DNA barcodes reveal species-specific mercury levels in tuna sushi that pose a health risk to consumers

Excessive ingestion of mercury—a health hazard associated with consuming predatory fishes—damages neurological, sensory-motor and cardiovascular functioning. The mercury levels found in Bigeye Tuna (Thunnus obesus) and bluefin tuna species (Thunnus maccoyii, Thunnus orientalis, and Thunnus thynnus), exceed or approach levels permissible by Canada, the European Union, Japan, the US, and the World Health Organization. We used DNA barcodes to identify tuna sushi samples analysed for mercury and demonstrate that the ability to identify cryptic samples in the market place allows regulatory agencies to more accurately measure the risk faced by fish consumers and enact policies that better safeguard their health.     

Frequency and Rates of Outdoor Activities, and Perceptions of Places to Perform these Activities by Native Americans and Caucasians Interviewed in Tennessee

Activity patterns and perceptions play a key role in human health risk, management, and planning. A sample of 233 people attending a Native American festival in Cookeville, Tennessee was interviewed to determine the types, percent participation, and outdoor activities rates, and their perceptions of the importance of characteristics of nuclear sites. Results indicate that: (1) a high percentage of respondents used outdoor environments, (2) they used them for consumptive (hunting, fishing), non-consumptive (hiking, walking, bird-watching), and religious/sacred activities, (3) a higher percentage of respondents engaged in non-consumptive than consumptive activities, (4) praying or meditating, communing with nature, and bird-watching had the highest uses rates (5) the environmental characteristics rated the highest were lack of radionuclides that presented a health risk, no visible smog, clean air, and unpolluted water, (6) the presence of people, buildings and roads were rated the lowest, and (7) Native Americans had higher outdoor participation rates, participated more frequently, and evaluated environmental characteristics higher than did Caucasians. This information can be used by managers to create and maintain outdoor habitats that fit the needs of local people. Planning and management require information on public policy, human needs and requirements, and human perceptions and evaluations of environmental characteristics.     

Intraspecific Social Stimulation and Temporal Displacement of Songs of the Lesser Skylark,Alauda gulgula

Temporal patterning of flight song activity was examined in a population of Lesser Skylarks in Viet Nam. Onset and termination of songs were timed. Temporal dispersion of songs was analyzed from the distribution of intersong intervals, and the tendency of songs to be started prior to, shortly after, or long after cessation of a neighbor's song was examined. Skylarks tended to sing sequentially, clustering their songs in time after long periods of silence. However, they showed a strong tendency to avoid overlapping songs, perhaps because of the possibility of jamming by songs of neighbors. These two factors, intraspecific social stimulation and temporal avoidance, appear to be important determinants of singing behavior in this species.     

Aposematic coloration does not deter corallivory by fish on the coral <Emphasis Type="Italic">Montastraea cavernosa</Emphasis>

Predation on corals by visual predators is a significant source of partial or total mortality on coral reefs, and corals have evolved strategies, including chemical defenses, to deter predation. One mechanism that organisms use to communicate the presence of chemical defenses is aposematic coloration, or the display of bright coloration as a warning to visual predators such as fish. Corals exhibit multiple colors, and it has been hypothesized that one role for this variability in coloration is as an aposematic warning of adverse palatability. Here, we test green and orange color morphs of the Caribbean coral Montastraea cavernosa for the presence of chemical defenses and whether their differences in coloration elicited different feeding responses. While M. cavernosa is chemically defended, there is no difference in feeding deterrence between color morphs; thus, the different color morphs of this coral species do not appear to represent an example of aposematic coloration.     

Comparisons of nine heavy metals in salt gland and liver of greater scaup (Aythya marila), black duck (Anas rubripes) and mallard (A. platyrhynchos)

Levels of nine heavy metals were measured in the livers and salt glands of greater scaup (Aythya marila), black duck (Anas rubripes) and mallard (A. platyrhynchos) from Raritan Bay, New Jersey to determine if the functioning avian salt gland concentrates heavy metals. Heavy metals examined were cadmium, cobalt, chromium, copper, lead, mercury, manganese, nickel and zinc. Heavy metal levels varied significantly by species and tissue for chromium, copper, lead, and manganese, and by tissue for cobalt, mercury, nickel and zinc. In comparing tissues cobalt was higher in the salt glands than in livers of all three species; chromium and nickel were higher in the salt gland than liver for mallard and black duck; and lead, manganese and zinc were higher in the liver than the salt gland in greater scaup. Generally metal levels were higher in the salt gland for mallard and black duck, and in the liver for greater scaup.     

COLONY AND HABITAT SELECTION OF SIX KELP GULL LARUS DOMINICANUS COLONIES IN SOUTH AFRICA

Kelp Gulls nested in six colonies on rocky islands, sand and rock cliffs, sand dunes and on a sand, gravel island in a salt lake. The colony sites selected were different from the surrounding areas and were generally inaccessible to ground predators. Kelp Gulls nested in a wide variety of habitats. Within colonies, the gulls did not nest randomly with respect to habitats but preferred to nest on flat, stable areas with some cover (either rocks or vegetation). They generally avoided heavily vegetated areas, areas devoid of vegetation and areas with steep slopes. Their specific habitat choices relate to predation and cannibalism pressures. Intermediate cover provides adequate protection for chicks while allowing for increased visibility and open escape routes for parents. Nearest neighbour distances were similar among colonies and habitats, indicating strong social attraction.     

Human Health Risk from Metals in Fish from Saudi Arabia: Consumption Patterns for Some Species Exceed Allowable Limits

Fish are a healthful source of protein, but contaminants in some fish pose a risk. While there are multiple risk assessments from Europe and North America, there are far fewer for other parts of the world. We examined the risks from mercury, arsenic, lead, and other metals in fish consumed by people in Jeddah area, Saudi Arabia, using site-specific data on consumption patterns and metal levels in fish. The U.S. Environmental Protection Agency's Hazard Quotient (HQ) and cumulative Hazard Index (HI) for non-cancer endpoints and Carcinogenic Index for cancer were used to determine the health risk based on fish consumption rates. Of the 13 fish species examined, HQ was greater than 1 (indicating elevated risk) in two species for arsenic, and seven species for methylmercury. The cumulative HI for all metals was above 1 for all but three species of fish at the mean consumption rates. Generally, fish species with HI above 1 for one sampling location, had HI above 1 for all sampling locations. The implications of these findings are discussed in the light of strategies for reducing risk from fish consumption while encouraging dietary intakes of fish with low mercury and arsenic levels.     

Aplysina red band syndrome: a new threat to Caribbean sponges

A substantial and increasing number of reports have documented dramatic changes and continuing declines in Caribbean coral reef communities over the past 2 decades. To date, the majority of disease reports have focused on scleractinian corals, whereas sponge diseases have been less frequently documented. In this study, we describe Aplysina red band syndrome (ARBS) affecting Caribbean rope sponges of the genus Aplysina observed on shallow reefs in the Bahamas. Visible signs of disease presence included 1 or more rust-colored leading edges, with or without a trailing area of necrotic tissue, such that the lesion forms a contiguous band around part or all of the sponge branch. Microscopic examination of the leading edge of the disease margin indicated that a cyanobacterium was consistently responsible for the coloration. Although the presence of this distinctive coloration was used to characterize the diseased state, it is not yet known whether this cyanobacterium is directly responsible for disease causation. The prevalence of ARBS declined significantly from July to October 2004 before increasing above July levels in January 2005. Transmission studies in the laboratory demonstrated that contact with the leading edge of an active lesion was sufficient to spread ARBS to a previously healthy sponge, suggesting that the etiologic agent, currently undescribed, is contagious. Studies to elucidate the etiologic agent of ARBS are ongoing. Sponges are an essential component of coral reef communities and emerging sponge diseases clearly have the potential to impact benthic community structure on coral reefs.     

Parrot behavior at a Rio Manu (Peru) clay lick: temporal patterns,associations, and antipredator responses

Although eating clay at licks (a form of geophagy) has been described, there are few behavioral data on temporal patterns, social interactions, species associations, or reactions to potential predators. We examined the behavior of nine species of macaws, parrots, and parakeets at the Machiguenga Ccolpa, a clay lick on the Rio Manu, Peru in the dry season. Three distinct mixed-species groups used the licks: in the early morning (parrots and small macaws), in mid-morning (large macaws), and in the early afternoon (parakeets), although the latter two groups used the licks at other times of day as well. The first parrots to begin eating at the lick in the early morning were yellow-crowned parrots (Amazona ochrocephala) and dusky-headed parakeets (Aratinga weddellii), followed by blue-headed parrots Pionus sordidus, and then by mealy (Amazona farinosa) and orange-cheeked (Pionopsitta barrabandi) parrots, and chestnut-fronted macaws (Ara severa). Although blue-headed parrots fed in dense groups of over 50, the others rarely exceeded 20 individuals. Scarlet macaws (A. macao) sometimes fed alone or joined the early morning groups, but most associated with a large group of red and green macaws (A. chloroptera) that arrived, often scaring off the smaller birds. On average, about 100 macaws and parrots fed in the early morning, macaw feeding groups averaging just over 40, and the parakeets averaged over 70. Average time at the lick ranged from 28 min for yellow-crowned parrots to 47 min for tui parakeets. Of the early morning group, blue-headed and mealy parrots were the most aggressive and orange-cheeked parrots were the least aggressive. Red and green macaws were more aggressive than scarlet macaws; the parakeets were equally aggressive. All species had more aggressive interactions with conspecifics than with other species. Responses to intruders and predators varied by species of parrot/macaw and type of intruder. In response to intruders or loud calls, responses could be partial (some individuals flew away, circled, and returned), temporary (all individuals flew away but returned within a few minutes), or total (all flew away and abandoned feeding for at least a half hour). The large macaws showed the lowest rate of total abandonment and the parakeets showed the highest. People passing up or down river in boats scared birds from the lick. The local residents (Machiguenga tribespeople in boats) elicited a much greater response than did the researchers. In the recent past, macaws and parrots were hunted for food, feathers, and the pet trade, and the birds response, as well as the presence of parrot and macaw feathers in local villages we visited, suggests some continued exploitation, or a long-term memory in the birds.Communicated by R.F. Oliveira     

DNA Double-Strand Breakage as an Endpoint to Examine Metal and Radionuclide Exposure Effects to Water Snakes on a Nuclear Industrial Site

This study examined metal levels (especially U and Ni) in the tail tissues of water snakes from contaminated (Tim's Branch) and reference areas on the Department of Energy's Savannah River Site (SRS). Home ranges of snakes were quantified to determine the ratio of the habitat that they use in relation to the contaminated areas to better estimate exposure Compared to conventional methods that do not. The exposure assessment indicated that water snakes in the contaminated areas could expect U exposure at 3–4 orders of magnitude greater than the Agency for Toxic Substances and Disease Registry's Minimum Risk Level (MRL) from ingestion of amphibians and fish. Ni and U, in addition to Se, Mn, and Cu, were related to increased DNA double-strand breakage (DDSB) in water snakes. We report burdens for each metal individually, but the results of the DDSB indicated that these metals did not behave independently, but as a suite. If we did not have a secondary endpoint (DDSB), we might have assumed from the exposure predictions and tissue burden analyses that U was the sole metal of concern to water snakes in Tim's Branch. These data also imply that these toxicants do not biomagnify at the spatial and temporal scale of this study.