Salinity Selection by Juvenile Brown Shrimp (<Emphasis Type="Italic">Farfantepenaeus aztecus</Emphasis>) and White Shrimp (<Emphasis Type="Italic">Litopenaeus setiferus</Emphasis>) in a Gradient Tank

Changes in freshwater inflow and salinity patterns may affect the nursery value of estuarine systems for penaeid shrimp, but the relationship between salinity and shrimp abundance is complex and likely confounded by other environmental variables. Laboratory experiments can provide insights into salinity selection, and we designed an experimental gradient tank to examine salinity preferences of juvenile brown shrimp and white shrimp. Our design uses gently flowing water to eliminate various physical constraints often associated with selection experiments. We conducted experiments with juvenile brown shrimp (12 trials) and white shrimp (seven trials), to examine selection for salinities along a gradient from 1 to 42. Data were analyzed using contingency tables and log-linear modeling to examine relationships with salinity and possible interactions with temperature. Both brown shrimp and white shrimp were present in all salinities examined within the experimental range. In general, brown shrimp showed a preference for salinities from 17 to 35 and demonstrated avoidance for the extreme low salinities along the gradient. Results for white shrimp were not statistically significant, and this species did not appear to avoid low salinities. There was no effect of water temperature on the observed selection patterns for brown or white shrimp. Our results suggest that although salinity preferences likely exist for these species, strong distribution trends associated with salinity gradients in estuaries are likely caused by other environmental factors.     

Modeling Bedload Transport of Juvenile Bivalves: Predicted Changes in Distribution and Scale of Postlarval Dispersal

The potential consequences of bedload transport of postlarvae for patterns of distribution of marine invertebrates were explored by developing a bedload transport model for juvenile bivalves in a small estuary in New Jersey, USA. A simple numerical model of tidal current hydrodynamics was developed based on field measurements of shear stresses near the bottom. Burrowing behavior of bivalves was incorporated into the model of bedload transport by using estimates of entrainment rates of Gemma gemma and Mya arenaria in a laboratory flume, and jump lengths of the bivalves were estimated by methods previously developed for noncohesive particles. Based on the flood domination and strong gradient of shear stresses in the Navesink estuary, our model predicted that juvenile bivalves would accumulate in the center of the estuary, traveling up to several kilometers over 30 days. Field distributions of juvenile bivalves were consistent with the model predictions for other species of bivalves but not for G. gemma, for which field distributions of both <500- and >500-μm individuals were concentrated in the eastern end of the estuary. Differences between the bedload model and G. gemma distributions suggest that spatial variation in burrowing behavior or biological interactions are playing an important role in maintaining distribution patterns of this species in spite of high levels of bedload transport. This modeling approach is applicable to other juvenile benthic invertebrates that disperse as bedload and is a useful model against which to compare field observations of rates of transport and patterns of distribution and abundance.     

Factors Affecting Macrobenthic Fauna in a Tropical Hypersaline Coastal Lagoon in Ghana,West Africa

The macrobenthic fauna in the large, hypersaline, shallow Keta lagoon in Ghana was sampled at 20 stations in the wet (September 2002) and dry seasons (March 2003) to elucidate the effects of abiotic factors on community patterns. The macrobenthic fauna was low in density and species diversity and numerically dominated by bivalves and capitellid polychaetes. These organisms appear able to withstand physical disturbance (when lagoon water levels become extremely low) and osmotic stress (when salinities are extremely high) and tend to redistribute along environmental gradients. Parallel seasonal differences in several environmental variables and the macrobenthic fauna indicate a highly dynamic system. Species richness and diversity were higher in the wet season than the dry season. Salinity, percent clay, pH, and turbidity in that order were the major significant variables structuring the macrobenthic faunal assemblage in Keta lagoon. The strong effect of seasonal salinity changes on macrobenthic faunal assemblages may have trophic consequences for higher organisms of commercial importance, such as fishes and shorebirds, in the Keta lagoon.     

Complex formation and the chemistry of selected trace elements in estuaries

The estuarine chemistry of several metals and anion-forming elements is compared. Differences in the estuarine behaviour of nickel and copper appear to be caused by differences in the stability and reaction rates of organic complexes of these metals. Nickel occurs partially in very stable organic complexes that have an estuarine pathway different from the electrochemically labile (weakly complexed) fraction as the two fractions are not in equilibrium on the estuarine time scale; whereas, the complexes of copper in the estuary are in equilibrium with each other. Titanium occurs largely in a nonlabile form and is subject to removal at low salinities; it is released again at intermediate salinities (25 practical salinity units) and behaves conservatively at higher salinities. Comparison of several anion-forming elements reveals differences; uranium, antimony, and molybdenum show nonconservative behaviour and selenium shows conservative behavior. Voltammetric measurements of the chemical speciation of molybdenum in estuarine waters indicated the unexpected presence of a nonlabile species for this element.     

Effect of salinity on osmoregulation and survival of a rhizocephalan parasite,Loxothylacus panopaei,and its crab host,Rhithropanopeus harrisii

The rhizocephalanLoxothylacus panopaei parasitizes the estuarine crabRhithropanopeus harrisii. Parasitized crabs are abundant during summers when salinities increase to around 15‰ in the crab–s habitat and scarce when salinities are lower. The two hypotheses that were proposed to explain this pattern were (1) that the parasite interferes with crab osmoregulation causing the host to die in low salinity water and (2) that salinity tolerance of the parasite larvae controls the incidence of parasitism. The first hypothesis was shown to be incorrect because (1) osmoregulation of infected crabs was, not altered by the parasite and (2) crab mortality did not increase in low salinity water down to 1‰. Unparasitized and parasitized crabs and the parasite itself were hypersomotic at low salinities (below 27‰ for the crabs). The parasite became slightly hyperosmotic at high salinities while the crabs were slightly hypoosmotic. The second hypothesis appears correct, becauseL. panopaei larvae survived poorly in salinities below 10‰ but well in salinities from 10 to 15‰. ThusR. harrisii, have a reproductive refuge at salinities below 10‰, because parasite larvae cannot survive and infect the mud crab at these low salinities.     

Distribution and abundance of grapsid crabs (Grapsidae) in a mangrove estuary: Effects of sediment characteristics,salinity tolerances,and osmoregulatory ability

Crabs (Grapsidae,Sesarma) are the dominant macrofaunal group of mangrove forest soils in northern Australia. Little is known about the ecology of these crabs or the factors that influence their distribution in mangrove forests. Pitfall traps were used to sample grapsid crabs in the Murray River estuary in north Queensland. Sampling was conducted at five sites along a salinity gradient from <1‰ at upstream sites to >35‰ at the river mouth. At each site, trapping was done in both low and high intertidal forests. We characterized the sediments at each site by measuring percent sand, silt, clay and organic matter, Eh, pH, and soil pore-water salinity. Four species of grapsids dominated the crab fauna along the Murray River (Sesarma semperi-longicristatum, S. messa, S. brevicristatum, andS. brevipes). Distinct zonation patterns were found along the salinity gradient and between high and low intertidal forests.S. messa was dominant in high intertidal, downstream forests, high and low intertidal forests in the middle to downstream portion of the river, and in low intertidal forests in the central reach of the river.S. brevipes was dominant in both low and high intertidal zone forests at low salinity upstream sites.S. brevicristatum was most abundant in the central reaches of the river and only in the high intertidal zone.S. semperi-longicristatum was found only in the low intertidal zone, downstream forest. Subsequently, tests of salinity tolerances of these crabs were carried out in the laboratory. These indicated very wide tolerances over salinities from completely fresh to hypersaline (60‰). The osmoregulatory abilities of the crabs were also found to vary. However, neither their salinity tolerance nor osmoregulatory ability adequately explain the zonation patterns were measured in the field. For example,S. brevicristatum had the most restricted distribution, but it had the second broadest salinity tolerance and osmoregulatory ability. Sediment characteristics explained a significant amount of the variation in abundance for two of the crab species. Pore-water salinity provided no explanatory power for any of the species. Individual species abundances are probably influenced by additional factors such as interspecific competition and predation.     

Influences of Salinity and Light Availability on Abundance and Distribution of Tidal Freshwater and Oligohaline Submersed Aquatic Vegetation

Submersed aquatic vegetation (SAV) communities have undergone declines worldwide, exposing them to invasions from non-native species. Over the past decade, the invasive species Hydrilla verticillata has been documented in several tributaries of the lower Chesapeake Bay, Virginia. We used annual aerial mapping surveys from 1998 to 2007, integrated with spatial analyses of water quality data, to analyze the patterns and rates of change of a H. verticillata-dominated SAV community and relate them to varying salinity and light conditions. Periods of declining SAV coverage corresponded to periods where salinities exceeded 7 and early growing season (April to May) Secchi depths were <0.4 m. Increases were driven by the expansion of H. verticillata along with several other species into the upper estuary, where some areas experienced an 80% increase in cover. Field investigations revealed H. verticillata dominance to be limited to the upper estuary where total suspended solid concentrations during the early growing season were <15 mg l⁻¹ and salinity remained <3. The effect of poor early growing season water clarity on annual SAV growth highlights the importance of water quality during this critical life stage. Periods of low clarity combined with periodic salinity intrusions may limit the dominance of H. verticillata in these types of estuarine systems. This study shows the importance of the use of these types of biologically relevant episodic events to supplement seasonal habitat requirements and also provides evidence for the potential important role of invasive species in SAV community recovery.     

Seasonal variation in temperature and salinity in the Gautami-Godavari estuary

Variation of temperature and salinity in the lower 22 km stretch of the Gautami-Godavari estuary are reported during four different seasons; hot-weather, south-west monsoon, post-monsoon and winter seasons. The seasonal variation in temperature is small, with a high of about 30°C during hot-weather season and a low of about 26°C during winter season. Unlike temperatures, the salinities in the estuary show large seasonal fluctuations. During south-west monsoon surface salinities were low (0 to 8‰) due to high fresh water run off into the estuary. During hot-weather season surface salinities of 25 to 30‰ were observed due to negligible fresh water run off.     

Growth and mortality rates of larval American shad,Alosa sapidissima,at different salinities

The tolerance of post yolk-sac American shad Alosa sapidissima larvae to salinities typically seen in estuaries was assessed experimentally. Sixteen-day-old Hudson River (experiment I) and 35-d-old Delaware River (experiment II) larvae were held for 8 d and 9 d respectively in low (0–1‰), medium (9–11‰), and highly (19–20‰) brackish water, and mortality and growth rates were measured. Growth rates did not vary significantly among salinity treatments. Mortality in experiment I did not vary significantly among salinity treatments however, in experiment II, mortality was zero at 10‰ but higher and statistically indistinguishable between 0‰ and 20‰ In experiment II relative condition increased with salinity. These results imply that estuarine salinities neither depress growth rates nor elevate mortality rates of larval American shad when compared with freshwater conditions. We conclude that ecological factors other than the physiological effects of salinity have played more important roles in the evolution of the upriver spawning and nursery preference shown by this species.     

Seasonal cycling of estuarine sediment and contaminant transport

The seasonal cycling of fine sediment in the upper reaches of a hypothetical macrotidal estuary and its possible consequences for the behaviour of a contaminant which partitions between dissolved and particulate forms are investigated theoretically. The simplest one-dimensional models are used as a starting point for future studies: (a) a within-tide hydrodynamic (tidal) model, (b) an associated sediment transport model and (c) a tidally-averaged contaminant dispersal model. The calculations are made for a four-year period and show that a cyclic migration of mobile sediment occurs in the upper reaches of the estuary. Sediment accumulates during spring to late summer, and is redistributed in the lower estuary during high runoff periods (autumn and winter). For a fluvial input of contaminant, the dissolved contaminant levels during summer are greatly depressed below conservative mixing values in the upper (turbidity maximum) region, whereas they are slightly enhanced in the lower reaches. During winter, the levels are substantially greater than conservative values except for a slight depression at very low salinities. Thus, sediment here acts as a source of contaminant for most of the salinity range. For a marine input of contaminant, levels are enhanced above the conservative mixing line at low salinities throughout the year, the effect being much larger during summer.     

A Before–After–Control–Impact Analysis of the Effects of a Mississippi River Freshwater Diversion on Estuarine Nekton in Louisiana, USA

Since 1991, the Caernarvon Freshwater Diversion has been reintroducing Mississippi River water into a previously hydrologically isolated estuary in an effort to restore wetlands. To determine the effect of freshwater inflow on estuarine nekton community structure, a Before?CAfter?CControl?CImpact study design was applied. As a result of the opening, salinities in the impact area decreased, and the nekton community structure in the estuary changed significantly. Species of economical or ecological importance either increased in biomass or exhibited no response to the opening of the diversion. Higher abundances of small fish were observed in the area receiving freshwater flow, which is an indication that the area serves as a refuge from large marine predators. Because a salinity gradient was established, as opposed to a uniform but lower salinity regime, aquatic habitat was available to nekton species from a wide spectrum of salinity tolerances.     

The behavior of trace metals in the Geum Estuary,Korea

The distributions of trace metals in the Geum Estuary of western Korea were studied with regard to changes in other estuarine chemical parameters. Dissolved oxygen, pH, and alkalinity increased with increasing salinity. Dissolved aluminum concentrations increased at low salinities and were perhaps influenced by the solubility of particulate aluminosilicate phases. Iron, managanese, cobalt, and zinc are removed from solution in the low salinity end of the estuary. Cobalt and nickel have mid-estuary concentration maxima that may be due to an anthropogenic source. Cadmium, copper, lead, and zinc concentrations also increased in the estuary, possibly as the result of remobilization in the sediments. Cadmium increases are also linked to remineralization from tidal flat sediments in the outer estuary. The source of an increase in dissolved lead at low salinity is unclear, but may be due to release from particles.     

Methods for determining minimum freshwater inflow needs of Texas bays and estuaries

In response to legislative directives beginning in 1975, the Texas Water Development Board (TWDB) and the Texas Parks and Wildlife Department (TPWD) jointly established and currently maintain a data collection and analytical study program focused on determining the effects of and needs for freshwater inflows into the state's 10 bay and estuary systems. Study elements include hydrographic surveys, hydrodynamic modeling of circulation and salinity patterns, sediment analyses, nutrient analyses, fisheries analyses, freshwater inflow optimization modeling, and verification of needs. For determining the needs, statistical regression models are developed among freshwater inflows, salinities, and coastal fisheries. Results from the models and analyses are placed into the Texas Estuarine Mathematical Programming (TxEMP) model, along with information on salinity viability limits, nutrient budgets, fishery biomass ratios, and inflow bounds. The numerical relationships are solved within the constraints and limits, and optimized to meet state management objectives for maintenance of biological productivity and overall ecological health. Solution curves from the TxEMP model are verified by TWDB’s hydrodynamic simulation of estuarine circulation and salinity structure, which is evaluated against TPWD’s analysis of species abundance and distribution patterns in each bay and estuary system. An adequate system-wide match initially verifies the inflow solution. Long-term monitoring is recommended in order to verify that implementation of future water management strategies maintain ecological health of the estuaries and to provide an early warning of needs for adaptive management strategies.     

Using submerged aquatic vegetation to establish minimum and maximum freshwater inflows to the Caloosahatchee estuary, Florida

Species of submerged aquatic vegetation (SAV) are frequently used in the management of estuarine systems to set restoration goals, nutrient load reduction goals, and water quality targets. As human need for water increases, the amount of freshwater required by estuaries has become an increasingly important issue. While the, science of establishing the freshwater needs of estuaries is not well developed, recent attempts have emphasized the freshwater requirements of fisheries. We evaluate the hypothesis that SAV can be used to establish freshwater inflow needs. Salinity tolerance data from laboratory and field studies of SAV in the Caloosahatchee estuary, Florida, are used to estimate a minimum flow required to maintain the salt-tolerant freshwater species,Vallisneria americana, at the head of the estuary and a maximum flow required to prevent mortality, of the marine speciesHalodule wrightii at its mouth. ForV. americana, laboratory experiments showed that little or no growth occurred between 10‰ and 15‰ In the field, lower shoot densities (<400 shoots m^?2) were associated with salinities greater than 10‰. Results forH. wrightii were more variable than forV. americana. Laboratory experiments indicated that mortality could occur at salinities <6‰, with little growth occurring between 6‰ and 12‰. Field data indicated that higher blade densities (>600 blades m^?2) tend to occur at salinities greater than 12‰ Relationships between salinity in the estuary and discharge from the Caloosahatchee River indicated that flows>8.5 m³ s^?1 would produce tolerable salinity (<10‰) forV. americana and flows<89 m³ s^?1 would avoid lethal salinities (<6‰) forH. wrightii.     

珠江口黄茅海河口湾表层沉积物中有孔虫和介形虫的分布及其影响因素*

珠江口黄茅海河口湾的表层沉积物100个站位样品中共发现有孔虫21属36种、介形虫16属20种。优势种组合分别为Ammonia beccarii-Quinqueloculina akneriana rotunda-Cavarotalia annectens-Elphidium advenum和Neomonoceratina delicata-Sinocytheridea impressa-Bicornucythere bisanensis。有孔虫及介形虫的丰度和分异度均表现出“北低南高”,即口门低、向海高的特点。样品中有孔虫和介形虫属种的去趋势对应分析（DCA）表明,盐度是影响该区有孔虫和介形虫分布的最重要因素,其次是水动力条件,水深对有孔虫和介形虫的分布也有一定影响,但并非主要控制性因素。由于受径流影响较大,河口湾北部的水体盐度较低、径流动力较强,不利于有孔虫和介形虫的生存,导致其丰度及分异度均较低。河口湾南部水体盐度升高,潮流动力较强,同时受众多岛屿屏障作用,环境较为稳定,有孔虫和介形虫的丰度和分异度均迅速上升。     

Axial zonation patterns of subtidal macrozoobenthos in the Gamtoos estuary,South Africa

The distribution of macroinfauna was quantified in subtidal, soft-bottom habitats, extending from the estuarine mouth to the tidal head of the Gamtoos—a small, shallow, temperate estuary situated on the south coast of South Africa. Sampling covered the full salinity gradient from fresh to marine waters, and all sediment types from marine sands to fluvial silts. A total of 35 taxa was recorded, of which 22 occurred throughout the year. Species richness and diversity declined from the seawater-dominated mouth region toward the fresh water section at the tidal head of the estuary. Sediment type generally bore no clear relation to biotic diversity. A marked drop in salinity between winter and summer sample series (Δ 0.2‰ to 24‰) coincided with a reduction of mean macrofaunal density by 70%, a more seaward relocation, and a compression of axial ranges of most taxa. Numerical classification and ordination of faunistically similar regions and of co-occurring species delineated four habitat zones along the longitudinal axis of the estuary which harbour four distinct macrofaunal assemblages: 1) A tidal inlet area with salinities close to seawater; clean, coarse, marine sands, rich in CaCO₃ harbour a stenohaline fauna normally found on adjacent, marine sandy beaches. 2) In the lower reaches, where fine, fluvial silts of high organic content prevail, euryhaline polychaetes dominate the macrozoobenthic community; bottom salinities in this zone seldom dropped below 25‰ 3) The middle reaches, characterized by oligohaline- to polyhaline waters, stretch over sandy sediments of intermediate carbonate, silt, and organic fractions; the fauna comprises typical estuarine forms, which occurred throughout most of the estuary except at its seaward and landward limits. 4) The upper reaches encompass the limnetic waters near the tidal head of the estuary with sediments in this zone being composed mostly of coarse, clean sands, low in CaCO₃; the macrobenthos in this region is dominated by taxa of freshwater origin, which generally do not penetrate seaward beyond the oligohaline waters, and by exceptionally euryhaline estuarine species. Salinity appears as the main factor in controlling faunal assemblages at both extremes of the estuarine gradient (i.e., tidal inlet and head), whereas sediment type delineates between communities in the mesohaline to polyhaline reaches. Axial (i.e., from tidal inlet to tidal head of the estuary) zonation patterns of macroinfauna broadly matched those of mesozooplankton and fishes, supporting the notion of a general structure underlying species distribution patterns in the Gamtoos estuary.     

Fouling community of the Loxahatchee River estuary,Florida, 1980–81

Monthly growth of the fouling community at eight test panel sites in the Loxahatchee River Estuary was related to salinity and temperature. Growth was lowest in January 1981 (averaging 23 g per m², dry weight), and increased during spring and early summer with increasing water temperature. Maximum growth occurred during early or midsummer at upstream locations, before river or canal discharge substantially reduced salinity, and in late summer at downstream locations. Growth was greatest at salinities slightly less than that of seawater and decreased at salinities less than about 10‰. Growth was suppressed throughout the estuary in August 1981, probably because of the sudden decrease in temperature and salinity, and perhaps the increase in physical scouring, caused by runoff from Tropical Storm Dennis. Large loads of nutrients transported to the estuary from storm runoff, however, may have subsequently stimulated growth, which increased in September 1981 to the maximum for the year (averaging 683 g per m², dry weight).     

Salinity preferences in the stage I zoeae of three temperate zone fiddler crabs,genus Uca

Zoeae of three species of temperate zone fiddler crabs, Uca pugnax, U. minax, and U. pugilator, were reared in the laboratory. The zoeae of each species were placed individually in artificial salinity gradients and observed for specific salinity preferences. Each species of zoeae displayed a salinity preference that reflected the salinity patterns of the adult crabs of the same species. Zoeae of U. pugnax and U. pugilator, like the adult crabs, displayed a preference for higher salinities (i.e., 20.6‰±3.5 and 21.5‰±3.0, respectively). Zoeae of U. minax, like the adult crabs, displayed a preference for lower salinities (i.e., 9.8‰±2.9).     

Invasions in Marine Communities: Contrasting Species Richness and Community Composition Across Habitats and Salinity

While many studies of non-native species have examined either soft-bottom or hard-bottom marine communities, including artificial structures at docks and marinas, formal comparisons across these habitat types are rare. The number of non-indigenous species (NIS) may differ among habitats, due to differences in species delivery (trade history) and susceptibility to invasions. In this study, we quantitatively compared NIS to native species richness and distribution and examined community similarity across hard-bottom and soft-sediment habitats in San Francisco Bay, California (USA). Benthic invertebrates were sampled using settlement panels (hard-bottom habitats) and sediment grabs (soft-bottom habitats) in 13 paired sites, including eight in higher salinity areas and five in lower salinity areas during 2 years. Mean NIS richness was greatest in hard-bottom habitat at high salinity, being significantly higher than each (a) native species at high salinity and (b) NIS richness at low salinity. In contrast, mean NIS richness in soft-bottom communities was not significantly different from native species richness in either high- or low-salinity waters, nor was there a difference in NIS richness between salinities. For hard-bottom communities, NIS represented an average of 79% of total species richness per sample at high salinity and 78% at low salinity, whereas the comparable values for soft bottom were 46 and 60%, respectively. On average, NIS occurred at a significantly higher frequency (percent of samples) than native species for hard-bottom habitats at both salinities, but this was not the case for soft-bottom habitats. Finally, NIS contributed significantly to the existing community structure (dissimilarity) across habitat types and salinities. Our results show that NIS richness and occurrence frequency is highest in hard-bottom and high-salinity habitat for this Bay but also that NIS contribute strongly to species richness and community structure across each habitat evaluated.     

Effects of storm-induced salinity changes on submersed aquatic vegetation in Kings Bay, Florida

Hurricanes and other major storms cause acute changes in salinity within Florida's streams and rivers. Winddriven tidal surges that increase salinities may have long-lasting effects on submersed aquatic vegetation (SAV) and the associated fauna. We investigated potential effects of salinity pulses on SAV in Kings Bay, Florida, by subjecting the three most common macrophytes,Vallisneria americana, Myriophyllum spicatum., andHydrilla verticillata, to simulated salinity pulses. In Kings Bay, we documented changes in salinity during three storms in September 2004 and measured biomass and percent cover before and after these storms. During experiments, macrophytes were exposed to salinities of 5‰, 15‰, or 25‰ for 1, 2, or 7 d, with a 28-d recovery period in freshwater. Relative to controls, plants subjected to salinities of 5‰ exhibited few significant decreases in growth and no increase in mortality. All three species exhibited decreased growth in salinities of 15‰ or 25‰.H. verticillata, exhibited 100% mortality at 15‰ and 25‰, irrespective of the duration of exposure.M. spicatum andV. american exhibited increased mortality after 7-d exposures to 15‰ or any exposure to 25‰ Maximum daily salinities in Kings Bay approached or exceeded 15‰ after each of the three storms, with pulses generally lasting less than 2 d. Total aboveground biomass and percent cover of vascular plants, were reduced following the storms.M. spicatum exhibited an 83% decrease in aboveground biomass and an 80% decrease in percent cover.H. verticillata exhibited a 47% and 15% decline in biomass and percent cover, respectively.V. americana, exhibited an 18% increase in aboveground biomass and a 37% increase in percent cover, which suggests greater tolerance of salinity pulses and release from competition with the invasiveH. verticillata andM. spicatum. Our results indicate that rapid, storm-induced pulses of high salinity can have important consequences for submersed aquatic vegetation, restoration efforts, and management of invasive species.