Honda Bay Research Articles

Distribution of total mercury in coastal sediments of Honda Bay, Palawan Island, the Philippines

Honda Bay is considered as one of the mercury hotspots in the world due to its proximity to the abandoned Palawan Quicksilver Mine. In this study, a detailed sediment sampling conducted in between 2021 and 2022 where a total of 166 sediment samples were collected along the coast and analyzed for total mercury (THg) concentration. The study assessed mercury toxicity using the geoaccumulation index and compared Hg levels to sediment quality guidelines. The findings revealed a wide range of THg concentrations, from 0.0040 to 11.4702 mg/kg, with hotspots identified at the Honda Bay wharf and Tagburos River mouth. Mercury spreads to a large coastal area brought by tidal currents and the wave energy actions. The geoaccumulation index indicated moderate to strong Hg contamination in the vicinity of the hotspots and around 24.7–36.1 % of samples exceeded the sediment quality guidelines suggesting adverse biological effects in aquatic biota will frequently occur.

Understanding Local Perspectives on Climate Change and Its Impacts on Small-Scale Fishing Communities in Honda Bay, Palawan, Philippines

Climate change's adverse impacts are already evident, particularly in coastal areas. However, local perception that is essential in formulating policies for mitigating its impacts remains limited. Thus, this study evaluated the level of perception of small fishing communities on climate change and its impacts on livelihood and the environment. The data were obtained using a face-to-face survey with the aid of a structured questionnaire. They were interpreted and analyzed using the Likert point scale, descriptive statistics, and chi-square. A total of 308 male fisherfolks participated in the survey. Majority belong to age 51-60 years old (38%) and 61 years old and above (32%). Most of them (65%) finished elementary and generally (94%) rely on fishing for main source of living. As for income, 47% earned an estimated monthly income of Php 2,501-5,000 and 28% got Php 5,001-7,500. Most of the respondents are full-time fishers (89%) for more than 11 years (87%), and fishing within the municipal water (92%). Majority (90%) have an idea about climate change as reflected by their very high score in Likert Perception (24.3±2.3%). The climate change impacts perceived by the respondents include: increasing sea surface temperature (87%); fish are sensitive to changing climate (87%); and fossil fuel consumption contributes to climate change (84%). They said they got the information from TV/ Radio (99%) and social media (10%). The age (p-value < 0.0032) and source of information (p-value < 0.0348) are among the variables with significant relationship to the perception of respondents on climate change impacts. In total, it appears that majority of fishers are aware of the impacts of climates. It is suggested that effective management actions, such as emergency preparedness schemes and livelihood diversification should be explored to address the specific needs of fishing communities that are vulnerable to the impacts of climate change. Furthermore, an ecosystem-based approach that focuses on socio-economic dynamics and climate-induced changes in assessments and management is essential for the sustainable use of fisheries resources amidst the changing climate.

Ecological and health risks from heavy metal sources surrounding an abandoned mercury mine in the island paradise of Palawan, Philippines

A recent survey that determined heavy metal concentrations in an abandoned Hg mine in Palawan, Philippines, found the occurrence of Hg with As, Ba, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, Sb, Tl, V, and Zn. While the Hg originated from the mine waste calcines, the critical knowledge about the origin of the other heavy metals remains unknown. This study assessed the ecological and health risks from heavy metal pollution surrounding the abandoned Hg mine. Principal component analysis (PCA) showed that the abandoned mine and natural sources (i.e., local geology) are the two main contributors of heavy metal pollution. Historically, the mine waste calcines (retorted ore) were used as construction material for the wharf and as land filler for the adjacent communities. There is highly strong ecological risk associated with the heavy metals: Ni, Hg, Cr, and Mn contribute 44.3%, 29.5%, 10.7%, and 8.9% to the potential ecological risk index (RI), respectively. Hazard index (HI) exceeded 1 for both adults and children in all the sampling locations, implying non-carcinogenic adverse effects. The total cancer risk over a lifetime (LCR) also exceeded the threshold limit of 10−4 for both adults and children, contributed mainly by Cr (91.8%) and As (8.1%). By combining the results of the PCA and risk assessments, a clear link between heavy metal source apportionment to ecological and health risks was established. It was estimated that the abandoned mine contributed to most of the ecological and health risks for people living near the wharf that was built using the calcine, as well as the nearby Honda Bay. The findings of this study are expected to help policy makers develop regulations that will safeguard the ecosystem and the general public from the damaging impacts of heavy metals from the abandoned mine.

Identification and Morphology of the Two Horseshoe Crab Species, Tachypleus tridentatus (Leah, 1819) and Carcinoscorpius rotundicauda (Latreille, 1802) (Merostomata: Limulidae) from Honda Bay, Palawan, Philippines

There were reports of the existence of horseshoe crabs in Palawan, Philippines, but there is a need to identify and confirm these species. A total of 128 adult horseshoe crabs were collected from Honda Bay, Palawan, Philippines. These were identified as Tachypleus tridentatus (68 males, 40 females) and Carcinoscorpius rotundicauda (2 males, 18 females). Morphology, morphometric measurements, and ratios of male and female of each species were described. Morphological characteristics in differentiating a male from a female crab involve examination of the appearance of the genitalia. Morphological characteristics in identifying the species include the presence or absence of notches in the frontal margin, arching in the frontal view, appearance of the chelae of the 2nd and 3rd prosomal appendages, number of lateral spines and the immovable spines in the opisthosoma, the presence of spinnerets on the surface of the telson, and shape of the telson and its cavity in cross-section. This study confirmed the identification of the two species found in Palawan, Philippines, and the morphological characteristics of the male and female of each species. In addition, a comparison was made of the size of the horseshoe crab species in Palawan with those found in other locations in the Asia-Pacific region.

Total Mercury in Soils and Sediments in the Vicinity of Abandoned Mercury Mine Area in Puerto Princesa City, Philippines

The abandoned mercury (Hg) mine area in Puerto Princesa City, Palawan was included in the list of abandoned and inactive mines in the Philippines which pose a high risk to human health and the environment, and require rehabilitation. The mine site, operated by Palawan Quicksilver Mines, Inc. (PQMI) from 1953 to 1976, is located approximately 3 km inland from Honda Bay coast and within the catchment of the Tagburos River, which is a local fishery and recreational area. In this study, total Hg levels in soils and sediments were measured to assess the possible release of Hg from the site into the surrounding natural environment. Results showed that total Hg (THg) concentrations found in soils (0.04–67.5 mg kg−1), mine waste calcines (52.7–924.2 mg kg−1), river sediments (1.8–119 mg kg−1), and marine sediments (0.04–12.7 mg kg−1) were elevated compared to the global background of 0.045–0.16 mg kg−1. The high concentrations of Hg in soils and river sediments were influenced by the different pathways for the release of Hg from its mine operations; while Hg in marine sediments was caused by the erosion of mine waste calcines near the pit lake, and calcines used to construct a wharf at the nearby Honda Bay. Mine wastes represent the largest source of Hg contamination in the area, due to the low efficiency of the recovery process during calcination. This work corresponds with the Minamata Convention on Mercury on the updated environmental assessments of abandoned Hg mines as potential source sites of mercury contamination.

Photo-ID and telemetry highlight a global whale shark hotspot in Palawan, Philippines

The Philippines is home to the second largest known population of whale sharks in the world. The species is listed as endangered due to continued population declines in the Indo-Pacific. Knowledge about the connectivity within Southeast Asia remains poor, and thus international management is difficult. Here, we employed pop-up archival tags, data mining and dedicated effort to understand an aggregation of whale sharks at Honda Bay, Palawan, Philippines, and its role in the species' conservation. Between Apr and Oct 2018, we conducted 159 surveys identifying 117 individual whale sharks through their unique spot patterns (96.5% male, mean 4.5 m). A further 66 individual whale sharks were identified from local operators, and data mined on social media platforms. The satellite telemetry data showed that the whale sharks moved broadly, with one individual moving to Sabah, Malaysia, before returning to the site <1 year later. Similarly, another tagged whale shark returned to the site at a similar periodicity after reaching the Malay-Filipino border. One individual whale shark first identified in East Kalimantan, Indonesia by a citizen scientist was resighted in Honda Bay ~3.5 years later. Honda Bay is a globally important site for the endangered whale shark with connectivity to two neighbouring countries, highlighting the need for international cooperation to manage the species.

Tree biomass quantity, carbon stock and canopy correlates in mangrove forest and land uses that replaced mangroves in Honda Bay, Philippines

Mangrove forests are important carbon (C) sinks in the tropics that are threatened by tropical deforestation and land use conversion, especially in Southeast Asia. Yet quantitative estimates are limited on the biomass (i.e. aboveground, belowground, downed woody debris) and tree C stocks of secondary, and converted mangroves in Southeast Asia. While some related studies have been conducted in Latin America and Central Asia, there is a need to assess different geographical areas and regional ecosystems, as well as to consider the impacts of mangrove conversion to other land use types. In this study, tree biomass and tree C stocks of secondary mangrove forests and four types of land uses that replaced intact mangrove forests (abandoned aquaculture pond, abandoned salt pond, coconut plantation, and cleared mangroves) in the coast of Honda Bay, Philippines were quantified. Their relationships with selected canopy variables were evaluated. Our measurements revealed that mean tree biomass (±SE) of intact mangroves ranged from 22.4 ± 9.0 to 178.1 ± 32.0 Mg ha−1, which store 10–80 MgC ha−1 (mean: 47.9 ± 5.1 MgC ha−1). Leaf Area Index correlated with mangrove tree biomass C stock (r=0.67, p<0.05). In contrast, the biomass and tree C stock of the replacement land uses ranged from 0.1 ± 0 Mg ha−1 and 0.12 ± 0.1 MgC ha−1, respectively, in the abandoned aquaculture ponds to 12.0 ± 4.0 Mg ha−1 and 5.7 ± 1.5 MgC ha−1 in coconut plantation. Our results indicate the importance of mangroves in storing considerable amounts of C in tree biomass in the coastal area, and the C losses (46.5 Mg C ha−1 or 97% decline) in tree C stocks from conversion of mangroves to other land uses.

INTEGRATION OF ECOTOURISM IN SMALL-SCALE COASTAL FISHERIES: LESSONS LEARNED IN HONDA BAY, PUERTO PRINCESA CITY, PALAWAN, PHILIPPINES

This study examines the ecological and economic benefits derived in transforming a small-scale fishing village of Sta. Lourdes, Puerto Princesa City into a community-based sustainable tourism site catering to about 1,000 visitors a day during the peak season from February to May. The establishment of Honda Bay Boatowners Association was vital in this community’s transformation. Before (Year 2007) and After (Year 2014) study method, which involved key informant interviews, household interviews, focus group discussion and site validation were used. Results indicate that the present condition of mangroves (+25%), beaches (+23%), and coral reefs (+14%) are progressively improving during the past seven years; however, seagrass beds (-2%) near the Sta. Lourdes Wharf are deteriorating due to oil spill from confiscated boats. There is a general view that the bay’s reef ecosystem is gradually restored as dominant catch composition are reef-associated species such as Coastal trevally, Dusky batfish and Golden-lined spinefoot, among others. Majority of fishers’ income source has shifted from fishing to tourist boat service. In 2007, fishing was the major source of income with 54% of boat owners and 61% of boatmen. However in 2014, tourist boat service has become the major income source of about 86% of boat owners and 93% of boatmen. A shift to higher income and more affluent material style of life is evident particularly on the part of boat owners. For inclusive economic growth, the association should establish spin-offs for the benefit of other community stakeholders.

FISHING TO ISLAND HOPPING: ECOTOURISM INITIATIVE OF HONDA BAY BOATOWNERS ASSOCIATION IN PUERTO PRINCESA, PALAWAN

Using participatory approach and co-management in community-based sustainable tourism initiated by the national government, the Honda Bay Boatowners Association, Incorporated (HOBBAI) was formed in partnership with local non-government organizations

Soil greenhouse gas fluxes in tropical mangrove forests and in land uses on deforested mangrove lands

Mangrove forests are important carbon sinks in the tropics, yet tropical mangrove deforestation and land use conversion still persists. Reporting of greenhouse gas (GHG) emissions from natural and anthropogenic sources in wetlands are important in regional and national emissions inventories. However, very few studies have been conducted to measure on the GHG fluxes in coastal wetlands, particularly in mangrove forest and non-forest land uses in deforested mangroves. We investigated the soil fluxes of CO2, CH4 and N2O in mangrove forest and non-forest land uses on deforested mangrove areas (i.e. abandoned aquaculture ponds, coconut plantations, abandoned salt ponds, and cleared mangroves) in the coasts of Honda Bay, Philippines. Results showed that the emissions of CO2 and CH4 were higher by 2.6 and 6.6 times in mangrove forests (110 and 0.6kg CO2e ha −1 day −1, respectively) while N2O emissions were lower by 34 times compared to the average of non-forest land uses (1.3kg CO2e ha −1 day −1). CH4 and N2O emissions accounted for 0.59% and 0.04% of the total emissions in mangrove forest as compared to 0.23% and 3.07% for non-forest land uses, respectively. Site-scale soil GHG flux distribution could be mapped with 75% to 83% accuracy using Ordinary Kriging. Unlike mangroves that can offset all GHG emissions through CO2 uptake from photosynthesis, the non-forest land uses cannot offset their emissions on-site as they are usually devoid of vegetation. Our results could be utilised in higher tier national GHG inventories, to refine regional and global estimates of GHG emissions in mangrove wetlands, and improve policy on coastal wetlands conservation.

Possible occurrence of the sea cucumber Actinopyga spinea (Cherbonnier 1980) in Arreceffi Island, Honda Bay, Puerto Princesa City, Palawan, Philippines

Sea cucumbers under the genus Actinopyga are among the commonly exploited species in the Philippines. At present, there are five species belonging to this genus in the country namely, A. echinites, A. lecanora, A. mauritiana, A. miliaris and A. obesa (Schoppe 2000, Akamine 2005, Kerr et al. 2006, Olavides et al. 2010, Purcell et al. 2012, Jontila et al. 2014). Recent surveys in different sites in Palawan did not show the occurrence of other Actinopyga species (Dolorosa and Jontila 2012, Collantes 2013, Pitong 2013, Sabay 2013, Saclet 2013, Dolorosa 2015). During the monthly monitoring of sea cucumbers in Arreceffi Island Resort and Spa on June 5, 2015, one individual of Actinopyga, suspected to be A. spinea was documented. The Island is located in Honda Bay (9°54’47.66″N, 118°52’35.64″E) about 16 km away from Sta. Lourdes Wharf, Puerto Princesa City (part of the mainland Palawan). It has approximately 20 ha land area, 30 ha mangrove forest and 170 ha intertidal and shallow subtidal areas, serving as safe habitats for diverse wildlife. Since its establishment in 1991, the island resort implemented no fishing or hunting activities that enabled the once overharvested species to recover. The substrate where the specimen was collected is mainly composed of sand and rubble, but patches of seagrasses (Cymodocea rotundata, Enhalus acoroides and Thalassia hemprechii) and stands of Rhizophora stylosa were also present in the area. The site is around 80 m away from the drop off and is exposed to moderate to strong wave action during high tide. The specimen was encountered during low tide in waters between 0.1 to 0.2 m deep. The specimen was first identified as A. miliaris due to its resemblance in external appearance and similarity in habitat with A. spinea (Figure 2). However, further examination of its external features based on the photos revealed that it is more likely to be A. spinea. Both species have brown to dark brown or blackish brown coloration, but A. miliaris has a lighter ventral part whereas A. spinea is entirely uniform in color. Similarly, the papillae of both species are long and slender but such are numerous on the dorsal of A. miliaris while it is only moderate in A. spinea (Figure 2) (Purcell et al. 2012). In addition, A. miliaris’ anal teeth are generally simple and conical in shape. In contrast, the specimen’s anal teeth are triangular with distinct nodules (Figure 3) that is a key feature of A. spinea (Conand 1998, Purcell et al. 2012). Actinopyga spinea is also similar in color with A. palauensis but the latter has textured dorsal surface with bumpy appearance, and the mouth is often projected as trunk-like (Purcell et al. 2012). Also, the papillae of A. palauensis on the dorsal are small and conical while they are long and slender in A. spinea. Furthermore, the anus of A. palauensis is more terminal while that of A. spinea is sub terminal. However, this feature of A. spinea was not noted when the specimen was collected. Further visual examination of the mouth position was also done on the specimen, which was collected and frozen for future studies, but such was difficult to determine for the sample has already collapsed after ejecting its internal organs during transport in 2015. Further search was made then in the area to look for other individuals of A. spinea but none was encountered. The specimen measured only 9 cm. This is far below the mean length of A. spinea that is 25 cm (Purcell et al. 2012). Thus, the individual could be in its juvenile or sub adult stage. However, this is difficult to ascertain due to lack of information on its growth and maturity (Purcell et al. 2012). Information on its distribution and population trend is also limited (Conand 1998). In fact, A. spinea is classified as a least concern species (Conand et al. 2013, IUCN 2016). Despite of the resemblance of A. spinea to A. miliaris and A. palauensis, the nodular anal teeth, the uniformly colored body, and the sparse conical papillae on the dorsal strongly suggest that the specimen is A. spinea. These characteristics were assumed to be sufficient for reasonable certitude but to complete the identification, ossicles examination is being undertaken for further examination of experts. If needed, DNA testing could also be done for the sample is kept viable for such procedure.

Soil C quantities of mangrove forests, their competing land uses, and their spatial distribution in the coast of Honda Bay, Philippines

Mangrove forests provide many ecosystem goods and services and they contain large amount of carbon (C) especially in their soil. Yet, their global area is still declining owing to conversion to non-forest land uses. While studies have been conducted on mangrove soil C stocks, our knowledge on how C stocks of mangrove forests compare with those of non-forest land uses that replaced them is still limited. This knowledge is crucial in land use planning and decision-making in the coastal zone. Site-scale mapping and assessments of mangrove soil C stocks and the land uses that replaced them are also limited. The aim of this study was to quantify and compare the soil C stocks in mangrove forests and their competing non-forest land uses (represented by aquaculture pond, coconut plantation, salt pond and cleared mangrove), estimate soil C loss arising from conversion, and model the soil C stock distribution in the entire study site. On the average, the soil C stock of mangrove forests was 851.9±87MgC ha−1 while that of their non-forest competing land uses was less than half at 365.1±31MgC ha−1. Closed canopy mangrove was highest at 1040±104MgC ha−1, followed by open canopy mangrove (640±131MgC ha−1) while aquaculture, salt pond and cleared mangrove had comparable C stocks (454±32, 401±9, 413±25MgC ha−1, respectively) and coconut plantation had the least (42±0.7MgC ha−1). Overall, the reduction in soil C stock (soil C loss) due to land use conversion in mangrove ranged from 398 to 809MgCha−1 (mean: 486.8MgCha−1) or a decline of 57% in soil C stock, on the average. It was possible to model the site-scale spatial distribution of soil C stocks and predict their values with 85% overall certainty using the Ordinary Kriging approach. Results from this study could help inform current discussions on Blue Carbon and REDD+ as well as policy and program development that advance research on soil C conservation and ecosystem services in coastal forested wetlands.

Patterns of Coral-Reef Finfish Species Disappearances Inferred from Fishers' Knowledge in Global Epicentre of Marine Shorefish Diversity.

In the Philippines, very high fishing pressure coincides with the globally greatest number of shorefish species, yet no long-term fisheries data are available to explore species-level changes that may have occurred widely in the most species rich and vulnerable marine ecosystem, namely coral reefs. Through 2655 face-to-face interviews conducted between August 2012 and July 2014, we used fishers’ recall of past catch rates of reef-associated finfish to infer species disappearances from catches in five marine key biodiversity areas (Lanuza Bay, Danajon Bank, Verde Island Passage, Polillo Islands and Honda Bay). We modeled temporal trends in perceived catch per unit effort (CPUE) based on fishers’ reports of typical good days’ catches using Generalized Linear Mixed Modelling. Fifty-nine different finfish disappeared from catches between the 1950s and 2014; 42 fish were identified to species level, two to genus, seven to family and eight to local name only. Five species occurring at all sites with the greatest number of fishers reporting zero catches were the green bumphead parrotfish (Bolbometopon muricatum), humphead wrasse (Cheilinus undulatus), African pompano (Alectis ciliaris), giant grouper (Epinephelus lanceolatus) and mangrove red snapper (Lutjanus argentimaculatus). Between the 1950s and 2014, the mean perceived CPUE of bumphead parrotfish declined by 88%, that of humphead wrasse by 82%, African pompano by 66%, giant grouper by 74% and mangrove red snapper by 64%. These declines were mainly associated with excess and uncontrolled fishing, fish life-history traits like maximum body size and socio-economic factors like access to market infrastructure and services, and overpopulation. The fishers’ knowledge is indicative of extirpations where evidence for these losses was otherwise lacking. Our models provide information as basis for area-based conservation and regional resource management particularly for the more vulnerable, once common, large, yet wide-ranging reef finfish species.

Protected versus unprotected area with reference to fishes, corals, macro invertebrates, and CPUE in Honda Bay, Palawan

The impact of Sabang Reef Fish Sanctuary in Honda Bay, Palawan was evaluated using fish, coral cover, macro-invertebrates and CPUE as measures for success. Visual census and LIT methods were used for fish, macro invertebrate and coral cover surveys, while administered interview was used to gather information on CPUE. The protection of fish sanctuary has shown its impact to the coral reef fisheries by the improvement in quantity of the resources. Fishes, macro-invertebrates, and hard coral cover inside the Sabang Reef Fish Sanctuary (Binduyan) showed increased in abundance, diversity, and number of commercial species compared to those outside of the sanctuary. This reflects the positive impact that a protected area gained over four years. Results indicated high exploitation rates of resources in the fished areas just outside the sanctuary. Furthermore, as a consequence of improved reef fisheries, more fishermen fishing in areas closest to the sanctuary have increased their catch.

Ecological State of Coral Reefs for Conservation and Developmental Planning in Pandan Island, Puerto Princesa City, Philippines

In Palawan, Philippines, Honda Bay is fast becoming a target recreational site for curious domestic and foreign visitors. The general objectives of this resource assessment are to gather information regarding status of the marine resources in Pandan Island, and to provide recommendations for their sustainable use. Assessment was done using line intercept transect (LIT), fish visual census (FVC) and an imaginary transect belt for coral cover, fish, and macro-invertebrates, respectively. Average live coral cover around Pandan Island can be categorized as good (57%), with stations 7 and 1 and 2 categorized as excellent (76-100%) and fair (26-50%) conditions, respectively. Some 178 fish species were recorded in Pandan Island waters of which seven (7) highly target and 29 common commercial fish species were found. The estimated total reef fish biomass around Pandan Island is 588 mt/ km2. A total of eight macro invertebrate (shells, etc.) species belonging to five families was found around Pandan Island. The study concluded that of these eight species, six are commercially important,Tridacnacro cea(taklobo), Tridacnasquamosa (taklobo), Hippopusporcellanus(taklobo), Trochusniloticus(topshell), Pinna nobilis (tarab), and Bohadschiamarmota (sea cucumber). Five of these species the T. crocea, T. squamosa, H. porcellanus, P. nobilis, and T. niloticus are listed as endangered species by International Union for Conservation of Nature. Keywords - target species, macro-invertebrates, coral cover, coral reefs, reef fish, conservation

Environmental and human exposure assessment monitoring of communities near an abandoned mercury mine in the Philippines: A toxic legacy

Abandoned mines are an important global concern and continue to pose real or potential threats to human safety and health including environmental damage/s. Very few countries had government mine regulation and reclamation policies until the latter part of the century where legal, financial and technical procedures were required for existing mining operations. Major reasons for mine closure may be mainly due to poor economies of the commodity making mining unprofitable, technical difficulties and national security. If the mine is abandoned, more often than not it is the government that shoulders the burden of clean-up, monitoring and remediation. The topic of abandoned mines is complex because of the associated financial and legal liability implications. Abandoned mercury mines have been identified as one of the major concerns because of their significant long-term environmental problems. Primary mercury production is still ongoing in Spain, Kyrgzystan, China, Algeria, Russia and Slovakia while world production declined substantially in the late 1980s. In the Philippines, the mercury mine located southeast of Manila was in operation from 1955 to 1976, before ceasing operation because of the decline in world market price for the commodity. During this time, annual production of mercury was estimated to be about 140,000 kg of mercury yearly. Approximately 2,000,000 t of mine-waste calcines (retorted ore) were produced during mining and roughly 1,000,000 t of these calcines were dumped into nearby Honda Bay to construct a jetty to facilitate mine operations where about 2000 people reside in the nearby three barangays. In October, 1994 the Department of Health received a request from the Provincial Health Office for technical assistance relative to the investigation of increasing complaints of unusual symptoms (e.g. miscarriages, tooth loss, muscle weakness, paralysis, anemia, tremors, etc.) among residents of three barangays. Initial health reports revealed significant elevation of blood mercury levels exceeding the then recommended exposure level of 20 ppb in 12 out of the 43 (27.9%) residents examined. The majority of the volunteers were former mine workers. In this study the abnormal findings included gingivitis, mercury lines, gum bleeding and pterydium. The most common neurologic complaints were numbness, weakness, tremors and incoordination. Anemia and elevated liver function tests were also seen in a majority of those examined. The assessment also revealed a probable association between blood mercury level and eosinophilia. The same association was also seen between high mercury levels and the presence of tremors and working in the mercury mine. To date, there are very limited environmental and health studies on the impact of both total and methylmercury that have been undertaken in the Philippines. Thus, this area of study was selected primarily because of its importance as an emerging issue in the country, especially regarding the combined effects of total and methylmercury low-dose and continuous uptake from environmental sources. At present the effects of total mercury exposure combined with MeHg consumption remain an important issue, especially those of low-dose and continuous uptake. Results of the study showed that four (4) species of fish, namely ibis, tabas, lapu-lapu and torsillo, had exceeded the recommended total mercury and methylmercury levels in fish (NV>0.5 ug/g f.w., NV>0.3 ug/g f.w., respectively). Saging and kanuping also exceeded the permissible levels for methylmercury. Total and methylmercury in canned fish, and total mercury in rice, ambient air and drinking water were within the recommended levels, however, additional mercury load from these sources may contribute to the over-all body burden of mercury among residents in the area. Surface water quality at the mining area, Honda Bay and during some monitoring periods at Palawan Bay exceeded total mercury standards (NV>0.002 ng/mL). Soil samples in two sites, namely Tagburos and Honda Bay, exceeded the EPA Region 9 Primary Remediation Goal recommended values for total mercury for residential purposes (NV>23 mg/kg). The hand to mouth activity among infants and children is another significant route for mercury exposure. Statistically significant results were obtained for infants when comparing the results after one year of monitoring for methylmercury levels in hair for both exposed and control sub-groups. Likewise, comparing the initial and final hair methylmercury levels among pregnant women/mothers in the exposed group showed statistically significant ( p<0.05) results. Comparing the exposed and control sub-groups’ mercury hair levels per sub-group showed statistically significant results among the following: (a) initial and final total mercury hair levels among children, (b) initial and final methylmercury hair levels among children, (c) final total mercury hair levels among pregnant women, (d) initial and final total mercury hair levels among mothers, and (e) initial and final methyl hair levels among mothers.

Knowledge, gender, and resources in small-scale fishing: the case of Honda Bay, Palawan, Philippines.

The coastal zone is a place of intense activity where resources, users, and resource-use practices interact. This case study of small-scale fisheries in Honda Bay, Palawan, Philippines shows that resources, space, and gender are intertwined. The study was conducted between June 1997 and July 1998. The data were gathered using free listing, pile sort, ranking, resource mapping, and key informant interviews. The results showed that women's knowledge about fishery resources and their fishing activities are associated with the intertidal zone whereas men's knowledge is associated with coral reefs. In classifying fishery resources, appearance is the main consideration for women whereas a combination of appearance, habitat, and type of fishing gear is the consideration used by men. Market price is very important because of its dependence on the demand of the export market as well as the local market. Women dominate the buying of fishery products. Many women market their husband's catch, process fish, or gather shells and sea cucumber for sale. Among the fishing households, type of fishing gear provides an indication of socioeconomic standing. This paper concludes that access to resources is shaped by gender and age. The differences in resource knowledge possessed by men and women lead to differential access to fishery resources. In addition, the differences in socioeconomic status also influence resource access. The socialization of children into fishing reinforces the gender division of labor and space in the coastal zone.

Mercury and methylmercury contents in mine-waste calcine, water, and sediment collected from the Palawan Quicksilver Mine, Philippines

The Palawan Quicksilver mine, Philippines, produced about 2,900 t of mercury during mining of cinnabar ore from 1953 to 1976. More than 2,000,000 t of mine-waste calcines (retorted ore) were produced during mining, much of which were used to construct a jetty in nearby Honda Bay. Since 1995, high Hg contents have been found in several people living near the mine, and 21 of these people were treated for mercury poisoning. Samples of mine-waste calcine contain high total Hg concentrations ranging from 43–660 µg/g, whereas total Hg concentrations in sediment samples collected from a mine pit lake and local stream vary from 3.7–400 µg/g. Mine water flowing through the calcines is acidic, pH 3.1–4.3, and total Hg concentrations ranging from 18–31 µg/l in this water significantly exceed the 1.0-µg/l drinking water standard for Hg recommended by the World Health Organization (WHO). Total Hg contents are generally lower in water samples collected from surrounding domestic wells, the mine pit lake, Honda Bay, and the nearby stream, varying from 0.008–1.4 µg/l. Methylmercury concentrations in water draining mine calcines range from <0.02–1.4 ng/l, but methylmercury is highest in the pit lake water, ranging from 1.7–3.1 ng/l. Mercury methylation at the Palawan mine is similar to or higher than that found in other mercury mines worldwide. Much of the methylmercury generated in Palawan mine-waste calcines and those in Honda Bay is transferred to water, and then to marine fish and seafood. A food source pathway of Hg to humans is most likely in this coastal, high fish-consuming population.

Polychaetes of the mangrove-fouling community at the Colombian Archipelago of San Andres and Old Providence, Western Caribbean

This study records the polychaetes found on the submerged roots of Rhizophora mangl on San Andres and Providence Islands, ColombianCaribbean. Sampling was done in 1998 during the rainy (July) and dry(November) seasons; each season, 17 roots were collected in threedifferent stations with different kinds of human impact, two in San Andresand one in Providence. At the same time temperature, salinity anddissolved oxygen were measured in situ. Aromatic hydrocarbons weremeasured in the laboratory. The polychaetes were removed from the rootsand identified. The available root area for the organisms was alsomeasured.Five genera and 11 species were newly recorded for the ColombianCaribbean. The most abundant families were Terebellidae in Old ProvidenceMc Bean Lagoon, Syllidae in Honda Bay and Nereididae in Hooker Bayon the San Andres Island. Thelepus `setosus' (Terebellidae) and Amblyosyllis sp. (Syllidae) were highly abundant in less polluted samplingstations such as Old Providence Mc Bean Lagoon and Honda Bay. On theother hand, Neanthes `succinea' (Nereididae) were abundant inHooker Bay which was the most polluted station. Salinity seemed to be the mostimportant parameter for the polychaete populations. The populations ofpolychaetes, as a total group, seemed to be related to the root areaavailable on both islands, independent of the season. However, during therainy season, the populations were independent of root area availability,while during the dry season, the populations were dependent on it.

Assessment by hair analysis of mercury exposure among mining impacted communities of Mindanao and Palawan, the Philippines.

Human mercury (Hg) exposure in two contrasting areas of mining and mineral processing activity on the Philippine islands of Mindanao and Palawan was evaluated using hair analysis. On Mindanao, samples were collected from residents of Apokon, a major regional centre for gold beneficiation. On Palawan, a former cinnabar mine and mine-waste disposal site in Honda Bay formed the focus of investigation. Relatively high hair Hg burdens (up to 13 mg Hg kg−1 at Apokon and 18.5 mg Hg kg−1 in Honda Bay) were observed in both populations, with occupational factors apparently constituting a first-order exposure control. At Apokon, hair burdens in excess 2 mg Hg kg−1 were recorded in 90% of Au processing plant workers, compared with 21% of other sectors of the population. In Bay, ex-mineworkers, although possibly subject to occupational Hg exposure in the past, now display no evidence of this influence. Fishermen, however, systematically yielded hair Hg concentrations a factor of 2.5 higher than those of the remaining population. Approximately 7% of the Apokon and Honda Bay residents sampled presented hair Hg concentrations equal to or in excess of the World Health Organisation (WHO) reference dose. There is little evidence to indicate that residential factors significantly influence Hg exposure in either area. Hazard mitigation strategies involving the isolation of resident populations from perceived contaminant sources such as ore processing plant and sites of mine-waste disposal are, therefore, unlikely to prove beneficial.