the fear that the white Globster had already been taken, by man, tide or seagull, but equally gone.

But there it was, caught in the seaweed pushed up during the afternoon’s high tide, but not washed away. I donned gloves and bagged the mass. I scanned the beach. Not another mass was to be seen.

Though it was the more dehydrated of the two large masses, the thing was heavy. Heavy enough that I wandered into town and into the supermarket, where I sat the inconspicuous bag on the vegetable scales. 450 grams – a full pound.

Heavier still was the news that Trump had won the presidency. There was gloom in the workshop as I went to fetch the car. “This will cheer you up,” I said, to the pair of mechanics languishing by the radio. I opened the bag. “Guess what this is.”

The head mechanic peered into the bag. The scent of clean seawater drifted back. “Um. Is that a squid?”

“It’s an anemone, obviously,” said the hired help, an erstwhile technician resembling a seagull. “Clear as day. Anemone.”

“Anemones have mouths,” I told him. “This thing doesn’t. They also have tapered tendrils; these are blunt. It’s not an anemone.”

“Then it’s worms,” he said, but like the rest of the seagulls, he kept his distance.

Back home in the lab* I filled a bucket with water and spread out the dissection kit. Armed with tweezers and a scalpel, I began the long work of extracting debris from the tendrils. Soon I could see that a grey rubbery net bound the mass together, forming a cylindrical body distinct from the fronds of tendrils. Floating the mass in the bucket, these fronds became apparent; tiers of tendrils arranged around the narrow body. Furthermore, the body extended into a dark grey, thick rubber knob. Roots extended from one end of the knob; a hank of seagrass from the other.

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*We used to have a sun room, but since I moved in we have a lab.

A housemate wandered into the lab. Trump’s election speech had just played twice on the television.

“What is that?” said my housemate, Mungus. “It looks like the state of American politics.”

Mungus is an avid dissector and taught me all I knew. I could use his help on this project. “I don’t know what it is. Wanna help me dissect it?”

“Ooh!”

“Take gloves though,” I said, indicating the pack of latex gloves I’d bought as a cover for using the supermarket’s vegetable scales. “It’s probably venomous.”

Mungus took a glove and a razor blade. He sliced of a tendril. While the tendrils had some size variation, they averaged about the size of my pinky finger. Each one contained five transparent lobes kind of like young beans in a pod. Mungus ran the razor blade over the membranous skin of the tendril, cutting it open and extracting a lobe. It dissolved into water in his fingers. It truly seemed like we had some alien on the cutting board.

I cut through another, careful to avoid the lobes. The tendril was the texture of a gummy worm on a hot day. A stretchy membrane hooked on the scalpel and refused to tear. I yanked it and the entire thing split open. Each lobe averaged 8 mm long and 4 mm wide. As carefully as I lifted a lobe on the edge of the scalpel, it dissolved into water.

“Let’s cut through this part,” said Mungus, indicating the dark grey knob. He held it and I cut, slicing through a 15 mm wall of warm rubber.

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Knob with seagrass growing through centre.

“This plant grows right through it,” I said, to break the stunned silence. It was as if the plant had grown right up through this thick rubber tube.

“Is that plant part of it?” said Mungus. “Is this thing part plant, part animal? See the beads on the roots – they look just like the lobes on the tendrils.”

There seemed to be no more to the Globster. No brain, no lungs, no recognisable organs at all. Just the white tendrils and this grey knob with its symbiotic plant. Mungus took a photo.

“I’ll send this to a biologist professor friend. He might be able to help.”

He sent the photo via Messanger and soon we had a reply. ‘No idea! is it an anemone?’

“It’s not an anemone,” I said to Mungus, before he could say it. “It’s nothing like an anemone. We need another biologist.”

It was with a bit of searching that I found an email address for a chap in the University’s marine biology department. But email is slow compared to IM, and it was unlikely I’d hear back that night. I wrapped the Globster in catalogues and stowed in the freezer.

“Maybe we’ve found something new,” I said to Mungus that night. “Maybe it’s something really different.”

“Maybe they’ll name it after us,” said Mungus. “The Mungusopus anemone.”

“Let’s hope not.”

Mungus made eyebrows, and kept his peace.

For the next 20 hours, I checked my phone at every opportunity. Mungus texted me on the hour, every hour. The professor’s reply (and the news of our Nobel Prize) was unforthcoming. The lifeguards asked if we’d had any luck; I had to tell them no.

When at last the email arrived, it was simple, one line.

‘Egg mass. Squid or octopus sp.’

I messaged Mungus immediately. ‘We found something AWESOME. Squid egg mass.’

He replied within the minute. ‘Holy crap. That’s incredible. That’s the coolest thing I’ve ever heard.’

A little research led to the tentative supposition that the eggs belonged to a Sepioteuthis australis, a Southern calamari squid. Common in shallow waters, the squid lays fronds of eggs that attach via a tough rubbery mass to plant matter on the seabed. Our grey knob was an anchor, tethering the mass to a hank of seagrass. The eggs were most likely freshly laid, being small and readily dissolved; as they develop, the eggs become more beadlike. The masses I’d found on the beach must have been yanked from their moorings like boats in a storm by the week of rough weather.

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Sepioteuthis australis, Southern calamari squid.

I went around to the surf club that evening to tell the lifeguards the news. “I’ve never seen anything like that on the beach,” said the older lifeguard. “You find anything else weird, come show us!”

Their enthusiasm was oddly charming. “Of course.”

That evening in the lab, I felt a slight sting of disappointed that we had not discovered anything new. The Mungusopus anemone was not to be. Yet so much more than disappointed, I realised I was thrilled. The ocean contains so many mysteries. The White Globster was only the first.

Crab Bluff

At low tide on a Thursday evening, Keen Wasabi and Salty (and every other dog on the beach) joined me for chicken sandwiches and rock pool-measuring at Thirroul Beach’s Crab Bluff.

I knew I wanted to do a population survey – I wanted to know every living species on Thirroul Beach. If only it were that simple.

As a landlubber all my life, it took me weeks of loitering at the Bluff to figure out just what I was looking for in a population survey. I could see that different species of sea snails preferred different areas of the beach – striped Zebra tops (Austrocochlea porcata) remaining submerged at low tide, while the nodular Pyramid periwinkles, (Nodilittorina pyramidalis) hung around at the dry edge of the spray zone.

However, what I was mainly aware of was that I knew nothing. I didn’t even know what I didn’t know, because I didn’t know anything. I wasn’t sure what was a limpet or a barnacle or a rock oyster or an urchin or an anemone. And the seaweed seemed important – but what kind of plant grows in saltwater? I knew so little in those early weeks that I inhaled information, spending hours browsing sites like the Australian Museum’s zoological resources, sea shells of Australia and endless Wiki pages on tides, littoral zones and marine snails.

At last I felt equipped with a basic knowledge set. I spent a few days at the south end of the beach past the pump house, out on Crab Bluff, which is above the tide in all but the heaviest storms. Rock pools on the Bluff each had different animals and algae, some webbed with Neptune’s necklace, others shallow and dotted with infant periwinkles and conniwinks. Still others held big red urchins, swift-footed crabs, elephant snails and gobies.

I had a vague idea that it may have been proximity from the ocean that determined what lived where. Out of the hundreds of pools on the Bluff, I settled on 11 that are close to each other, display a variety of depths, volumes and distances from the ocean, and that can be accessed even at high tide.

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Map of pools chosen on Crab Bluff.

Next I needed data. Lots of it. Data about the pools, the beach, and the animals that lived there. While some of the information, such as tide times and heights and ambient temperature, could be sourced online, the bulk of info I was going to have to collect myself. To do that required narrowing down and focussing on what I wanted to do, resulting in a series of actionable steps.

  1. Choose pools based on proximity to ocean and variety of life.
  2. Measure pool area and depth to calculate volume. Note substrates.
  3. Measure pool temperatures and compare to air and ocean. Note species.
  4. Conduct water testing for pH, ammonia, nitrate, phosphate and salinity. Count populations.
  5. Compile results and draw conclusions about what’s there and why it’s there, and how it interacts with other species.

Splitting the steps this way meant I could gather information across different days, giving me time to reflect on what I’d learnt and what needed improvement. It would also mean that I could modify my hypothesis: if proximity to the ocean turned out to be a dead end, I could add additional testing for salinity, temperature and other factors that I may not yet be aware of.

But there’s no time like the present. The pools were selected, a yard stick made from a length of bamboo, and the aid of Salty and Keen sequestered.

We met on the Bluff as the sun sank below the escarpment. Salty and I shared a chicken sandwich. The tide was low, leaving the pools isolated, and crabs hung thick on the wall above the water. Keen took up pen and paper as I wrestled Salty for the yard stick.

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Salty offers Keen instructions on proper yard stick use.

Results for pool measurement:

# 01 Tiny crater

Shape: Circle, 13 cm diameter
Surface area: 132.73 cm 2
Average depth: 1.8 cm
Max depth: 2.5 cm
Volume: 238.91 cm3 (0.24 L)
Distance from ocean: 5.0 m
Substrate: rock

# 02 Dry triangle

Shape: Triangle, 116 x 83 x 126 cm
Surface area: 4682.56 cm2
Average depth: 4.5 cm
Max depth: 9.5 cm
Volume: 21071.52cm3 (211 L)
Distance from ocean: 5.0 m
Substrate: sand on rock, small pebbles

#3 Left twin

Shape: Rectangle, 110 x 53 cm
Surface area: 5830 cm2
Average depth: 18 cm
Max depth: 31.5 cm
Volume: 104,940 cm3 (105 L)
Distance from ocean: 6.3 m
Substrate: sand

#4 Smoking gun

Shape: Triangle, 154 x 147 x 173 cm
Surface area: 10644.48 cm2
Average depth: 8 cm
Max depth: 15 cm
Volume: 85155.85 cm3 (85 L)
Distance from ocean: 5.5 m
Substrate: rock, black lichen

#5 High pool

Shape: Square, 180 x 110 cm
Surface area: 19800 cm2
Average depth: 5 cm
Max depth: 9 cm
Volume: 99000 cm3 (99L)
Distance from ocean: 4.5 m
Substrate: rock, sediment

#6 Big pool

Shape: Rectangle, 610 x 295 cm
Surface area: 179950 cm2
Average depth: 50 cm
Max depth: 65 cm
Volume: 8997500 cm3 (8998 L)
Distance from ocean: 1.1 m, 2.7 m
Substrate: Sand, rock, small rocks

#7 Stream pool

Shape: Rectangle, 80 x 30cm
Surface area: 2400 cm2
Average depth: 4 cm
Max depth: 6.5 cm
Volume: 9600 cm3 (9.6L)
Distance from ocean: 4.5 m
Substrate: rock

#8 Elephant pool

Shape: Rectangle, 36 x 85 cm
Surface area: 3060 cm2
Average depth: 53 cm
Max depth: 54 cm
Volume: 162180 cm3 (162 L)
Distance from ocean: 0.5 m
Substrate: sand

#9 Big crater

Shape: Semi-circle, diameter 230 cm
Surface area: 20773.78 cm2
Average depth: 11 cm
Max depth: 34 cm
Volume: 228511.58 cm3 (229 L)
Distance from ocean: 1.3 m
Substrate: Rock, small rocks

#10 High half-crater

Shape: Semi-circle, diameter 135 cm
Surface area: 7156.94 cm2
Average depth: 9.5 cm
Max depth: 13.5 cm
Volume: 67990.93 cm3 (68 L)
Distance from ocean: 1.2 m
Substrate: Rock, lichen

#11 Neptune’s crater

Shape: Rectangle, 40 x 25 cm
Surface area: 1000 cm2
Average depth: 4 cm
Max depth: 4 cm
Volume: 4000 cm3 (4 L)
Distance from ocean: 0.5 m
Substrate: Sand

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Big Pool, with a view towards the back of the Bluff, and the oft-inundated crab wall.

While these are only the initial observations for the Bluff, it was the beginning of many discoveries. Much of it is rehashed ground – the littoral zone is readily accessed and people have been doing so for the last 150 years, even in Australia. But for me it’s new. For Salty, it’s new. For Keen, even though he has always been a beach bum, there exists this entire other world just below the waterline. A world fraught with battles and courtship, a world where tiny creatures overcome enormous odds in the everyday fight for survival.

Join Salty and I again soon as we peer upon this miniature world, and discover some damned strange things washed up on the beach. Here’s an exclusive preview:

Dangerpus: “Just what is that weird white lumpy thing, Salty?”
Salty: “…”
Dangerpus: “It looks like some mass of anemones – or maybe sea spaghetti!”
Salty: “S:(”
Dangerpus: “Let’s bag it and take it back to the lab.”
Salty: “!”

*Over and out*

Part 2 here: Secrets of the Rock Pools

The Hunt for Life

Hidden life beneath the waves inspires a quest to uncover the ocean’s mysteries.

Waves foam on pale sand. In the shallows, children leap white crests. Pairs of mothers idle on the warm sand, and grandparents sit along the low wall spanning the south leg of the beach.

At the end of the walkway, the old pump house has been painted the same blue as the sky. Its barnacle-encrusted pipes extend 30 metres out into the ocean, terminating in a big green lump of cunjevois like a sunken tropical island. South of the pump house, low rocky cliffs split the beach in two. Black heads of surfers speckle the waves south to Sandon Point. Further north, far beyond the freshly painted, resplendent yellow surf club, a long rock shelf juts out beneath the striped masses of Austinmer cliffs.

Thirroul is a historic but thriving town planted between the ocean and the escarpment some 13 kilometres north of Wollongong. From its farming and coal mining origins, Thirroul has reinvented itself to cater to the well-to-do drifting down from Austinmer. Recently the old shoe shop, Buck Hamlin’s, was reopened as a cafe. The black painted brickwork of the Finbox surf shop are especially iconic, in the hazy afternoon sun fading into the dark bulk of the escarpment behind. In summer the beach is flooded with tourists and the locals complain of a dilution of familiar faces on the streets.

I fell in love with Thirroul Beach working at Rutledges’ garage, but it wasn’t until my brush with death that I became more interested in life beneath the waves. A beach can seem deserted. Yet underneath the surface there is such an abundance and variety of life that the mind can scarcely comprehend. All but the densest jungle on the surface is barren by comparison.

The Thirroul Beach survey will be my first marine survey and aims to uncover types and numbers of living organisms in the littoral regions. It’s a learning experience for me: six months ago I couldn’t tell a limpet from a barnacle. Exploring the beach has uncovered mysteries I never knew existed, and given me the motivation to live, and live a good life.

First to be surveyed is the supralittoral zone nicknamed Crab Bluff, just south of the pump house. Second will be the eulittoral/ intertidal zone on the northern rock shelf; and lastly forays will be made into the permanently inundated sublittoral zone, likely from the entrance point of the sandy beach.

In all zones, species will be identified and populations counted, water temperature, salinity and quality measured, interactions observed, and sea stars hunted.

Join me in the coming weeks for the hunt for life on Thirroul Beach.

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