Shark cave reefs

This week, our Malaysian community workers and our international volunteers have been making shark hiding reefs. This is the TRACC version of proactive marine conservation. Our philosophy is that if we see a problem, then we should work towards a solution.
From the plastic recycler, we aquired a number of large flat trays which were ideal for the roofs for caves for sharks. We attached crate reefs filled with plastic waste (cutup water bottles) which increases the surface area for sponge and cryptic organism settlement as well as providing a myriad of small spaces for post larval and juvenile fish crabs and other tasty small organisms to hide. The design gives a sheltered cave environment similar to the caves we have seen being used by bamboo and coral cat sharks. The upper surface of the cave and the crate supports will be planted with corals which will eventually completely camoflage the artificial reef structure.
During our surveys, it was noted that there was a lot of food for benthic sharks such as coral cat sharks, brown banded bamboo sharks epaulete sharks and nurse or leopard sharks. Unfortunately the sharks are rare if not completely absent from the reefs where we are working. When the proposed new Marine Protected Area, Tun Mustapha Park MPA is finally gazetted then we hope to witness an increase of fish life as the overfishing is brought under control. With sustainable fishing, we should eventually see an increase in small sharks numbers. We hope that a demonstration of the value of community action such as our SGP/GEF project near the Tip of Borneo (Simpang Mengayu) will lead to more projects around the region using the techniques we are developing to improve and rebuild the reefs close to each village.
The whole assembly of the shark cave reefs is fixed to the sea floor by glass bottle reefs attached to each corner. Because of the size the reefs were assembled on land and then taken underwater in pieces. The various parts were put back together and large cable ties were used fix all he components into place. The area of seabed chosen has considerable wave action so the reefs were staked to the seabed using steel rods. A total of 12 shark cave reefs were made and positioned in three different areas.
The finished shark cave reefs look suitable for lobsters as well as bottom living sharks, only time will tell which marine creatures take up residence.


Crate reefs for larval fish

Crate reef for larval fish recruitment.

Crate reefs were filled with cut pieces of plastic to make many small spaces.  The plastic was recycled from the trash on the beach.  The crate was bedded into cement to make it heavy and to hold everything together.

You may also want to read about our coral planting for world ocean day or Growth of the branching corals in the coral nursery.  or Step reefs or Bottle reefs or Shark cave reefs or igloo reefs

More blogs about TRACC marine conservation centre 
More info about learning to dive or volunteering to help save the ocean with TRACC in Malaysia - Turtle Snorkellers - Divers