20 facts for 20 years of the Adelaide Dolphin Sanctuary

Where is the Ade­laide Dol­phin Sanctuary?

The Sanc­tu­ary is only about a 20 minute dri­ve from Ade­laide’s city cen­tre. It encom­pass­es the Port Riv­er and Bark­er Inlet and stretch­es north to Port Gawler, cov­er­ing the waters of Out­er Har­bour and inter­tidal areas. It’s a world of con­trasts, includ­ing unchanged nat­ur­al habi­tat, recre­ation­al activ­i­ties, major indus­try and a busy, liv­ing city port. Amongst all this, dol­phins have proven them­selves to be high­ly adaptable.

The Kau­r­na Peo­ple have lived with­in this area for thou­sands of years, and it con­tin­ues to hold impor­tant val­ues for them. Sev­er­al tra­di­tion­al sto­ries are con­nect­ed with the Ade­laide Dol­phin Sanc­tu­ary area, includ­ing The Wan­der­ings of Tjirbruke.

What’s changed over 20 years?

One of the most vis­i­ble changes has been the reha­bil­i­ta­tion of Gar­den Island, pre­vi­ous­ly a land­fill site. It has been capped with 1.4 mil­lion tonnes of clay and soil, and plant­ed with native grass­es, trees and shrubs. 

​“The way this place looks and is man­aged has changed dra­mat­i­cal­ly; it’s val­ued and cared for,” says Marine Parks ranger Jon Emmett.

Less vis­i­ble but very impor­tant, Jon says, has been the reg­u­la­tion of local indus­try, such as the pow­er plant, ship chan­dlery and inter­na­tion­al ship­ping oper­a­tions. 

​“The EPA devel­oped a water qual­i­ty improve­ment plan for the Port water­ways. The water qual­i­ty has become much, much bet­ter for sus­tain­ing pop­u­la­tions of fish and oth­er ani­mals.” 

The ADS plays a promi­nent role in assess­ing any fur­ther devel­op­ment in the area, togeth­er with the Coast Pro­tec­tion Board, the EPA and local government.

Human behav­iour has also seen changes for the bet­ter. Before the estab­lish­ment of the Sanc­tu­ary, dol­phins in the area had been shot and speared in sense­less attacks. 

With the pres­ence of rangers and pub­lic recog­ni­tion of the Sanc­tu­ary, there have been no delib­er­ate attacks in many years.
 

A key loca­tion for dol­phin research

Dr Mike Boss­ley, a lead­ing fig­ure in the estab­lish­ment of the ADS, has been con­duct­ing research into the behav­iour­al ecol­o­gy of the Port Riv­er estu­ary’s dol­phins since 1988.

The ADS rangers have under­tak­en sur­veys since 2015. Today, ranger Dr Nik­ki Zanar­do assists Hon­ours and PhD stu­dents from South Aus­tralian uni­ver­si­ties to sur­vey the ADS dol­phins in mul­ti­ple stud­ies of dol­phin health, habi­tat use, social behav­iour and pop­u­la­tion ecology.

“We have a unique oppor­tu­ni­ty here, as ani­mals spend so much time close to the shore,” says Dr Zanardo. 

“We can under­take research and share find­ings with the com­mu­ni­ty, who can observe what’s hap­pen­ing for them­selves. The research can real­ly help peo­ple con­nect to the local marine environment.”

Is the algal bloom affect­ing the dolphins?

The algae has been detect­ed in the Port Riv­er, home to the Ade­laide Dol­phin Sanc­tu­ary. Right now, the dol­phins are not believed to be at imme­di­ate risk, but the water qual­i­ty is being close­ly monitored.

A big thanks to ded­i­cat­ed volunteers

Vol­un­teers have played an inte­gral part in mon­i­tor­ing dol­phins and col­lect­ing sur­vey data in the ADS. They’re fre­quent­ly the first to observe sig­nif­i­cant events like new calves or entan­gle­ments with fish­ing gear. Over the last 20 years, vol­un­teer groups such as the Ade­laide Dol­phin Sanc­tu­ary Action Group and the Whale and Dol­phin Con­ser­va­tion have show­cased the sig­nif­i­cance of the ADS and its wildlife, attend­ing com­mu­ni­ty events and pro­vid­ing edu­ca­tion talks to count­less school and com­mu­ni­ty groups.

What’s the best way to enjoy the Dol­phin Sanctuary?

Jon rec­om­mends vis­it­ing the boat ramp and pic­nic area at Gar­den Island.

“On a warm day in sum­mer, the whole grassy area is cov­ered with peo­ple, they’re hav­ing bar­be­cues, swim­ming, kick­ing a footy,” says Jon.

Stroll on the board­walk over the water and keep an eye out for dol­phins, nor­mal­ly seen in the area a cou­ple of times a day. Kayak tours launch from here to enjoy the calm waters, man­groves and tidal creeks.

What can peo­ple do to help the dolphins?

“Look after the habi­tat, and the dol­phins will look after them­selves,” says Jon. 

“We don’t need to man­age dol­phins or fish, we just need peo­ple to behave in a way that respects the environment.”

Actions you can take include:

• Leave no trace – dis­card­ed fish­ing gear pos­es a high threat to dol­phins, and float­ing rub­bish may be ingest­ed. Use bins or take rub­bish with you.
• Sup­port clean­er stormwa­ter – do not dump any pol­lu­tants such as deter­gents and chem­i­cals into gut­ters, drains or waterways.
• Do not feed the dol­phins or touch them – they are curi­ous and intel­li­gent, and can quick­ly adopt behav­iours that could put them in dan­ger and cause loss of nat­ur­al sur­vival skills.
• Boat own­ers should stick to speed lim­its with­in the sanc­tu­ary and know the marine mam­mal approach dis­tances for boats and kayaks.
• If you are fish­ing and you see a dol­phin close by, reel in your lines or change location.

Twen­ty facts about the Ade­laide Dol­phin Sanc­tu­ary and its dol­phins to mark its 20^th anniversary

1. The ADS cov­ers 118 square kilo­me­tres of water, man­groves, salt­marsh, tidal flats and tidal creeks.

2. The dol­phins found here are Indo-Pacif­ic bot­tlenose dol­phins (Tur­siops aduncus).

3. Many of the dol­phins seen close to shore are ​‘year-round res­i­dents’ of the ADS. Oth­er ​‘tran­sient’ indi­vid­u­als use the sanc­tu­ary as well as the wider Ade­laide coastal area and Gulf St Vin­cent. Based on Dr Mike Bossley’s long term data set 1993 – 2020, dol­phin abun­dance varies across the sea­sons, with high­est in sum­mer (aver­ag­ing 85 indi­vid­u­als), and low­est in win­ter (aver­ag­ing 69 individuals).

4. A ful­ly-grown bot­tlenose dol­phin can be around 120 – 160 kilo­grams and over two metres long.

5. Indi­vid­ual dol­phins can be recog­nised by nicks, notch­es and scratch­es on their dor­sal fins, which wild dol­phins accu­mu­late over their lives.

6. With­in the ADS is a ships’ grave­yard where the remains of at least 40 ves­sels, scrapped here dur­ing the first half of the 20^th cen­tu­ry, can be seen at the water’s edge.

7. Some of the ​‘tran­sient’ dol­phins have learnt to use the lock sys­tem to get in and out of Patawa­lon­ga Lake, where there are lots of fish to eat. As a boat enters the lock, they’ll go in too, wait while the water lev­el is man­aged, and exit with the boat.

8. The man­groves, which grow between the high and low tide points, are an impor­tant breed­ing ground for fish, includ­ing many species that you prob­a­bly enjoy eating.

9. Man­groves are esti­mat­ed to have been grow­ing here for around 10,000 years.

10. The shel­tered nature of Bark­er Inlet makes it a very pop­u­lar place for kayak­ers, from begin­ners to the more experienced.

11. Dol­phins are nat­u­ral­ly curi­ous and play­ful, and delib­er­ate­ly inter­act with humans and water­craft. Remem­ber, a dol­phin can approach you, but you must not attempt to get clos­er than 50m from a dol­phin, or 150m from a dol­phin with a calf.

12. You might spot long-nosed fur seals or endan­gered Aus­tralian sea lions with­in the Sanc­tu­ary. After days at sea for­ag­ing for food, they haul out on the shore or rocks. Please don’t dis­turb them — they need lots of rest before return­ing to sea.

13. On Gar­den Island, old bricks and rub­ble can be seen at the water’s edge – a reminder of the site’s his­to­ry as a land­fill dump.

14.The Sanc­tu­ary is part of a larg­er marine, estu­ar­ine and ter­res­tri­al pro­tect­ed area net­work, includ­ing Upper Gulf St Vin­cent Marine Park, Ade­laide Inter­na­tion­al Bird Sanc­tu­ary Nation­al Park – Winaity­i­naityi Pangkara, and Tor­rens Island Con­ser­va­tion Park.

15. Many seabirds and shore­birds live, roost, nest and feed at the Sanc­tu­ary, includ­ing rare and endan­gered species. Look for pel­i­cans, cor­morants, oys­ter­catch­ers, red-capped plovers and osprey. There’s also a breed­ing rook­ery for the endan­gered fairy tern. 

16. The ADS takes a min­i­mal inter­ven­tion approach to sick and injured dol­phins. Allow­ing nat­ur­al events to take their course can sup­port a healthy pop­u­la­tion. Where human activ­i­ty has caused an issue, such as a fish­ing line entan­gle­ment, they will col­lab­o­rate with vets and water police to help.

17. The Sal­is­bury and Port Ade­laide Enfield coun­cils have cre­at­ed large areas of urban wet­land, which have sig­nif­i­cant­ly improved the qual­i­ty of stormwa­ter enter­ing the ADS.

18. The Ade­laide Speed­boat Club oper­ates over one stretch of water in the Sanc­tu­ary, and on race days has dol­phin spot­ters at either end, with rac­ing paused if dol­phins are present.

19. OzFish (Ade­laide Chap­ter) is work­ing with vol­un­teers and the local com­mu­ni­ty to restore local­ly extinct native oys­ter reefs.

20. Major new water­front hous­ing is in devel­op­ment at Port Ade­laide. It is hoped that the res­i­dents will see the ben­e­fits of sup­port­ing a healthy Dol­phin Sanc­tu­ary, to pro­vide a wel­com­ing ecosys­tem for all inhab­i­tants into the future.

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