Mangrove habitats are such fascinating ecosystems because they straddle the worlds of land and water because of tidal movements. I was fortunate in January 2022 to have time to head down to the ever beautiful Jervis Bay where I ignored the stunning white beaches because I was heading for the wonderful Currambene Creek to explore a mangrove habitat. Although the beaches of Jervis Bat are deservedly famous for their beauty I was captivated by being among the mangrove trees. I was captivated by the life in the habitat, especially the crabs. The Red Fingered Marsh Crab has such striking colours with its lime green carapace contrasting with its red claws. I was fascinated to see these crabs moving on the exposed trunks of the mangrove trees. Even more fascinating, was when I approached the trees, the crabs did not head into the water but they shot up the trees to holes and crevices higher up in the trunks, well above the hide tide mark. While it was not significant behaviour it still brought home to me how this habitat provided for different creatures in a variety of ways and how much I enjoyed drifting between the crooked trunks of those amazing trees. I hope that you enjoy the photographs below.
The actual route that I took
Screenshot from Google Earth
Currambine Creek entered Jervis Bay at the township of Huskisson, which is the main tourist destination in the bay. The creek was not deep but has a protected boat mooring location in its lower reaches. The gentle waters can be paddled for approximately 15km upstream in a roughly north-westerly direction to the hamlet of Falls Creek, to near where the Princes Highway crosses the creek. The NSW Government classed the creek as a barrier river estuary that was intermittently closed, although the mouth looked to be very healthy, with plenty of pleasure boats moored upstream, whose owners would have been annoyed if sand closed the river mouth.
When I was there in January 2022, the creek was very busy due to school holiday crowds but paddling away from Huskisson reduced the level of holiday-related activity, with the mangroves providing calm and solitude on a busy recreational waterway.
Between Myola and Huskisson, pleasure and recreational craft were moored ether side of the channel along the creek. Some people looked to be enjoying just being on those boats with no plans to sail anywhere else at that time. I can’t blame them, it seemed a nice way to spend a serene day.
Commercial aquaculture controversially returned to Jervis Bay about six years ago when mussels, oysters and seaweed were established at three commercially leased sites a few kilometres offshore from Huskisson. The company that had the leases, South Coast Mariculture, planned to serve the Sydney market, and ABC’s Landline profiled the company in this report from October 2020. While the company was focused on the major east coast markets it was possible for people to sample the produce locally at the Jervis Bay Shellfish Market as well, according to the utilitarian looking vessel the ‘Blue Revolution’ that was tied near the Woollamia Boat Ramp. Although you need to go to Bolten Road not Bolton. This commercial aquacultural enterprise showed the carefully balancing needed to presreve the natural beauty of a location but allow some activities to occur so that a greater range of people felt invested in the area and didn’t want to see it lost. However, some locals also saw it as a weakening of the marine reserve status. If one commercial activity can occur, why not more and more until there was a reserve in name only. Let’s hope this was a case of the former and not the latter.
One of a number of pleasure craft lining both sides of the channel along Currambene Creek
(Canon EOS 6D Mk II with a Canon EF100-400mm f4.5-5.6L IS II USM [ISO 160, 100mm, f/10 and 1/250 SEC])
Sign that was displayed on the utilitarian bare metal of the vessel the Blue Revolution, pointing to seafood for sale
(Canon EOS 6D Mk II with a Canon EF100-400mm f4.5-5.6L IS II USM [ISO 160, 100mm, f/10 and 1/160 SEC])
I drove into the carpark at the Woollamia Boat Ramp just before 8:30 in the morning and there were hardly any car spots remaining. The main part of the carpark was for vehicles with trailers but further away from the ramp was an area for cars without trailers. The road around the actual ramp was very busy with boats being reversed into the creek, so I avoided the action there and headed to a quieter area just downstream from the boat ramp. There was an obvious path near the information. board that led over a pedestrian bridge with yellow buffers. This route brought me to a small sandy area where people were launching all their paddle-powered craft.
Woollamia Boat Ramp, which was very crowded but there was a good launch spot down a path to the right
Apple iPhone 8 [ISO 20, 3.99mm, f/1.8 and 1/2000 SEC])
The path leading to where I actually launched from
Apple iPhone 8 [ISO 20, 3.99mm, f/1.8 and 1/620 SEC])
Even before commencing the paddle I observed an interesting human-wildlife interaction. At the time I was loading my kayak with my things for the paddle when a returning amateur boat fisherman must have thrown the scraps from the catch to an eagerly waiting Australian Pelican (Pelecanus conspicillatus). I only saw the bird after it had the scraps in its large, pinkish coloured bill. The pelican seemed to have some trouble handling the fish, because with just a head, backbone and guts, the fish’s innards were dragging outside the pelican’s bill making it hard for the bird to swallow. The bird shook the somewhat grotesque offering, dipped its bill into the water but eventually swam off in a low profile with its white head pulled back and bill out horizontally, dragging a greyish line of fish guts in the water on the far side form me. The tossing of fish remains is common along the south coast and in a way solved the problem for the council of what to do during hot summers if bins were left outside in 40 degree temperatures filled with fish guts. That would not be pleasant. The birds obviously know that a feed is on hand but there were no other pelicans around so I suspect that the birds are not dependant on this food source. This discarded fishing waster was probably not a regular way for pelicans to gain food because the numbers of returning fisherman outside of holidays and weekends would be low, reducing the dependancy of birds upon this means for gaining food.
Australian Pelican with the remnants of an angler’s catch
(Canon EOS 6D Mk II with a Canon EF100-400mm f4.5-5.6L IS II USM [ISO 200, 400mm, f/8.0 and 1/500 SEC])
After enjoying the pelican and its antics I remembered why I was at the creek and hurried to finish my preparations. The creek was beautiful to paddle in. The water was beautifully clear so I could see the sandy bottom as well as a number of fish swimming about. My planned route initially took me down river towards Huskisson, against the current of the incoming tide which I was definitely able to notice acting against me. I paddled past so many mangrove trees and I had to contain my desire to head among their leafy branches.
Not far into my trip I came across the lookout part of a mangrove boardwalk that started in Huskisson. I had walked its wooden boards a very long time ago, thinking what a brilliant idea to allow people to comfortably venture in among mangroves to see for themselves all the life present throughout the day, at both high and low tides.
Lookout point of the mangrove boardwalk at Huskisson
(Apple iPhone 8 [ISO 20, 3.99mm, f/1.8 and 1/1000 SEC])
Approaching the mouth of Currambene Creek a sandspit was pointing far out from the opposite Myola bank into the water. This constriction to the flow of water made the incoming current stronger the closer I approached to the wharves at Huskisson. I still could have paddled out into the wider bay but the waterway was busy and I noticed that returning boats were being swung widely by the incoming current. And I did not wish to get hit by one of those boats. I turned my kayak and was immediately rewarded with a natural thrust from the current that pushed me towards some private wharves before I was edged the kayak over to ensure a faster turn to the starboard.
After making that turn I decided to head to the sandspit where the water was quieter in the natural lee away from the current. Although, I did have to make sure that I dragged my kayak well out of the water to stop even this weaker current whipping my blue friend up the river without me.
The sandspit had water lapping over the end but some seabirds were standing firm on the still dry point of the spit. They were facing out into the bay, toward the wind thet was picking up in speed. The spit was also a nice vantage point to photograph the very aptly named straight, vertical cliff of Point Perpendicular; an iconic sight in Jervis Bay. The old 1899 constructed lighthouse was visible as was the replacement framework-only lighthouse. The lighthouses sit on top of the rocky cliff, 80 metres above the rolling waves of the Pacific Ocean.
Huskisson seen from the sandspit on the Myola side of Currambene Creek
(Apple iPhone 8 [ISO 25, 3.99mm, f/1.8 and 1/4000 SEC])
Point Perpendicular, with a cloud buildup, seen from the sandspit
(Canon EOS 6D Mk II with a Canon EF100-400mm f4.5-5.6L IS II USM [ISO 160, 400mm, f/8.0 and 1/500 SEC])
Turning my camera back to the end of the sandspit I could see that Crested Terns (Thalasseus bergii) were the main bird species resting there. There were adults and juveniles, many resting on one leg looking out to the waters of the bay while others went about the important task of preening. These birds are brilliant flyers, able to pick out small fish from the sea before heading swiftly back just above the wave tops. They have also learnt to follow fishing boats to enjoy the discarded by-catch.
Immature Crested Tern at the tip of the sandspit
(Canon EOS 6D Mk II with a Canon EF100-400mm f4.5-5.6L IS II USM [ISO 100, 400mm, f/8.0 and 1/500 SEC])
Besides all the terns the only other bird on the sandspit was a lone Pied Oystercatcher, resting there with its long red beak tucked between its wings. Its bold red eye was bright in the sun as it kept watch to the area where us humans were. The oystercatchers have very strong beaks that cut the muscle holding the two shells of bivalves together, allowing the bird to eat the soft creature inside. They normally scour sand and mudflats for animals to eat but can also find food on rocky shores, so the whole coastline of rocks and sand is open to them. They are a stunning bird with the simple black and white plumage interrupted by the striking red of their eyes and beaks. I love photographing these birds as well as their relative, the Sooty Oystercatcher.
Pied Oystercatcher resting
(Canon EOS 6D Mk II with a Canon EF100-400mm f4.5-5.6L IS II USM [ISO 100, 400mm, f/8.0 and 1/500 SEC])
Because the sandspit had grown out from the Myola side of the creek, turning around from the gay facing beach, there was bush behind me that extended back for many kilometres. The sandspit had a thin mane of trees growing along this sand that widened out once it was part of the coast proper. While I was on the sandspit I heard the unmistakable call of a Yellow-tailed Black Cockatoo (Calyptorhynchus funereus) and sure enough two of these gorgeous mainly black birds, with their tell-tale yellow cheeks and tails, were in a tree feeding. I could only photograph one of them and even that was through a tangle of branches. I enjoyed seeing these large birds while they ate the plentiful seeds on the tree. However, after a little while I knew that I had to get paddling again because I needed to head back up the creek to get to some mangroves.
Yellow-tailed Black Cockatoo in a tree feeding
(Canon EOS 6D Mk II with a Canon EF100-400mm f4.5-5.6L IS II USM [ISO 400, 400mm, f/9.0 and 1/400 SEC])
Getting back into my kayak was easy and pushing off I was immediately in the current pushing me upstream. It seemed strange to have a current pushing me up the creek but it showed how this creek was influenced by the tidal movements. I also took the opporuntity to cross the channel that was closer to the eastern bank of th creek, so that I would be away from boats using it. The channel was lined with moored pleasure craft on both sides, which had lines to boys both at the bows and sterns of the craft to keep them from swinging into the channel when the tidal current changed. The still relatively strong current made me conscious of paddling quickly across the channel so as not to be pushed into one of the moored boats. Once I was away from the channel and moored boats I enjoyed the added propulsion of the current while I paddled up the creek
There was a bit of congestion when I passed my entry point at the Woollamia Boat Ramp because boats were launching while other were trying to exit, and to add to the hectic scene a large sailing yacht was being lowered by a big, yellow crane into the water beside the wharf. Fortunately, everybody was being conscious of other users and there was no trouble, and once past that area I was back to contented paddling on the beautiful blue waters of the creek.
Not surprisingly, before I could get to the mangroves, I was distracted by three Australian Pelicans swimming across the front of me as they made their way towards the mangroves that formed an island off Woollamia in a bend of the creek. They did not want to be near me but they did not rush either, sedately but surely swimming across my projected path on their course to the mangroves. Once they were deeper in among the trees one of them climbed out of the water onto the trunk of a tree that was almost horizontal. Seeing these birds reminded me that they were part of the ecosystem that I was exploring. The mangroves would provide them protection from human powered water craft. The birds could also hunt for the larger fish that were swimming around trying to eat the smaller fish hiding among the mangroves. In this habitat, the pelicans would be one of the apex predators at the time that the mangroves existed as a watery habitat.
Australian Pelicans swimming to the mangroves
(Canon EOS 6D Mk II with a Canon EF100-400mm f4.5-5.6L IS II USM [ISO 100, 400mm, f/8.0 and 1/400 SEC])
I followed this bend of Currambene Creek, circling around the large patch of the mangroves the pelicans had swum into but I did not follow them. Instead, I wanted to enter the mangroves that bordered the shore so that I could be assured of finding a place to secure my kayak.
It was easy to spot an opening between trees, indeed I chose one that had a well lit sunny circle of water deeper in so that I could do some snorkelling and underwater photography with plenty of ambient light. Entering this labyrinth of trees, gliding past the twisted mangrove trunks I was buzzing with excitement because the water was so high, it would be good for snorkelling to really see the mangrove habitat as an inundated world. Crossing over the sunny patch, I saw the shore very nearby. Unfortunately the bank was steep but I was able to wedge my kayak on some fallen branches that had crossed over and the water was not deep enough to make getting out of my kayak too comical.
Among the mangroves where I spent a bit of time snorkelling and photographing
(Canon EOS 7D Mk II with a Canon EF16-35mm f/4L IS USM [ISO 800, 35mm, f/11 and 1/400 SEC] in an Aquatech Elite II sport housing and PD-140 Lens Port)
Not surprisingly, the mangrove trees are the foundation for this ecosystem, and the Grey Mangrove (Avicennia marina) was the dominant species. This species is a hardy plant that can tolerate periods of freshwater as well as periods of hyper salinity, when the water is saltier than seawater, and the species also grows the furthest south of Australian mangroves, being the main mangrove in NSW.
Mangroves are terrestrial plants that have moved back into a salty environement so they still need fresh water and have to expel the salt they inadvertently allow in. They have pores on their roots that they can close to stop saltwater getting in. When they do have salt in their system they pass it through the tree to the underside of the leaves where it is expelled as salt crystals. In addition, if a leaf is in poor condition the tree may direct the excess salt to that leaf because the leaf will fall off soon enough. The leaf will turn a sickly yellow from all the salt but the sacrifice of a leaf assists the rest of the tree. In the long run, the leaf will help the tree again because when it breaks down those resulting nutrients will enter the poor quality sand or mud around the tree providing some much needed chemical assistance to the tree. Another adaptation this tree has are its roots that poke up from the ground, seen in the photograph below. These vertically straight aerial roots are called pneumatophores.
The tree itself was also a habitat in miniature. Small barnacles were starting to colonise the lower parts of the sampling while higher up on the second branch from the left a Turban Shell was perched. Later two small fish poked around the tree as well. More widely in this area I saw a range of marine life, some of which I was able to photograph.
Mangrove saplings seen underwater with dead leaves that will become nutrients, and barnacles as well as a Turban Shell using it for support
(Canon EOS 7D Mk II with a Canon EF16-35mm f/4L IS USM [ISO 1000, 35mm, f/11 and 1/250 SEC] in an Aquatech Elite II sport housing and PD-140 Lens Port)
Underwater close up of mangroves leaves and buds
(Canon EOS 7D Mk II with a Canon EF16-35mm f/4L IS USM [ISO 1000, 35mm, f/11 and 1/250 SEC] in an Aquatech Elite II sport housing and PD-140 Lens Port)
In the middle of the sunny patch of the mangroves a school of Common Hardyheads (Atherinomorus vaigiensis) were sheltering around the large submerged trunk of the mangrove that appeared to have fallen over at some stage but continued to grow. The fish did not want to leave the shelter of this tree, even as I photographed them. They would move away from the camera but continued to swim near the trunk and underwater branches of the tree. This species is common in this habitat and estuaries where they feed on small animals and larvae as well as small plant matter.
School of Common Hardyheads swimming at the base of a mangrove tree
(Canon EOS 7D Mk II with a Canon EF16-35mm f/4L IS USM [ISO 1000, 35mm, f/11 and 1/250 SEC] in an Aquatech Elite II sport housing and PD-140 Lens Port)
There were a number of Mud Whelks (Pyrazus ebeninus) all around the mangroves, some of which were most certainly dead. I did not disturb this one to see if it was dead but as it was right under my kayak, I was happy to take a photo of it. A second, clearly dead whelk is on the right, with some of its shell missing. These are mud specialists and are very common in estuaries and mangroves where they scour the mudflats for food. They are detritus feeders meaning that they help the breakdown of the plant matter that falls from the mangroves, so are a key part of the cycle of getting sustenance back into the trees.
Mud Whelk shell underwater, with a broken one to the right
(Canon EOS 7D Mk II with a Canon EF16-35mm f/4L IS USM [ISO 1000, 35mm, f/11 and 1/250 SEC] in an Aquatech Elite II sport housing and PD-140 Lens Port)
Sydney Rock Oysters (Saccostrea glomerata) were also plentiful, making use of mangrove roots, trunks or small rocks, whatever they could find as a solid foundation for growth. Because it was high tide the shells were slightly open, allowing them to filter their food out of the water. These shellfish were doing well and would spawn other oysters that would continue to create larvae that could be used by commercial fisherman. They can also make walking in mangroves painful, should an errant foot find its way onto the sharp edge of the shell. I liked this particular group because of the way the sun was lighting them, letting the purple colouration show through.
Sydney Rock Oysters underwater feeding on the mudflats between the trees
(Canon EOS 7D Mk II with a Canon EF16-35mm f/4L IS USM [ISO 800, 35mm, f/11 and 1/200 SEC] in an Aquatech Elite II sport housing and PD-140 Lens Port)
I was also surprised to find some Water Striders speeding across the surface of the same waters that supported the animals shown above. These amazing insects aggressively hunt along the surface of the water, using the water tension to move as quickly as land insects use solid ground. The small male, hanging onto the back of the larger female may have already mated with his partner but was sticking around to prevent other males also mating with her.
Water Striders mating among the mangroves
(Canon EOS 6D Mk II with a Canon EF100-400mm f4.5-5.6L IS II USM [ISO 100, 400mm, f/8.0 and 1/400 SEC])
One of the most startling sights I noticed during the paddle were so many Red Fingered Marsh Crabs (Parasesarma erythodactyla) on the rough trunk bark of the Grey Mangroves. Even more interesting to me was that these crabs were exploring well above the high tide mark and when my presence disturbed them, rather than fleeing into the water, the crabs normally ascended the tree to a convenient hole where they quickly ducked inside, sometimes a couple of them into one hole. I thought that it was interesting that these crabs chose to move away from the water when threatened by danger. I also loved the splash of colour they brought to the dried, rough grey of the mangrove bark. I became obsessed with trying to get a good photograph of these colourful crabs on the bark that I continued to paddle deeper into the mangroves, where the water was getting shallower. Almost every tree that I passed had at least one if not a handful of these crabs on the frunks. It was deep in the mangrove forest that I encountered a nice local couple out on their SUPs who confirmed that whenever they paddled through that area of the mangroves they also saw those colourful, small crabs scurrying up the tree bark.
Red Fingered Marsh Crab crawling on the trunk of a Grey Mangrove
(Canon EOS 6D Mk II with a Canon EF100-400mm f4.5-5.6L IS II USM [ISO 1250, 400mm, f/9.0 and 1/400 SEC])
I was only truly among the mangroves for less than an hour, including have a snorkel around the trunks and across the muddy flats between trees. I am sorry that I am not a better underwater photographer and was unable to capture more of the marine life that I saw. There were more fish, including bream, and a number of prawns. All these little animals adding to the biomass interacting with in the ecosystem.
Looking at my watch I realised that time was leaving me so I reluctantly paddled back to the boat ramp at Woollamia. It had been such an enjoyable paddle and snorkel, and although I had not covered much distance I had enjoyed the wealth of life that I encountered.
After packing my things into the car and lashing the kayak to the roof rack I started the drive home. However, I did not want to go straight home, I wanted to visit the Jerrawangala Lookout that I had passed on previous trips but never stopped at. The lookout was at the top so the escarpment behind the coast, about 4km down an unsealed road but was worth a stop. It had a panoramic view to the east, wth St Georges Basin in the distance around to the south across the rugged, tree-covered gorges of Morton National Park. The lookout had a small but easily accessible carpark and a metal raised walkway slightly above the rocks that allowed visitors to walk to the edge of the cliff before being able to peer down past the vertical rock face to the steeply sloping ground that fell away under a canopy of gums.
The ruggedness of the country blunted the senses, there even seemed to be a silence because the terrain had a stoicism along the solid rock walls of the escarpment that defied humans to disturb this place with development.
Strolling along the walkway I had to stop to photograph a Saw Banksia (Banksia serrata). This high, yellowish flower spike was so close to the walkway and contrasted with the overcast sky that was developing. The serrated, stiff leaves give this plant one of its common names, the Saw Banksia, however it is also called Old-man Banksia. Either way, it was a great example of the banksia plant.
Saw Banksia
(Canon EOS 6D Mk II with a Canon EF100-400mm f4.5-5.6L IS II USM [ISO 500, 164mm, f/13 and 1/400 SEC])
While I was photographing the banksia an Eastern Spinebill (Acanthorhynchus tenuirostris) started exploring through the plant, sticking its tongue out in an attempt to find some nectar. These little birds will take nectar from a wide variety of plants but will also eat insects. This particular one did not stay in one spot long and as the photograph shows, it was perfectly happy to perform contortions in a search for sustenance.
Eastern Spinebill on the Saw Banksia tree
(Canon EOS 6D Mk II with a Canon EF100-400mm f4.5-5.6L IS II USM [ISO 200, 400mm, f/14 and 1/100 SEC])
Some movement at the edge of the cliff drew my attention to a Grey Shrike-thrush (Colluricincla harmonica) that was moving along the bare rocks right at the top of the precipice. I suspected that a bird would not have the same trepidation as a human would moving so close to a sheer void. Indeed, eventually this brown and grey carnivorous bird took to the wing over and down the cliff. I really liked the way the bird was almost silhouetted against the distant floor of the valley below and how the shrike-thrush itself is almost contemplating something. I was also impressed at how the dull colours of the bird suited the lichen covered rocks it was moving over, which was not its usual habitat.
Grey Shrike-thrush looking for food on the edge of the cliff
(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])
There was also a Pied Currawong (Strepera graculina) perched on the top of the black painted handrails at the edge of the lookout. The currawong seemed to be very pleased that it had a dried bit of discarded bread or biscuit firmly gripped in its sinister black beak from some visitor that was long gone. The way that the bird looked back over its shoulder while it perched on the rails overlooking the sheer drop below reminded me of a Hollywood jewel thief caught at the moment of a daring escape. A figure dressed all in black, openly grasping a large item of very expensive jewellery; who looked back at the pursuers without a care because the escape would not end with the thief stuck on the edge. Just like the Hollywood thief this currawong turned its head to face forward as it plunged down, its wings opening wide cape-like with end feathers curling up in a fashionable twist. Again, like the Hollywood pursuers I dashed to the railing to see what had happened to this darkly dressed thief and just like the cheeky jewel thief in the movies, the bird was safely away from me, among the branches of a tree and still grasping its prized food in its strong, black beak.
Pied Currawong with food scrap on the railing at Jerrawangala Lookout
(Canon EOS 6D Mk II with a Canon EF100-400mm f4.5-5.6L IS II USM [ISO 500, 321mm, f/13 and 1/400 SEC])
The lovely birds that I saw at the lookout seemed a fitting end to the day. I climbed back into the car for the final leg of the drive home. It had been a wonderful day on Currambeene Creek among the mangrove trees where I seemed to be in my own peaceful world, contentedly watching the small creatures of the ecosystem live their lives in their regularly flooded world. I thoroughly enjoyed it and I would recommend a quiet drift through a mangrove forest as a soothing antidote to a hectic life.
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.