Fish Lab & Aquaria – Marine Life in the Maldives

In July, we marked the fourth anniversary of our ‘Immersion Tour’ of the redesigned and expanded Marine Discovery Centre. This month, we welcomed 124 curious visitors (from 17 different countries including the USA, Russia, and Dubai) bringing our total to more than 3,000 guided tours of our facilities (just in the last 4 years).

Large Aquarium

Following the seasonally elevated ocean temperatures, there are now plenty of natural coral recruits and healthy levels of coral growth around our large aquarium, so it will be interesting to see how the ecosystem matures.

Specimen Tanks

Our ‘overgrown’ marine plant displays are receiving a good level of interest from Fish Lab visitors. There is a selection of invertebrate specimens thriving amongst the algae, highlighting the importance of species diversity on the reef.

Plankton Production

We have incorporated the 100L grow-out tanks (Artemia, Algae) into the public-facing display in our Fish Lab, to gauge visitor interest.

• Rotifers – numbers have boomed, so we have reduced the food to 6ml/day.
• Artemia – production is still operating at 4g/day, which is providing ample feed.
• Algae – remained constant. Changes required every four days.

Linckia multifora sea stars

• SS3 – remains in good health, despite lack of growth in recent months.
• SS4 – no growth this month, but now healed after suffering from lacerations (following a crab attack).

Small Aquarium One

• Mushroom coral – continues to regain colour and exhibit good health (see photo).
• Mini coral frame – healthy and continuing to grow.

Small Aquarium Two

• Clark´s anemonefish (Amphiprion clarkii) breeding pair – laid eggs in their usual spot.
• Mini coral frame – continues to have steady and evident growth (see photo, showing coral encrusting onto frame).
• Goniopora coral – became colonised by encrusting polychaetes, so was removed. 

With the help of our Four Seasons Apprentices, we have started to induce strobilation on another tile from the polyp tank. We aim to have 500 juvenile jellyfish in circulation in the Fish Lab, to allow us to keep the main cylinder regularly stocked, and to free up space in the polyp tank for new production.

We have drained, cleaned and refilled our main display jellyfish cylinder to improve water quality. The larger remaining jellyfish specimens have grown to a good size and are looking healthy.

from: Jellyfishes – Diversity, Biology

Zooplankton Study

We have now received all of our zooplankton collection equipment, and have made some successful trials with our homemade net.

• We have determined that a one-minute tow with the 150µm mesh net will provide a good quantity of zooplankton for analysis.
• Thorough cleaning of the flow metre is a time-consuming task, so we are exploring methods for disassembly and reassembly (see photos). The flow metre allows us to determine speed, distance and volume, facilitating data entry without extra equipment.
• We will need a ‘spin checker’ to perform periodic calibration of the flow metre.
• We are experimenting with various apps to determine GPS coordinates for plot points on ‘Google Earth Pro’.
• The splitter and dehydration process are successful, but we need to fine-tune the measurements.
• Identifying the large number of zooplankton specimens will be time-consuming, although we do have both a stereo microscope (preferred) and a compound microscope.
• Hannah, a zooplankton expert, has recently arrived at Landaa, and will soon be commencing her study. We aim to collaborate as much as possible over the coming months to solidify a methodology that is replicable and can continue long into the future.

Many thanks to our overseas mentors at MBA [UK] (Dave Conway) and CSIRO [AUS] (Dr Anthony Richardson and Frank Coman).