Genetic Diversity, Population Structure, and Demographic History of Exploited Sea Urchin Populations (Tripneustes Gratilla) in the Philippines

The sea urchin Tripneustes gratilla is ecologically and economically important in the Indo-Pacific region. We use population genetic methods to investigate the population structure and historical demography of exploited populations in the Philippines. Sea urchins sampled in 6 localities in western Luzon and 4 outgroup sites were sequenced for mitochondrial cytochrome oxidase-1 gene (n = 282) and genotyped for seven microsatellite loci (n = 277). No significant genetic structure was found for either class of markers, indicating either extensive gene flow across the archipelago, or that populations have high genetic diversity and have not yet attained equilibrium between genetic drift and migration following large changes in demography. Interestingly, demographic inferences from the two types of markers were discordant. Mitochondrial lineages showed demographic expansion during the Pleistocene while microsatellite data indicated population decline. Estimates for the date of each event suggest that a Pleistocene expansion could have preceded a more recent population decline, but we also discuss other hypotheses for the discordant inferences.The high genetic diversity and broad distribution of haplotypes in populations that recently recovered from fishery collapse indicate that this species is very resilient over evolutionary timescales

The application of genetics to marine management and conservation: examples from the Indo-Pacific

Molecular tools and analyses have played pivotal roles in uncovering the processes and patterns of biodiversity in the Indian and Pacific oceans. However, integrating genetic results into management and conservation objectives has been challenging, with few examples that show practical applicability. This review aims to address some of the perceived barriers to an enhanced approach that integrates molecular data into management and conservation goals, by reviewing papers relevant to both conservation and fisheries management in the Indo-Pacific region, particularly with respect to phylogeography, connectivity, and species identification, as well as stock delineation, restoration of depleted wild stocks, mislabeled marine resources and "molecular forensics." We also highlight case studies from each of these areas that illustrate how molecular analyses are relevant to conservation and management in the Indo- Pacific, spanning a variety of vertebrate and invertebrate species. We discuss the application of genetic data to the design and evaluation of the effectiveness of marine protected area networks, stock delineation, and restoration and the usage of exclusion tests and parentage analyses for fisheries management. We conclude that there is a distinct need for increasing public awareness and ownership of genetically unique lineages and, ultimately, the increased inclusion of genetic research into management policy and conservation. Finally, we make a case for the importance of clear and effective communication for promoting public awareness, public ownership, and for achieving conservation goals within the region

The littoral sea cucumbers (Echinodermata: Holothuroidea) of Guam re-assessed – a diversity curve that still does not asymptote

The Micronesian island of Guam has been an important site for the study of littoral tropical holothurian taxonomy for almost 200 years. Despite substantial attention by both expeditions and resident taxonomists, new records are still regularly added to the fauna, demonstrating the challenge of documenting even such large and well-known animals in a small hyper-diverse area. Guam is the type locality of species described by Quoy & Gaimard (1833) and Brandt (1835). A survey of the sea cucumber fauna by Rowe & Doty (1977) led to one of the most used guides for the identification of tropical Pacific sea cucumbers because of the color illustrations of living animals it presented. Focus on echinoderms including holothurians continued with numerous new records added in the following decades. Paulay (2003a) summarized the fauna last, recording 46-47 species. At this stage the fauna was thought to be well documented. A week-long workshop on holothurian systematics sponsored by the National Science Foundation PEET (Partnerships for Enhancing Expertise in Taxonomy) project in 2010 included a substantial field work component, sampling both during the day and night, with snorkeling and SCUBA, across a variety of habitats. This survey yielded 40 species, including numerous new records and even species. Further sampling by Kerr’s lab since the workshop has added additional records. The littoral holothuroid fauna of Guam now comprises 65 species in 17 genera and 7 families. Half of the 19 newly recorded species are the result of unravelling cryptic species in complexes, the other half are based on new collections. Eleven species are known from single specimens, suggesting that much still remains to be learned about the fauna

Community-based experimental culture of sea cucumbers and siganids as tool for resource enhancement

In ARCHIV 115463 v. 1The table of contents for this item can be shared with the requester. The requester may then choose one chapter, up to 10% of the item, as per the Fair Dealing provision of the Canadian Copyright Ac

Sea urchin grow-out culture : assessment of potential for implementing community-based coastal resource management (the case in Arnedo)

In ARCHIV 115463 v.

Preparation for the establishment of marine protected area : the case in Arnedo

In ARCHIV 115463 v.

Population genetic structure of the sea urchin Tripneustes gratilla from selected sites in Western Luzon and Eastern Philippines

The genetic structure of the sea urchin Tripneustes gratilla was investigated for six wild populations in western Luzon and eastern Philippines and one batch of hatchery-reared sea urchins. Analysis of six polymorphic allozyme loci revealed low levels of genetic differentiation (Nei’s unbiased D = 0.0 – 0.014, overall FST =0.0122), implying extensive gene flow between populations. The batch of cultured T. gratilla showed no apparent genetic distinctness from wild populations. Genetic differentiation was slightly higher in one eastern population (Ticao, Masbate). Structuring was not associated with geographic distance, but might be a result of heterogeneous recruitment. Initial results suggest that intensively-fished T. gratilla populations in northwestern Luzon should be managed as a single unit, hence a region-wide fishery management scheme needs to be implemented. The establishment of a network of marine protected areas along the western coast of Luzon is also recommende

Enhancing the recovery of depleted Tripneustes gratilla stocks through grow-out culture and restocking

Grow-out culture in sea cages and restocking were undertaken to help rebuild the spawning population of Tripneustes gratilla in Bolinao, Philippines. Higher population densities and incidence of recruits in 2004–2006, as well as steady increase in the catch per unit effort of gatherers, indicate that the sea urchin population is recovering. Growth of reseeded, hatchery-produced sea urchins in two sites was high and comparable to those in grow-out cages. However, natural mortalities were very high (91–99%). Good growth, high survivorship, and potential reproductive output of sea urchins in grow-out cages, aside from immediate socio-economic benefits, demonstrate that grow-out culture is a cost effective option for reestablishing effective spawning populations. Higher recruitment success in Lucero, compared to other sites, may be attributed to local favorable biophysical conditions and to maintenance of an effective spawning population due to enforcement of marine sanctuary rules, size regulation, and the presence of broodstock cages. Results suggest that the establishment of a network of marine protected areas in tandem with grow-out culture may be strategic in enhancing the recovery of depleted populations by maintaining larval exchange to sustain the production of sea urchin fishery stocks along NW Luzon