Mortality of Oysters and Abundance of Certain Associates as Related to Salinity

Gunter, Gordon

doi:10.2307/1931298

Cited by 42 publications

(21 citation statements)

References 1 publication

Supporting

Mentioning

Contrasting

Order By: Relevance

“…These findings could lead to harvesting and processing interventions to ameliorate V. parahaemolyticus O3:K6 levels in shellfish. Most bivalves are classified as osmoconformers, that is, their internal osmolarity fluctuates in accordance with the osmolarity of their external environment, which may be either estuarine or oceanic or any level in between (14,36). The effect of growth in 3% NaCl was quite pronounced under acid conditions and was correlated with increased expression of cadA.…”

Section: Discussionmentioning

confidence: 99%

Modulation of Responses of Vibrio parahaemolyticus O3:K6 to pH and Temperature Stresses by Growth at Different Salt Concentrations

Whitaker

Parent

Naughton

et al. 2010

Appl Environ Microbiol

View full text Add to dashboard Cite

Vibrio parahaemolyticus inhabits marine, brackish, and estuarine waters worldwide, where fluctuations in salinity pose a constant challenge to the osmotic stress response of the organism. Vibrio parahaemolyticus is a moderate halophile, having an absolute requirement for salt for survival, and is capable of growth at 1 to 9% NaCl. It is the leading cause of seafood-related bacterial gastroenteritis in the United States and much of Asia. We determined whether growth in differing NaCl concentrations alters the susceptibility of V. parahaemolyticus O3:K6 to other environmental stresses. Vibrio parahaemolyticus was grown at a 1% or 3% NaCl concentration, and the growth and survival of the organism were examined under acid or temperature stress conditions. Growth of V. parahaemolyticus in 3% NaCl versus that in 1% NaCl increased survival under both inorganic (HCl) and organic (acetic acid) acid conditions. In addition, at 42°C and ؊20°C, 1% NaCl had a detrimental effect on growth. The expression of lysine decarboxylase (encoded by cadA), the organism's main acid stress response system, was induced by both NaCl and acid conditions. To begin to address the mechanism of regulation of the stress response, we constructed a knockout mutation in rpoS, which encodes the alternative stress sigma factor, and in toxRS, a two-component regulator common to many Vibrio species. Both mutant strains had significantly reduced survival under acid stress conditions. The effect of V. parahaemolyticus growth in 1% or 3% NaCl was examined using a cytotoxicity assay, and we found that V. parahaemolyticus grown in 1% NaCl was significantly more toxic than that grown in 3% NaCl.Vibrio parahaemolyticus is a Gram-negative bacterium that inhabits coastal waters worldwide. Vibrio parahaemolyticus grows optimally in warmer waters and is most commonly isolated during the summer months, often in association with plankton, crustaceans, mollusks, and fish (16,17). During the winter months, the organism is typically scarce and usually is isolated from sediment samples (16). While V. parahaemolyticus has been shown to be the etiological agent of disease in several kinds of crustaceans and shellfish, it is most notably a pathogen of humans (17). Vibrio parahaemolyticus was first discovered in Japan during an outbreak of gastroenteritis in 1950 (12). It is the leading cause of seafood-related bacterial gastroenteritis in the United States and much of Asia (6,39). Infection is most frequently associated with the consumption of oysters harvested from warm waters, particularly along the U.S. Gulf Coast, where vibrios grow to high levels during the summer months (6, 7, 42). Newly released data from the CDC comparing the incidence rates of laboratory-confirmed infections by gastrointestinal pathogens in 1996 to 2008 revealed an increase of 47% for Vibrio infections, of which V. parahaemolyticus accounted for 55%, while rates for all other enteric pathogens decreased or remained the same (5). An outbreak of V. parahaemolyticus infections which caused rapid hos...

show abstract

Section: Discussionmentioning

confidence: 99%

Modulation of Responses of Vibrio parahaemolyticus O3:K6 to pH and Temperature Stresses by Growth at Different Salt Concentrations

Whitaker

Parent

Naughton

et al. 2010

Appl Environ Microbiol

View full text Add to dashboard Cite

show abstract

“…In addition, 4 Barataria Bay Nestier sites classified as marine (~10% of sites) were excluded, as these sites may have experienced increased mortality resulting from enhanced predation or increased disease due to their more saline waters (Gunter 1955). We developed dose-response curves for the period from 2007 through 2012, (excluding 2010), as well as for 2010 only.…”

Section: Nrda Spatial Assessmentmentioning

confidence: 99%

“…the protozoan parasite Perkinsus marinus) that leads to reduced survivorship (e.g. Gunter 1955, Davis 1958, 1979, Chatry et al 1983, Brown & Richardson 1988, Soniat & Brody 1988, Fodrie et al 2008, La Peyre et al 2009. Although the specific thresholds of these triggers varied from study to study, the general pattern of oysters thriving in waters whose average annual salinities fall be tween 8 and 22 ppt with frequent brief pulses of freshwater input is well established and accepted by oyster biologists.…”

mentioning

confidence: 99%

Consequences of large-scale salinity alteration during the Deepwater Horizon oil spill on subtidal oyster populations

Powers¹,

Grabowski²,

Roman³

et al. 2017

Mar. Ecol. Prog. Ser.

View full text Add to dashboard Cite

Response actions associated with oil spills often have significant impacts on ecological communities. During the 87 d long Deepwater Horizon oil spill, the State of Louisiana (USA) released vast quantities of Mississippi River water into 2 estuarine basins (Barataria Bay and Black Bay/Breton Sound) in response to the approach of oil. We assessed the impact on subtidal oyster populations of this novel oil spill response action using 3 independent methods: (1) comparison of fisheries-independent post-spill densities to a pre-spill temporal baseline; (2) comparison of oyster density collected during natural resource damage assessment sampling between the area of maximal freshwater impact and reference areas in the 2 basins; and (3) estimation from a doseresponse model derived from an analysis of an in situ mark and recapture study conducted in 2010 to assess the relationship between salinity and oyster mortality. A substantial portion of both basins (483 km 2 of Barataria Bay and 362 km 2 of Black Bay/Breton Sound) experienced prolonged periods of very low (< 5 ppt) salinity in 2010 that lasted at least 1 mo longer than the average duration of low salinity between 2006 and 2009. The 3 approaches all indicate that dramatic losses occurred in the number of market-sized (> 75 mm) oysters as a result of a system-wide lowering of salinities, with an estimated 1.16 to 3.29 billion market-equivalent oysters lost. The efficacy of the large-scale response action of altering hydrographic conditions during the summer oyster growth period should be examined in light of the major perturbation to oyster communities.KEY WORDS: Estuary · Oil spill response · Natural resources damage assessment · Oyster reefs · Gulf of Mexico · Crassostrea virginica · Hydrography OPEN PEN ACCESS CCESS Contribution to the Theme Section 'Response of nearshore ecosystems to the Deepwater Horizon oil spill'Mar Ecol Prog Ser 576: [175][176][177][178][179][180][181][182][183][184][185][186][187] 2017 Too much freshwater reduces local salinity to levels where survivorship, growth, or reproduction of oysters is impaired, whereas too much ocean water generally elevates salinities and is associated with higher levels of predators (e.g. the oyster drill Stramonita haemastoma) or disease (e.g. the protozoan parasite Perkinsus marinus) that leads to reduced survivorship (e.g. Gunter 1955, Davis 1958, 1979, Chatry et al. 1983, Brown & Richardson 1988, Soniat & Brody 1988, Fodrie et al. 2008, La Peyre et al. 2009. Although the specific thresholds of these triggers varied from study to study, the general pattern of oysters thriving in waters whose average annual salinities fall be tween 8 and 22 ppt with frequent brief pulses of freshwater input is well established and accepted by oyster biologists. Because settlement of oysters is gregarious on existing oyster shells, sustainable populations of oysters require that the position of this green zone of water stays relatively fixed over time. A substantial perturbation of this salinity zone away from are...

show abstract

“…Larvae raised in low salinity seawater exhibit slowed growth rates, increased mortality, a n d a possible delay of metamorphosis (bivalves : Gunter 1955; gastropods: Scheltema 1965, Rosenberg & Rosenberg 1973, Zimmerman & Pechenik 1991crustaceans: Costlow et al 1971). Larvae raised under conditions of low temperature or an insufficien.t food supply show similar effects: the larvae take longer to develop, and frequently delay metamorphosis in stressful physical conditions (bivalves: Lucas & Costlow 1979, Lima & Pechenik 1985gastropods: Scheltema 1962, 1967, Scheltema & Williams 1982polychaetes: Qian et al 1990; multiple taxa : Pechenik 1987: Pechenik , 1990.…”

Section: Introductionmentioning

confidence: 99%

Short-term fluctuations in salinity:effects on planktonic invertebrate larvae

Richmond¹

1996

Mar. Ecol. Prog. Ser.

View full text Add to dashboard Cite

ABSTRACT. Estuarine habitats are characterized by environmental changes on many time scales. While certain physical parameters change on a regular, predictable basis, rapid environmental fluctuatlons can also occur as a result of stochastic events. For example, rainstorms are frequent, unpredictable events that can cause dramatic changes in the estuarine environment, in short periods of time As a result of storm precipitation and terrestrial freshwater runoff, estuarine sallnity can drop in excess of 2 0 ?~ in 6 h. Our research focuses on the effects of these storm-induced salinity fluctuations on estua n n e embryos and larvae in terms of growth, mortality, rate of development, and activity. We studied 2 species of estuarine invertebrates: the embryos and larvae of the mud snail Ilyanassa obsoleta and the larvae of the marine polychaete Arenicola cristata. In both species, greater reductions in salinity resulted in smaller larvae. Both the duration of salinity reduction and the age of embryos and larvae when exposed to a sallnity reduction affected growth rates: longer and earlier (relative to embryonic or larval age) storms had a greater effect on growth rates, resulting in smaller larvae. Both species also exhibited changes in activity when exposed to salinity reductions: I. obsoleta larvae swam significantly less at 10'!:*), while A. cristata larvae displayed a delay in activities associated with the sequence of development from s w i m m~n g trochophore, to crawling larva, to settled metamorphic juvenile. Our results show that stochastic events may have a significant impact on the growth and development of pre-settlement estuarine invertebrates, implying ecological effects on recruitment success.

show abstract

Mortality of Oysters and Abundance of Certain Associates as Related to Salinity

Cited by 42 publications

References 1 publication

Modulation of Responses of Vibrio parahaemolyticus O3:K6 to pH and Temperature Stresses by Growth at Different Salt Concentrations

Modulation of Responses of Vibrio parahaemolyticus O3:K6 to pH and Temperature Stresses by Growth at Different Salt Concentrations

Consequences of large-scale salinity alteration during the Deepwater Horizon oil spill on subtidal oyster populations

Short-term fluctuations in salinity:effects on planktonic invertebrate larvae

Contact Info

Product

Resources

About