Sea Cucumbers (Holothuroidea) of Northeastern and Western Mindanao, Philippines: The Potential Role of Marine Protected Areas in Maintaining Diversity and Abundance

Abstract

Marine protected areas (MPAs) are considered strategic tools in conserving biodiversity and maintaining stocks of valuable resources. We assessed sea cucumbers in five provinces in northeastern and western Mindanao to describe the state of diversity and abundance and evaluate the role of MPAs in sustaining stocks of exploited species. We identified 36 species of sea cucumbers from fishery-independent surveys on shallow reef flats and deeper reef slopes, of which 33 species (92%) belong to order Aspidochirotida and three species belong to Order Apodida. The majority are shallow-water holothurians occurring on reef flats and seagrass beds, while a few species are found along reef slopes or in fresh catches by fishers sold to local traders or processors in some sites. Nine species are considered high-value to the global trepang trade but occur at low densities, while the rest are abundant or common species with low commercial value. Species richness (S=17-30 spp.) varies across sites, but species composition similarity is relatively high (Sørensen’s SQ = 0.62-0.78). Mean population densities and variances of high-value species are significantly higher inside enforced MPAs than in non-MPA sites(t-test, p <0.05; F-test, p<0.005) across five survey sites. The abundance of high-value H. scabra in Tubajon and H. fuscogilva in Capayas Island demonstrates the critical role of MPAs in conserving biodiversity, maintaining population levels, and ensuring natural recruitment of sea cucumber resources. Urgent management measures such as formulating a national management plan, regulating harvests, and establishing no-take MPAs are recommended.

Status of Sea Cucumber Fisheries in Mindanao: Harnessing Local Knowledge in Determining Diversity and Production Values

“…In the study, the dominance of medium to low-value species in the catch may reflect the scarcity of highvalue sea cucumbers in most areas. Our results concur with several reports that the sea cucumber fishery in many areas of the Philippines is mainly composed of low-value and few medium-value species, such as in Maasin City, Southern Leyte (Gajelan-Samson et al 2011), and some areas in Mindanao (De Guzman and Quiñones 2021;Arriesgado et al 2022). The shift from a high to a low value of the sea cucumber catch might indicate overfishing these valuable resources (Friedman et al 2008).…”

“…Many sea cucumber studies in the Philippines mainly focus on population assessments (Olavides et al 2010;Jontila et al 2014;Romero and Cabansag 2014;Dela Cruz et al 2015;Pitogo et al 2018;De Guzman and Quiñones 2021) with limited information on the catch data and fisheries of the exploited sea cucumbers (Schoppe 2000;Gamboa et al 2004;Olavides et al 2010), especially in Mindanao (De Guzman and Quiñones 2013). Limited site-specific data are often cited as an obstacle in formulating a management plan (Gamboa et al 2004).…”

Socio-demographic and Perception of Sea Cucumber Gatherers in Selected Areas in Mindanao, Philippines

“…Aside from the high prices, the easy access to harvest, the late age at maturity, slow growth, and low recruitment rates make the sea cucumber slowly replenish the wild stocks (Uthicke and Benzie 2000;Bruckner et al, 2003;Uthicke et al, 2004;Bruckner, 2005). It calls for management and interventions for sustainable fishery resources, especially since sea cucumber gathering is one of the major fishery livelihoods that sustain the economy and trade in the Philippines (De Guzman and Quiñones, 2021).…”

“…However, the lack of comprehensive data regarding the socio-demographic and economic well-being of the fishers in relation to the fishery, and the incomplete socio-economic status information, pose a significant hurdle to the effective implementation of management plans (Labe, 2009;Nishanthan et al, 2019). In the country, research is focused more on the population status (Olavides et al, 2010;Arriesgado et al, 2022b;De Guzman et al, 2021) while accounts of the sociodemographic and economic profile of fishers are limited and focused on local scales, such as the study by de la Cruz et al, (2015); Jontila et al (2018a); and Arriesgado et al, (2022a). This inadequacy of information has often led fishery managers to make insufficient or ineffective management decisions or policies, affecting the sustainability of the resource.…”