Marine Biotoxins: Emergence of Harmful Algal Blooms as Health Threats to Marine Wildlife

Harmful algal blooms (HABs) affect aquatic ecosystems around the world, adversely affecting marine animal and human health, coastal ecosystem integrity, and economies that depend on coastal resources. Shellfish poisoning events involving humans who had ingested bivalves contaminated with HAB toxins primarily drove early scientific and social interest in HABs. More recently, research efforts have shown that HABs are often temporally and spatially correlated with the occurrence of acute morbidity or mortality of marine animals (Landsberg et al. 2005), and to date at least four classes of algal toxins have been associated with such events. Although fish, seabirds, and many other groups of marine wildlife are affected, these mortality events frequently involve marine mammals, and as such this chapter will focus primarily on the latter. In addition, since marine mammals are important sentinel species that act as barometers of ocean health and demonstrate the link between ocean and human health, the importance placed on these species in this context is warranted (Aguirre and Tabor 2004; Tabor and Aguirre 2004; Wells et al. 2004; Bossart 2006)

South Carolina\u27s Probability Based Approach for Assessing Water Quality and Estuarine Condition using Integrated Indices

2008 S.C. Water Resources Conference - Addressing Water Challenges Facing the State and Regio

Marine Biotoxins: Emergence of Harmful Algal Blooms as Health Threats to Marine Wildlife

Harmful algal blooms (HABs) affect aquatic ecosystems around the world, adversely affecting marine animal and human health, coastal ecosystem integrity, and economies that depend on coastal resources. Shellfish poisoning events involving humans who had ingested bivalves contaminated with HAB toxins primarily drove early scientific and social interest in HABs. More recently, research efforts have shown that HABs are often temporally and spatially correlated with the occurrence of acute morbidity or mortality of marine animals (Landsberg et al. 2005), and to date at least four classes of algal toxins have been associated with such events. Although fish, seabirds, and many other groups of marine wildlife are affected, these mortality events frequently involve marine mammals, and as such this chapter will focus primarily on the latter. In addition, since marine mammals are important sentinel species that act as barometers of ocean health and demonstrate the link between ocean and human health, the importance placed on these species in this context is warranted (Aguirre and Tabor 2004; Tabor and Aguirre 2004; Wells et al. 2004; Bossart 2006)

Offshore Earthquakes Do Not Influence Marine Mammal Stranding Risk on the Washington and Oregon Coasts

The causes of marine mammals stranding on coastal beaches are not well understood, but may relate to topography, currents, wind, water temperature, disease, toxic algal blooms, and anthropogenic activity. Offshore earthquakes are a source of intense sound and disturbance and could be a contributing factor to stranding probability. We tested the hypothesis that the probability of marine mammal stranding events on the coasts of Washington and Oregon, USA is increased by the occurrence of offshore earthquakes in the nearby Cascadia subduction zone. The analysis carried out here indicated that earthquakes are at most, a very minor predictor of either single, or large (six or more animals) stranding events, at least for the study period and location. We also tested whether earthquakes inhibit stranding and again, there was no link. Although we did not find a substantial association of earthquakes with strandings in this study, it is likely that there are many factors influencing stranding of marine mammals and a single cause is unlikely to be responsible. Analysis of a subset of data for which detailed descriptions were available showed that most live stranded animals were pups, calves, or juveniles, and in the case of dead stranded mammals, the commonest cause of death was trauma, disease, and emaciation

The condition of South Carolina's estuarine and coastal habitats during 2003-2004 : technical report

There are several specific, yet critical, attributes of the SCECAP initiative that set it apart from other ongoing monitoring programs being conducted in South Carolina by SCDHEC (primarily for water quality) and SCDNR (primarily for fishery stock assessments). These include: sampling sites throughout the coastal zone using a random, probability-based approach, using integrated measures of environmental and biological condition that provide a more complete evaluation of overall habitat quality, and monitoring tidal creek habitats. This technical report is the third in a series of reports describing the status of South Carolina’s estuarine habitats

The condition of South Carolina's estuarine and coastal habitats during 1999-2000 : summary report

Results obtained from the 1999-2000 SCECAP survey indicate that most of South Carolina’s estuarine habitats are in good condition. Portions of the state’s estuaries that coded as marginal were primarily located in developed watersheds, although a few sites had no obvious sources of human influence. The data obtained from the 1999-2000 survey, combined with future data to be collected by the SCECAP program, provides a valuable database on the environmental and biological conditions in tidal creek and open water habitats located in both pristine areas and sites near industrial and residential development

Microarray validation: factors influencing correlation between oligonucleotide microarrays and real-time PCR

Quantitative real-time PCR (qPCR) is a commonly used validation tool for confirming gene expression results obtained from microarray analysis; however, microarray and qPCR data often result in disagreement. The current study assesses factors contributing to the correlation between these methods in five separate experiments employing two-color 60-mer oligonucleotide microarrays and qPCR using SYBR green. Overall, significant correlation was observed between microarray and qPCR results (ρ=0.708, p<0.0001, n=277) using these platforms. The contribution of factors including up- vs. down-regulation, spot intensity, ρ-value, fold-change, cycle threshold (C(t)), array averaging, tissue type, and tissue preparation was assessed. Filtering of microarray data for measures of quality (fold-change and ρ-value) proves to be the most critical factor, with significant correlations of ρ>0.80 consistently observed when quality scores are applied

A temporal and spatial study of invertebrate communities associated with hard-bottom habitats in the South Atlantic Bight

Species composition, biomass, density, and diversity of benthic invertebrates from six bard-bottom areas were evaluated. Seasonal collections using a dredge, trawl, and suction and grab samplers yielded 432, 525, and 845 taxa, respectively. Based on collections wltb the different gear types, species composition of invertebrates was found to change bathymetrically. Inner- and mlddle-shelf sites were more similar to each other in terms of invertebrate species composition than they were to outer-shelf sites, regardless of season. Sites on the inner and outer shelf were grouped according to latitude; however, results suggest that depth is apparently a more important determinant of invertebrate species composition than either season or latitude. Sponges generally dominated dredge and trawl collections in terms of biomass. Generally, cnidarians, bryozoans, and sponges dominated at sites In terms of number of taxa collected. The most abundant smaller macrofauna collected in suction and grab samples were polychaetes, amphipods, and mollusks. Densities of the numerically dominant species changed botb seasonally and bathymetrically, with very few of these species restricted to a specific bathymetrlc zone. The high diversity of invertebrates from hard-bottom sites is attributed to the large number of rare species. No consistent seasonal changes in diversity or number of species were noted for individual stations or depth zones. In addition, H and its components showed no definite patterns related to depth or latitude. However, more species were collected at middle-shelf sites than at inner- or outer-shelf sites, which may be related to more stable bottom temperature or greater habitat complexity in that area. (PDF file contains 110 pages.

Immunomodulatory Effects of Domoic Acid Differ Between In vivo and In vitro Exposure in Mice

The immunotoxic potential of domoic acid (DA), a well-characterized neurotoxin, has not been fully investigated. Phagocytosis and lymphocyte proliferation were evaluated following in vitro and in vivo exposure to assay direct vs indirect effects. Mice were injected intraperitoneally with a single dose of DA (2.5 μg/g b.w.) and sampled after 12, 24, or 48 hr. In a separate experiment, leukocytes and splenocytes were exposed in vitro to 0, 1, 10, or 100 μM DA. In vivo exposure resulted in a significant increase in monocyte phagocytosis (12-hr), a significant decrease in neutrophil phagocytosis (24-hr), a significant decrease in monocyte phagocytosis (48-hr), and a significant reduction in T-cell mitogen-induced lymphocyte proliferation (24-hr). In vitro exposure significantly reduced neutrophil and monocyte phagocytosis at 1 μM. B- and T-cell mitogen-induced lymphocyte proliferation were both significantly increased at 1 and 10 μM, and significantly decreased at 100 μM. Differences between in vitro and in vivo results suggest that DA may exert its immunotoxic effects both directly and indirectly. Modulation of cytosolic calcium suggests that DA exerts its effects through ionotropic glutamate subtype surface receptors at least on monocytes. This study is the first to identify DA as an immunotoxic chemical in a mammalian species