CetusGeoIssue 6 I Dec 2019 & EMAGAZINE

Northern Territory’s False Killer

Sounds Beneath the Waves: PLUS The acoustic world of whales & fact file

Latest news South America’s Complexities of the Dammed River Dolphins Sea Sponge Ocean Inspiration with Kohola Kai Creative

SCIENCE I CULTURE I ART I CONSERVATION EDITOR’S NOTE

The delicate BALANCE

he delicate balance of this world In amongst the seemingly endless greed we live in is incredibly intricate, of human societies; whether in relation to T interconnected and sensitive. risking the extinction of endangered river Who would have thought that mangrove, dolphins in the Amazon by the construc- seagrass and saltmarsh systems store tion of dams (pg. 20), kidnapping belugas huge amounts of greenhouse gases and and orcas and holding them in small can absorb carbon dioxide up to 40 times jail-like pens with the intent to sell them faster than forests on land? These under- to captive facilities in China (pg. 12), or estimated systems are finally getting a the inaction of our politicians to address little credit for their importance in keeping global warming, it can be hard for us to the global balance (pg. 4). Yet, the human see the positive light. thirst for coastal encroachment still sees these systems disturbed and destroyed. Our world is an amazing place and one of With each disturbance, they release their a kind. Each new discovery and explora- carbon stores. In Australia, this results in tion reminds us of this. By diving into the 2-3 million tonnes of CO2 being released acoustic world of whales and dolphins each year. (pg. 8), or exploring the lives of false killer whales (pg. 17), and discovering the Our world is changing and we are begin- intricacies of sponges, there is much to ning to see the impact of the warming celebrate and conserve. In this issue, we climate. How marine life will be impacted gain inspiration from artist Tracie Sugo and respond to these changes is not fully from Kohola Kai Creative whose detailed understood. New research has found artworks help viewers to connect to the that warmer waters can have immediate lives of marine life and the need for their biological consequences to dolphins. In conservation through immediate positive Shark Bay, Western Australia, the impact action (pg. 26). of a warm water plume was evident in significantly lowered reproductive success I hope you enjoy and gain inspiration from of the Indo-Pacific this issue of CetusGeo! population (pg. 5). This raises concerns in relation to how well and how quickly these Best Wishes (and others) can adapt to the changing world. Liz

Photo: NOAA

CetusGeo Dolphin & Whale EMagazine is produced and published by Dolphin Research Australia Inc., a marine research, education & conservation charity.

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2 I Issue 6 Intrigue Contents

Cetus Geo Contributors

Editors: Liz Hawkins & Pete Garbett Article Contributors this issue: In this ISSUE: Carol Palmer CONTENTS Jessica Tsitonakis NEWS Heather Pheloung Lara Pogson-Manning 4 The marine predator’s vital role in protecting carbon Mia Gustavsson stocks Liz Hawkins

Tammy Brown Global Warming causes decline in reproduction and 5 Design: Belinda Nelson survival in resident bottlenose dolphin populations.

5 Do drones bother you? Would you like to 6 Microplastics found in 50 stranded marine Contribute? along the British Coast. CetusGeo is written by 7 Counting whales from space passionate people for your pleasure. If you have an idea for an article that you 7 Wading birds increase foraging efficiency would like to contribute, please email us and pitch your proposal. INTRIGUE

8 Sounds Beneath the Waves Image Credits Cover Image: C. Palmer ISSUES

12 Russian Whale Jail - The Harsh Reality of the Captive Whale Industry Subscriptions Annual subscriptions to CetusGeo DISCOVER Dolphin & Whale magazine are complementary with 17 False killer whales – Are they regular users or resident Dolphin Research Australia Inc. species of Australia’s Northern Territory coastal waters? memberships and dolphin adoptions. CRITICAL BY NATURE $30/year Dolphin Research South America’s Dammed River Dolphins 20 Australia membership $60/year Dolphin Research FACT FILE Australia dolphin adoption 24 Boto Fact File

IN CONVERSATION Enquiries [email protected] 26 Ocean Inspiration with Kohola Kai Creative www.dolphinresearchaustralia.org

FACT FILE

30 Absorbing the subtle complexities of the sponge

Issue 6 I 3 News

The marine predator’s vital role in protecting carbon stocks

habitats. These relationships are incred- ibly complex, context-specific and influ- enced by the structure of the food web, trophic levels and species present. The presence of predators can both maintain the abundance and alter the behaviour of herbivore species along with the seques- tration of C in the system.

The majority of C is stored in anoxic sed- iments where organic material is trapped underneath vegetation. The deposition of sediment is greatly influenced by the density and height of the vegetation (i.e. roots, trunks and canopies). If herbivores, for example, are too abundant or graze too heavily on root systems, the plants can be restricted in growth, and this can lower sedimentation rates and reduce the size of the habitat, ultimately reducing the biomass of the ecosystem.

The loss of predator species directly or indirectly can result in an increase in the abundance of foraging/grazing behaviour of herbivores/bioturbators, ultimately

Image: E Hawkins leading to a cascading effect and top- down loss. Imbalances in the system can egetated coastal habitats including subsequently lead to loss, die-off, and Vseagrass, mangrove and saltmarsh, fragmentation of coastal vegetation, and have a ‘disproportionately large role in the with it, the capacity for these habitats to global capture and storage of natural car- sequester CO2. bon (C)’ according to researchers from the University of Queensland and elsewhere. Researchers conclude that ‘the future role This is largely due to a process called that vegetated coastal ecosystems play biosequestration, which is the process of in climate change mitigation will in part CO2 being absorbed from the atmosphere depend on the preservation of marine and stored in plants, algae and sediment predators, and therefore, policy and man- where it can be retained for millennia (as agement need to reflect this important blue C). realization as a matter of urgency’.

Predators, such as finfish, sharks, pinni- Reference: Atwood, T.B. et al. (2015) peds and dolphins, play important direct Predators help protect carbon stocks in and indirect roles in maintaining the func- blue carbon ecosystems, Nature Climate tion of, and preserving, coastal vegetation Change. 5(12), 1038.

4 I Issue 6 News

Global Warming causes decline in reproduction and survival in resident bottlenose dolphin populations

esearchers from the Universities of for a plethora of marine species, including RZurich and Bristol conducted a study the resident bottlenose populations. on the population status of resident Indo-Pacific bottlenose dolphins, following The simultaneous loss of extensive an unprecedented heatwave in Western habitat and consequently prey species, the two groups suggests that the use of Australia’s Shark Bay, a UNESCO World likely prevented fish stocks from recov- ‘foraging aids’ may have shielded those Heritage Site. ering in the following years. Researchers individuals against the effects of habitat speculate lower prey abundance would loss by allowing them exclusive access to The heatwave occurred in the summer have prompted higher foraging efforts a less-severely affected foraging niche. of 2011 and caused coastal waters within from keystone predators such as the the heritage site to rise by 2-4 degrees dolphins, and a subsequent lack of Scientists predict that the occurrence of above the average temperature for a total vigilance from mothers when hunting heatwaves could increase by 41% by the of two months. Following the event, would have resulted in higher rates of end of the century. As global warming researchers detected a long-term calf mortality from shark predation. continues to have a more drastic and reduction in both the survival and Additionally, survival rates for both widespread effect in our ecosystems, reproductive rates of the dolphins. mothers and calves could have plummet- researchers investigating this incident are ed from their inability to meet the higher concerned that the inability of species to Analysis of data collected over a ten-year energy requirements their respective life recover after such an extended period of period between 2007 and 2017, revealed stages demand. time will mean that they become function- that even 7 years after the event, normal ally extinct as reproductive output will be levels of survivability and reproduction Researchers surmised that even if calves, outcompeted by the rate of mortality. had not returned. The sudden climatic their growth may be stunted due to lower shift also destroyed an overwhelming nutrient intakes during vital life stages and Reference: S. Wild et al. (2019) Long-term 36% of seagrass habitat within Shark may not become reproductively active. decline in survival and reproduction of Bay, drastically reducing the availability Researchers believe that the differing resil- dolphins following a marine heatwave, of crucial foraging and nursery grounds ience to external changes seen between Current Biology, 29

Do Drones Bother You?

f you were a dolphin, the answer would be yes. New Zealand researchers recently flew Ian Unmanned Aerial Vehicle (UAV) over bottlenose dolphins (Tursiops truncatus) near Great Barrier Island in New Zealand and tested their response. The researchers flew the UAV at 10m, 25m and 40m altitude and observed their behaviours before, during and after the flights. They detected more behavioural changes, including orientation chang- es and tail slaps, when the UAV was flown at 10m altitude. At higher altitudes, the UAV had little effect on evident behavioural changes. Different age-sex classes and species may have different responses to drones, with some being more sensitive to others. While the research in this field is still young, the use of UAVs is extensive, both by researchers and the public. This study shows that the effects of UAVs are not always benign, as many may assume.

Reference: Fettermann, T. et al. (2019) Behaviour reactions of bottlenose dolphins (Tursiops truncatus) to multirotor Unmanned Aerial Vehicles (UAVs), Scientific Reports, 9 (1), 8558.

Issue 6 I 5 News

Microplastics found in 50 stranded marine mammals along the British Coast

ervasive microplastics (described as , a juvenile short-beaked common detected was relatively low with an Pplastic fragments less than 5mm in dolphin was found to have macroplastic, average of 5.5 pieces per animal. This size) are an increasing threat to marine which was a piece of green netting. may be due to microplastics being ecosystems globally. Ingestion of micro- egested (discharged or excreted from plastics can occur by way of accidental Nylon was the most prevalent polymer the body) along with other dietary waste consumption through filter feeding type, along with the other unwelcome and cetaceans (particularly toothed techniques, or by indirect consumption classes of polymers identified during the whales) being able to regurgitate foreign through trophic transfer when predators study. Blue and black were the most objects from their stomachs. consume contaminated prey. common particle colours found. This pattern of dominant blue and black There were three categories of possible Researchers recently examined the microplastics has also been found to be causes of death for the stranded digestive tracts of 43 cetaceans of the case in other studies of turtles, fish animals examined; infectious disease, eight species (including an Atlantic and zooplankton. trauma and other. Researchers white-sided dolphin, bottlenose dolphin, concluded that “a possible relationship harbour , pygmy , Interestingly, all species examined in this was found between the cause of Risso’s dolphin, and study were raptorial feeders (using only death category and microplastic white-beaked dolphin) that were their jaws and teeth to catch prey) mean- abundance, indicating that animals stranded along the British coast. ing they expel seawater through their that died due to infectious diseases Seven pinnipeds that were also teeth so as not to ingest it. Presumably, had a slightly higher number of particles examined in the study. Microplastics fewer microplastics are consumed directly than those that died of trauma and other were found in all animals examined. through this feeding technique and more drivers of mortality’. They further indirectly via the transfer from prey. emphasise that further research is In total, 273 particles of plastic were For example, studies have shown that needed to understand the chronic effects detected (261 were less than 5mm in size). 11-30% of fish in the English channel and of microplastic pollution on marine The majority of microplastic particles Portuguese coast contain microplastics1,2. mammals as there remains very little identified were in fibrous forms whilst the known about the biological impacts on remaining particles were plastic frag- Despite all of the marine mammals these animals which are sentinels of ments. The stomach contents of only one studied having microplastics, the amount environmental health.

Citation: Nelms, S. E. et al. (2019). Microplastics in marine mammals stranded around the British coast: ubiquitous but transitory? Scientific Reports, 9(1), 1075. 1,2 Lusher et al. (2013) Occurrence of micro- plastics in the gastrointestinal tract of pelagic and demersal fish from the English Channel. Mar. Pollut. Bull. 67, 94-99 Neves et al. (2015) Ingestion of microplstics by commercial fish off the Portuguese coast. Mar. Pollut. Bull. 101, 119-126. Author: Tammy Brown

6 I Issue 6 News Image: Vreni Haussermann Image: Vreni

ollowing the mass stranding of at discovered that the number of stranded Counting Fleast 343 baleen whales, primarily sei animals had originally been underesti- whales ( borealis) in 2015, mated. The authors concluded, “Satellite whales researchers investigated if it was possible imagery may be a cost effective alternative to actually see and count these events to aerial surveys for future assessment of from space using Very High Resolution satellite (VHR) the extent of mass whale stranding events, imagery. The mass stranding event that especially in remote and inaccessible occurred in the Gulf of Penas, central areas”. The cause of the mass stranding Patagonia, Chile, was the largest on event remains unknown. record for baleen whales. While aerial and boat surveys were completed to locate the whales, the assessment was made Reference: Fretwell et al. 2019 ‘Using remote difficult due to, among other reasons, the sensing to detect whale strandings in remote remote location and inaccessible terrain. areas: The case of sei whales mass mortal- Researchers found that whales could be ity in Chilean Patagonia, PLoS ONE 14 (10): detected visually using VHR imagery and e0222498

Wading Birds foraging effiency

ading birds increase their foraging gather to capture the unsuspecting prey Wefficiency by taking advantage of displaced on the shore by the dolphins. unique feeding behaviours of bottlenose Researchers from Coastal Carolina Uni- dolphins. Along the saltmarshes of South versity reported that wader birds that took Carolina and Georgia, USA, bottlenose advantage of these events had greater dolphins (Tursiops truncatus) use a unique foraging efficiency than others that did strand-feeding technique. The dolphins not feed in association with the dolphins. dash towards the shore creating a ‘bow’ Those birds that joined the dolphins had wave that pushes the fish into the shal- higher strike success and energy intake lows and onto the shore. The fish per hour. They suggested that this rela- are then caught by the dolphins that tionship allows ‘individual birds to meet temporarily strand themselves before their existence energy requirements by sliding back into the water. This behaviour providing access to normally inaccessible is only performed by particular communi- prey.” ties of dolphins that efficiently coordinate Image: E Hawkins themselves to optimise the drive and capture of prey. Reference: Fox, A. G. & Young, R. F. (2012) Foraging interactions between wading birds and strand-feeding bottlenose dolphins This behaviour attracts numerous wading (Tursiops truncatus) in a coastal salt marsh. birds, including herons and egrets who Can. J. Zool. 90: 744–752

Issue 6 I 7 Intrigue: Sounds beneath the waves

Sounds Beneath the Waves

8 I Issue 6 Intrigue: Sounds beneath the waves

s humans, we use sight as our such as the humpback, blue and Aprimary sense; light travels well right whales. As they evolved from through air and we use our sight in land mammals, the way they produce almost all aspects of our lives. But in sound has some similarities with us. the marine environment, light doesn’t Air passes over a membrane, causing travel as well. The deeper you go, the it to vibrate and create noise. Unlike us harder it is to see. However, sound however, they do not need to exhale travels particularly well in the ocean. to make noises. Cetaceans can often Consequently, a lot of marine animals make noises underwater for long rely heavily on sound for all aspects periods of time, and instead of exhal- of their lives. This can take the form ing it is thought that they “shuttle” air of percussive sound such as fish back and forth across their membrane, drumming their swim bladders, or recycling the oxygen present. This humpback whales breaching. Howev- means that they do not use up pre- er, in the world of cetaceans, this more cious oxygen reserves while diving. In often takes the form of vocalisations. Odontocetes sound is produced by a complex nasal system while in Cetaceans (whales, dolphins and Mysticetes it is believed to be ) can produce a wide range produced in the larynx, somewhat of vocalisations, from the infrasound similarly to humans. However due to of blue whales which is so low that the difficulty of studying such large, it cannot be heard by human ears, to migratory animals, this is still not the high-pitched ultrasound whistles completely understood. of dolphins, which are too high for human hearing. Despite evolving from Odontocetes a land-dwelling ancestor, cetaceans are now so well-adapted to the marine Odontocetes produce a wide va- environment that they rely heavily on riety of sounds which can broadly sound for a great many aspects of be grouped into three categories. their lives, including socialising, prey Echolocation clicks are perhaps the detection and hunting, group cohe- most well-known. Not unlike sounds sion, and mating. However, the exact generated by a bat, or a boat’s sonar, methods they use to produce and these sounds enable the Odontocete Lara Pogson- detect sound have evolved in varied to “see with their ears”. These clicks ways among cetacean species. are produced in pulses that travel Manning dives to the object, bounce back, and are beneath the Cetaceans can be separated into two then interpreted by the Odontocete’s ‘groups’: the Odontocetes, or toothed brain. Because echolocation enables waves to discover whales which includes dolphins, Odontocetes to “see” very effectively the acoustic world porpoises and species such as sperm underwater, it is often used for hunting and beaked whales; and the Mys- and foraging. In addition to echoloca- of cetaceans ticetes, which are the baleen whales tion, Odontocetes can also produce

Issue 6 I 9 Intrigue: Sounds beneath the waves

Each dolphin has its own individual signature whistle, which they produce as self-identifiers. These signature whistles are thought to be used as ‘contact calls’ to help with group cohesion.

als, and that some species of dolphins, such as bottlenose dolphins ( spe- cies) and humpback dolphins (Sousa species) have signature whistles which are the dolphin equivalent of a human name.

Each dolphin has its own individual signature whistle, which they produce as self-identifiers. These signature whistles are thought to be used as ‘contact calls’ to help with group cohe- sion. Basically, they appear to be used when individuals move out of visual contact of the group they are with so that they can still find one another. They are of particular importance be- tween mothers and calves, with calves calling most just before re-joining their mother. In addition to this, the male appears to develop a signature whistle which is similar to that of its mother, unlike females who have entirely dis- tinct signature whistles. It is thought that this may be because males tend to disperse more from their mothers, and this similarity to their mother’s ‘name’ may reduce in-breeding. a different type of ‘click’. These are called burst-pulse sounds, however Mysticetes in these, the clicks are produced so close together we perceive them as Mysticetes are similar to Odontocetes one continuous sound. Burst-pulse in that they produce a large variety of sounds are one of the least under- sounds. However, as most Mysticete stood of Odontocete vocalisations. We species are very large (usually over do not yet know exactly what function 10 metres), they are generally able to they have, but they are thought to be produce sounds which are lower than used for short-distance communica- Odontocetes. Blue and fin whales tion. After echolocation, the next most produce infrasounds which are well familiar type of sounds Odontocetes below our threshold of hearing. These make are whistles. When people think sounds are thought to be used for of dolphin noises they often immedi- long-distance contact calls. Blue ately imagine whistles. However what whales also produce the loudest call many people don’t know is that these of all baleen whales. These low- whistles are thought to be mainly used pitched calls are able to be heard up for communication between individu- to several hundred kilometres away.

10 I Issue 6 In fact they are so low-pitched that for as a song evolves, it gradually gains us to be able to hear them we need complexity. However when a revolu- to speed it up about 5-6 times the tion occurs and a new song appears normal speed. Right whales produce in a population it is always simpler. a different type of contact call, termed We also do not know if this is because an ‘upcall’, while bowhead whales only the simpler songs are copied, and humpback whales produce if some of the complexity is ‘lost in ‘songs’ during their mating seasons. translation’ or if there is some other In addition to these known uses of reason. Regardless of why this occurs Explore sound, there are still many weird and it does seem that ‘new is better’ in wonderful sounds out there that we the whale musical charts with simpler the Acoustic are unsure of the function of, including new songs being favoured over more the famous “Star Wars sound” made complex versions of old songs. World of by minke whales. However, probably the most famous of all whale sounds Cetaceans use sound for most Cetaceans is the song. aspects of their lives and it is vitally important that it be considered in con- Click on the links below Humpback whales produce one of the servation and management initiatives. to listen to the different most complex acoustic displays in the Whilst most people are aware of other vocalisation marine environment. Males produce issues facing cetaceans such as ship long complex songs mainly during strike, entanglement, and pollution, their migration between the polar few realise what an impact noise feeding grounds and the breeding pollution can have. Noise pollution Echolocation clicks grounds near the equator. This song is has the ability to either impede or a part of their breeding system, howev- completely mask their communication Burst pulse er it isn’t currently known if it is aimed that in turn can have impacts on their sequence of the at other males, females, or both. Each social systems, breeding and health. boto population of whales will sing approx- Those of you living near train tracks imately the same song at the same and noisy roads know how noise can time, however this song is constantly impact sleep, and as sound travels vocalisation changing and evolving. In the South- further underwater than in air, noise ern Hemisphere, not only does this sources can impact a much larger song evolve, but it also goes through range than you expect! So, the next vocalisation what is termed a ‘revolution’. This time you’re out on the water and occurs when the song from the popu- come across some of these amazing Upcall of a lation to the west rapidly takes over as animals, make sure you give them the the main song of the next population space they need and spare a thought to the east. We do not know why or for their noisy world. exactly how this occurs but at some point these populations need to come Humpback whale Lara Pogson-Manning is a doc- into acoustic contact with each other. toral candidate at the University The other thing we don’t know is why Marine of Queensland. She is currently some songs rather than others take Sound Library studying humpback whale song, over in the next population, but these but has a passion for all dolphins, songs all seem to have something whales, and marine life. in common. In the southern basin,

Issue 6 I 11

12 I Issue 6 ISSUES: WHALE JAIL Image: Greenpeace I Free Russian Whales Russian Image: Greenpeace I Free Russian Whale Jail The Harsh Reality of the Captive Whale Industry

releasing footage online and to the media, of the appalling conditions in the “Whale Heather Pheloung Jail”, where the 11 orcas and 89 belugas investigates the controversy were being kept before being sold on to surrounding the capture of China for entertainment purposes. The orca and belugas in Russian name “Whale Jail” is indeed appropriate waters and their intended and draws attention to the 13 overcrowd- ed, unhygienic, undersized pens (10 fate to be sold to China for metres by 12 metres) that these animals captive display. have been living in for a year, in Srednyaya Bay, near the Russian east coast city of Nakhodka. While the term “Whale Jail” he term “Whale Jail” sounds is a new way to describe the cruel and horrendous, unbelievable and torturous conditions these whales have Tsurely not possible, however been living in, this is not, unfortunately, a captive orcas and belugas are living a new practice for Russia. nightmare - their suffering is real and their imprisonment is sadly only part of the For the last six years or so, Russia has story. In July 2018, Russian activists began been at the forefront of catching wild to expose the illegal, unmonitored and orcas and belugas, selling these ani- brutal business of capturing orcas and mals to countries such as China to meet belugas, filming the companies respon- demand for the ever-increasing number sible during the capture process and of entertainment-based marine parks and

Issue 6 I 13 ISSUES: WHALE JAIL

aquariums. China has 75 of these parks Whale Jail in Srednyaya Bay. The secretive and a further 25 are scheduled to be built operations surrounding the consortium’s in the next few years. Russian law allows capture and holding of cetaceans have led the export of captured wild cetaceans for to Russian activists bringing the whale jail scientific or public education purposes to the attention of the Russian government Russia does not only, and since 2013 they have put quotas and media as well as the international me- restrict the number on the number of orcas permitted to be dia and scientific community in November caught in Russian waters, which has 2018. Since then, positive steps have been of belugas captured increased to 13 per year. Furthermore, taken. The Russian government banned and this has led to Russia does not restrict the number of the export and sale of live orcas and belugas captured and this has led to high belugas held in the whale jail, and refused high numbers of numbers (81 were caught in 2013 with 34 to issue new permits to capture orcas and these whales being killed during capture, 89 caught in 2018) belugas from the wild in 2019. of these whales being caught and sold caught and sold to to other countries. Not only are these An online petition at change.org asking for other countries. animals being exploited for money (the the cetaceans’ rehabilitation and release, Chinese marine entertainment parks and gathered over a million signatures, with aquariums pay approximately $(US)6 mil- support from celebrities such as Leonardo lion for one wild orca), they are being sub- DiCaprio and Pamela Anderson. Interna- jected to an unnatural, restricted and cruel tional conservation charities and scien- life, forcefully and traumatically removed tists, including Jean-Michel Cousteau from their family members and their social (Chairman & President of Ocean Futures connections, trained to perform and pan- Society), wrote letters to President Vladi- der to the wants of paying customers. mir Putin, resulting in a signed agreement with Russian government committing Their capture is also contributing to to the release of the captive orcas and the decline of wild populations that are belugas. already under serious threat from other human activities. Scientists have been Jean-Michel Cousteau offered advice on calling for a zero quota to be imposed by the best ways to rehabilitate the whales the Russian government as the studies of to give them the best chance of survival. population estimates of wild orcas and be- Cousteau visited the whales to assess lugas living in the Okhotsk Sea along the their health and decided they were fit to east coast of Russia, where they are cap- be released into the wild. Various plans tured, are very limited. Russian activists were put forward for their release, and in have put the number of orcas living in the mid-June President Putin announced his Okhotsk Sea at 250, and taking 13 orcas government was planning to release ani- per year (not to mention any others that mals over four months with two orcas and are killed during the capture process) will six belugas being the first to be returned have serious ramifications on the popula- to the Sea of Okhotsk where they were tion leading to a decline in numbers. caught. Three out of the four consortium companies had since been fined approx- In the past, the companies catching and imated $500,000, $500,000 and $900,000 selling cetaceans have somehow found respectively, for capturing wild cetaceans a way around the Russian export laws for entertainment purposes, however they and profited hugely from it. For example, are planning on appealing these fines. The a consortium of four companies - Bely other company is yet to be fined. Kit, Afalina, Oceanarium DV, and Sochi , have sold 13 orcas to China The first stage of release of these ceta- from 2013 to 2016 for entertainment ceans has not been ideal and very disap- purposes and against Russian law, with pointing. The 1,800 km journey back to no intervention from the Russian govern- their original habitat in the Sea of Okhotsk, ment. This same consortium owns the involved both basic ground and water 100 whales (the largest known number transport and took about seven days. The of marine mammals to be captured and Russian government claimed the release held in tiny enclosures) held in the Russian of these animals would be monitored

14 I Issue 6 and supported by over 70 scientists and professionals, and that it would be a gradual reintroduction to the wild for these animals. However, this has not been the case and All-Russian Research Institute of Fisheries and Oceanography (VNIRO) which is responsible for their release is

being very guarded about the operation - Whales Russian Image: Greenpeace I Free completely lacking in transparency. Video and photos that are circulating from the release of the two orcas and six belugas raise serious questions about the welfare of these animals and show high levels of neglect and abuse of these poor animals that have already endured too much. Their chance of survival upon release in the wild has been greatly reduced due to the lack of rehabilitation they have received. There is no confirmed information of how many belugas were successfully transported and released, and there is no communi- cation regarding when the next release of the remaining captive cetaceans will be.

The international spotlight on the Rus- sian captive whales has already brought about so much positive change for the welfare of the Russian orcas and belugas, and people power will continue to help the remaining jailed whales be properly rehabilitated and prevent cetaceans from being caught and subjected to abuse, cruelty and neglect in the future.

UPDATE Since this article was written, there have been rapid changes arising in this case. On 11th November 2019, it was reported by the Free Russian Whales coalition, who confirmed that all orcas were released in August and all belugas had been released on 10th November. The whale jail is thankfully over and the world’s response was enormous with more than 1.5million people signing the Change.org petition. Every voice counts, the fight is worth it.

Heather Pheloung is a passionate nature lover with Bachelor’s degree in Environmental Science from Melbourne and is currently a Sources: Research Assistant with Dolphin Free Russian Whales - freerussianwhales.org/en/the-issue/ International Marine Mammal Project - savedolphins.eii.org/news/campaign/immp/ Research Australia. The Whale Sanctuary - whalesanctuaryproject.org/whale-aid-russia/ Ocean Futures Org - www.oceanfutures.org/ Watch the latest statement from Jean-Michel Cousteau on the release of the two orcas and six belugas www.youtube.com/ watch?v=AcsZD6rBnlo The face of the sea is always changing, Crossed by colours, lights & moving shadows, sparkling in the sun, mysterious in the twilight, its aspects & its moods vary hour by hour.

Rachel L. Carson The Sea Around Us DISCOVER: FALSE KILLER WHALES False killer WHALES Dr Carol Palmer uncovers some of the mysteries of the False Killer Whales along the top end of Australia Image: Peter Zeroni Image: Peter

The false (FKW), crassidens, is conservation planning and management. Potentially this species is a more regular a tropical and warm temperate oceanic species that user of coastal waters or a resident in is broadly distributed, but naturally rare throughout its Northern Territory coastal waters. If this is range. The FKW is one of the larger members of the the case, it is likely that false killer whales will have different conservation manage- dolphin family, Delphinidae, and despite its world-wide ment requirements to that of coastal dol- distribution throughout the tropics and subtropics, it is phins, that have smaller ranging patterns.

one of the least known of the large tropical dolphins. Most of what is known about FKWs comes from studies around the Hawaiian Archi- he species is classified as Near pelago and was the basis for two pilot Threatened globally and in the projects in the Northern Territory. Three Tmost recent review of its conser- populations have been described within vation status in Australian waters the Hawaiian waters based on photo-identi- species was also considered to be Data fication, satellite telemetry, and genetic Deficient. The lack of enough information data. The two Hawaiian coastal popula- on population size and trends, area of tions are estimated at 151 and 552 individ- occupancy, movement patterns and other uals respectively. The offshore population relevant conservation parameters is likely abundance within the 200 nautical mile to substantially hinder its consideration in Exclusive Economic Zone (EEZ) around

Issue 6 I 17 DISCOVER: FALSE KILLER WHALES Image: Peter Zeroni Image: Peter

Hawai’i is estimated at 1,552. All three second tagging project occurred in 2018 populations are managed as separate around the Groote Archipelago, Northern The Northern Territory population stocks under the US Marine Territory and two individuals were tagged. could be in an ideal position Mammal Protection Act. Due to evidence The total distance covered over 23 days that one of the coastal populations has un- was 1,614 km by one individual and the to contribute to the dergone a dramatic decline over the past second individual 2,424 km over 67 days. understanding of FKW two decades, the population was listed Interestingly, the distances travelled in coastal habitat requirements as endangered under the US Endangered 2014 compared to 2018, highlight that Species Act (Federal Register 2012). there are more than likely distinct coastal and stock structure / island populations of FKWs in Northern The first ever satellite tagging of four Territory waters. false killer whales in Australia (indeed the Southern Hemisphere!) took place in Past analyses of FKW biopsy samples 2014 and the satellite tracking movement (haplotypes) from samples across the patterns occurred within the Arafura and globe and including the Northern Timor Seas. When initially tagged, the four Territory, suggest that there may be a individuals occurred in a single group; comparable difference between coastal they then showed generally similar move- and offshore populations. Three FKW bi- ment patterns and regularly re-associated. opsy samples from the Northern Territory Total distance travelled by tagged individ- were included in a global FKW analysis. uals ranged from 5,161 km (over a 54-day Compared with all the global samples, period) to 7,577 km (over 104 days). The the NT haplotype was only shared with

18 I Issue 6 DISCOVER: FALSE KILLER WHALES

The population was listed as endangered under the Dr Carol Palmer began the first research and monitoring of coastal US Act (Federal Register 2012) dolphins in the Northern Territory (NT), Australia in 2007. The research and moni- toring has included a PhD on four dolphin species (including the FKW), on-ground one other sample, a Hawaiian Islands To improve the management engagement with Indigenous sea ranger resident (coastal) FKW. of FKW populations, further groups across the NT coast; working with evidence is required relating to: government agencies; managing the first The FKWs in Australian waters are helicopter surveys across the entire NT truly Olympic swimmers!! However, . populations coast for coastal dolphins (2014 /15) and the unresolved factors influencing the in the shallow waters of the organised the first Indigenous sea ranger movement and habitat-use patterns Northern Territory (i.e., are they marine megafauna conference in the NT observed in the two tagging studies, small demographically isolated involving 13 sea ranger groups (2017). highlight the fact that further satellite (insular) populations from other tracking and genetic analysis of FKW inshore or offshore populations? Carol worked in partnership with NT populations in Northern Territory and Parks and Wildlife and Anindilyakwa Australian waters are warranted. In ad- . The ecological drivers of the Land and Sea Rangers in deploying dition, the Northern Territory could be movement patterns. the satellite tags on false killer whales in an ideal position to contribute to the in Australia for the first time, which understanding of FKW coastal habitat . The extent of overlap between has helped identify ranging patterns, requirements and stock structure and areas used by this species and commercial fisheries overlap and the thus contribute to defining appropriate the incidence and severity of need to review conservation assess- geographical scales for management of some current and future potential ment and on-going research. populations in NT and Australian waters. threats. Image: Peter Zeroni Image: Peter CRITICAL BY NATURE: RIVER DOLPHINS Artwork: E Hawkins

South America’s Dammed River Dolphins

Jess Tsitonakis Construction is underway for as many as reports on the status of 400 hydroelectric dams in the Amazon South America’s River Basin, with some already operational. Blueprints place dozens of reservoirs River Dolphins who face throughout the range of two dolphin uncertain times ahead. species; the dolphin or ‘boto’ ( geoffrensis) and the ( fluviatilis), both endemic to the area and already facing a multitude of anthropogenic threats.

20 I Issue 6 CRITICAL BY NATURE: RIVER DOLPHINS Artwork: E Hawkins

he construction of such dams is an ex- Both the boto and tucuxi face countless Ttensive and environmentally disruptive process that has already proven to impact adversities from human activity, including ecosystems throughout the world, and in entrapment in fishing nets, pollution and boat some cases, such as the Three Gorges Dam in China, they force the relocation collisions and now, even deliberate culling for of entire communities of people. The use as bait for highly prized in the size of reservoirs is primarily dependent upon the topography of surrounding land, commercial fishing industry. with flatter landscapes, like rainforests, requiring demolition of the largest areas. Construction of the Balbina Hydroelectric been shown to pose significant repercus- Plant, located in the Amazon Rainforest’s sions on local biodiversity, specifically the Uatumã River, flooded 2360 square survival of migratory species, by disrupting kilometres of forest, to only provide water flow and nutrient deposition. 250MW of power-generating capacity, equivalent to more than 2000 acres of A recent study conducted by Dr Claryana destroyed land for each MW of power Araújo, from the Federation University of produced. Goiás, Brazil investigated the effects of damming on local boto and tucuxi Aside from the physical risk to wildlife populations and uncovered that as many posed by turbine blades, researchers as 26 dams negatively impacted the argue that the indirect harm caused by dolphins’ populations and prey abun- these dams has the most profoundly dance. Despite being charismatic devastating impact on the survival of emblems of rainforest biodiversity, little native species and functionality of is definitively known about the species’ surrounding ecosystems. Water within basic ecology and survival rates. Both spe- reservoirs is typically stagnant, and cies were previously listed as ‘Data Defi- contains higher concentrations of cient’ by the IUCN, as minimal information sediment and nutrients, forming an existed regarding their population size ideal breeding ground for algae. This and trends over previous years. However, water is periodically released to prevent a 22-year study, led by Vera da Silva from downstream river segments from dry- the Instituto Nacional de Pesquisas da ing out. Apart from potentially exposing Amazonia, Brazil, complimented Araújo’s mainstream waterways to pest species, findings and confirmed that there was a water, which is normally released from linear decline in local populations of both the reservoir’s base, is deoxygenated and species. This contributed to a reform of significantly colder than normal. This can the IUCN status for Inia geoffrensis and prove detrimental to local fish and in 2018, were formally declared an invertebrate species that are hypersen- endangered species. Although the work sitive to such environmental change. from both studies has inarguably changed Tropical dams are amongst the most perceptions of the stability of these environmentally destructive and have species in the face of human growth,

Issue 6 I 21 CRITICAL BY NATURE: RIVER DOLPHINS

insufficient research exists specifically America. No estimates exist for its current entrapment in fishing nets, pollution and investigating the long-term effects population size. However, it is considered boat collisions and now, even deliberate escalated damming would impose upon one of South America’s most endangered culling for use as bait for highly prized their populations. This inherent lack of aquatic mammals and although they do catfish in the commercial fishing industry. baseline data renders scientists unable to not inhabit the Araguaia/Tocantins, three Thus, the widespread and long-term forecast the effects large-scale dams already exist within their range, impacts from hundreds of dams may disturbance and geographical segre- another three are under construction and be too much for the already vulnerable gation from the dams would impose on two more are planned. These specific species to withstand. Fragmentation and the dolphins, who already exist within a dams were identified by Dr Araújo to have habitat degradation from damming and heavily restricted range in small group a negative influence on local prey increased human interference contribut- formations. abundance. ed to declines of both the (Lipotes vexillifer) and the (Platanista Botos typically form pods of two to four Dr Enzo Aliaga-Rossel, an IUCN SSC ceta- gangetica) in Asia, with the individuals. During the rainy season, cean specialist for South American rivers, former being declared functionally extinct individuals migrate over 2500 kilometres highlighted that dams impede annual in 2006. As the status of the two South upstream into inhospitable territory as the spawning migrations for numerous fish American species have not yet become forest floods. This seasonal extension of species. He believes the addition of more quite as critical, researchers believe their range drastically increases the dams will only exacerbate already evident immediate investment and monitoring species’ foraging and mating potential, changes to their reproductive behaviour of the effectiveness of dam mitigation fostering the progression of their genetic and distribution, prompting even faster measures may be enough to prevent the fitness and population. The species is rates of decline in prey availability for species from suffering a similar fate. currently comprised of eight subgroups aquatic megafauna, which will likely affect throughout upper South America, geo- the predation success, diet composition graphically segregated by 13 existent and displacement of local dolphins as dams. The majority of these occur within they attempt to source dwindling food Jess Tsitonakis is a marine the Araguaia/Tocantins watershed, which supplies to maintain their survival and biology graduate, with an avid has been shown by Dr Araújo’s research that of their young. passion for animal welfare and to have the highest overall impact on both conservation and currently works dolphin and prey abundance. Both da Silva’s and Dr Araújo’s investiga- for the RSPCA and as a research tions revealed that the populations of both assistant for Dolphin Research Planned construction for 10 more dams dolphin species are halving every decade Australia. She is a passionate could further split the existing population and, as mothers only give birth to a single free diver and advocate for into twelve subgroups. Scientists fear calf every four to five years, scientists are environmental sustainability. that fragmentation of already isolated imploring governing officials to fund more populations could initiate a rapid decline extensive long-term research into the in species abundance, as limited interac- species’ behavioural and ecological References: tions between groups will eliminate gene responses to existent dams, in order to Araújo, C. C. and Wang, J. Y, 2015. The flow and prohibit future generations from better advise current conservation dammed river dolphins of Brazil: impacts adapting to an inevitably changing and measures before more structures are and conservation. Oryx, 49, 17–24 da Silva V. M.F. & Martin, A.R. 2018. Amazon degenerated environment. added and potentially plummet their River Dolphin: Inia geoffrensis, Encyclopedia of populations to an unrecoverable state Marine Mammals (Third Edition), pages 21-24 The tucuxi is confined to an even smaller (Araujo et al. 2015). Smith, Julian, 28 August 2015, “400+ dams distribution than the boto, living could irrevocably harm Amazon ecology — exclusively between coastal and inland Both the boto and tucuxi face countless but solutions exist”, Mongabay Series: Special Reporting Initiative waters of northern and central South adversities from human activity, including

22 I Issue 6 Issue 6 I 23 FOCUS ON: RIVER DOLPHINS Image: https://www.flickr.com

Fact File

Scientific name: Inia geoffrensis

Alternative names: Pink River Dolphin, , Bolivian River Dolphin

Recognised : Inia geoffrensis geoffrensis, and I. g. humboldtiana

IUCN Status: Endangered with decreasing trend Largest of the five known species of river dolphin

Length: Adult: Males 1.5m-2.8m; Females 1.6m-2.4m; Newborns: 0.8m

Weight: adults 204kgs, newborn calves 10kgs,

Teeth: 24-34

Distinguishing features:

• Neonates are born light grey, and this begins to transform as the animal matures to eventually form a partially or fully pink colouration. The species is the most sexually dimorphic of all river dolphins. Aside from being typically smaller than their female counterparts, males typi- cally appear significantly ‘pinker’ than their female counterparts. It is believed pigmentation loss to form their famous pink hue is a result of scarring from fights with conspecifics (members of the same species). However, researchers have also BOTO stated that the pink flush is intensified when the dolphins become excited or exert more energy as the capillaries lay close to the skin’s surface and dilation from higher cardiac activity exacerbates dolphin 24 I Issue 6 FACT FILE: RIVER DOLPHINS

their rosy colour. As is common of most source their prey and navigate through • The species engages in polyamorous dolphin species, Botos are darker on their the submerged forest. mating. Males will often carry lumps of Fact File dorsal surface, whilst their ventral side clay, sticks and even turtles as socio- (underside), as well as their pectoral fins, Gestation period: 9 months sexual displays to gain the attention of is lighter grey or pink. This helps them Sexual maturity: 2-3 years females. evade predators by providing camouflage Lifespan: 12-15 years against the variations of light between the Current threats and population status water’s surface and riverbed below. Distribution: • Despite these ancient beliefs, the • Botos are strongly distinguished by their They are endemic to South America and dolphin is being increasingly harassed by bulbous heads (melons) and elongated resident populations are found exclusively local fisherman, who consider the dolphin rostrums, both of which are unique adap- within the Amazon, and Madeira an unwanted competitor for fish. However, tations which assist them in successfully River systems. During the rainy season, all human-induced deaths are typically living and hunting in such murky water. between October to March, the river unintentional, resulting from either boating Whilst their enlarged heads assist with floods and this enables the dolphins to accidents or by-catch in fishermen’s nets. emitting sonar for hunting prey, their long navigate through the previously inhospi- beaks enable them to successfully capture table grasslands and forests, extending • In addition to the degradation caused concealed or evasive prey in tight crevices their range to several thousand square ki- by land-clearing, the petroleum industry or amongst tangled tree roots. Botos have lometres across the six countries they are has also contributed to further pollution molar shaped teeth, rather than conical, known to inhabit; Bolivia, Brazil, Columbia, within the waterways the Boto inhabits, as meaning they must crush food with a Ecuador, Peru and . When water armed forces have blown up oil pipelines, grinding motion before swallowing. levels lower, they return to the rivers and resulting in irreversible levels of water riverbanks. pollution. Their habitat is also threatened • Botos also have a dorsal ‘ridge’ instead by damming. Hydroelectric and irrigation of pronounced dorsal fin to assist with Diet: schemes separate rivers in bodies of wa- stabilisation when moving through the ter. This fragmentation restricts species’ flooded forest. Unlike other marine dol- An array of prey items, including fish, range and ability to feed and breed and as phins, this species has unfused neck ver- crustacean and even turtle species. the Boto already exists in small sub-pop- tebrae, a specialised feature that enables ulations, this could pose a detrimental them to bend their bodies at a 180 degree Social structure: threat to its survival. angle, allowing them to easily navigate and move through the entanglements of • The Boto is quite an elusive and solitary Text by: Jes Tsitonakis submerged trees and narrow passage- species, normally travelling in pods of no ways. Additionally, the pectoral (side) more than 2-4 individuals, with moth- References: fins of Botos can paddle in independent er-calf assemblages common. Although, da Silva V. M.F. & Martin, A.R. 2018. Amazon River Dolphin: Inia geoffrensis, Encyclopedia of directions to one another, further assist- occasionally 20-40 individuals have been Marine Mammals (Third Edition), pages 21-24 ing them with motility in their somewhat observed feeding cooperatively within a hazardous landscape. small range. F. da Silva VM, Freitas CEC, Dias RL, Martin AR (2018) Both cetaceans in the Brazilian Amazon • Botos have evolved extremely small • During mating season between late show sustained, profound population declines eyes in comparison to their marine October and November, females have over two decades. PLoS ONE 13(5): e0191304. relatives. However, their eyesight is been observed retreating deep into the Hrbek T, da Silva VM, Dutra N, Gravena W, Martin relatively good but is of little use due to forest, possibly to avoid contending males, AR, Farias IP. A new species of river dolphin from the river’s generally poor visibility. Instead, who often display aggression when Brazil or: how little do we know our biodiversity. they rely heavily on echolocation to competing for females. PLoS One. 2014;9(1):e83623. Published 2014 Jan 22.

Issue 6 I 25 In Conversation

26 I Issue 6 In Conversation

In Conversation with Tracie Sugo from Kohola Kai Creative

Where do you live & what is it friend or a friend of a friend that I run into! I use a variety of mediums, including Q about the place you live that you My dream is to put my full time and effort A inks, acrylic paint, watercolors and enjoy? into Kohola Kai Creative, creating artwork sculpting media. My stippling and line I am based in Southern California. inspired by the ocean. For now, in addition work with ink is what I share the most A I’m very thankful to have the ocean to being a marine mammal naturalist, I online. Although it’s time consuming to nearby, along with all the marine species am also an assistant teacher at a local art stipple, it can also be therapeutic in a that roam it! studio. way. It’s easy to get lost in all the dots, and escape from “adulting” for a few hours. What is your profession & did you Did you think you would be doing Q do any study to do this job? Q this job when you were a child? What inspires you the most for My career is a mix of my passions. Growing up, I have always been Q your artistic creations? A For about 3 years up until last year, A drawn to creative outlets, as well as Inspiration comes in many forms. I worked for a local dolphin and whale to the ocean. For a time, wanted to pursue A Sometimes I am inspired by a real-life eco-tour company, and to this day I remain marine biology but was afraid that I would encounters with marine wildlife, sometimes I active in the local com- not be able to find a paying job in the field. am inspired by watching a nature docu- munity. Rather than going to school for I ended up getting a degree in accounting mentary or seeing photographs in books. this career path, I was led to it by passion. and working for a while in the field, but I also spend a lot of my own time and energy I connected with my local chapter of the quickly discovered that I could not stand focused on ocean conservation issues, such American Cetacean Society, took the being confined in an office setting! I don’t as the plight of the Southern Resident marine mammal naturalist course they think I expected to be on this career path, Killer Whales, dolphin captures for the offered and grew from there! Meeting but I am extremely grateful to be where I captivity trade, shark finning, and marine like-minded “whale nerds” helped me am now and to be enjoying the work I do. pollution. One of the goals I have with my learn a lot about cetaceans, and a lot work is to create imagery that provokes about industries connected to whales and What media/medium do you use? thought on these issues- it doesn’t feel right dolphins. No matter where I travel to whale Q Is there an aspect to this medium to call them “inspiration” but I am definitely watch now, it seems that there is always a that you particularly enjoy? motivated by them to use my skills to help.

Issue 6 I 27 In Conversation

What is it about the subjects that I also enjoy snorkeling, kayaking, and most Q you paint that draws you to them anything that involves being in the ocean! and inspires you? If the weather is foul, a good hike or walk The movement or flow of a piece is near the beach is another good way to go. A an aspect that engages me the most. I like to understand how my subject looks What is your most memorable from a variety of angles, not just a static Q interaction with wildlife? or photogenic pose. That and having a That is a tough question- I’ve been genuine interest in the subject matter A lucky enough to have a lot of amazing itself. Being so drawn to the ocean, my encounters! I would probably have to go urge to draw or paint most often manifests with an orca encounter I had earlier this as marine wildlife. year in Monterey Bay. It was on an all-day whale watching trip, and we were with a As marine lovers, what is it about family group of Bigg’s killer whales. We Q dolphins, whales and the ocean stuck with them, or they stuck with us, for that intrigues you? the majority of the day. At one point, they Having a lifelong interest in the took off chasing a sea lion and two adult A ocean, I’ve been particularly fasci- males started porpoising in our wake! nated with megafauna- whales, dolphins, They then appeared to be teaching the sharks, rays, turtles and the like. There calf in the group how to hunt- repeatedly is so much about them that captivates chasing a few sea lions and breaching me, like their shape, their movement, the while knocking them out of the water. complexity of their underwater world and Getting a glimpse into their lives, and them how they can seemingly appear from or continuing to be so close to the boat was disappear into the blue as they please. just so fascinating. The collective energy and excitement of everyone on the boat added to the experience as well.

I am inspired by watching a nature If you could talk to your 7-year old documentary or seeing photographs in books. Q self, what advice would you give? I would tell myself to more seriously I also spend a lot of my own time and energy A pursue marine biology and art once I focused on ocean conservation issues got to college!

What do you hope for the future Q (this could be in reference to your How did you become interested own goals or more in the context of Q in the welfare and conservation of your vision for the environment)? wildlife and the environment? My hope for the future is that people I think that having an interest in the A will be more compassionate, mean- A animals and ocean themselves, it ing to care more about the environment was a natural progression to become inter- and its other inhabitants (people and ested in their conservation. Having such a wildlife alike), and less about themselves. great love for them, I am driven to do what I hope that people would make better I can to protect them. I believe that every- choices to create less waste, be more ef- one should not only ask themselves what ficient, and to change their daily habits to they love, but also what are they willing to be more environmentally-friendly. There is do for what they love? a long list specific things I hope for within that, but most of all I hope that people will What is your favourite way to start to care more about our planet. Q connect with nature? Having worked in the whale watch- A ing industry, I love being on boats, Tracie Sugo searching for cetaceans and spending Kohola Kai Creative time with them on their terms. I don’t think https://www.koholakaicreative.com/ I would every get bored out on the ocean!

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www.dolphinresearchaustralia.org [email protected] BETWEEN LAND & SEA

Absorbing the subtle complexities of the sponge

Mia Gustavsson explores the intricacies of the not so simple sea sponge

Dolphins on numerous occasions have been observed to use sponges to help protect the sensitive rostrum while they forage amongst the sediment. This skill is learned – passed down from mother to offspring. Testament to the depth of their social bonds and their intelligence; dolphins’ usage of sponges.

ou may hear the word sponge and think of the slightly soggy bright Yyellow thing sitting in your sink or bathtub. While most commercial sponges are now synthetically made, people first used real sponges from the ocean. But what are they? Are they an animal? A plant? Many people are surprised to find out that sponges are animals – and among the oldest surviving animals at that. Evolving approximately 750 million years ago, sponges are found in both shallow and deep seas, and in some freshwater environments. Sponges come in a variety of colours, shapes and sizes – the largest ever found being the size of a minivan!

30 I Issue 6 BETWEEN LAND & SEA

The sponge life cycle starts with an adult microorganisms from the mother sponge, sponge releasing sperm into the water but can also acquire them from their envi- which enters a “female” sponge, fertilising ronment. Many sponges (and often their an embryo which is brooded inside its symbionts) also produce toxic compounds chambers. Finally, a tiny larva smaller than to protect themselves from predation and half a grain of rice is released from these parasites and to compete for space in a chambers and swims out into the ocean busy reefscape. In recent years, these in search of a place to settle and meta- toxins have become the focus of research morphose into its adult form. Many marine into new drugs for cancer treatment. invertebrates have this kind of biphasic life cycle, with a free-swimming larval phase, As well as being an important part of the and a bottom-dwelling adult phase. This ecosystem on the reef, sponges can shed means the larval stage is incredibly im- light on the origins of animal life. They are portant in allowing a species to disperse, the organism most closely related to the and survival of larvae is critical for the last common ancestor of all animals, and animals to reach the age of reproduction. have changed relatively little since they Therefore, larvae have acquired a sensitiv- first evolved. Scientific consensus has ity to chemical and physical signals which been that multicellular animals evolved indicate to them that their environment is from a single-celled ancestor which looks a suitable (or unsuitable) place to settle almost identical to the sponge choanocyte down and grow into an adult. This sen- cells. However, a study published in Na- sitivity is usually unique to each species, ture just this year reveals that the sponge for example the sponge Amphimedon cell with the most similar genetic profile to queenslandica requires both a chemical this ancestor is actually the archaeocyte cue from a coralline algae (the larvae’s – like the stem cell of the sponge. This rev- favourite place to settle) and a shift from elation contradicts one of the most basic light to darkness in their physical environ- assumptions as to how animals evolved, ment to trigger metamorphosis. and may provide insight into our own stem cells and how they function. Who knew we As adults, sponges have a very simple could squeeze this much insight from the body plan, with no nerves, muscles or humble sponge? even any distinct tissues at all. Instead they have a porous epithelial layer which Reference: Sogabe, S., W. L. Hatleberg, K. M. connects to an internal network of cham- Kocot, T. E. Say, D. Stoupin, K. E. Roper, S. L. bers. Cells called choanocytes lining these Fernandez-Valverde, S. M. Degnan, and B. M. chambers beat their flagella (a thread-like Degnan. 2019. Pluripotency and the origin of projection) in unison to draw water in from animal multicellularity. Nature 570, 519-522. the surrounding environment. From this water, sponges filter out everything they need to survive, and deposit back into it Mia Gustavsson has a degree in any waste products before the water is with honours from the whisked away through their excurrent University of Queensland where channels. In this way, sponges are thought she specialised in sponge ecology. to play an important role in nutrient cycling She is a former Research Assistant on the reef – they are the filters of the sea. at Dolphin Research Australia and Sponges harbour a number of symbiotic is passionate about the biology and microorganisms which help them to fix ecology of the marine world, as well carbon, nitrogen and phosphorous and as how we as humans impact these make it available to other organisms. delicate ecosystems. Sponges appear to pass down their

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32 I Issue 6