Tuesday, March 22, 2016

Unsustainable Harvesting of Sea Cucumbers and the Consequences for Coral-Reef Ecosystems of Palau

by Dr. Peter Houk
Chief Biologist, Pacific Marine Resources Institute
Editor, Journal of Micronesian Fishing

Upon my first visit to Palau in 1994, I was immediately impressed by the seemingly endless diversity and abundance of marine life. While Palau is clearly blessed with an amazing natural setting (geology, geography, and oceanography), I found out that traditional management, culture, and respect were equally influential in creating the healthy, thriving coral-reef ecosystems I witnessed.For me, these early experiences in Palau confirmed my passion to better understandhow these magnificent underwater scenes evolve and function.

I have since moved on to coestablish a non-governmental organization dedicated to assisting Micronesian jurisdictions collect and interpret scientific data for their use in sound management planning, the Pacific Marine Resources Institute (www.pacmares.com). Research across Micronesia over the past decade has provided me with a wealth of insight into coral-reef ecosystems, their associated fisheries, and the tradition and culture that is interwoven into the coral-reef food webs.At the numerous regional meetings I’ve attended over the years, Palau continues to lead the way in implementing conservation and management policies that aim to provide long-term economic gain and sustainable fisheries into the future. However, the perceived success must be put into the perspective of the changing world we live in.

In comparison to many coral reefs around the world, Palau clearly represents a unique natural wonder. However, the pressures of enhanced westernization and economic growth continue to influence marine resources around the world, and the stories that elders have shared with me clearly portray declining marine resource abundances through time across Micronesia, including Palau (see www.micronesianfishing.com). It seems clear that it is becoming harder and harder to preserve the fishery stocks that once seemed endless, and although Palau is a regional conservation leader, this conservation success might best be defined in relative terms, while many people fail to understand the absolute decline in marine resources that have been occurring through time. It goes without saying that healthy fish stocks are needed to keep coral-reef ecosystems thriving, so insight from Palauan elders should be taken as a sincere concern for the livelihoods of future generations.

However, most recently, I learned about the sale and export of large quantities of Palau’s sea cucumbers, with limited study or documentation to ensure that sustainable stocks remain, which can fulfill their ecological functions. This was extremely surprising to me, because across Micronesia, many jurisdictions strictly limit or prohibit sea cucumber harvesting due to their slow growth rates and importance to the coral-reef ecosystem. It’s ironic that over the years I’ve witnessed Palau to be a conservation leader, however, just recently, they have decided to exploit marine resources in a manner that is already obsolete within much of Micronesia. This decision is ultimately what encouraged me to write this article, and describe what many already know as the functional roles of sea cucumbers on coral reefs.

Sea cucumbers feed on sediment and detritus (decaying organic matter) that originate from larger coral-reef fish and invertebrates (fish poop for example), and also from surrounding watersheds. The very fact that so many sea cucumbers exist in Palau highlights just how much of this food source is available for processing. But, what happens if detritus is not processed? Left unchecked, detritus can slowly be consumed by the bottom dwelling corals and algae that live on the reefs. However, the key is that when too much detritus becomes available, algae and other undesirable can grow and outcompete corals for space on the reef. Translated, the once coral-dominated reef will slowly (over ~10 years) become dominated by algae, reducing structure and habitat, and all of the socioeconomic benefits that a healthy reefs offers Palauan livelihoods. As a last note, the combined impact of reduced fish populations, many of which also eat algae and detritus (parrotfish, Melemau, and Kemedukl), and sea cucumber declines represents an intensified threat to Palau’s nearshore coral-reef ecosystems.

You might draw a comparison with the dirt that accumulates in your house. Without sweeping, the accumulated dirt would eventually build up so much that you no longer want to live inside, and bacteria, mold, and fungus would take over your residence. Sea cucumbers and fish represent the “skobang”. While fighting the national policy of permitting sea cucumber harvesting may seem like a daunting challenge to many, I think that providing education and outreach to the state governments represents a better means towards solving this issue for Palau. To my knowledge, the states decide how to manage their resources, and generating a wealth of profit from sea cucumber harvesting today, in exchange for a compromised coral-reef ecosystem 10 years later, seems illogical. I strongly encourage all the state governments to take a deeper look at the consequences of uncontrolled sea cucumber harvesting.

Pacific Marine Resources Institute is a non-profit organization based in Saipan, CNMI, dedicated to improving scientific research and monitoring across Micronesia for their use in sound resource management planning (www.pacmares.com).

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