Intertidal Waters Research Articles

The dispersal dynamics of juvenile plantigrade mussels ( Mytilus edulis L.) from eelgrass ( Zostera marina) meadows in Maine, U.S.A.

Field and modelling studies of the distribution of mussel larvae and juvenile plantigrade mussels in and around eelgrass meadows at Mt. Desert Narrows, Lamoine, Maine have demonstrated the following sequence of events which results in the establishment of mussel beds in shallow subtidal and intertidal waters. Mussel larvae increase on the flood tide in early July and are concentrated in the low current regions above the eelgrass blades. Larger mussel pediveligers decrease in concentration in water masses as they pass over the eelgrass meadow on the flood tide, where they settle on the eelgrass blades, especially the taller reproductive shoots. Mussel plantigrades grow from setting size to about 1 mm shell length by mid-August, when they detach from the eelgrass blades and drift inshore on the flood tide using a byssal sail. A wave of secondary settlement in late summer results in a significant drop in mussel concentration on the eelgrass blades, just prior to the release of eelgrass shoots during their fall die-off. A combined flow and particle tracking model of Mt. Desert Narrows, Maine successfully predicted the patterns of both primary and secondary settlement of mussels in the eelgrass meadows at Old Point, and their eventual dispersal inshore of the meadows in late summer. By using size frequency distributions of mussels collected from plankton tows, eelgrass blades, floating collectors and bottom cultch, we observed the absence of drifting juvenile mussels in the 0.4–0.8 mm size range, and most drifting juveniles in the 1–2 mm size groups. Eelgrass blades provide a predator refuge for mussels during metamorphosis, and allow growth of the stem glands in the foot to form a byssal sail. Successful recruitment to bottom cultch results from the combination of available substrate (eelgrass) for primary settlement, and hydrodynamics.

First Report of Rust Disease Caused by Puccinia sparganioides on Spartina alterniflora in Louisiana.

Spartina alterniflora Loisel. (smooth cordgrass) is the dominant plant species of intertidal salt marshes in the Atlantic and Gulf Coast regions of the United States. It is a perennial deciduous grass that can reduce and reverse coastal erosion by buffering wave energy and storm surges and by accumulating suspended solids from intertidal waters. Therefore, smooth cordgrass is utilized extensively in coastal restoration projects in Louisiana. In July 2009, smooth cordgrass leaf samples with signs and symptoms of a rust disease were collected from plant material grown at the Aquaculture Research Station near Baton Rouge, LA. Numerous hypophyllous, narrow, linear lesions were observed in which the uredinia were pale orange, erumpent, and arranged seriately. Urediniospores were yellowish to orange, obovoid to oblong, echinulate with a thickened apical wall and obscure germ pores, and measured 27.5 to 44.9 (-48.3) × 17.3 to 27.6 (-31.05) μm. Telia and teliospores were not observed. The pathogen was identified as Puccinia sparganioides Ellis & Tracy based on the DNA sequence of nuclear ribosomal large subunit (28S) and internal transcribed spacer region 2 (ITS-2) amplified with rust-specific primers (1). The sequence (deposited in GenBank as No. GU327649) was found to share 99.8% identity (1,077/1,079 bp) with sequence No. GU058027 of P. sparganioides from S. patens (Aiton) Muhl. and did not match any other species of Puccinia in GenBank. P. sparganioides has previously been reported on S. alterniflora in Connecticut, Delaware, Florida, Maine, Massachusetts, Mississippi, North Carolina, New Hampshire, Rhode Island, Vermont, and Virginia (2). To the best of our knowledge, this is the first report of P. sparganioides on S. alterniflora from Louisiana. Efforts to screen for rust-resistant lines for use in coastal restoration projects are underway to prevent land loss that could occur due to smooth cordgrass stress from infection. Voucher material (LSU00121657) has been deposited in the Bernard Lowy Mycological Herbarium (LSUM).

Modeling the Effects of Salinity and pH on the Cadmium Bioabsorptive Properties of the MicroalgaeIsochrysis galbana(T-Iso) in Coastal Waters

The changes in cadmium ion bioabsorptive properties were investigated for the brown microalgae Isochrysis galbana (T-Iso) in various saline solutions (0, 10, 20, 30, 40, and 50 parts per thousand, or ppt) and pH environments (pH 3, 4, 5, 6, 7, and 8) modeling those of coastal and intertidal waters. Optimal saline growth conditions for T-Iso were observed at 30 ppt. Under these optimal saline conditions, the effective concentration at 50% lethality for cadmium ion for T-Iso is 2.3 parts per million (ppm), with a maximum intracellular absorption of 8.6 fg/cell. T-Iso maximal surfacial cadmium binding was determined from Langmuir isotherm plots; Qmax = 98 mg/g (pH 6.00, 0 ppt), falling to 19 mg/g in higher salinities (pH 6.00, 50 ppt). The Freundlich constants n and Kf followed a similar cadmium binding trend: at 0 ppt, Kf = 16.6 and n = 2.83, while at higher salinities (50 ppt), the values dramatically decreased to Kf = 3.64 and n = 1.34. Direct relationships between ln Qmax (98, 70, 45, 28, 23, and 19) and ln Kf (16.6, 12.8, 8.36, 4.63, and 3.64) versus respective salinity (0, 10, 20, 30, 40, and 50 ppt) produced linear correlations. The pseudo-second-order binding kinetic rate in distilled water is 8.5 × 10−3 g/mg/min, while in saline conditions (30 ppt) the rate decreased to 4.4 × 10−3 g/mg/min. The percentage of adsorption loading capacity of the algae in the water column increases with initial cadmium exposure: the highest percentage of adsorbance (C0 = 25 ppm) in 0 ppt is 92%, while under equivalent conditions in saline water (50 ppt), adsorption falls to 31%.

Examination of Nutrient Fluxes and Influence of Intertidal Sediments on Coastal Water in a Season

In coastal areas around big cities such as Tokyo Bay, intertidal flats decreased due to man-made reclamation lands constructions. Such a loss of tidal flats make, water quality environments deteriorated. In the study, we carried out field studies to estimate nutrient fluxes between inter tidal sediment and overlying water and intertidal water and neighbor sea water. In conclusion, we found the following results. (1) Function of this tidal flat is net source of phosphorus and net sink of nitrogen and chlorophyll-a in summer. And function of net source of phosphorus in summer changes to net sink of that in winter. (2)The fluxes of phosphorus and nitrogen from the intertidal sediment are 20% and 87% of the fluxes through the changes between tidal flat and neighbor sea water.

What Dives Beneath: Diving as a Measure of Performance in Lizards

Abstract Measures of performance are used to quantify the ability of an individual to execute specific activities. In lizards, sprint speed is the most commonly evaluated measure of performance due to its relationship with biological fitness, presumably via increased effectiveness of foraging and escaping predators. Some lizards also use the aquatic environment and dive underwater as an effective means of foraging and/or escaping predators. We tested the usefulness of diving as a measure of performance in a small, diurnal lizard that frequently dives into intertidal water. Adults of Oligosoma smithi were encouraged to dive and the maximal duration of their dive as well as their behavior were recorded. Eighty-three percent of the 46 individuals dove in the six trials, with the longest dive time recorded at 6 min 36 s in a pregnant female. The diving ability of O. smithi was not related to pregnancy, whether an individual had eaten, or any of the morphological measures taken. We also searched for records of...

Remote Sensing of Biologically Reworked Sediments: A Laboratory Experiment

The present study aims to test the application of remote sensing to address the impact of bioturbation on physical sediment properties. Therefore, a laboratory experiment was developed, using microcosms mimicking a marine intertidal water–sediment interface to test the influence of Corophium volutator densities on sediment properties. Three main variables (water content, clay content, and mean grain size) were measured in three treatments (no Corophium, 5,000 Corophium per square meter, and 20,000 Corophium per square meter) after 16 days of bioturbation. Results obtained with conventional—destructive—techniques showed a significant increase of water content and a significant, but small decrease of clay content in the presence of Corophium. The remote sensing technique detected the impact of Corophium on water content as an increase in absorption at 1,450 nm, but was not able to detect the animal impact on clay content. This study demonstrates that remote sensing data could be significantly modified by bioturbation activities and that remote sensing can be applied in the laboratory to address the impact of bioturbation on sediment properties. This possibly opens new perspectives for long-term experiments concerning the role of bioturbation on sedimentary processes.

Diversity and ecological remarks of ectocommensals and ectoparasites (Annelida, Crustacea, Mollusca) of echinoids (Echinoidea: Mellitidae) in the Sea of Cortez, Mexico

The diversity of symbiotic invertebrates on intertidal and shallow water echinoids of the northwestern Gulf of California was studied. Five ectosymbionts were found: three pinnotherid crabs, Dissodactylus lockingtoni Glassell (1935), Dissodactylus nitidus Smith (1870), and Dissodactylus xanthusi Glassell (1936); one eulimid gastropod, Turveria encopendema Berry (1956); and one polychaete, Struwela sp. We discovered seasonal fluctuation in D. nitidus Smith (1870) and D. xanthusi Glassell (1936), which result in these species being undetectable during the winter season when the temperature in the head of the Gulf of California drops to 14-18 degrees C; the rest of the species are permanent residents in this area. An updated list of all external macrosymbionts of echinoids of the Mexican Pacific is presented.

Growth and survival differences among native, introduced and hybrid blue mussels (Mytilus spp.): genotype, environment and interaction effects

The Mytilus species complex consists of three closely related mussel species: Mytilus trossulus, Mytilus edulis, and Mytilus galloprovincialis, which are found globally in temperate intertidal waters. Introduction of one or more of these species have occurred world-wide via shipping and aquaculture. Stable hybrid zones have developed in areas where these species have come into contact, making the invasion process complex. On the east coast of Vancouver Island (VI), British Columbia (BC), Canada, the native (M. trossulus) and introduced species (M. edulis and M. galloprovincialis), as well as their hybrid offspring, occur sympatrically. This study used a common environment experiment to quantify growth and survival differences among native, introduced, and introgressed mussels on VI. Mussels were collected from an area of known hybridization and reared in cages from May to August 2006. The cages were deployed at a local site as well as a remote site (approximately 150 km apart), and the mussels were genotyped at two species-specific loci. Growth and survival, as fitness measures, were monitored: native, introduced, and introgressed individuals were compared between and within sites to determine whether growth and survival were independent of site and genotype. Overall, mussels reared at Quadra Island performed better than locally-reared mussels at Ladysmith. Specifically, introgressed mussels reared at Quadra Island performed better than all genotypes reared at Ladysmith, as well as better than native mussels reared at Quadra Island. Differences in survival and growth among the native, introduced and introgressed mussels may serve to explain the complex hybridization patterns and dynamics characteristic of the VI introgression zone.

A numerical study of tidal asymmetry in Okatee Creek, South Carolina

The Okatee River, South Carolina is characterized by a narrow tidal channel and an extensive area of intertidal salt marshes. Current measurements in the upstream portion Okatee Creek show that tidal flow features an asymmetric pattern: ebb current is stronger than flood current. The ebb dominance is mainly caused by deformation of the dominant astronomical tidal constituent M 2. An unstructured grid, finite volume coastal ocean model (FVCOM) with wet-dry point treatment method is applied to examine physical mechanisms of M 4 overtide generation. Model experiments show that mean absolute amplitude and phase errors are 3.1 cm and 1.7 ° for M 2 elevation, 2.4 cm s −1 and 0.8 ° for M 2 current major axis, 2.1 cm and 1.8 ° for M 4 elevation, and 2.1 cm s −1 and 24.6 ° for M 4 current major axis. The overall pattern of tidal asymmetry is qualitatively reproduced. Various sensitivity experiments suggest that the generation of M 4 overtide is a result of nonlinear interaction of tidal currents with irregular creek geometry and bottom topography. Consistent with the classical view, the large volume of intertidal water storage is the major reason for ebb dominance in the creek. However, the zero-inertia assumption (i.e., negligible advective terms) is probably not valid for the entire tidal cycle. Besides the pressure gradient force and the bottom friction force, terms related to lateral shear of the along-estuary velocity (i.e., advective inertia and horizontal eddy viscosity) may also contribute in horizontal momentum balance. Exclusion of the flooding-draining processes over the intertidal zone will severely underestimate tidal currents in the river channel and make the tidal asymmetry less prominent.

An Historic Chinese Abalone Fishery on California’s Northern Channel Islands

Beginning in the 1850s, Chinese abalone fishermen developed an intensive commercial fishery focused on the abundant black abalone (Haliotis cracherodii) stocks of Alta and Baja California. They systematically harvested and dried tons of abalone meat and shells from intertidal waters and shipped them to markets in mainland China and America. Several legislative attempts were made to curtail Chinese involvement in the fishing industry, claiming they were harvesting abalone without regard to size. Recent research documents the abundance, distribution, and constituents of historic abalone sites and discusses the impact of “Chinese” abalone fishermen on San Miguel Island, California. Thousands of shell measurements show that the Chinese harvested larger abalones than those collected by Native American foragers for 10,000 years prior to European contact, providing important data on local ecology during the early historic period.

Two New Species of Doridicola (Copepoda: Cyclopoida: Rhynchomolgidae) Associated with Opisthobranch Mollusks from Korea

Two new species of the genus Doridicola are described as associates of opisthobranch mollusks from Korean intertidal waters: Doridicola virguatus n. sp. associated with the notaspidean Pleurobranchaea japonica Thiele and D. portincola n. sp. associated with the nudibranch Hoplodoris armata (Baba). This is the first record for the copepod associates of opisthobranch mollusks from Korea.

Habitat related growth and reproductive investment in estuarine waters, illustrated for the tellinid bivalve Macoma balthica (L.) in the western Dutch Wadden Sea

In estuarine areas, bivalve species can be found in a variety of environments, where they experience large differences in environmental conditions. In the present paper, the importance of different habitats (intertidal, subtidal and adjacent coastal waters) for the persistence of the population was evaluated for the bivalve Macoma balthica (L.) in the western Dutch Wadden Sea estuary. Intra-specific variation in growth and reproductive output were followed during the year and related to local abiotic conditions. Significant differences in growth and reproductive investment were found between locations. Young individuals were mostly found in the intertidal area, where growth in terms of somatic mass was good. These areas were not favourable for adult individuals, since growth in shell length was low and many individuals did not reproduce. In the subtidal, where the highest densities were found, somatic and gonadal mass indices were low. Coastal areas had the lowest densities and showed high growth in terms of shell length and body mass. The habitat with the highest reproductive effort per individual was not the most important habitat in terms of reproductive output due to differences in density and in size of the habitat type. For M. balthica, the subtidal habitat contributed the most to the reproductive output of the western Dutch Wadden Sea population although the highest reproductive output per individual was in the coastal area.

A revision of the Australian intertidal water beetle genus Hughleechia Perkins (Coleoptera: Hydraenidae)

The Australian intertidal water beetle genus Hughleechia Perkins, 1981, is revised, based on the study of 123 specimens. The genus and the type species, H. giulianii Perkins, are redescribed. One new species, H. gracilis, is described. High resolution digital images of the primary types are presented (online version in color), male genitalia and elytral microsculpture are illustrated, scanning electron micrographs of selected morphological features are given, and geographic distributions are mapped. Both species are intertidal, but differ markedly in habitus, elytral setae, and some ventral characters, whereas they share basic morphology of the exocrine secretion delivery system and have similar aedeagal form. H. giulianii is known from several localities on the southwestern and southern coasts of Australia, being collected from rock crevices that are covered by high tides, dry rock crevices in the high tide splash zone, and in rock pools a few feet above the water line, created by splash and spray but seldom or never reached by waves. H. gracilis is known from two localities in Tasmania, all specimens being collected from high intertidal rock faces, by pyrethrin fogging.

Patterns of RAPD markers and heavy metal concentrations in Perna viridis (L.), collected from metal-contaminated and uncontaminated coastal waters: Are they correlated with each other?

Genetic variation due to heavy metal contamination has always been an interesting topic of study. Because of the numerous contaminants being found in coastal and intertidal waters, there is always much discussion and argument as to which contaminant(s) caused the variations in the genetic structures of biomonitors. This study used a Single Primer Amplification Reaction (SPAR) technique namely Random Amplified Polymorphic DNA (RAPD) to determine the genetic diversity of the populations of the green-lipped mussel Perna viridis collected from a metal-contaminated site at Kg. Pasir Puteh and those from four relatively' uncontaminated sites (reference sites). Heavy metal levels (Cd, Cu, Pb and Zn) were also measured in the soft tissues and byssus of the mussels from all the sites. Cluster analyses employing UPGMA done based on the RAPD makers grouped the populations into two major clusters; the Bagan Tiang, Pantai Lido, Pontian and Kg. Pasir Puteh populations were in one cluster, while the Sg. Belungkor population clustered by itself. This indicated that the genetic diversity based on bands resulting from the use of all four RAPD primers on P. viridis did not indicate its potential use as a biomarker of heavy metal pollution in coastal waters. However, based on a correlation analysis between a particular metal and a band resulting from a specific RAPD primer revealed some significant (P < 0.01) correlations between the primers and the heavy metal concentrations in the byssus and soft tissues. Thus, the correlation between a particular metal and the bands resulting from the use of a specific RAPD primer on P. viridis could be used as biomonitoring tool of heavy metal pollution.

Reencuentro de Iluocoetes facali Lloris & Rucabado, 1987 (Perciformes: Zoarcidae) en el sector norte del archipiélago patagónico occidental

The first record of the species Iluocoetes facali Lloris & Rucabado, 1987 in Chilean waters is given, extending its northern distribution in the western South American Cone in more than 2,500 km. Morphometrics and meristic characteristicsof the specimen caught in intertidal waters of the Putemun Fjord (42°28'S- 73°51'S), located 15 km north of Castro, Chiloe Island, is given. This one is the second specimen known of the species after its description. Additionally, in the present note, a taxonomic key to recognize the Chilean species of Iluocoetes and photographic material that allows corroborating the new record are included

Estuarine shore platforms in Whanganui Inlet, South Island, New Zealand

Whanganui Inlet is a low mesotidal environment where wave energy at the shoreline is limited due to a small fetch, a narrow entrance and tidal flat accretion to intertidal elevations. Wave energy is therefore only an erosive force at high tide and under storm conditions. Despite this low-energy environment extensive shore platforms occur within the inlet. They are sub-horizontal and range in width from 4.1 to 185.2 m with an average of 44.9 m. All the platforms are formed in sandstone of low resistance (mean N-type Schmidt Hammer rebound value of 17 ± 8) and have their seaward edges buried by intertidal sediment flats. The majority of platforms occur at around MHWN level, corresponding to the elevation of those flats. Where wave energy is highest, opposite the inlet's entrance and at those sites with the largest fetch, platforms develop to 0.5–1.0 m below MSL. A higher platform level is also found at MHWS elevations, however it appears to be relict with active erosion of its seaward edge occurring and therefore is most likely related to a higher mid-Holocene sea level. Apart from the location of the lowest platforms little correspondence is found between platform morphology and wave energy. Platform evolution appears to be intrinsically linked to the intertidal sediment flats which determine the degree of surface saturation of the bedrock and, hence, the number of wetting and drying cycles the platforms may undergo. As the seaward edge is buried platform development is primarily through retreat of the landward cliff. This process can, however, be complicated by the migration of intertidal water channels onto the seaward edge of the platforms or relative sea level fall which may rejuvenate landward retreat of the low-tide cliff.

Use of different soft tissues of Perna viridis a s biomonitors of bioavailability and contamination by heavy metals (Cd, Cu, Fe, Pb, Ni, and Zn) in a semi-enclosed intertidal water, the Johore Straits

Green-lipped mussels, Perna viridis, were collected from the eastern and western parts of the Johore Straits in September 2004 and January 2005. Based on the heavy metal concentrations in the different soft tissues (gonad, foot, mantle, gills, muscle, and remaining soft tissues) of these mussel samples, the eastern part of the Johore Straits (which is divided into two portions by a causeway), recorded higher levels of bioavailability and contamination by Cd, Cu, Fe, Ni, and Zn when compared to the western part, while Kg. Pasir Puteh in the eastern part was found to record the highest bioavailability and contamination by heavy metals. The use of different soft tissues of P. viridis as biomonitors of bioavailability and contamination by Cd, Cu, Fe, Pb, Ni, and Zn in the semi-enclosed Johore Straits is proposed, since erroneous results due to spawning and the problem of defecation before dissection could be overcome. Hence, a more accurate interpretation of the bioavailability and contamination by heavy metals in coastal waters could be obtained. To our knowledge, this is the most detailed study on the bioavailability and contamination of heavy metals in the Johore Straits on the Malaysian side of the waterway carried out by using the different soft tissues and metal distribution based on the Mussel Watch approach.

High diversity of deep-sea Gromia from the Arabian Sea revealed by small subunit rDNA sequence analysis

Gromia is a large marine protist with filose pseudopodia and ovoid test, common in coastal intertidal and sublittoral waters. Although deep-water Gromia-like morphospecies were discovered in the 1990s, their relations to the shallow water species have never been established. Moreover, very little is known about the diversity within Gromia, reflecting the fact that these morphologically relatively simple protists have few characters useful for species identification. Consequently, we have analysed the SSU rDNA and ITS rDNA genes to examine gromiid diversity in two different areas located on the Oman and Pakistan margins of the Arabian Sea (water depths 1,000–2,000 m). In total, 27 deep-sea gromiid sequences of the SSU rDNA gene and six sequences of the ITS rDNA region were obtained. Our data confirm that Gromia-like protists from the bathyal deep sea are related to the shallow-water gromiids. Within Arabian Sea Gromia, we identified seven distinctive lineages, five of which form a monophyletic group branching as a sister group to shallow-water species. Six lineages of Arabian Sea Gromia can be defined morphologically, while one lineage includes specimens that look identical to specimens from two other lineages. This indicates that each Gromia lineage represents probably a separate species and suggests that deep-sea gromiid diversity is higher than indicated by their simple morphology.

Intertidal water column meiofauna in relation to wave intensity on an exposed beach

Since the 1970s, various studies have shown that some meiofaunal taxa frequently occur in the water column. Water currents or any process that disturbs the sediments are possible factors that can facilitate the passive entry of meiofauna in the water column. Wave action has been predicted as one of these factors (Armonies, 1994), suggesting a correlation between the number of eroded specimens and wave intensity should exist. As a test of this prediction, replicated samples were taken in the water column, swash sediment and back-swash water in an exposed beach (Island of Sylt, northern Wadden Sea). Wave height and period were measured to characterise the energy regime. Samplings were carried out over a nine day period in August 2000, at diurnal mid-tide time. Wave height and period varied significantly among collections. Densities of nematodes, harpacticoids, nauplii, platyhelminthes, ostracods and bivalve larvae in the water column, swash sediment and back-swash water varied significantly among collections. Nevertheless, no significant correlation was found between water column density and wave characteristics. Density of meiofauna in the water column was not correlated with density in the sediment or in back-swash water. Therefore wave intensity did not explain the variability of meiofaunal densities present in the water column.

Biostratigraphy and palaeoecological interpretation of the Miocene–Pleistocene sequence at El-Dabaa, northwestern Egypt

Abstract. Thirteen shallow boreholes were drilled by the Qattara Project Authority (QPA) on the top of the second limestone ridge in the El-Dabaa area, along the Mediterranean coast, northwest Egypt. Five foraminiferal biozones could be recognized in ascending stratigraphic order: the Heterostegina costata, Praeorbulina sicana, Borelis melo melo, Globigerinoides obliquus extremus zones and an un-named zone, embracing the Middle Miocene Marmarica Formation and the Pliocene–Pleistocene Alexandria Formation.The deposition of the fossiliferous carbonate rocks of the Marmarica Formation probably took place in a warm water, inner shelf environment (0–20 m palaeodepth) subjected to some current activity, and with salinity ranging from normal to slightly hypersaline (35–50‰). The sediments of the oncolitic/shelly rocks were deposited in slightly deeper water than the overlying fossiliferous rocks and in less agitated conditions, as indicated from the high percentages of rotaliids and rarity of miliolids.The foraminiferal associations in the Alexandria Formation indicate a clear, relatively agitated, near-shore marine depositional environment in a vegetated inner neritic zone (10–25 m palaeodepth) with 25°C surface water isotherms. On the other hand, the accumulation of the clayey sediments and some geosoils (basal part of the Alexandria Formation) occurred in less agitated, intertidal water conditions, as deduced from the occurrence of planktic foraminiferal species as Globigerinoides trilobus trilobus, G. trilobus immaturus, G. obliquus extremus, G. obliquus obliquus, Globorotalia inflata, and Orbulina universa.