Bay Residents Research Articles

A217 EVALUATING PREDICTIVE SCORING AND OUTCOMES OF PATIENTS DISCHARGED HOME FROM THE EMERGENCY DEPARTMENT WITH UPPER GASTROINTESTINGAL BLEEDING

Abstract Background Upper gastrointestinal bleed (UGIB) is a common emergency department (ED) presentation. The Glasgow-Blatchford Bleeding Score (GBS) is a validated tool for predicting UGIBs requiring admission for endoscopic evaluation. Utilization of GBS in Northern Ontario EDs may help risk stratify UGIB to decrease return to care. Aims This study aimed to evaluate factors and outcomes of patients discharged from the ED with suspected UGIB. Methods A total of 1,139 charts were identified with an ICD-10 ED diagnosis of gastrointestinal hemorrhage from 2016-2022. Of these, 92 charts met inclusion criteria. Patients admitted to hospital from the index ED visit, who were below the age of 18 years at the time of presentation, or with clinically suspected lower gastrointestinal hemorrhage were excluded. Patient were further grouped by place of residence if their primary address was within Thunder Bay city limits or not. Results There were 48 males (52%) with a median age of 58.7 (IQR 32.2) at presentation with UGIB to ED. The median (IQR) Charlson Comorbidity Index (CCI) and GBS were 3 (5) and 3 (6), respectively. The odds ratio for returning to the ED and being admitted for UGIB within sixty days was 4.07 times greater for patients from the region compared to Thunder Bay residents (95% CI 1.28–12.97). GBS was found to be significantly greater (p=0.048, Mann-Whitney U-Test) among seven patients who underwent emergent endoscopy from the ED and were discharged home. In univariate K-M survival analysis, the mean survival time to hospital admission at sixty days was 45 days among those with a presenting GBS score of ampersand:003E3, compared to 57 days when GBS was 3 or less (pampersand:003C0.005, log rank Mantel-Cox). After adjustment for age, sex, place of residence, and CCI, there was a 17% increase in the expected hazard for hospital admission at sixty days for each point increase in GBS (95% CI 1.03–1.34). Similarly, the expected hazard for follow-up hospital admission was 2.95 times higher (95% CI 1.11–7.85) in patients living outside Thunder Bay travelling to seek care. There were no statistically significant hazards identified between age, sex, or CCI and hospital admission (Cox proportional hazards model, p=0.001). Of patients admitted to hospital within sixty days of ED discharge (n=17), the median length of stay was five days with 56% requiring blood transfusion and 83% receiving endoscopy. Conclusions Higher GBS scores and residence outside of Thunder Bay increase the likelihood of revisit and admission to hospital for UGIB following ED discharge. Future research will aim to compare outcomes among larger urban centers. Funding Agencies NOAMA

National blood bank services as a platform for national human biomonitoring - A proof-of-concept study.

BackgroundHuman biomonitoring (HBM) is crucial for identifying potential risks to human health from exposure to environmental hazards. However, it is an expensive and labor-intensive endeavor. To save on samples’ collection process we suggested using a national blood banking system as a platform for a national HBM program. For the case study, we used a comparison of blood donors from heavily industrialized Haifa Bay region, northern Israel, with donors from the rest of the country. MethodsThe study population comprised a random sample of blood donors donating blood all over Israel. Samples of whole blood were tested for arsenic (As), cadmium (Cd), chromium (Cr) and lead (Pb). Donors’ donations sites and residential locations were geocoded. Smoking status was verified based on Cd levels, after calibrating their concentrations vs Cotinine in a sub-sample of 45 subjects. Metal concentrations were compared between regions using a lognormal regression, while controlling for age, gender, and predicted probability of smoking. ResultsDuring Mar 2020–Feb 2022, we collected 6230 and tested 911 samples. Concentrations of most of the metals were modified by age, gender, and smoking. Cr and Pb appeared to be 1.08–1.10 times higher among Haifa Bay residents than in the rest of the country (although with borderline significance of 0.069 for Cr). Cr and Pb were 1.13–1.15 times higher for those who donated blood in the Haifa Bay region, but not necessarily resided in the area. Donors from Haifa Bay had lower levels of As and Cd as compared to other donors in Israel. ConclusionsUsing a national blood banking system for HBM proved to be feasible and efficient. Blood donors from Haifa Bay area were characterized by elevated levels of Cr and Pb and lower levels of As and Cd. An extensive investigation of industries in the area is warranted.

Non-persistent exposures from plasticizers or plastic constituents in remote Arctic communities: a case for further research

BackgroundPersistent organic pollutant exposures are well-documented in the Arctic, but fewer studies examined non-persistent chemicals, despite increased market food and consumer product consumption.ObjectiveTo measure phenol, paraben, phthalate, and alternative plasticizer concentrations in Inuit adults.MethodsThe study included 30 pooled urine samples from Qanuilirpitaa? 2017 Nunavik Inuit Health Survey (Q2017) participants. Creatinine-adjusted geometric mean concentrations (GM) and 95% confidence intervals (CI) were compared across sex, age, and regions, and compared to those in the Canadian Health Measures Survey (CHMS) and the First Nations Biomonitoring Initiative (FNBI).ResultsQ2017 bisphenol-A concentrations were double the CHMS 2018–2019 concentrations [GM (95% CI): 1.98 (1.69–2.31) versus 0.71 (0.60–0.84) µg/g creatinine], but in line with FNBI [1.74 (1.41–2.13) µg/g creatinine]. Several phthalate concentrations were higher in Q2017 versus CHMS, particularly monobenzyl phthalate, which was was 19-fold higher in Q2017 versus CHMS 2018–2019 [45.26 (39.35–52.06) versus 2.4 (2.0–2.9) µg/g creatinine] and four-fold higher than FNBI. There were also four-fold higher concentrations of the two alternate plasticizer 2,2,4-trimethyl-1,3-pentanediol diisobutyrate (TIXB) metabolites in Q2017 compared to CHMS 2018–2019. Women and people living in Ungava Bay had generally higher concentrations of non-persistent chemicals.SignificanceThe results suggest higher concentrations of certain non-persistent chemicals in Inuit versus the general Canadian population.ImpactFew studies have explored non-persistent chemical distributions in Northern communities, despite the increasing consumer product and market food consumption. We analyzed 30 pooled samples from the Qanuilirpitaa? Nunavik Inuit Health Survey 2017 to assess exposures to common plasticizes and plastic constituents and compare their levels with the general Canadian population and First Nation groups. We observed particularly higher levels of bisphenol-A, of monobenzyl phthalate, and of two 2,2,4-trimethyl-1,3-pentanediol diisobutyrate (TXIB) metabolites among Nunavimmiut compared to the general Canadian population, notably among women and Ungava Bay residents. Larger studies are required to confirm our findings and identify potential adverse health effects from these exposures.

Scalar Claims, Worker Strategies, and ‘South Africa’s Labour Empire’ in Namibia, 1943–1979

This article seeks to place Namibia’s contract labour system, and those whose lives it shaped, in histories of labour migration and South African empire-building in southern Africa. In order to do so, it traces South African and South West African (SWA) officials’ attempts to re-scale a trans-colonial migrant labour system to fit nominally decolonised, national scales. Secondly, it examines how African contestations of state power on a municipal scale undermined officials’ scalar projects. In asserting a transnational zone of migrant labour recruitment that straddled the SWA–Angola boundary and articulated with the sprawling recruitment networks of the Witwatersrand Native Labour Association (WNLA), the SWA Native Labour Association (SWANLA) laid claim to the same scale of practice as recruiters for the Rand mines. Labour shortages in SWA and South Africa in the 1950s led then Minister of Native Affairs Hendrik Verwoerd to place the ‘controlled bringing in and sending away’ of foreign Africans at the centre of South Africa’s labour empire. In the 1960s, in response to African migration and international pressures, South African and SWA officials sought to replace SWANLA with a territory-wide labour bureau system, run partly out of bantustan governments, that would support claims of decolonisation through ‘separate development’. The article then examines African engagements with urban influx control infrastructures and practices on a small scale, in the port and fishing town of Walvis Bay. Whether leveraging house rental payments as a promise of secure urban tenure or using beer to escape infrastructural ties to the state, African Walvis Bay residents emphasised the importance of the urban scale in the colonial exercise of power. Since these contestations had African urbanisation at their core, they proved the lie of bantustans as the physical and political homes of essentially rural Africans.

Redefining spatial population structure of winter flounder (Pseudopleuronectes americanus): implications for stock assessment and management

The southern New England – mid-Atlantic (SNE–MA) stock of winter flounder (Pseudopleuronectes americanus) collapsed in the 1990s without discernable recovery to date. Owing to the lack of recovery, consideration of population subcomponents, which are currently ignored in fisheries stock structure definitions, may be necessary for rebuilding. We used the otolith chemistry tracer manganese–calcium ratios (Mn/Ca) to estimate inshore- versus ocean-nursery contributions of 77.3%/22.7% in SNE–MA, 15.7%/84.3% in the Gulf of Maine (GOM), and 60.0%/40.0% in Georges Bank (GB). In addition, we used strontium–calcium ratios (Sr/Ca) to estimate migratory- and resident-contingent membership of nursery-classified fish. Across all stocks, 30.2% of fish were classified as bay residents, 25.2% as bay migrants, 25.8% as ocean residents, and 18.8% as ocean migrants. Finally, model selection indicated that both nursery-specific and contingent-specific growth models were more appropriate than a common model. Nursery-specific models exhibited increasing deviations in length with age. Contingent-specific model reflected moderate differences at the youngest ages but convergence at older ages. These findings are informative for the population structure and migration ecology of winter flounder; however, simulation is required to determine whether partial migration and substock structure are necessary inputs for sustainable fisheries management.

Differential migration in Chesapeake Bay striped bass.

Differential migration—increased migration propensity with increasing individual size—is common in migratory species. Like other forms of partial migration, it provides spatial buffering against regional differences in habitat quality and sources of mortality. We investigated differential migration and its consequences to survival and reproductive patterns in striped bass, a species with well-known plasticity in migration behaviors. A size-stratified sample of Potomac River (Chesapeake Bay) Morone saxatilis striped bass was implanted with acoustic transmitters and their subsequent coastal shelf migrations recorded over a 4-yr period by telemetry receivers throughout the Mid-Atlantic Bight and Southern New England. A generalized linear mixed model predicted that ≥ 50% of both males and females depart the Chesapeake Bay at large sizes >80 cm total length. Egressing striped bass exited through both the Chesapeake Bay mouth and Delaware Bay (via the Chesapeake and Delaware Canal), favoring the former. All large fish migrated to Massachusetts shelf waters and in subsequent years repeatedly returned to regions within Massachusetts and Cape Cod Bays. Within this dominant behavior, minority behaviors included straying, skipped spawning, and residency by large individuals (those expected to migrate). Analysis of the last day of transmission indicated that small resident striped bass experienced nearly 2-fold higher loss rates (70% yr-1) than coastal shelf emigrants (37% yr-1). The study confirmed expectations for a threshold size at emigration and different mortality levels between Chesapeake Bay (resident) and ocean (migratory) population contingents; and supported the central premise of the current assessment and management framework of a two-contingent population: smaller Chesapeake Bay residents and a larger ocean contingent. An improved understanding of differential migration thus affords an opportunity to specify stock assessments according to different population sub-components, and tailor reference points and control rules between regions and fishing stakeholder groups.

‘To unite as one’: resisting slum clearance in Freemans Bay, 1951–1968

This article examines the activities of the Freemans Bay Residents Welfare Association, which formed to promote residents’ welfare and to retain the neighbourhood’s integrity in the face of slum clearance during the 1950s and 1960s in Auckland, New Zealand. The Association’s objective was: ‘To combine socially for the cultural good of all people in the area. To unite as one, regardless of race, colour or creed, for the peaceful and fruitful existence of our residents.’ John (Johnny) James Mitchell, secretary of the Association, invoked working-class solidarity – to unite as one – to bring together residents who could also be classified by race, religion, political belief, employment status, ‘respectability’ and housing occupancy. This solidarity was assisted by the Auckland City Council who zoned the Reclamation Area for clearance, affecting all residents within its bounds. However, racial discrimination practised by private landlords, local government and state departments meant that Māori were more likely to occupy condemned housing to begin with and were the last to be assisted by the state in the slum clearance process. As a result, race remained a more potent signifier for Māori residents and they organised through the Māori Women’s Welfare League and the Māori Community Centre, in alliance with the Association.

Population Structure of Alligator Gar in a Gulf Coast River: Insights from Otolith Microchemistry and Genetic Analyses

AbstractGrowing interest in the Alligator Gar Atractosteus spatula among anglers and fishery managers has inspired efforts to better manage populations. Successful management requires identifying population structure and understanding the distribution of stocks and associated differences in life history. This is particularly important in river systems along the coast of the Gulf of Mexico, where transitions from freshwater rivers to saltwater bays provide the potential for life history diversification. We used otolith microchemistry and genetics to assess population structure of Alligator Gars in the Guadalupe River–San Antonio Bay system, Texas. Lifetime Sr:Ca revealed three, distinct life histories that differed in prevalence across the system. River‐resident fish (i.e., fish exclusive to freshwater) were present throughout the river but were most common in the uppermost river reach (74% of upper river fish). Transient fish that used both river and bay habitats were also found throughout the river but were most prevalent in the lowermost river reach (66% of lower river fish) and bay (91% of bay fish). Bay residents (i.e., fish exclusive to salt water) were detected but comprised only 9% of bay fish. Haplotype diversity based on mitochondrial DNA was lowest in the upper river, indicating limited gene flow compared with the lower river and bay. Similarly, nuclear DNA analyses indicated nonrandom mating between fish from the upper river, lower river, and bay. The differences in Alligator Gar movement and genetics along the river–bay continuum suggest the presence of a river resident stock that predominates the upper river, and a transient stock that predominates the lower river and bay. Therefore, a local‐scale management approach, consistent with the spatial partitioning between stocks, would conserve life history and genetic diversity within the system and provide opportunities to meet the needs of a diverse angling constituency. Understanding how population dynamics differ between stocks is needed to develop appropriate fishery management objectives and corresponding regulations for Alligator Gar.Received May 20, 2016; accepted December 2, 2016 Published online February 27, 2017

A survey informed PV-based cost-effective electrification options for rural sub-Saharan Africa

A comprehensive survey is carried out in Kendu Bay area of Kenya to determine electrification patterns of a typical rural sub-Saharan Africa community and to determine the reasons behind such energy choices. The data from the survey is used to build a transition probability matrix (TPM) for different electrification states for Kendu Bay households. The TPM and the survey data are used to model temporal diffusion of PV systems and PV-based communal (mini/micro) grids in the area. Survey data show that majority of Kendu Bay residents shun the national grid due to high connection fees, unreliability of the system, and corruption; people who can afford-to choose small solar home systems for their basic electricity needs. Without any government policy intervention or help, simulation results show that once 100% electrification status has been achieved in Kendu Bay, only 26% of the residents will be found to be electrified through the national grid alone; the majority (38%) will be electrified through PV-based communal grids while the remaining 36% will be electrified through grid connected PV home systems (26%) or grid connected communal grids (10%).

Community perceptions of collaborative processes for managing freshwater resources

Six of New Zealand’s 16 regional councils are trialling collaborative planning as a means of addressing complex challenges in freshwater management. Although some work has been undertaken to evaluate similarities and differences across those processes, the success or failure rests with the public’s acceptance of the processes and their outcomes. This is the first study to evaluate public perceptions of freshwater management in regions with collaborative processes. We surveyed 450 respondents in Hawke’s Bay, Northland, and Waikato, some of whom live in catchments in which collaborative processes are under way and some of whom do not. In addition to assessing awareness of the collaborative planning processes, the survey measured perceptions regarding the regional council’s management of freshwater resources, the extent of agreement regarding freshwater management among various interests, the fairness of freshwater management, and the extent to which respondents believe that their interests and concerns are included in freshwater management. We hypothesized that relative to respondents in parts of the region in which traditional processes are in places, respondents in catchments with collaborative management of freshwater resources would have more positive perceptions of management, agreement, fairness, and interests, even if there is low awareness that a collaborative planning process is under way. Survey results indicate that knowledge of collaborative processes is generally low and that living in catchments with collaborative processes does not impact respondents’ perceptions of management, agreement, fairness, or interests in Northland or Waikato. However, relative to Hawke’s Bay respondents living outside of the collaborative catchment, respondents living inside the collaborative catchment believe that the regional council’s freshwater management is better and fairer. Moreover, Hawke’s Bay residents living inside the collaborative catchment perceive less conflict over freshwater management than Hawke’s Bay respondents living outside the collaborative catchment. Further research is needed to identify the reasons for this regional variation.

Concentrations and trends of halogenated flame retardants in the pooled serum of residents of Laizhou Bay, China

The south coast of Laizhou Bay, in northeastern China, is a production area for halogenated flame retardants (HFR). In 2007, the authors measured serum concentrations of polybrominated diphenyl ethers (PBDEs) in Laizhou Bay residents. To assess the PBDE concentration trend, and determine the concentrations of the emerging flame retardants Dechlorane Plus (DP) and bis(2-ethylhexyl)-3,4,5,6-tetrabromophthalate (TBPH), the authors measured the concentrations of 8 PBDE congeners, 2 DP isomers, and TBPH in 10 composite samples, which were pooled from the serum collected from 305 Laizhou Bay residents in October 2011. The average concentration of the total PBDE (∑8 PBDE) concentration in all serum pools was 240 ng/g lipid weight, and the highest serum pool concentration (in the 30- to 39-yr-old male group) was 780 ng/g lipid weight. Brominated diphenyl ether-209 was the dominant congener, accounting for 87% of ∑8 PBDE. Compared with a previous study, ∑8 PBDE serum concentrations in the present study showed no change in order of magnitude, but the relative contribution of BDE-209 to ∑8 PBDE was higher. The average concentration of ∑DP in all serum pools was 3.6 ng/g lipid weight, ranging from 1.4 ng/g lipid weight (in the 50- to 59-yr-old male group) to 11 ng/g lipid weight (in the 20- to 29-yr-old male group). The concentration of DP was lower than in other reported studies. The study also detected TBPH in the 30- to 39-yr-old female group, suggesting that TBPH, as an emerging HFR, requires further monitoring.

A Spatial Analysis of Cultural Ecosystem Service Valuation by Regional Stakeholders in Florida—A Coastal Application of the Social Values for Ecosystem Services (SolVES) Tool

How can we measure how Sarasota Bay residents value their area’s cultural ecosystem services? This 4-page fact sheet describes a project to use a geographic information system application, SolVES 2.0, to assess, map and quantify environmental benefits to people to assist in coastal development decision making. Written by Alisa Cofin, Robert Swett, and Zachary Cole, and published by the UF Department of Sea Grant, November 2012. 
 Retired from EDIS September 2018.

Socioeconomic Factors and Their Relation to Eating Habits in Two Communities in Nova Scotia, Canada

Household food purchases and hence consumption are representative of household education, income, employment, and health. This study compares 2 communities in Nova Scotia, Canada: Glace Bay, located east of Sydney on Cape Breton Island, and King's County, west of Halifax. Glace Bay fares less well in the previous 4 categories and, consequently, it was hypothesized that Glace Bay would also rank lower in terms of nutritional quality of food purchases and their consumption compared to King's County. Questionnaires regarding socioeconomic conditions and food consumption patterns were completed by households in both communities. Glace Bay residents consumed similar levels of meat and dairy but lower levels of fresh and canned fruits and vegetables compared to King's County. Glace Bay also had a higher consumption of eggs, bread, carbonated beverages, and french fries and purchased fewer organic foods. It is concluded that lower levels of the 4 factors in Glace Bay contribute to these poorer food intakes and to some indicators of health. Action is required to improve nutrition in Glace Bay.

Marine Habitat Use by Anadromous Bull Trout from the Skagit River, Washington

AbstractAcoustic telemetry was used to describe fish positions and marine habitat use by tagged bull trout Salvelinus confluentus from the Skagit River, Washington. In March and April 2006, 20 fish were captured and tagged in the lower Skagit River, while 15 fish from the Swinomish Channel were tagged during May and June. Sixteen fish tagged in 2004 and 2005 were also detected during the study. Fish entered Skagit Bay from March to May and returned to the river from May to August. The saltwater residency for the 13 fish detected during the out‐migration and return migration ranged from 36 to 133 d (mean ± SD, 75 ± 22 d). Most bull trout were detected less than 14 km (8.5 ± 4.4 km) from the Skagit River, and several bay residents used the Swinomish Channel while migrating. The bull trout detected in the bay were associated with the shoreline (distance from shore, 0.32 ± 0.27 km) and occupied shallow‐water habitats (mean water column depth, <4.0 m). The modified‐minimum convex polygons (MMCPs) used to describe the habitats used by 14 bay fish showed that most areas were less than 1,000 ha. The mean length of the shoreline bordering the MMCPs was 2.8 km (range, 0.01–5.7 km) for bay fish and 0.6 km for 2 channel residents. Coastal deposits, low banks, and sediment bluffs were common shoreline classes found within the MMCPs of bay fish, while modified shoreline classes usually included concrete bulkheads and riprap. Mixed fines, mixed coarse sediments, and sand were common substrate classes found within MMCPs; green algae and eelgrass (Zostera sp.) vegetation classes made up more than 70% of the area used by bull trout. Our results will help managers identify specific nearshore areas that may require further protection to sustain the unique anadromous life history of bull trout.Received October 25, 2010; accepted May 5, 2011

Learning from nature: bottlenose dolphin care and husbandry

The world's longest-running study of a wild dolphin population, operated by the Chicago Zoological Society since 1989, has focused on the multi-generational resident community of about 160 bottlenose dolphins in Sarasota Bay, Florida, since 1970. Observational and capture-release research on the biology, behavior, life history, ecology, and health of individually identifiable bay residents of up to 59 years of age and spanning five generations has helped to inform collection managers at the Brookfield Zoo and partner institutions. Age, sex, and genetic compositions of colonies at cooperating institutions have been based on observations of social structure and genetic paternity testing in Sarasota Bay to optimize breeding success. Breeding success, including calf survivorship, is evaluated relative to individual wild dolphin reproductive histories, spanning as many as nine calves and four decades. Individual rearing patterns for wild dolphins provide guidance for determining how long to keep mothers and calves together, and help to define the next steps in the calves' social development. Health assessments provide data on expected ranges of blood, milk and urine values, morphometrics, and body condition relative to age, sex, and reproductive condition. Calf growth can be compared with wild values. Target weights and blubber thicknesses for specific age and sex classes in specified water temperatures are available for wild dolphins, and caloric intakes can be adjusted accordingly to meet the targets. A strength of the program is the ability to monitor individuals throughout their lives, and to be able to define individual ranges of variability through ontogenetic stages.

Love Thy Neighbour? The Relationship Between Kahurangi National Park and the Border Communities of Karamea and Golden Bay, New Zealand

The establishment of national parks can generate significant changes for the people living in and around these protected areas. This paper describes a qualitative study that investigated the nature of the people-park relationship for two rural New Zealand communities: Golden Bay and Karamea, near Kahurangi National Park. Data were collected through semi-structured, in-depth interviews with 20 Karamea residents and 21 Golden Bay residents. Three dimensions of the people-park relationship were explored: 1. lifestyle, place attachment and recreation; 2. tourism; and 3. interactions with the national park management agency. Despite their relative proximity, important differences emerged between the two communities in terms of residents’ relationships with the park, and their perceptions of the park’s effects. These differences are discussed in the context of the primary people-park dimensions.

Do non-estuarine mangroves harbour higher densities of juvenile fish than adjacent shallow-water and coral reef habitats in Curaçao (Netherlands Antilles)?

Most mangroves occur in tropical estuaries and generally contain higher densities of fish than adjacent habitats such as seagrass beds and sand flats. The question of whether these fishes depend on estuaries per se has given rise to the concept of estuarine-dependence. On several Caribbean islands, mangroves are only found in non-estuarine bays and lagoons. To test whether fishes also depend on mangroves in non-estuarine conditions we determined juvenile and adult densities of a complete reef fish community in 4 bay habitats (mangrove, seagrass bed, channel, subtitdal mud flat) in the Spanish Water Bay and 4 depth zones (2, 5, 10 and 15 m depth) on the adjacent coral reef of the Caribbean island of Curacao (Netherlands Antilles), using a single visual census technique in all habitats. The results showed that non-estuarine mangroves did harbour a much higher total juvenile fish density, density of juvenile temporary bay residents (i.e. nursery species), and density of juvenile permanent bay residents (i.e. bay species) than adjacent seagrass beds, channel and mud flats, but a similar total juvenile fish density as the coral reef. The different patterns of abundance of juvenile fish are probably related to the degree of structural habitat complexity. For a number of nursery and bay species, juvenile fish were found almost exclusively in the mangroves and sometimes to a lesser extent in other bay habitats, but rarely on the coral reef, giving rise to the concept of 'bay habitat dependence'. Juvenile and adult habitats differed for at least 21 of the 50 most common reef species, suggesting partial or complete ontogenetic habitat shifts from the mangroves to the reef, from the channel to the reef, and from the shallow to the deeper coral reef. Different associations with habitat type were also found at the level of fish families.

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.

Assessment of mercury contamination and human exposure associated with coastal disposal of waste from a cinnabar mining operation, Palawan, Philippines

An integrated geochemical and toxicological assessment of environmental mercury contamination and attendant human exposure in Honda Bay, Palawan was undertaken in 1995 following a nationally reported pollution scare centered on a coastal jetty, Sitio Honda Bay, constructed using approximately 1 million tons of tailings and beneficiation waste from a cinnabar mine. Mercury (Hg) data for marine and fluvial sediments, fish tissues and human hair indicate that the toxicological hazard is considerably lower than initially reported by state environment and health officials. Typical Hg concentrations in surficial Honda Bay sediments were found to lie within the global background range (<60 μg/kg). Downcore profiles provide no evidence of enhanced Hg fluxes coincident with the onset of mining and/or coastal tailings disposal. The mean and median Hg concentrations recorded in tissues of six species of Honda Bay fish are compliant with thresholds established by the US Environmental Protection Agency (US-EPA) for marketable stocks. Earlier reports of 'Minamata range' Hg concentrations in fish and shellfish from Honda Bay remain unsubstantiated. Geochemical analyses of samples of the Sitio Honda Bay substrate have confirmed the prevalence of solid-phase Hg concentrations to ca. 340 mg/kg. The speciation of Hg is, however, dominated by secondary oxides of low bioavailability. The mean Hg concentration in hair from Sitio Honda Bay residents (4.41 mg/kg) was found to be statistically analogous to that for a neighbouring coastal community unimpacted by the coastal disposal of mine waste. A negligible residential exposure factor is thus inferred for the former. Relatively high hair Hg burdens prevail throughout the coastal Honda Bay population, consistent with significant methyl Hg ingestion through daily fish consumption. The data presented provide no environmental or toxicological justification for immediate remedial action.

Summer Habitat Suitability for Striped Bass in Chesapeake Bay: Reflections on a Population Decline

We evaluated summer water temperatures, dissolved oxygen concentrations, distribution of striped bass Morone saxatilis subadults and adults, and juvenile abundance indexes in Chesapeake Bay to discern any influences of summer habitat suitability on historical changes in populations. Criteria for habitat suitability were those identified in freshwater reservoirs (temperature below 25°C and dissolved oxygen above 2–3 mg/L), which we confirmed for the York-Pamunkey estuary in the lower bay. Habitat suitability in the upper central basin in July declined significantly from 1962 to 1987, as did juvenile abundance indexes (mean catches per standard seine haul). Thickness of suitable temperature-oxygen habitat correlated significantly with Maryland juvenile indexes the following year. Relative reproductive performance of upper (Maryland) and lower (Virginia) bay stocks changed between 1967–1973 and 1980–1988 in parallel with reduction in upper bay summer habitat. The annual temperature-oxygen cycle in the bay revealed two key areas for striped bass subadults and adults: (1) a zone of cool water in north-central Chesapeake Bay near Annapolis, Maryland, where fish of these ages congregate in summer, and (2) a shallow sill across the lower bay near the mouth of the Rappahannock River, Virginia, where warm surface waters (>25°C) in summer impinge on the bottom and may block egress from the bay. The importance of year-round bay residents for reproduction in the upper bay may have been underestimated previously, at least for the recent low population levels. Reduced juvenile production at the head of the bay and population decline would be consistent with limitation of historically important habitat in summer and resultant physiological stresses of high temperature and low dissolved oxygen that affect reproductive competence the following year.