Marine Biodiversity of Southern Sydney Harbour's Journal

April 03, 2024

Photo Observation of the Month of March - Sea Slugs Anonymous

I know I sound like a broken record, but congratulations to Erik Schogl, once again, for his amazing Photo Observation of the Month of March of the sea slug Pleurobranchus weberi at Camp Cove in Southern Sydney Harbour. Erik remains atop the leaderboard for the Marine Biodiversity of Southern Sydney Harbour project, with 890 observations and 215 species (including this sea slug). This identification was aided by Hsini Lin, the founder of the Sea Slugs of Taiwan group, and a self taught sea slug expert with a staggering 138315 iNaturalist identifications of species within this amazing group of animals.
This sea slug observation is so important because this species has only recently been recorded in Australia. In fact, there are only 13 total records on Atlas of Living Australia, 12 of those records contributed by iNaturalist citizen scientists and 1 record sourced from the Sea Slug Survey in the Gold Coast, also a citizen science led initiative. As a rundown of the ALA records: one record was contributed by co-Director of the Lizard Island Research Station Dr Anne Hoggett in 2011, two were recorded in 2023 on Queensland's Sunshine Coast, 3 were recorded on Queensland's Gold Coast (one in 2020 and two in 2023), 2 were recorded near the entrance of Lake Macquarie in New South Wales in 2023, and 5 (including our observation of the month) were recorded in Sydney Harbour. The remaining observations in Sydney Harbour were all in Chowder Bay at various points in 2022.
Previously, this species was only known from Indonesia and the Philippines, can get quite large (up to 20 cm), and can be distinguished from closely related species in the size of the mantle tubercles, placement of the white circles relative to their tubercles, and completeness of the circles. I will never say no to a new nudie!
This journal post was written by project leader and iNaturalist member, Dr Joseph DiBattista.
Posted on April 03, 2024 07:02 AM by joseph_dibattista joseph_dibattista | 0 comments | Leave a comment

March 07, 2024

Photo Observation of the Month of February - What are you, eel?






Congratulations to Erik Schogl, once again, for his amazing Photo Observation of the Month of February of the Southern Conger, at least provisionally, in what appears to be a hidey hole in Parsley Bay.

The Southern Conger (Conger verreauxi) is taxonomically stable and has 239 records on Atlas of Living Australia, of which only one record is from Sydney Harbour (in the upper reaches of Middle Harbour). Some of its congeners however, specifically the Eastern Conger (previously known as Conger wilsoni), is much more taxonomically ambiguous. According to John Pogonoski, an Ichthyologist and eel expert at the CSIRO Australian National Fish Collection in Hobart, and following Smith & Stewart (2015), the Australian Faunal Directory recognises Conger monganius (Philipps, 1932) as the valid name for the Eastern Conger. Conger monganius was described from NZ. This months observation is particularly challenging to identify as the placement of the dorsal fin origin in relation to the pectoral fin cannot be seen, which is one of the key characters distinguishing the Southern Conger (C. verreauxi) from its congeners. Indeed, for C. verreauxi, the dorsal fin origin commences at or slightly behind the tip of the pectoral fins. On the other hand, in C. monganius, the dorsal fin origin is well behind the tip of the pectoral fins. Conger verreauxi (153-159) also has more vertebrae than Conger monganius (145-151), noting that colour is a less reliable character to use as it can be variable in all species. There are likely additional Conger species awaiting formal description across Australia's temperate coastline. Thankfully we have a few motivated taxonomists in Australia on the case!

This journal post was written by project leader and iNaturalist member, Dr Joseph DiBattista.

Posted on March 07, 2024 11:49 PM by joseph_dibattista joseph_dibattista | 0 comments | Leave a comment

February 17, 2024

Photo Observation of the Month of January - How Blue are Your Buttons

Congratulations to Robbie Belchamber for their photo observation of the month of January of the blue button from the Porpita genus at the northern end of Camp Cove beach in southern Sydney Harbour. This is not a jellyfish, but instead a marine organism consisting of a colony of hydroids or hydrozoan polyps found in most warmer, tropical, and sub-tropical waters of the planet.
The blue button lives on the surface of the sea and moves vertically in the water column by using its float, though mostly moving passively with the ever shifting currents and prevailing winds, with the hydroid colony responsible for capturing planktonic prey via its stinging nematocyst cells. This is one of those "look but don't touch" organisms, as its sting can be an irritant to human skin. Blue buttons are also thought to be moving further and further south down the east Australian coastline with our warming oceans and rapidly changing climate. Please check out this video from the folks at James Cook University to see its beauty in real time.
This journal post was written by project leader and iNaturalist member, Dr Joseph DiBattista.
Posted on February 17, 2024 04:52 AM by joseph_dibattista joseph_dibattista | 0 comments | Leave a comment

January 29, 2024

We need your help in Parsley Bay, pretty please!

I am here asking for everyone's help with the habitat restoration component of the Blue World funded Valerie Taylor Prize project on "Marine Biodiversity of Southern Sydney Harbour". Our seahorse hotels have now been deployed for just over 10 months in Parsley Bay but we have not had the opportunity to dive and photograph them for at least 4 months. The four seahorse hotels were installed by Sealife Aquarium on March 23rd, 2023 in approximately 6 metres of water about 10-15 metres north of the swimming net, which is in the process of being replaced with a new one. The approximate location of the four seahorse hotels is flagged in the Google Earth image displayed above. Time permitting, I encourage everyone (anyone!) to get in for a dive in the month of February and report back with photographic evidence demonstrating that these structures remain in place after the new swimming net construction (which began January 22nd, 2024 and included the anchoring of barges to import construction materials), the state of marine growth and accretion on the seahorse hotels themselves, and whether any White's Seahorses are using this habitat as their new home.
This journal post was written by project leader and iNaturalist member, joseph_dibattista Dr Joseph DiBattista.
Posted on January 29, 2024 12:47 AM by joseph_dibattista joseph_dibattista | 2 comments | Leave a comment

January 11, 2024

Photo Observation(s) of the Month of December - Little Rays of Sunshine

We thought we'd do something a little different for the Photo Observation(s) of the Month of December, and include four amazing observations of a particular group of fish. And so congratulations to Erik Schlogl and Nic Katherine for their observations of two Common Stingarees (Trygonoptera testacea) (observation one and observation two) and two Coffin Rays (Hypnos monopterygius) (observation one and observation two) at Parsley Bay.
The reason that these observations are both timely and important is that in December 2023, a research project commenced on characterising the Stingaree and Stingray population at Parsley Bay and Camp Cove in Southern Sydney Harbour led by Nic Katherine. Rays in the order Myliobatiformes (which includes cownose rays, devil rays, eagle rays, manta rays, stingarees, and true stingrays, among others) and Torpediniformes (which includes coffin rays, numbfishes, and torpedo rays) started diversifying in the late cretaceous (~100 million years ago), with the former having 63 species and the latter 7 species known from Australia.
In New Zealand for example, these amazing creatures are believed to be spiritual guardians (or Kaitiaki) protecting the shellfish beds within their harbours and estuaries. In Māori culture, a Stingray barb, deeply thrust in, which cannot be withdrawn, is a metaphor to describe an idea that has taken hold in the mind or a grudge between people that was difficult to overcome. Nicole is excited to learn more about the amazing lives of rays right here in Southern Sydney Harbour.
Nicole's first observation at Parsley Bay as part of her standardised, "timed swim" visual survey approach was a 2 metre Smooth Stingray (Bathytoshia brevicaudata), gliding around and underneath the wharf, eating the bait from the sea floor discarded by fishers on the jetty. The Smooth Stingray is the largest species in the world within the Dasyatidae family of true stingrays. On her first survey at Parsley Bay, Nicole observed one Smooth Stingray, ten Estuary Stingrays (Hemitrygon fluviorum), two Kapala Stingarees (Urolophus kapalensis), one Coffin Ray (Hypnos monopterygius), and three Common Stingarees (Trygonoptera testacea). Not bad for her first time out to survey rays in Parsley Bay!
This self-directed project is supported by Dr Joseph DiBattista, now at Griffith University in the Gold Coast, and complementary data collected by fellow citizen scientists as part of this Marine Biodiversity in Southern Sydney Harbour iNaturalist page. The project aim is to learn more about the diversity and residency of rays in Southern Sydney Harbour. Nicole has been enjoying the experience of immersing herself in the rays world, with some of the juveniles dancing and chasing one another in the shallow waters, whereas others were more cryptic, tucked beneath overhangs or covering themselves with sand. The surveys will continue over the next 4 months.
This journal post was written by project leader and iNaturalist member, Dr Joseph DiBattista, as well as iNaturalist member, Nic Katherine.
Posted on January 11, 2024 01:56 AM by joseph_dibattista joseph_dibattista | 2 comments | Leave a comment

November 29, 2023

Photo Observation(s) of the Month of November - The Elusive Elysia

Congratulations to Karolyn Landat for their Photo Observation(s) of the Month of November of the sea slug from the Elysia genus at Camp Cove in southern Sydney Harbour, also observed on the same day here. This genus of colourful sea slugs is nested within the Plakobranchidae family, but do not be fooled! Even though they superficially resemble nudibranchs, they are not closely related to them at all. Instead they are sacoglossans, sometimes referred to as the solar-powered sea slugs.
At least some species of Elysia sea slugs have extraordinary feeding strategies. When nibbling on their primary food source of algae, they often retain the associated chloroplasts in the lining of their digestive tract, enabling them to survive solely by photosynthesis (without further feeding) for several months at a time. Other species of this genus can be stressed to sadistic extremes. Indeed, some Elysia are capable of regenerating their entire body anew from a severed head (gasp!!!). The observation by Karolyn Landat may be the elusive Elysia australis, but this will require a few more experts providing identification suggestions on iNaturalist given that there are over 100 species in the genus, many with ambiguous taxonomy.
This journal post was written by project leader and iNaturalist member, Dr Joseph DiBattista.
Posted on November 29, 2023 12:52 AM by joseph_dibattista joseph_dibattista | 0 comments | Leave a comment

November 01, 2023

Photo Observation(s) of the Month of October - Shrimpgobies

Congratulations to the "Goby Whisperer" Erik Schlogl for his Photo Observation(s) of the Month of October of the Broad-banded Shrimpgoby (Amblyeleotris periophthalmus) from Parsley Bay in southern Sydney Harbour, and the Redspotted Shrimpgoby (Amblyeleotris ogasawarensis) from Camp Cove. The former Broad-banded Shrimpgoby represents the very first record from Sydney Harbour, and a southern range extension from South West Solitary Island in NSW. This is also only the 34th record of this species for all of Australia. Given the time of the year (spring) and size of this photographed fish, this tropical species may have even survived the unseasonably warm 2023 Sydney winter. For the latter Redspotted Shrimpgoby, this represents only the second observation from Sydney Harbour, ever, and only the 16th record for all of Australia. The other Sydney Harbour observation was also in Camp Cove, and no surprise, also by Erik Schlogl.
Shrimpgobies are curious beasts in that they form mutualistic relationships with alpheid shrimps, even sharing the same burrows. The shrimp has poor eyesight and so it perpetually builds the burrow while the able-eyed goby serves as a sentry at the burrow entrance. Each time the shrimp emerges from the burrow entrance, it rests one of its antennae on the body of the goby. If the goby detects danger its body quivers to alert the shrimp. If the threat escalates, the goby darts straight back into the burrow. The shrimpgobies on the other hand, feed by filtering mouthfuls of sand through their gill rakers at points near their burrows in search of benthic invertebrates.
This journal post was written by project leader and iNaturalist member, Dr Joseph DiBattista.
Posted on November 01, 2023 11:41 PM by joseph_dibattista joseph_dibattista | 1 comment | Leave a comment

October 05, 2023

Photo Observation of the Month of September - Red-lined Bubble Snail - Pretty in Pink

I'd like to congratulate user eschlogl for his Photo Observation of the Month of September of a Red-lined Bubble Snail (Bullina lineata) from Camp Cove. Erik has been on an absolute tear in the month of September, submitting 53 observations from Parsley Bay or Camp Cove alone, which represents 90% of the total input to the Marine Biodiversity in Southern Sydney Harbour project in that month. All of these observations are now "Research Grade", bar this goatfish, this sea urchin, this sponge, this wrasse, this leatherjacket, and this cardinalfish.
The Red-lined Bubble Snail is found throughout the tropical and subtropical Indo-West Pacific intertidal zone, but generally subtidally in temperate locations like Sydney Harbour, where it can be found in moderate numbers, then not again for years. Mini boom and bust perhaps? It is an interesting species in that it displays an intermediate phenotype and phylogenetic placement relative to its heavily shelled and lightly shelled congeners. You also cannot help but notice the spirally grooved shell with a characteristic pattern of pink lines. This species is thought to feed primarily on polychaete worms. Yum, yum, yum...
The observation of this species is a reminder for the Annual Sea Slug Census that runs at a range of Australian locations from the Gold Coast to Melbourne and offshore on Lord Howe Island. This census is now well and truly entrenched in Australian citizen science circles, and regularly makes the news. The initiative represents a rapidly expanding citizen science program in which volunteers photographically record observations of sea slugs during nominated events. The observations contributed by citizens have led to much improved distributional data for sea slugs, the discovery of new species, increasing evidence of poleward range extensions, all of which can act as key indicators of our changing environment. Indeed, sea slugs serve as "canaries in the coal mine" based on their short generation times, which means that they rapidly adapt to changing environmental conditions (i.e., shifting temperatures and food availability). Southern Cross University (SCU) marine scientist Professor Steve Smith helped establish the first census in 2013 at Nelson Bay in New South Wales. Keep an eye out for calls to action later in the year in your local area.
This journal post was written by project leader and iNaturalist member, Dr Joseph DiBattista.
Posted on October 05, 2023 12:00 AM by joseph_dibattista joseph_dibattista | 0 comments | Leave a comment

September 11, 2023

Photo Observation of the Month of August - White's Seahorse - Up Close and Personal

We are forging ahead with the monthly photo submission competition with renewed support from Blue World, and so I'd like to congratulate user eschlogl for his Photo Observation of the Month of August of a White's Seahorse (Hippocampus whitei) from Parsley Bay. Erik’s amazing photo truly highlights the yellow to brown body colouration on this seahorse, the numerous pale flecks, and its ability to camouflage from predators. Typical of other seahorses, the female will transfer her eggs into the abdominal pouch of the male, where he will fertilize them, provide physical protection to the embryos, aerate them, and provide initial-stage nourishment.
The observation of this species is extremely timely in the conversation about threatened species and habitat restoration in Sydney Harbour, particularly with some of the upscaled restoration efforts being led by Project Restore based out of the Sydney Institute of Marine Science. Pollution, urban development (including the installation of boat moorings and anchors), and illegal trade are major sources of the decline of seahorses, though illegal trade is less of a concern in Australia. Indeed, the motivation behind the Seahorse Hotels we now see at select locations around NSW harbours was that severe storms, about 10 years ago, reduced the population in NSW by 90%. These storms shift huge volumes of sand, smothering the soft corals, sponges and seagrass that they associate with. More recently, in 2022, a one-in-100-year flood event nearly wiped out an already rapidly declining White's Seahorse population in Port Stephens. Based on this, any pollution spilling into the Harbour would be a threat to seahorses and the marine habitat that they depend on. All the more reason to protect the inner harbour ecosystem that hosts these endangered sea creatures in Parsley Bay from further construction and infrastructure projects.
This journal post was written by project leader and iNaturalist member, Dr Joseph DiBattista.
Posted on September 11, 2023 06:40 AM by joseph_dibattista joseph_dibattista | 0 comments | Leave a comment

September 07, 2023

Final eDNA Results - Parsley Bay and Camp Cove

The results are in!!! I am excited to announce that we have now completed our environmental DNA (or eDNA) seawater sampling at Parsley Bay (Vaucluse) and Camp Cove (Watsons Bay) for the Marine Biodiversity of Southern Sydney Harbour project. This represents 13 months of sampling at both sites. As mentioned previously, eDNA can be thought of as genetic “breadcrumbs” left behind in the environment that can identify every living thing, from microbes to mammals. This was all thanks to DNA sequencing provided by our friends at Wilderlab in New Zealand (https://www.wilderlab.co.nz/). Feel free to look through the "explore" tab on their webpage to view our sampling data populated on their map. Also feel free to view all the amazing flora and fauna that were detected at each of these locations.
Based on the “Wheels of Life” you see here constructed for Parsley Bay and Camp Cove, we detected 133 and 150 species of fish (with approximately 77% faunal overlap), respectively, with a number of cryptic species detections as well as detections of commercially important species. Almost all the usual fishy suspects were well represented (bream, goatfish, kelpfish, leatherjackets, longtoms, morwong, mullet, snapper, whiting, wrasses), with some of the more interesting detections including at least seven species of weedfish (Heteroclinus sp. and Cristiceps sp.), seahorses (genus (Hippocampus), at least two species of pipefish, a butterflyfish (Chaetodon flavirostris sp.), moray eels, at least six species of ray (including an eagle ray), a blind shark, and even mahi-mahi. We also detected 43 mollusc taxa at each site (including chitons, clams, cowries, limpets, mussels, nudibranchs, oysters, periwinkles, sea hares, turbans, warreners, and whelks); 31 and 23 worm taxa, respectively; 41 and 47 crustacean taxa (including amphipods, barnacles, lots and lots of copepods, crabs, and shrimps), respectively; 7 and 16 sponge taxa, respectively; 33 and 42 cnidarian taxa (including anemones, hydroids, hydromedusa, hydrozoans, snowflake corals, and jellyfish, including jellyfish blubber!), respectively; 6 bryozoan taxa at each site ; and 73 and 77 algal taxa (including brown algae, green algae, oyster theifs, kelp, seaweed, and sea rubber), respectively. These detections were in addition to hundreds of species of rotifers, fungi, insects, plants, diatoms, ciliates, bacteria, birds (ducks, gulls, shags, and teals), common dolphins (Delphinus delphis), New Zealand fur seals, humpback whales, two types of starfish (Astropecten sp., Parvulastra sp.), two types of sea urchin (Centrostephanus sp., Heliocidaris erythrogramma), three types of ascidian (Microcosmus sp., Pyura sp., and Styela sp.), two species of skink (Eastern Water Skink and Gully Skink, likely lounging on the adjacent shoreline), and unidentified penguins! These data will be used in a scientific publication under preparation, with your valuable iNaturalist observations used to ground truth our detections and put them into context. Thank you so much for your continued contributions.
This journal post was written by project leader and iNaturalist member, joseph_dibattista Dr Joseph DiBattista.
Posted on September 07, 2023 02:14 AM by joseph_dibattista joseph_dibattista | 0 comments | Leave a comment