Guam’s Balate’ are in a bit of a pickle
Figure 1. An array of colorful balate’ found throughout Guam’s waters.
a = Actinopyga capillata, b = Holothuria coronopertusa, c = Labidodemas spp.,
d = Holothurian sp. C., e = Holothurian sp. D, f = Actinopyga cf. echinites.
(Photo Credit: David Burdick, Guam Reef Life).
Sea cucumbers are important
Of the many marine organisms populating Guam’s waters, sea cucumbers (balate’), shown in Figure 1, remain important and unique creatures that provide a crucial cleaning service to the ocean. Many islanders may reminisce of a time when they played with balate’ with their friends and family on the beach.
Like soil earthworms, they may not be much to look at, with no faces, eyes, or limbs, but their janitorial role on the seafloor allows for the distribution of nutrients and the removal of excess organic matter from the water and sediment.
However, they are a delicacy in parts of Asia and are consumed throughout the Micronesian islands. Their commercial value has led to the illegal over-harvesting of sea cucumbers throughout Southeast Asia and the Pacific, even in Guam.
Balate’ biology and behavior
Figure 2. The elongated body of Holothuria leucospilota. (Photo Credit: David Burdick, Guam Reef Life).
Figure 3. The long, yellow-tipped, conical papillae of Stichopus chloronotus. (Photo Credit: David Burdick, Guam Reef Life).
Figure 4. The anus of Bohadschia koellikeri. (Photo Credit: David Burdick, Guam Reef Life).
Sea cucumbers are invertebrate marine animals, such as octopuses, that belong to the Phylum Echinodermata and the Class Holothuroidea. They have an elongated and tubular body, shown in Figure 2, with a body surface that is thick, slimy, and in some species, bears papillae (rounded and small protuberances on the body), shown in Figure 3.
Their body is muscular and can loosen and tighten at will, essentially allowing them to liquefy their body and squeeze through small spaces, such as crevices in the reef. Their mouth is at the anterior end and contains tentacles that can be extended to obtain food; the anus is at the posterior end, shown in Figure 4.
Their tentacles can sift through the ocean floor, grab, and digest organic matter, and excrete clean sand through the anus. This process aerates the seafloor and recycles decomposing matter. Research has shown that by also dissolving calcium carbonate from the sand and releasing it into the water, sea cucumbers help coral growth and may adjust seawater pH (i.e., acidity) associated with rising CO₂ levels. This can reduce the effects of ocean acidification.
Some species, when attacked, extrude toxic and sticky tubules (cuverian tubules) through their anus, towards their attacker and then regrow their tubules back. Other species burrow into the sand in an attempt to hide from predators.
A history of health and wealth
Balate’ have played a major economic role in the Pacific since the 19th century. The balate’, or “trepang,” trade was brought to Guam in the 1800s by the Spaniards. Although not generally eaten on Guam, the sea cucumbers were (and still are) dried and cured for trade and consumed as Chinese and Japanese delicacies, as well as used in traditional medicine.
According to traditional Chinese medicine, consuming sea cucumbers nourishes the blood, treats kidney disorders, and helps with constipation.
In a 2018 review that presented the potential pharmacological effects of sea cucumbers from several studies, Yuri Khotimchenko discussed biologically active compounds isolated from sea cucumbers that had several activities, including: anticoagulant, antioxidant, and anti-infectious. Specialized lipids, polyunsaturated fats, and bioactive amino-acid chains, to name a few, are compounds found within these organisms that synergistically may be creating an antioxidant effect. Thus, the combination of these active compounds in sea cucumbers has led to their beneficial properties and increasing interest for pharmacological studies.
Previously, it was only eaten by China’s wealthiest, however, in the 1980s demand exploded and continues to grow with knowledge of its benefits and availability. Currently, prices vary depending on size and species (typically, more papillae equal a higher price), and some go for $3,000 a kilo, which is markedly higher than the average garden cucumber!
Balate’ harvesting regulations
In Guam, balate’ are protected by law, and only 100 pieces of balate’ per person, per day are allowed for harvesting. However, in 2010, 11,092 balate’ were illegally harvested and confiscated at a single residence in Guam.
Environmental concern due to the exploitation of sea cucumbers has led to proposals for stricter regulations and fines, including an increased fine per piece of sea cucumber caught, and jail time. Some senators are attempting to bring allowable harvest down to only five per person, per day. To avoid the harm caused to the ecosystem by over harvesting, while still providing access to medicinal benefits, some scientists also suggest culturing and farming sea cucumbers for use in the healthcare system.
Lourdes Mafnas, born and raised on Guam, was pursuing a master’s degree in environmental science at the University of Guam under the advisement of Dr. Jason Biggs. She conducted research on the pathological signs of toxicity found in fish throughout the island.
This author was a beginning graduate student in 2019 taking a course in scientific writing at the University of Guam. This article was assigned to provide the student with practice in communicating science to non-scientists. The student chose the topic which is related either to her thesis project or work experience. The instructor in the course is Dr. Laurie Raymundo, a UOG Marine Laboratory faculty member.
For further reading
Lee, Nathaniel, and Shira Polan. Sea cucumbers are so valuable that people are risking their lives diving for them. Business Insider. Streamed live 2 October 2020. Insider video, 5:15.
Livingston, Stephanie. “Rewriting the evolutionary history of sea cucumbers.” Florida Museum, 14 July 2014.
Khotimchenko, Yuri. “Pharmacological Potential of Sea Cucumbers.” International Journal of Molecular Sciences 19, no. 5 (2018): 1342.