Marine Savers pod of pilot whales

Fish Lab & Aquaria – Marine Life in the Maldives

Plankton Production – Our plankton and algae cultures are used as the main food source for the residents of our Fish Lab.

– Algae – Our Fish Lab algal culture has been stable overall. 1000L have been produced this month, to feed our juvenile fish and shrimps, and to grow Artemia brine shrimp to adult size
– Rotifers – population increased to 433 individuals/mL on average
– Artemia – maintained to 6.5g of cysts a day for most of the month, to accommodate our growing populations of fish, shrimps, and moon jellyfish (Aurelia aurita). The adult Artemia population is currently stable, to feed our larger fish residents (clownfish, yellow boxfish, saddleback pufferfish).
– Copepods – 70 individuals were collected from the lagoon; we are maintaining them in a 20L bucket with an added air-stream, and Lab-grown algae as a food source. We hope to keep a continuous copepod culture to diversify the diets of our Fish Lab residents, especially the larvae that rely on early-life stage copepods (‘nauplii’) as an important food source. Copepods are more nutritious than rotifers, and can increase the survival rate of some species of larvae.

Jellyfish – Aurelia aurita

60 jellyfish from our February batch have been moved from the Kreisel tank to the large display cylinder. As some jellyfish started to decrease in size, we increased brine shrimp from 250mL to 350mL per meal to keep up with demand.

Jellyfish Kreisel cylinder Maldives

Photo1: Our dedicated jellyfish Kreisel cylinder at Landaa Giraavaru.

Photo2: Specialised food chain, behind the scenes in our Fish Lab

Fish Lab Food chain

Groupers

The food source for our grow-out groupers has changed from tuna (kitchen) to reef fish (fishermen). We tried finely-cut mackerel initially, but the lengthy prep time was impractical so we switched to fusiliers.

Seaweed Mariculture – edible sea lettuce (Ulva lactuca)

The two batches from last month have settled well under the following protocol: – aeration is via air stones; water is partially-changed daily; 1mL fertiliser (F2P) is added every day.
We now have another species of algae growing alongside (thought to be ‘gutweed’) after being accidentally introduced via the water intake.

Sea Urchins – New Project 2024

Sea urchins are herbivores found in many different marine habitats around the world, and often harvested for food (a delicacy in some cuisines). Some countries have experienced over-harvesting from the wild, causing excessive algal growth and a degraded ecosystem.
We have launched a new sea urchin echinoculture project to investigate breeding viability of the collector urchin (Tripneustes gratilla) due to its small spines making for easy handling.

Our sea urchin adult residents continue to thrive in our Fish Lab. We are feeding additional vegetables, and have added rocks and substrate from different tanks for food and for cleaning, as they are useful biological controllers against algae expansion.

We have received delivery of potassium chloride (KCl) to induce spawning in adult sea urchins, and we are revising our breeding protocols.

Fish Lab urchin breeding
Fish Lab urchin breeding

Ornamental Fish & Shrimp Breeding

Dancing shrimp (Thor amboinensis) – On March 14, 80-90 dancing shrimp larvae were collected from our November generation. They are growing in a tank with a continuous airflow, with rotifers and algae as added food source.

Boxer shrimp (Stenopus hispidus) – On 26 March, larvae were collected and divided into three batches
1. Fish Lab Aquarium (300 individuals)
2. Indoor 15L Kreisel tank with a heater set at 29°C
3. Outdoor 15L Kreisel tank with an air stone (ambient temperature).

Maldivian cardinalfish (Apogonidae family) – On 22 March, a clutch of 30 Cardinalfish larvae were collected and placed in a 15L Kreisel tank. They were fed with rotifers and algae, but sadly died after four days. We will continue to experiment with different Lab conditions and food sources (including copepods).

Maldivian clownfish (Amphiprion nigripes) – popular exhibits!

Clark’s anemonefish (Amphiprion clarkii) – The overall population is growing steadily. Our January batch of 118 individuals has been moved to a public-facing tank, making for an impressive display! We also added a few clownfish juveniles to our sea urchin tank, to help clean up the encrusting algae. [Lifecycle graphic]

Fish Lab Shrimp breeding cycle
Marine Savers jellyfish
Marine Savers jellyfish

Megafauna and Marine Life

At Landaa, we held 18 excursions for 200+ guest placements, with our Dolphin Cruise and Turtle Safari remaining popular. We were excited to observe various megafauna species including hawksbill turtles, blacktip reef sharks, and nurse sharks, plus the occasional grey reef shark (Carcharhinus amblyrhyncos), spotted eagle ray (Aetobatus narinari), and a large Napoleon wrasse (Cheilinus undulatus) measuring 150cm!

At Kuda Huraa, we conducted 29 excursions for over 200 guest placements. We are continuing our shark-awareness project, and throughout the month, 64 lucky guests visited nearby ‘Shark Point’ to spend time with nurse sharks, blacktip reef sharks, and pink whiprays (totalling over 200 megafauna individuals).

It is with great surprise that we can already consider manta season to have officially started at Kuda Huraa! The Lankan Dive Site is an important cleaning station for these giant Mobulids within Kaafu Atoll. Cleaning stations host an array of fish species that focus on removing parasites and dead skin from different parts of the manta ray’s body… like a marine spa session!

Marine Savers mantas from the air

Maldives Sea Turtle Rescue & Rehabilitation

Marine Savers Maldives turtle rehab
Marine Savers Maldives turtle care

Noonu’s Journey 5,871 km

After 115 days of deployment, Noonu’s satellite tag sent its final data transmission. She has travelled a total of 5,871 km, looping all the way back to us here in Baa Atoll ! We can see that Noonu was travelling in the same direction as the prevailing currents, first heading north-east towards India, and then back again towards the Maldives after the change in monsoon seasons.

See our interactive Satellite Map for further details.

Maldivian Sea Turtle Identification Program

During March, our ID project is currently on hold as we have been busy with our rescued turtle patients (eight new admissions, and two turtle release events).

Spotted a turtle?  Share your photos

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.

Turtle ID Maldives - unique facial scales

REEFSCAPERS Coral Propagation & Reef Restoration in the Maldives

Monthly Update Summary

At Kuda Huraa during March, we transplanted eight new coral frames, and monitored a further 302 mature frames at various sites around the island.

At Landaa this month, we transplanted 37 coral frames, kindly sponsored by guests (28), and the Resort (nine), adding more than 3,000 coral fragments to the reef. We monitored (cleaned, repaired, photographed) a total of 563 established coral frames at various sites around the island.

Work is continuing on the generous corporate sponsorship of 50 frames (+10 Resort-sponsored) at Voavah. We are using coral fragments harvested from a deep, healthy coral garden (~15m) and replanting the completed frames even deeper (20m). Many thanks to our Resort colleagues at Dive and Recreation for their invaluable assistance in completing 20 frames so far.

Preparing for the Coral Bleaching Season

The ‘summer’ hot season in the Maldives runs from January to May, with March and April being particularly hot and dry. The extra hours of seasonal sunshine, combined with the current elevated global sea surface temperatures (SSTs) cause increased stresses on coral reefs (April-June), which can lead to temporary paling of the coral colonies, or even permanent coral bleaching and death.
Global climatologists are forecasting 2024 to be exceptionally hot, due to a combination of the cyclical El Niño event and the ever-increasing effects of anthropogenic climate change. Over on our Reefscapers
Climate Change page, we are following developments very closely by curating the news reports from climate experts and marine scientists worldwide.

We have been tracking NOAA’s Coral Reef Watch bleaching guidelines, and over the next few weeks, the Maldives will reach “Alert Level 2”, indicating severe bleaching and significant mortality. So far, we have recorded moderate paling for some colonies along Landaa’s House Reef. We are continuing to track bleaching and will be monitoring the situation closely over the coming months.

Coral Bleaching Mitigation Measures

Over the last year at Landaa, we have been locating new frames at our cooler deep sites, to minimise the risk caused by any increases in ocean temperatures. Frames created during our Trainee Coral Biologist guest program were sited in the shallows (2m), so these have now been have been relocated to depths of 10m. We have also started relocating healthy mature frames to deeper locations, with good results so far (minimal relocation stress) so this work will continue.

At Kuda Huraa, many of our healthy mature frames are vulnerable to increasing water temperatures and light levels, so we have started to relocate them from shallow sites down to 10m (at the Reef Crest) using airlift methods (ropes and buoys)

Many thanks to all our Resort colleagues in the Recreation, Dive, and Carpentry teams for their invaluable assistance.

Reefscapers coral frame relocation airlift bags
Reefscapers coral frame relocation airlift bags
Junior Marine Savers activities

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.

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.

Junior Marine Savers children turtle care Maldives