Erin's Monthly Marine Musings
What an incredible year 2022 has been! We thank our supporters for their passion and perseverance as we transformed both ourselves and our Marine Discovery Centres! As 2023 gets underway, we maintain our team-first mantra to focus on why we do what we do, to keep the excitement alive! We will continue to connect deeply with not just the sea creatures, but other people too, to find the little joys… tiny ocean miracles and Maldivian magic!
- Dive deep into the ocean…and you will see that the greatest treasures you find are the illusions you leave behind. — Christopher Pike
Fish Lab & Aquaria – Marine Life in the Maldives
🗓️ 2022 Fish Lab Summary
In the Fish Lab during 2022, the average survival rate to ‘Juvenile’ stages across our breeding species is similar to (or slightly higher than) that seen in the wild. For shrimp breeding, our survival rates up to the pre-juvenile stage are excellent, but this is followed by high losses at developmental stages 6/7 (often due to late-stage predation).
Fish Lab Research – Two research papers on shrimp breeding and juvenile development are currently in the works. They will be written up as the data is collected – over the next three months (for Lysmata amboinensis) and six months (for Thor amboinensis).
- Algae supply dropped in December, so we are attempting to restart the culture using two 20L buckets.
- Artemia production is keeping up with the demand of the main tank at 6g of cysts a day.
- Rotifer volumes remain consistent and stable, despite a slight dip in the middle of the month.
Zooplankton Survey Study
Our Zooplankton Survey is on hold until after the tourist high season.
Jellyfish – Aurelia aurita
There has been no change to the jellyfish in December. All specimens in both the cylinder and lab are doing well, with no shrinkage or loss.
Zebra (or Leopard)?
During the month of December, a very special visitor made a new home at one of our dive sites. The Zebra shark has been seen twice, and is easily recognisable by the characteristic notches on its tail. Due to its spotty adult appearance, it is often mistakenly referred to as a Leopard shark, whereas the name actually comes from its juvenile Zebra-like pattern.
🗓️ 2022 Guest Excursions & Awareness (Landaa)
- During 2022, we welcomed 461 visitors to our Marine Discovery Immersion Tour, representing 31 different nationalities. The 142 tours totalled 3525 minutes (almost 60 hours).
- Throughout the year, a total of 1618 guests participated in 356 excursions, with the Dolphin Cruise and Afternoon Guided Snorkel being most popular.
- During our 254 in-water trips, we recorded 450 megafauna sightings, most commonly Hawksbill sea turtles, followed by various species of sharks and rays.
- From photographs taken during our Dolphin Spotting excursions, we were able to uniquely identify 72 new Spinners (from notched patterns on their fins) and confirmed resightings of 77 Spinner individuals. For Bottlenose dolphins, we identified seven new individuals and confirmed two resightings. The total number of cetaceans sighted was approximately 4600 individuals.
Outreach – Girl Guides (BAEC)
In December, we welcomed Girl Guide leaders (BAEC) from the local community of Eydhafushi (Baa Atoll Education Centre). Following a tour of our Marine Discovery Centre, we had informative talks on conservation work in the Maldives, and both a coral frame building and hologram session.
Ornamental Fish Breeding
Our focus is to produce replicable and consistent data for our research paper on Thor amboinensis, and to continue tracking and describing the reproductive cycle of Lysmata amboinensis.
- Clark’s clownfish (Amphiprion clarkii) – There were two spawning events in December; however, the eggs were again eaten by the parents prior to hatching. This is a known challenge within aquaculture circles; we have attempted to vary parental diet to prevent this, but with little current success.
- Maldivian clownfish (Amphiprion nigripes) – New pairs were collected, and all pairs are now bonding. The pair we rehomed in the main tank produced two clutches this month, so we are working on methods to collect the larvae.
- Sexy shrimp (Thor amboinensis) – We collected two clutches this month, with good survival rates. Further settlement of the late-stage larvae on the new protocol resulted in seven new juveniles (now introduced into the display tanks). We have also started our formal scientific research, for future publication.
- Boxer shrimp (Stenopus hispidus) – Two clutches produced this month, and we continued our observations and study of the reproductive cycle and ovarian development.
- Camel shrimp (Rhynchocinetes durbanensis) – There have been three clutches produced this month, one of which was successfully collected. These larvae are developing well, with a total of 15 individuals remaining after 17 days (now at developmental stages #3 – 4).
Our four late-stage larvae have been transferred to a bucket in anticipation of settlement (morphological signs indicated a readiness for metamorphosis).
- Skunk cleaner shrimp (Lysmata amboinensis) – We collected both spawning events this month, resulting in a total of 844 larvae from the two individuals. All larvae are growing well in the Fish Lab for rearing and continued observation.
Research for our scientific paper is progressing well, with our first fully assessed reproductive cycle for both individuals. We aim to continue tracking this cycle for the next three months, which should demonstrate a total of five to six cycles, creating a timeline of hermaphroditic transitions, larval comparisons between individuals, and biometric measurements to compare formation of the ovotestes.
Maldives Sea Turtle Rescue & Rehabilitation
At the close of December, we were caring for two Olive Ridleys (Lepidochelys olivacea), one Hawksbill (Eretmochelys imbricata), and zero Green sea turtles (Chelonia mydas) in our Rehabilitation Centre at Landaa.
At Kuda Huraa, we continue to care for Emma, found in October floating on the ocean surface with a missing flipper. She has started to use her front left flipper again, and is attempting to dive below the water surface as she chases her food (pieces of prawns and squid)… great progress!
Our long-term Olive Ridley patient Ari is always high in energy, winning over everyone’s hearts and being an important ambassador by highlighting the threats that sea turtles face due to ghost nets (discarded fishing gear).
Scientific Research Papers
Drawing on twelve-years of data, our study of sea turtle injuries was submitted for publication this month! Entitled ‘Evaluation of sea turtle morbidity and mortality within the Central Indian Ocean’, it’s an exciting milestone that will add significantly to the published literature on turtles in the Maldives.
During 2023, we are planning to submit further research for publication:
(1) our collated satellite tag data of sea turtles (rehabilitated and subsequently released);
(2) our ongoing sea turtle behavioural study that we believe to be the first of its kind in the world (we plan to use adaptive AI analysis).
🗓️ 2022 Sea Turtle Conservation
Over the last year, we have made significant progress in all major aspects of our turtle conservation program.
– At our Turtle Rehabilitation Centres, our resident veterinarian, Katrina, has successfully performed several complex surgeries, using medications made available through our newly acquired controlled-drugs licence.
– We have identified several key pieces of equipment to improve the standards of care for our patients, and we are on our way to achieving funding goals.
– We have been very fortunate to be included in consultations with the Maldivian Government’s Environmental Protection Agency (EPA), discussing exciting new legislation to protect the welfare of marine species.
On the outreach front, we have participated in several conservation and turtle festivals, presented our work at a national seminar celebrating World Sea Turtle Day, been involved with local school visits and educational programs, as well as working to launch our very own new outreach program. We have established a new ‘24h emergency hotline’ to make it easier to report injured turtles, produced educational posters and videos, and we are now planning in-person workshops on local islands during 2023.
Are Hawksbill Sea Turtle Populations in Decline in the Maldives?
A hot talking point among ourselves and our colleagues recently is the worrying but noticeable decrease in turtle sightings over the past five years. After compiling the data, we can see a noticeable decline in the sightings trendline since 2019. Further analyses and investigation into a variety of factors is required, however, initial findings do raise concerns.
But it’s not all bad news! Hawksbill turtle ‘CoolDude’ (EI0210) – who was first sighted in July 2013 – was recently resighted and photographed again! Cooldude is clearly thriving in the wild, despite missing a front flipper, providing inspiration for all the rehab patients we get through our doors.
On 26 December, our Kuda Huraa Dive Team colleagues reported the very rare sighting of a free-swimming Olive Ridley sea turtle. This is the first sighting since 2019, as these sea turtles are not usually native to the Maldives, despite being the most common species of injured turtle found in Maldivian waters (they become entangled in ghost nets and drift vast distances on ocean currents). Sadly, no photos of this turtle were taken, so we were unable to search our ID database.
Our Olive Ridley sea turtle patient ARI
expertly illustrated by Taz, our junior marine biologist
2022 Maldivian Sea Turtle Sightings
2018 – 2022 Maldivian Sea Turtle Sightings
Maldivian Sea Turtle Identification Program
During December, from the 35 new photo sets submitted by the public this month, we were able to add 10 new individuals to our national turtle database, and confirmed resightings of 23 named turtle already in our database.
Our current database now has uniquely identified totals of:
1387 Hawksbills, 297 Greens and 97 Olive Ridleys (from 5400+ separate sightings, across 17 different atolls of the Maldives).
Submissions consist of close-up photographs of the turtle facial profile, enabling us to outline the unique pattern of scales (scutes) that act like a human fingerprint.
REEFSCAPERS Coral Propagation & Reef Restoration in the Maldives
At Landaa during December, we transplanted 32 new coral frames, kindly sponsored by guests (21), the Resort (8), and online (3), using a total of 1858 new coral fragments. In addition, we monitored (cleaned, repaired, photographed) 273 coral frames at various sites around Landaa Giraavaru. As part of the festivities, we recycled a Christmas tree frame and deployed it at the House Reef site along with three heart-shaped frames.
At Kuda Huraa, we transplanted 12 new guest coral frames, kindly sponsored by guests (5), the Resort (3), online (2), and media (2).
🗓️ Reefscapers 2022 Annual Coral Statistics
- At Landaa, 4,158 coral frames were monitored, and emails were sent out to all of our kind sponsors linking to their latest frame photographs. 374 new frames were created (using 22,146 fragments) plus 60 frames were recycled (2,310 fragments) giving a total of 24,456 coral fragments replanted back onto the reef.
- At Kuda Huraa, 1,205 coral frames were monitored, and emails were sent out to our sponsors linking to their latest frame photographs. 141 coral frames were created, and a further 577 frames were recycled. A total of 7,775 fragments were added to the reef, from 25 species representing five different genera.
Using our in-house AI technology, we analysed coral growth in all of our small-sized coral frames across both Kuda Huraa and Landaa. In 2022, Acropora increased from 3000 to 6000 litres, and Pocillopora increased from 10,000 to 15,000 litres.
Read our Reefscapers Diaries for further details and photographs of our ongoing coral propagation efforts and reef regeneration experiments, both in the Lab and out in the lagoon, updated each month.
Further News & Updates
You might also be interested in:
– our ongoing Dolphin ID Project,
– our specialised Sea Turtle Lagoon Enclosure, and
– our Zooplankton Monitoring Project (launched in 2021).
Looking for details of our Reefscapers coral propagation and reef restoration program ? Then head over to our Reefscapers Diaries for all the latest updates.
You can sponsor your own frame and see photographs (updated every 6 months) in our Coral Frame Collection.
Junior Marine Savers activities: (1) Reefscapers corals, (2) turtle care.