Adele Island and the Lacepede Islands Expedition 10th to the 19th March 2019 Aboard The Diversity
This Expedition visits a unique and poorly understood region of Australian maritime territory, associated Islands and Reefs. Many of the Islands support large breeding colonies of seabirds, marine turtles and complex coral reefs with an extraordinary diversity. The Timor Sea and Sahul shelf boast a significant variety of cetaceans, some using shallow inshore waters while others have a preference for deep sea canyons located on the edge of the continental shelf. This expedition is designed around exploring four islands and enjoying what they have to offer. There will be fantastic photographic opportunities of nesting seabirds, turtles and the challenge of taking that perfect shot of whales or dolphins. The snorkelling is excellent at Ashmore Reef so remember to bring your gear.
Sail from Broome boarding at 7 AM (you will be advised of the pickup time from your accommodation) We take a northerly course running parallel to the coast towards the Lacepede islands located about 30 km offshore from Beagle Bay on the Dampier Peninsular This run is good for a rare and unusual species of cetacean often referred to as Dwarf Spinner Dolphin Stenella longirostris roseiventris. We arrive at the lacepedes at about 1pm and drop anchor on the northern side of West Island at 16° 50’ S 122° 06 E. Our arrival co-insides roughly with high tide. We’ll land on West Island which has the greatest diversity to observe Lesser Frigatebird & Brown Booby breeding colonies. Huge numbers of Common Noddy congregate in large flocks on the beach, while Bridled Terns fly overhead. A lagoon with mudflats attract good numbers of shorebirds while at least 6 other species of terns are found here.
The Lacepede Islands encountered by Nicholas Baudin in 1801 who named them in honour of the Compte de Lacepede because of the large number of birds and wildlife observed on the islands. Lacepede was a noted French marine taxonomist (his son was aboard the expedition as the Naturalist). The Islands, particularly Middle Island were exploited for guano (phosphates) for several decades from the 1870’s, during this period, an infamous international incident occurred when the captain of an American Whaler claimed sovereignty over the islands! The introduction of rats from shipwrecks associated with the removal of phosphates saw a dramatic decline of breeding seabirds, luckily the rats were eradicated in the mid 1980’s and the seabird numbers have recovered.
Having steamed from the lacepedes very early in the morning we arrive at Adele Island, anchorage at 15° 28’ 123° 09’ (located 95 Km NE of Cape Leveque) mid morning. With a spring series of tides, the high (6.9m) is around 1.30 in the afternoon so we may have to wait for the tide so we can access the Island easily. Following the tide in on the tenders at Adele can be spectacular, drifting over sand bars and coral reefs. Sharks including White & Black tipped Reef, Tiger, Lemon and Hammer-head are a few species that can be seen amongst numerous other common fish. Shovel-nosed Ray, Eagle Ray and Sting Ray are generally obvious and common. Marine Turtles including Green, Australian Flatback, Loggerhead and Hawksbill occur regularly here. Estuarine Crocodiles are also present at Adele in low numbers, usually smaller animals but we still have to be aware of their presence. Adele Island is a unique place supporting huge numbers of breeding seabirds but it’s a tough place to explore due to dense Beach Spinifex. We can attempt to visit a breeding colony of Red-footed Booby and Great Frigatebird that utilize a grove of small shrubs called Indian Lantern Flower Abutilon indicum. Both Red foots and Great frigatebird have a preference for breeding in trees, In contrast Masked Booby are happy breeding in loose colonies on the beach and are easily accessed. Large flocks of migratory Shorebirds, Terns and Noddies congregate on the beaches and sand flats which makes it easy with spotting scopes to study them.
Interestingly Black & Lesser Noddy were first discovered breeding on Adele in 2012 by Rohan Clarke and I while conducting counts on the Island. Adele Island is also the most southerly and only breeding location for Red-footed Booby and Greater Frigatebird in Western Australia apart from Ashmore Reef which actually comes under federal jurisdiction. Towards the late afternoon we may be lucky to witness Greater Frigatebird’s klepto-parasitic behaviour, forcing Masked Boobies to regurgitate their fish as they fly back to hungry Juveniles waiting to be fed on the beach. We will probably have dinner at the Adele anchorage before leaving for Browse Island.
Leaving Adele Island the itinerary takes us north to Browse Island, the journey is around 120 NM so a 12 hour steam. (Anchorage at 14° 06’ 123°33’) The High tide is 4.5m at around 12.45hrs luckily we only need 1.6 m to get over the reef in the tenders so we should be ashore by 8 AM.
Browse has a rather sad history ornithologically, The Island was mined for phosphates by a number of companies starting in 1870 through to the 1890. Prior to this exploitation the number of seabirds breeding on Browse would have been significant, likely species would have included Brown and Masked Booby, Lesser Frigatebird, Common Noddy, Sooty and Bridled Tern. Crested Terns still breed occasionally.
Unfortunately there are virtually no records of the species present in those days although a painting exists showing large flocks of birds flying over the workings while vessels are anchored off the island. A tram way is also depicted for transporting the phosphate down to the shoreline. The phosphate would have been bagged and loaded into rowing boats for transfer back to the transport ships. This must have been a hazardous exercise rowing well laden tenders through a continuous swell breaking over the reef. Browse Island is not particularly well protected and vessels anchored off the surrounding reef would have been exposed to storms and cyclones. There are nine known wrecks located at Browse, occasionally one can find small fragments of copper sheeting used to protect wooden hulls and Coal presumably abandoned as ballast or surplus to requirements this being the age of sail and steam. Clay Bricks have also been found on the beach, worn from tumbling in the surf presumably these would also have been ballast. Records do exist of feral cats being present on the Island in the 1950’s so they would have precluded any chance of seabirds recolonising the Island. House Mice are also present but luckily the cats have gone and studies are being undertaken to work out the best way to encourage the seabirds to return. Being the only land for many miles land birds are attracted to the island including common Australian migrants and occasionally vagrant Asian species. Migratory shorebirds of a number of species are recorded regularly.
As Browse is fairly small (14 hectares) it’s unlikely we will spend more than the morning on the island recording everything we find.
We Continue our journey NW towards Ashmore Reef in the afternoon with 120 NM to cover we will reach Ashmore in the small hours unless we slow up to time our arrival for the early morning.
On the journey from Browse to Ashmore Leather-backed Turtles have been spotted very occasionally so something to keep an eye out for. This leg is also good for seabirds and cetaceans.
On arrival at Ashmore we liaise with Australian Customs who maintain a presence on the Reef (aboard Australian Customs Vessel Thaiyak) we then tie up to an inner mooring at 12° 14’ 122° 59’. This will be our spot for the next three nights situated about a kilometre East of West Island. It’s important that I point out that you can jump off the boat at this location and be snorkelling over beautiful reef with fish everywhere in five minutes! The high tide is at 14.25 hrs at 3.8 meters which is ample for a visit to East Island and associated sandbars.
We set out to East Island at about 1130 am aboard the tenders for the 13 km journey travelling over reefs and sand flats in about 2 to 3 metres of crystal clear water. Turtles, rays and occasionally dugong are spotted as we speed towards East Island, on our approach to the island we experience the usual welcoming committee of Boobies and Sooty Terns. Usually at this time of year the Islands are green with a lush covering of grass and herbs after recent rain. Breeding will be in full swing so huge numbers of birds will be swirling about and birds on nests everywhere so we have to stick to the beach to avoid too much disturbance. This experience is unique in Australia with all three species of Noddy (Common, Black & Lesser) breeding in close proximity to one another. Amongst the Noddies are thousands of Sooty Terns while Brown, Red-footed & Masked Booby, Greater and Lesser Frigatebird, Bridled, Roseate & Greater Crested Tern will also be breeding. We are very lucky to have access to these Islands as they are closed to the public. A short distance to the east of East Island is a small vegetated sandbar that is one of the main wader roost on Ashmore. With careful use of the tide we have time to explore the sandbar and enjoy some spectacular shorebird watching.
As with the Kimberley Coast any marine activity at Ashmore is tide dependant and although the tide range at Ashmore is smaller it still affects our activities. As we are moored close to West Island its ideal to visit the Island early in the morning while still relatively cool. This requires a short tender ride and a kilometre walk over sand bars to reach the Island. West Island is reasonably well vegetated with a narrow fringe of Octopus Bush Heliotropium foertherianium and a central herb field. Over the last 17 years the island has turned up an extraordinary list of birds, many of them new species for the Australian list, consequently birders and twitchers are drawn to the Island. Over the next three days we have the opportunity to visit West Island early in the morning and again in the afternoon to take advantage of the islands potential. White-tailed Tropicbird and Red-tailed Tropicbird both breed on the Island. Many other seabird species have recolonised West Island in the last couple of years having been absent for decades due to a number factors including guano extraction, rats and human habitation. The tide is high at 3pm so we have plenty of water to visit Middle Island. Located much closer to our mooring, Middle Island supports huge numbers of breeding seabirds much like East Island but a bit smaller. Located just to the east of Middle Island is a horseshoe shaped sandbar that’s another great wader roost.
A rest day at Ashmore for those who don’t want to walk out to West Island in the morning. Excursions can be organised to various snorkelling spots or wader roosts, tides willing, we can visit throughout the day and fishing is an option once out of the reserve boundary which is only a short tender ride from the mooring.
We leave Ashmore heading SW to Waypoint 1 12° 24’ 122° 26’ this way point is located beyond the continental shelf in a depth of over a thousand metres. These waters can be highly productive with cool nutrient rich water moving closer to the surface and Pacific seawater pouring through into the Indian Ocean. (Indonesian flow through) Tropical oceans are often regarded as unproductive and lacking diversity however the amount of life here surely proves otherwise with substantial and diverse pods of Cetaceans commonly recorded on previous trips. The presence of Blue and Sperm Whale in these waters adds to the exciting potential. Large flocks of Noddies, Boobies and Terns mix in with occasional Bulwers and Tahiti Petrel that can be common on this leg. Amongst this congregation of marine life the chance of spotting the elusive Jouanin’s Petrel a species that wanders the Indian Ocean from its only known breeding location on Socotra Island.
Scott Reef 14° 03’ 121° 47’ located 154 NM SW of Ashmore will take at least 16 hours of steaming seeing us arrive late at night.
Early in the morning we take the opportunity to visit Sandy Islet, the only speck of dry land on this vast reef system, several wrecks still remain perch up on the reef as a stark reminder of the dangers these reefs pose to shipping. Obvious Wildlife at Scott includes lots of Sea Turtles, Eastern Reef Egret, Brown Booby and Crested Tern. The Reef itself is rich with corals and Reef fish but has unfortunately been over fished. The continental shelf is very close to the western side of the reef and drops from sea level to 1100 m in less than 10 km. Under water cliffs and canyons are known hot spots for Cetaceans particularly Beaked Whales that are notoriously difficult to see and identify. Beaked Whales have a habit of logging on the surface of the ocean for long periods between very deep dives.
From Scott Reef our route follows the shelf break in a South Westerly direction (depths between 700m to 400 m) towards Waypoint 2 15° 50’ 120° 40’ Depth 400m With the distance of 157 NM we will reach the way point well after dark but this really makes no difference to us as we will have been scanning throughout the day looking for wildlife. The shelf waters that we traverse are good for a number of unusual and rarely recorded Seabirds including, Bulwers & Tahiti Petrel, with a rare chance of Jouanin’s Petrel. Abbott’s Booby and Red-necked Phalarope are also a good chance. The two all dark Storm Petrels we see in these waters in Spring (October/November) namely Swinhoe’s & Matsudaira’s are unlikely but possible. Cetaceans are often present with mixed pods of Dolphins and Pilot whales. These pods can be deceiving and it’s important to try and get photographs of as many animals as possible, because rare and less commonly seen species like Frasers Dolphin and Rough-toothed Dolphin often mix in with Spinner and Pan Tropical Spotted Dolphins and Pilot Whales. It has to be said that occasionally on these transects spotting wildlife can be slow and hard work but overall the quiet periods are quickly forgotten when some unique or spectacular interactions come about.
With 150 NM to cover we spend day 9 traversing over shelf waters with depths shallowing off as we make our way closer to Broome. Species that we see in deeper waters of around 100m plus generally don’t venture into these seas and are replaced by species that prefer shallow shelf waters. Large flocks of Terns often dominated by Bridled and Sooty Terns work in with Common Noddy chasing “work ups or bait balls” formed by tuna species that round up the baitfish. Brown Booby Join these feeding frenzies and occasionally a number of “Tube noses” including Wedge-tailed, Streaked, and Hutton’s Shearwater. The odd Wilson’s Storm Petrel join these congregations although in early March many are still making their way north from Antarctica. As we get closer to the mainland “White Terns” dominate the work ups including Common, Roseate and White-winged Black Tern, All three species at this time of year are developing breeding plumage. The shallow water allows Sea Snakes to feed, as they need to breathe fresh air its common to see them on the surface with commonest species being Olive (Golden) Sea Snake and Stokes Sea Snake. The Australian Flatback Turtle are common and occasionally Inshore Bottle-nosed Dolphins will perform a bow ride display for everybody. If we have some luck Indo Pacific Humpback Dolphins will make an appearance often in discreet mobs of four to five animals. Unfortunately they are not prone to bow ride.
Depending on our progress we should arrive in Broome around lunchtime or mid-afternoon and if we arrive a little bit earlier it will probably be a relief for some after a long journey at sea! Inshore waters still provide plenty of entertainment for the wildlife enthusiast.