Narooma is on the coast and is built around the beautiful Wagonga Inlet so a lot of the wildlife lives on both land and water. With the movement of tides every six hours those creatures that can exist in both domains increase their chance of finding food and avoiding becoming food. Often, a good hiding place in the water is still a good hiding place when it is dry. However, sometimes things do not work out. Such as with this sad looking Variegated Shore Crab safe from most predators in a rock crevice but a wave probably wrapped a small bluebottle with its stinging tentacles around the crab. I am unsure if the tentacles can kill the crab or if it even felt them but I thought it made for a very colourful photograph.
This is the fourth post in a series of five looking at different aspects of wildlife at Narooma. In this post I am covering the wildlife that makes its home where land and water meet. I had a lot of fun wandering around all different types of shores and I hope that you enjoy the photos below.
In Narooma, there are really two general environments where the water meets the land; the coast and the inlet. Basically, the coast around Narooma is sandy beaches broken by rocky sections, while the inlet has many similarities along its length and reaches about five kilometres deep into the surrounding country. This post will start by looking at the coastal environment before moving to the inlet.
The waves rolling across the Pacific Ocean arrive on the coast of Australia with a lot of force. They easily rip plants and creatures off the bottom to toss them onto the beach. Walking along a beach after big seas through the area there is much life, especially seaweed, which the water has carried on to the beach.
Seaweed washed ashore
(Canon EOS 6D Mk II with a Canon EF100-400mm f4.5-5.6L IS II USM [ISO 640, 100mm, f/8.0 and 1/500 SEC])
A Soldier Beetle found one mass of stranded kelp a great place to explore. The sand on the beetle’s carapace showed that it was no stranger to exploring the beach. Soldier beetles are omnivorous but are more interested in pollen than other parts of plants, although maybe this beetle was pursuing a soft-body prey within the seaweed itself. A couple of seconds after I took this shot the beetle disappeared into the seaweed and did not immediately re-emerge.
Soldier Beetle just before it crawled inside the kelp
(Canon EOS 6D Mk II with a Canon EF100-400mm f4.5-5.6L IS II USM [ISO 100, 400mm, f/13 and 1/640 SEC])
Some creatures are more beholden to tides and winds that others. The blue armada of creatures are a number of different species that exist together on the open seas but sometimes strong winds and seas blow them on to beaches, The most famous example is the Bluebottle (Physalia physalis), or Indo-Pacific Man o’War, which has long stinging tentacles dangling underneath it when it is on the open ocean. On the sand they tend to clump together. The animal is actually a colony of specialised cells working together as a single Bluebottle. The wind and waves bring these Bluebottles close into shore where their sting can injure unsuspecting swimmers and surfers. When they wash on to a beach their stingers are still potent and able to deliver a painful sting.
Bluebottle stranded on the sand
(Canon EOS 6D Mk II with a Canon EF100-400mm f4.5-5.6L IS II USM [ISO 250, 400mm, f/8.0 and 1/500 SEC])
Another member of the blue armada is this By-the-Wind Sailor (Velella velella) that was also stranded on the beach by waves. As its names suggest, this creature is at the whim of the wind with its central ‘sail’ helping it to blow across the ocean.
By-the-Wind Sailor blown onto the sand
(Canon EOS 6D Mk II with a Canon EF100-400mm f4.5-5.6L IS II USM [ISO 200, 400mm, f/14 and 1/400 SEC])
Sponges are normally secured to the sea bottom by a strong anchor but the power of big waves and surf can pull the anchor off or just rip parts of the sponge away.
Sponge washed onto the beach
(Canon EOS 6D Mk II with a Canon EF100-400mm f4.5-5.6L IS II USM [ISO 100, 100mm, f/10 and 1/640 SEC])
Moving away from the sand there was a lot of life on the rocks between the sandy beaches. However the one animal that caught my eye was this Variegated Shore Crab (Leptograpus variegatus) with a small Bluebottle. The crab was in a crevice that was open to the waves below, and occasionally water would boil past it. I wondered if the Bluebottle had been carried by one of those waves and became wrapped around the crab. Initially, I thought the crab had caught the Bluebottle to eat it but then I noticed the blue tentacles wrapped around the crab. I am not sure what the impact of the tentacles were on the crab but I did like the mix of colours. Sorry, poor crab.
Variegated Shore Crab with a Bluebottle wrapped around it
(Canon EOS 6D Mk II with a Canon EF100-400mm f4.5-5.6L IS II USM [ISO 640, 400mm, f/9.0 and 1/320 SEC])
Turning now to the inlet, there were other crabs there as well. One of the most prevalent crabs were the Soldier Crabs (Mictyris longicarpus) that formed a moving blue carpet on the exposed sandflats at low tide. This was the first time that I had seen such masses of Soldier Crabs. I wandered out to be among me but they always fled. Eventually I learned that I just needed to stay still then an empty bit of sand would look like it was bubbling up as a Soldier Crab corkscrewed up from where it was concealed below the surface. Sand was not just where they hid but it was also where they found their food, which they did by filtering the sand through their mouthparts. They were continuously filtering, even as they moved. It occurred to me, in looking at a group moving in my direction, how they looked like science-fiction aliens. Their bodies were hunched and their claws bent upwards creating a sightly sinister appearance.
Masses of Soldier Crabs on an exposed sand flat
(Canon EOS 6D Mk II with a Canon EF100-400mm f4.5-5.6L IS II USM [ISO 200, 400mm, f/11 and 1/500 SEC])
Soldier Crab slowly carefully emerging from being concealed in the sand
(Canon EOS 6D Mk II with a Canon EF100-400mm f4.5-5.6L IS II USM [ISO 160, 400mm, f/8.0 and 1/400 SEC])
Soldier Crab processing sand for food
(Canon EOS 6D Mk II with a Canon EF100-400mm f4.5-5.6L IS II USM [ISO 160, 400mm, f/8.0 and 1/400 SEC])
Soldier Crabs looking somewhat alien-like as they feed across the mud flats
(Canon EOS 6D Mk II with a Canon EF100-400mm f4.5-5.6L IS II USM [ISO 320, 400mm, f/8.0 and 1/400 SEC])
One morning, after I finished a kayak and I had slid onto the semi-exposed sand at a half-tide around Lewis Island. I was just sitting in the craft, enjoying the tranquility of the early morning, when I glanced down at the sand to see all these shells moving in a most un-shellfish like manner. Closer inspection showed that these shells were the homes now of small hermit crabs. I thought that the crabs would have dragged the shells but many crabs seemed to be pushing backwards, with the pointy bit of the shell indicating the direction of travel. I thought that was strange so I kept looking for more crabs doing it and indeed most were moving that way. Maybe it was better for the strong shell to bump into something rather than the crab at the other end.
Hermot Crab in a Mud Whelk shell
(Canon EOS 6D Mk II with a Canon EF100-400mm f4.5-5.6L IS II USM [ISO 500, 400mm, f/8.0 and 1/400 SEC])
Further up the inlet there was a small gathering of water striders near Wagonga Wharf. They were mainly in mating couples while they skated over the water surface. The water there was definitely salt water but the insects did not seem to mind.
Mating pair of water striders further up the inlet
(Canon EOS 6D Mk II with a Canon EF100-400mm f4.5-5.6L IS II USM [ISO 1000, 400mm, f/9.0 and 1/400 SEC])
I also need to mention Sydney Rock Oysters (Saccostrea glomerata), because they were such obvious inhabitants of Wagonga Inlet, both naturally and in oyster leases. They grew everywhere, even a dis-used oyster lease was still a good place for oysters to grow.
Old oyster lease but the oysters continue to grow
(Canon EOS 6D Mk II with a Canon EF100-400mm f4.5-5.6L IS II USM [ISO 400, 100mm, f/14 and 1/400 SEC])
Within the inlet Grey Mangroves (Avicennia marina) are being encouraged to grow again. There are so many trees springing up, helping to stabilise the sandy contours. Little shoots are sprouting, coping with the salt water, trying to survive to become fully grown trees.
Solo Grey Mangrove sapling on an exposed shore
(Canon EOS 6D Mk II with a Canon EF100-400mm f4.5-5.6L IS II USM [ISO 400, 100mm, f/8.0 and 1/500 SEC])
Grey Mangrove shoot
(Canon EOS 6D Mk II with a Canon EF100-400mm f4.5-5.6L IS II USM [ISO 250, 248mm, f/6.3 and 1/320 SEC])
Grey Mangroves are more than just a single tree, they form an ecosystem. A group of trees stabilises the sand beneath them making it easy for Bubble Weed and Seagrass to establish themselves. This algae and plant growth encourages animals that eat it, or consume the animals that eat it. The tree routes and other submerged growth provide shelter for juvenile animals while they mature. Plentiful mangroves are a sign of a healthy and thriving habitat that helps the growth in numbers of sea life.
Grey Mangroves from an ecosystem
DJI Mavic Air 2 [ISO 200, 4.5mm, f/2.8 and 1/640 SEC]
One species of animal that was prevalent among the mangroves was the Semaphore Crab (Heloecius cordiformis). These crabs are the most abundant species of crab within mangroves, where they live in burrows. Sometimes their quick disappearance into a burrow, which is filled with water just below the surface, creates an unexplained plop. The noise seems too loud and to have come from the exposed mud where there is no reason for such a noise. In this species, juvenile crabs have orange claws and adults have purple. The males have larger claws than females. This crab gets its name from the habit of males who wave their claws in the air like a sailor with semaphore flags. Scientists debate if this waving is for mating or a territorial display, or both depending on the situation and movements.
Semaphore Crab juvenile among mangrove pneumatophores
(Canon EOS 6D Mk II with a Canon EF100-400mm f4.5-5.6L IS II USM [ISO 500, 286mm, f/16 and 1/320 SEC])
Semaphore Crah male
(Canon EOS 6D Mk II with a Canon EF100-400mm f4.5-5.6L IS II USM [ISO 400, 400mm, f/9.0 and 1/320 SEC])
I don’t know why but one shell I always enjoy seeing is a Mud Whelk (Pyrazus ebeninus). Maybe because they can be sizeable shells and feel so solid. The easiest large shell to come across on the shore, and often still intact once the mollusc is dead because the hard shell has not been broken by the surf on the coast. These animals are plentiful around the inlet. Their movement through the soft mud leaves a distinct track that shows where the animal has travelled. One day I actually saw a shell crawling across a recently exposed bit of mud. The soft, black body of the mollusc clearly visible. It would stretch out its leg, although not too far then slightly heave itself up and onto the new position, all the while leaving a furrow in its wake.
Mud Whelks in the mud among the mangroves
(Canon EOS 6D Mk II with a Canon EF100-400mm f4.5-5.6L IS II USM [ISO 640, 188mm, f/14 and 1/400 SEC])
Mud Whelk crawling across the exposed flat
(Canon EOS 6D Mk II with a Canon EF100-400mm f4.5-5.6L IS II USM [ISO 640, 100mm, f/13 and 1/500 SEC])
Wandering along the beach, rocks and the mangroves was always enjoyable. There was always something to see and it was just nice walking in a beautiful coastal environment. Returning to the same place under different tidal conditions revealed new creatures, often making it feel like a new location. Especially around the mangroves it was nice just to stop and wait for the small life forms to accept my presence, whereupon they returned to going about their business and the habitat came alive. It was a really peaceful experience and filled much of my time at Narooma.
Thanks for reading this post and thanks also for looking at my photos. I hope you come back again to read more about some of the wonderful natural things that the south coast of New South Wales has on offer. All the best until the next post, Wonders of life under shallow water - Beautiful Narooma Part 5, Summer 2022/23