Sea Cucumber Types and Basics

Sea Cucumber Basics

• Sea cucumbers are popular in China and Southeast Asian countries.
• They are also a source of income in Indo-Pacific countries like the Philippines, Indonesia, Fiji, Papua New Guinea, Tonga, and the Maldives.
• Other names include sea slugs, trepang, or beche-de-mer.
• Balatan or balat are local names for the sea cucumbers depending on what region of the Philippines they are in.
• They have a cylindrical, elongated body with different colors from pitch black to light yellow or white, or a blend of colors.
• Fully grown sea cucumbers can measure 20-70cm in size and 2-5kg in weight, with around 80% moisture content.
• Over 1000 species exist, but only about 20 are commonly exploited in Pacific Islands.

Valuable Species

• Teat fish (Holothuria nobilis)
• Sandfish (H. scabra)
• Black fish (Actinopyga miliaris)
• Lolly fish (H. atra)
• Deep-water red fish (A. echinites)
• Prickly red fish (Thelenota ananas)
• Thick body walls make them the most valuable.

Harvesting Regulations

• Collection must be regulated to avoid over-exploitation of immature animals.
• Sea cucumbers must be allowed to grow enough to reproduce before capture.
• Under-sized raw material leads to a finished product that does not meet size requirements and cannot be marketed.
• Administrative Circular (AC) No. 248 imposes a minimum size limit of 5 cm for traded sea cucumbers.
• It is illegal to harvest and trade three species of teatfish, Holothuria fuscogilva, H. whitmaei, and H. nobilis, except in dried form with a minimum size of 2 inches, or 5 centimeters in length.
• Only collect the large animals and leave the small species so that they can grow and be collected in following years.
• Only use bare hands to collect sea cucumbers and do not damage corals or seagrass.
• Collect only the number of sea cucumbers that are needed and leave some to reproduce them for future years.
• Leave rare species to preserve good biodiversity on the reef.
• Avoid fishing at night or use SCUBA if those practices are not allowed in the fishery.

Collection

• Collection can happen in several ways including by hand in shallow waters or by Skin divers in deeper water
• Fork-ended rods and skiff trawls are other methods that can be employed but fishing with a barbed weighted spear should be avoided

Eco-Friendly harvesting in Mindanao

• Gleaning gathers sea cucumbers at shallow tide.
• Skin diving combines free diving and snorkeling using simple breathing equipment and no special suit.
• Compressor diving utilizes equipment and a compressor for underwater breathing assistance.

Ecological Roles

• Sea cucumbers recycle food material left on reefs.
• Sea cucumbers aid algae and coral growth with their urine.
• Sea cucumbers stir sand which helps keep the reef healthy.
• Harvesting too many sea cucumbers reduces the number being produced which can impact growth of other species and overall health of reefs

Sea Cucumber Collection in the Philippines (Mindanao)

• 47 species are collected across 32 municipalities.
• These species include: Actinopyga lecanora, Stichopus chloronotus, S. vastus, Thelenota rubralineata
• Collection is primarily for local consumption as food, but many cucumbers are intended for export.
• Some species have disappeared between 2010 to 2020.

Handling Reminders

• Efficient handling practices are required during processing to reduce losses and improve market value.
• Sea cucumbers need to be kept alive in seawater until processing but avoid direct sun as they may be deformed or melted.
• Careless handling leads to evisceration-autotomy which is the ejection of internal organs used by animals as a defensive strategy.

Processing

• The steps involved are cleaning, first boiling, gutting, de-scumming, slitting, second boiling, smoke drying and packaging.
• Processing mainly consists of cooking and drying.
• Chinese people introduced the process in Pacific Islands.
• These steps are applicable to all species except sandfish.
• Sandfish is gutted before cooking, while teat fish and other species are cooked whole.

Processing: Cleaning

• Freshly eviscerated sea cucumbers are cleaned before cooking by lightly brushing the surface with coconut husk or any other suitable material to remove sand or material adhering to the surface.
• The animals are washed in clean sea water while remaining material in the belly is gently squeezed out.

Processing: Gutting

• Sea cucumbers can be gutted before or after the first boiling.
• Internal organs are removed but it is important that no stubs are left at the ends and that the tissue lining of the inner walls of the body cavity are not removed.
• Asian customers want a straight cut that is in the right place for each species.
• Do not cut all the way through the mouth and anus and it is best to make small cuts.
• Keep them in salt or on ice (but not frozen) so they do not spoil for fishing trips longer than one day.

Processing: First Boil

• Sort by species and size before immersing in boiling water.
• Water immersion must be complete for inspection with wire mesh basket and to make removal easier.
• A wooden spatula or paddle is suitable to stir the animals continuously.
• The animals are taken out of the boiling water and put into cold seawater to cool, they will burst if left boiling for too long.
• General cooking time depends on animal size and when cooked material bounces like a rubber ball when dropped onto a hard surface.
• White and black teat fish need around 10 to 20 mins
• Larger species need around 20-30 mins
• Other species need around 15-30 mins.

Processing: Descumming (Sandfish)

• Calcareous (lime) or chalk-like material in the skin of sandfish is removed to produce an accepted finished product.
• Descumming happens following the first boil by burying the cucumbers in a shallow flat bottomed pit (20-30cm deep) at an appropriate spot in a clean, sandy beach.
• They will then be packed densely at the bottom and covered with moist cloth before covering pit with sand.
• After 15 or 18 hours they are removed from the pit and washed in clean sea water while scrubbing away outer and ventral layers.

Processing: Slitting

• The animals are placed on a flat board with the belly side down and a neat cut is made along the back using a sharp knife.
• The cut must be clean and around 2-3cm of the mouth and anus must be left intact to properly close the animals.

Processing: Second Boil

• The cucumbers are boiled again under continuous stiring for around 15-30 minutes or until they are at the correctly sized.

Processing: Smoke Drying

• The animals are opened up and short sticks (not more than 2.5cm) are inserted for smoke drying but the materials used must be either coconut husk or mangrove wood.
• Copra dryers, are used a good, they are placed on drying trays split sides down, and move for 24–48 hours.
• Smoking can happen after either cooking but remember that while mild smoke smell is okay, strong smells can be damaging and a small smouldering fire is best and can be done instead of salting.
• Keep cucumbers well above fire for an even smoke, too hot and quick can cause hardening.

Processing: Sun Drying

• Place cucumbers after brushing off ash and dirt from the smoke curing process to remove soot, ash and dirt in the sun and air until the sea cucumber is hard as wood and the moisture content is down to 15-20%.

Processing: Packaging and Storage

• Sea cucumbers are ready to package when they are firm and have dried in the sun.
• The product is cleaned of soot, ash and dirt and stored in sacks or carton boxes

Packaging and Storage

• Store after packing them in clean, dry copra sacks or carton boxes lined with polythene in a cool dry place.
• They are hygroscopic– tend to absorb moisture from the atmosphere so are sensitive for long time.
• Exposure to direct sunlight or heat should be avoided.

Grading

• Sea cucumbers are graded according to species, size, and quality and also based on high value and low value
• The various sizes when grading are generally extra large, medium, small and extra small -In South Pacific Region the cucumbers can also be graded according length

Selling for a High Price

• Proper preparation of sea cucumbers increases their value.
• The sea cucumbers need to have been cut in the proper place, all the sand removed, cleaned of residue, undamaged, unbroken, straight not bent, fully drained, good color.