Species In Coastal Waters Research Articles

The importance of the compound community on the parasite infracommunity structure in a small benthic fish

The extent to which the structure of parasite infracommunities and component communities is determined by the composition of the compound community was assessed by determining the importance of unspecific larval parasites relative to the other guilds (ectoparasites and adult endoparasites). This was analyzed under the hypothesis that the infracommunities harbored by any fish species in coastal waters of the northern Argentine sea will be dominated by unspecific larval stages, which also will be the determinants of the infracommunity structure. These predictions were tested in the Atlantic sea robin, Prionotus nudigula. A total of 1,570 metazoans belonging to 11 species were found in the overall sample (total prevalence = 98%). Larval endoparasites, especially Corynosoma australe and Grillotia sp., were the best represented species, with a deep influence on the infracommunity structure, accounting for the highest proportion of individuals, dominating about 60% of the infracommunities, greatly determining all infracommunity descriptors, and producing marked changes in the similarity among infracommunities. Given the abundance and broad distribution of unspecific larval parasites in the compound community, infracommunities can be considered as subsets of the species available regionally. They are obtained by passive sampling of infective stages as fish feed, and lead to predictable assemblages, with a non-random composition and structure modeled mainly by ecological filters.

Fecundity and growth-dependent mortality of Pacific anchovy ( Engraulis japonicus) in Korean coastal waters

We propose a method of estimating natural mortality of marine pelagic fishes, especially for early-life stages, based on their fecundity. To estimate size-dependent fecundity, growth and mortality of Pacific anchovy ( Engraulis japonicus), the most abundant fish species in coastal waters off the Korean peninsula, we undertook a synthesis of results from past studies and data. Assuming that the growth coefficient K varies with water temperature, we derived a modified von Bertalanffy growth equation covering all life stages based on otolith analysis of anchovies collected from southwestern coastal area of Korea in 1996. By revisting a past study on spawning and egg production of anchovies in the southern Korean coastal waters, we calculated a monthly-averaged fraction of mature females spawning per day to estimate that an average female anchovy spawns 36 times per year, and that the mean number of eggs produced by an average female is ca. 160 × 10 3 yr −1. Accepting the ‘bigger-is-better’ hypothesis, we derived a theoretical mortality curve that assumes instantaneous natural mortality as an inverse function of anchovy body length. Assuming equilibrium status of stock, estimated annual instantaneous mortality of anchovy between egg to age-1 stage was 11.3 yr −1 and estimated size-specific mortality was 1.24 d −1 mm in fork length. The derived theoretical mortality curve fit well the stage-specific mortalities, which were estimated independently based on ichthyoplankton surveys and anchovy samples collected by commercial nets, but underestimated the egg mortality (0.89 d −1 vs. 0.83 d −1).

Detection of Phaeocystis globosa using sandwich hybridization integrated with nuclease protection assay (NPA-SH)

Phaeocystis globosa Scherffel is one of the common harmful algae species in coastal waters of the southeastern China. In this study, sandwich hybridization integrated with nuclease protection assay (NPA-SH) was used to qualitatively and quantitatively detect P. globosa. Results showed that this method had good applicability and validity in analyzing the samples from laboratory cultures and from fields. The linear regression equation for P. globosa was obtained, and the lowest detection number of cells was 1.8 x 10(4) cells. Statistics showed that there was no distinct difference between the results of detecting the microalgae by NPA-SH and traditional microscopy. This technique has good reliability, accuracy, and can give a remarkably high sample processing rate. Sandwich hybridization integrated with nuclease protection assay will provide an efficient alternative to microscopic method for monitoring and investigating the bloom of P. globosa.

The Effect of Seafood Processing Plant Effluent on Sentinel Fish Species in Coastal Waters of the Southern Gulf of St. Lawrence, New Brunswick

Abstract This study evaluated effects of effluents discharged by seafood processing plants on populations of fish living in shallow estuarine waters of the southern Gulf of St. Lawrence. To monitor potential nutrient and/or toxicity impacts on fish populations living and possibly feeding in the effluent, we measured indices of survival (age), growth (weight-at-age), reproduction (gonad weight), and energy storage (liver weight, condition factor) on mummichog (Fundulus heteroclitus) and Atlantic silverside (Menidia menidia) in spring, summer, and fall. Fish exposed to effluents in three bays were compared to fish from a local reference site within the same bay and from regional reference sites in bays without seafood plants. Mummichog caught near seafood processing plants showed a number of differences from reference fish consistent with a localized nutrient enrichment effect including elevated growth (3 of 3 plants), liver size (2 of 3), and condition factor (1 of 3) in at least one of the months sampled. Female silverside caught near one of the three fish plants showed an elevated condition factor in spring, but otherwise silverside did not differ significantly from all four reference sites. In a number of cases, fish exposed to effluent differed from reference fish sampled from bays without fish plants but not from the local reference site, implying that the entire bay was affected either by the seafood processing plant or by some other factors. No harmful impacts such as reduced growth or survival were found in our study, possibly because the processing plants studied were relatively small and the amounts of waste discharged could be flushed by tides and currents and/or assimilated by the fish and other biota in the receiving environments.

Intermittent turbulence and copepod dynamics: Increase in encounter rates through preferential concentration

Turbulence has a strong influence on plankton contact rate, which is a crucial parameter for plankton ecology. In the field of particle-turbulence interactions, it is now well known that fully developed turbulence does not always homogenise particle distributions, but instead creates, in some well-defined conditions, preferential concentrations of heavy particles. Many studies have considered the influence of this type of preferential concentration on particle contact rate. We consider here the possible application of these results to copepods, assuming that some results obtained for heavy particles are still valid for light particles. Using parameter values representative of copepod species in coastal waters and open ocean, we numerically estimate the possible enhancement of copepod contact rates due to the preferential concentration by turbulence. The assessment is done by using data from a laboratory experiment: we find from the trajectory analysis of small neutrally buoyant particles, that the preferential concentration effect increases the contact rate up to 140%. We argue that this effect may be more pronounced for higher Reynolds numbers, and may have important ecological applications.

Factors influencing the oxidation, reduction, methylation and demethylation of mercury species in coastal waters

The objective of this study was to examine the redox reactions and other transformations of mercury (Hg) species in surface waters, and the factors determining the rates of these reactions. For the redox studies completed at the Chesapeake Biological Laboratory (CBL), two isotopes ( 199Hg II and 202Hg 0) were added into different types of filtered water (fresh to seawater) to examine the oxidation and reduction reactions. Further studies of both the redox reactions and methylation/demethylation reactions of Hg were conducted with unfiltered water on board research vessels during cruises in May and July 2005 on the Chesapeake Bay and shelf. While CH 3 199Hg II was added to allow the examination of demethylation, 201Hg II was used to examine both reduction and methylation, and 202Hg 0 was used to examine oxidation. Overall, the results showed that both Hg oxidation and reduction were simultaneously occurring and were photochemically mediated in the waters investigated. In contrast to the previously assumed “unreactive” nature of Hg 0, the studies found that the magnitude of the rate constant for Hg 0 oxidation was greater than that for reduction, indicating its importance in estuarine and coastal waters. In addition, both experiments at CBL and on board ship showed that Hg II reduction was similar in magnitude, suggesting that biotic processes were relatively unimportant. While no measurable methylation occurred during the incubation period during the on board studies, concentration of CH 3 199Hg II decreased over the time during the experiments. It appeared that the demethylation processes were not dominantly photochemically driven, but could be microbially mediated. Further studies are needed in order to help better understand Hg redox and transformations in natural water systems.

Anisakid Nematodes From Stranded Pygmy Sperm Whales, Kogia breviceps (Kogiidae), in Three Localities of the Yucatan Peninsula, Mexico

The present paper reports the presence of 3 adult and juvenile anisakid nematode species: Anisakis simplex, A. brevispiculata, and Pseudoterranova ceticola, which were recovered from the digestive tract of stranded pygmy sperm whales (Kogia breviceps) from 3 localities along the coast of the Yucatan Peninsula. The presence of these anisakid adult nematodes suggests that larval stages may occur in cephalopods or fishes used for human consumption, which represents a potential danger to public health. The occurrence of the 3 anisakid species in coastal waters of the Yucatan Peninsula represents new geographical records for Mexico.

Feeding ecology of sympatric European shags Phalacrocorax aristotelis and great cormorants P. carbo in Iceland

The feeding ecology of the European shag (Phalacrocorax aristotelis) and the great cormorant (P. carbo) in Iceland was studied. These bird species may affect their marine environment, for instance, by predating on several commercially important fish species in coastal waters. The shag and cormorant diets were studied throughout the year in the period 1996–2000 by analysing the content of about 300 stomachs from each species. The shag relies heavily on sandeel (Ammodytes marinus) in the breeding season, whereas bull-rout (Myoxocephalus scorpius) and gadoids (Gadidae) become increasingly important in autumn and winter. The main food of the cormorant in all areas and seasons is the bull-rout. Depending on location and season, secondary food consists mainly of butterfish (Pholis gunnellus), gadoids and flatfishes (Pleuronectiformes). Similarity in diets of these two co-existing bird species was least in the breeding season when overlap in the birds’ distribution was greatest. The results suggest that predation by shags and cormorants could sometimes affect the stocks of the commercially important saithe (Pollachius virens) and plaice (Pleuronectes platessa) in Iceland.

Identification of a new Irgarol-1051 related s-triazine species in coastal waters

A previously unknown s-triazine species present in commercially available Irgarol-1051, a booster biocide additive in copper-based antifouling paints for the replacement of organotin-based antifoulants, has been identified in the coastal aquatic environment. After careful isolation, purification and characterization by high resolution MS-MS and 1H NMR, the molecular structure of that unknown species is found to be N,N′-di- tert-butyl-6-methylthiol- s-triazine-2,4-diamine (designated as M3). Levels of Irgarol-1051, its major degradation product (M1) and the newly identified M3 in the coastal waters of Hong Kong, one of the world's busiest ports located in the southern coast of China, were monitored by SPME–GC-MS and SPME–GC-FID. Water samples from five locations within Hong Kong waters were analysed and the levels of Irgarol-1051, M1 and M3 were found to be 0.1–1.6 μg l −1, 36.8–259.0 μg l −1 and 0.03–0.39 μg l −1, respectively. Our results indicate that M3 is relatively stable against photo- and bio-degradation and may pose considerable risk to primary producer communities in the coastal marine environment.

Molecular phylogenetic perspective on speciation in the genus Sebastes (Scorpaenidae) from the Northwest Pacific and the position of Sebastes within the subfamily Sebastinae

In the Northeast and the Northwest Pacific, 26 and 68 species of Sebastes occur, respectively, the similar appearance of some pairs of shallow coastal water species in the two regions having been interpreted as evidence either for migration of ancestral species or of morphological convergence. To distinguish between these competing hypotheses, a portion of the mitochondrial DNA (mtDNA) cytochrome b gene was sequenced from 23 species of Sebastes from the Northwest Pacific and phylogenetic trees constructed so as to include the existing data from Northeastern species of Sebastes. The results clearly indicated separate origins for external morphology in Northeast and Northwest Pacific species. The shallow coastal water species in the Northwest Pacific are thought to have diverged from about 9.8 MYA. Furthermore, the phylogenetic position of Sebastes was inferred among the subfamily Sebastinae, Helicolenus, Hozukius, Sebastes, and Sebastiscus, the results suggesting that Helicolenus and Hozukius are more closely related to Sebastes than Sebastiscus.

Movements of Spotted Seatrout (Cynoscion nebulosus) in Mississippi Coastal Waters Based on Tag–Recapture

Movement patterns of spotted seatrout (Cynoscion nebulosus) were evaluated in Mississippi coastal waters by an angler-based tagging study from 1995 through 1999. During this period, 505 anglers tagged 15,206 spotted seatrout, the majority of which (84%) did not meet the state's legal minimum size limit of 14 inches (356 mm) total length. Overall, 408 (2.7%) tagged fish were recaptured and reported to project personnel. Over 90% of these recaptured fish moved less than 10 km from site of tagging to site of recapture (mean = 3.0 ± 0.41 km), and 82% moved less than 3 km. The greatest movement from tagging to recapture site by any fish was 60 km over a period of 200 d, and only three fish (0.7%) moved 50 km or more. Study results suggest that spotted seatrout in Mississippi waters comprise a nonmigratory fish stock, as has been found for this species in coastal waters of neighboring states along the U.S. Gulf of Mexico.

Osmoregulation and Spatial Distribution in Four Species of Mysid Shrimps

This study investigates the osmoregulatory capacities of four mysid species, viz. Mesopodopsis wooldridgei, Rhopalophthalmus terranatalis, and Gastrosaccus brevifissura which occur in different zones along salinity gradients in southern African estuaries, and the psammophilic, surf-zone mysid, Gastrosaccus psammodytes. All four species maintain body fluid concentrations at species-specific levels over a range of environmental salinities. Analysis of Covariance (ANCOVA) indicated no statistical difference in body fluid concentrations among juveniles, immatures, males, and females for M. wooldridgei, R. terranatalis, and G. brevifissura. Available information suggests that biological and physical factors other than salinity are more important in determining spatial distribution of these four species in coastal waters.

Relationships between diet and body size, mouth morphology, habitat and movements of six sillaginid species in coastal waters: implications for resource partitioning

The dietary compositions and breadths of sequential 50 mm size classes of the six whiting species found in nearshore (<1.5 m), shallow inner-shelf (5 to 15 m) and/or deep inner-shelf (20 to 35 m) waters of the lower west coast of Australia were determined. Comparisons between the results of principal components analysis of head and mouth dimensions and the dietary compositions of Sillago bassensis, S. vittata, S. burrus, S. schomburgkii, S. robusta and Sillaginodespunctata suggests that any differences in the dietary composition of similar-sized representatives of different species, when they occur in the same habitat, are more likely to be due to differences in foraging behaviour than mouth morphology. Classification, ordination and Schoener's overlap indices showed that, in nearshore waters, the juveniles of Sillago bassensis, which colonise relatively exposed areas, have a different diet to those of the smallest representatives of the other whiting species that occupy more sheltered habitats. S. bassensis consumes mainly amphipods, whereas the smaller representatives of S. vittata, S. burrus, S. schomburgkii and Sillaginodes punctata ingest large volumes of copepods, which are typically abundant in protected nearshore waters. Although the mouth dimensions of S. punctata tend to be smaller than those of Sillago schomburgkii, the larger individuals of the former species ingest greater quantities of larger prey, such as crabs and carid shrimps. As S. bassensis, S. vittata and S. burrus increase in size and migrate out into shallow inner-shelf waters, the latter two species tend to concentrate more on benthic prey, while the former species ingests fauna that is more epibenthic. The largest S. bassensis subsequently migrate out into deep inner-shelf waters, where they co-occur with S. robusta, which is restricted to those waters. In these waters, S. bassensis feeds to a far greater extent on large benthic prey, whereas S. robusta consumes a greater quantity of small epibenthic crustaceans, differences that reflect the far larger lengths of the former species in that region. The above data emphasise that the distribution and ontogenetic movements of the six abundant species of whiting play a major role in facilitating a partitioning of food resources amongst these species found in coastal waters of the lower west coast of Australia.

ANOTHER CAPRELLID AMPHIPOD WITH EXTENDED PARENTAL CARE: AEGININA LONGICORNIS

ABSTRACT The caprellid amphipod Aeginina longicornis is a common species in coastal waters of the North Atlantic. Here, I report on aquarium observations of 2 females. After hatching from the brood pouch the juveniles remained on the bodies of the females for at least 2 weeks. Both females with all attached juveniles (N = 31 and N = 42) were collected 5 June 1995. One female with relatively large juveniles was ovigerous, the other was attended by a male. Aeginina longicornis belongs to the group of epibenthic peracarids with extended parental care, most members of this group being suspension feeders

The discovery of hidden arsenic species in coastal waters

AbstractThe analysis of ultraviolet (UV)‐irradiated and untreated seawater samples has shown that the dissolved arsenic content of marine waters cannot be completely determined by hydride generation–atomic absorption spectrophotometry without sample pretreatment. Irradiation of water samples obtained during a survey of arsenic species in coastal waters during the summer of 1988 gave large increases in the measured speciation. Average increases in the measured speciation. Average increases in total arsenic, monomethylarsenic and dimethylarsenic were 0.29 μg As dm−3 (25%), 0.03 μg As dm−3 (47%) and 0.12 μg As dm−3 (79%), respectively. Overall, an average 25% increase in the concentration of dissolved arsenic was observed following irradiation.This additional arsenic may be derived from compounds related to algal arsenosugars or to their breakdown products. These do not readily yield volatile hydrides when treated with borohydride and are not therefore detected by the normal hydride generation technique. This has important repercussions as for many years this procedure, and other analytical procedures which are equally unlikely to respond to such compounds, have been accepted as giving a true representation of the dissolved arsenic speciation in estuarine and coastal waters. A gross underestimate may therefore have been made of biological involvement in arsenic cycling in the aquatic environment.

Tintinnines ( Ciliophora, oligotrichida, tintinnina) in eastern Adriatic Bays

Twenty-five species of tintinnines were found in 10 bays of the Yugoslav coast of the Adriatic Sea. This work indicates the qualitative composition and numerical abundance of tintinnines. Their appearance in the plankton and the succession of dominant coastal water species are related to hydrographic conditions.

Heavy metals in molluscan, crustacean, and other commercially important Chilean marine coastal water species.

The work reported here is part of a general program to monitor the marine chemical pollution along the Chilean coast. The present investigation was designated to provide information on the nature and levels of the heavy metals present in the marine species commonly consumed by the population, and to learn whether these levels may constitute a hazard to consumers. The authors report here the typical contents of 10 heavy metals in 12 commercially significant marine species from the Chilean coastal waters (Valparaiso, Concepcion and Puerto Montt). The analyzed species included 7 molluscs, 3 curstacea, and 2 other shellfish species of wide consumption. The metals chosen for analysis were copper, zinc, cadmium, lead, mercury, nickel, antimony, selenium, iron and chromium.

A histopathological report of some epidermal anomalies of Dover sole, Solea solea L., and other flatfish species in coastal waters off south‐east England

The gross pathological and histological changes of typical examples of epidermal anomalies of Dover sole, Solea solea L., and other flatfish from the sewage dumping areas of the Thames Estuary and two ‘control’ areas are described. Five per cent of flatfish showed anomalies including trawl damage abrasions, fin‐rot, ulcers, nodules and tumours, lymphocystis and skeletal anomalies. Many of the anomalies suggested a traumatic aetiology and were often chronic. There was no significant difference in disease incidence between the areas sampled, except more evidence of lymphocystis in one of the control areas.

The Labidocera pectinata group: an Indo-West Pacific lineage of planktonic copepods with descriptions of two new species

The Labidocera pectinata species group is recognized as a unique monophyletic lineage within the primarily tropical Indo-West Pacific radiation of coastal water species encompassed by the Labidocera kroyeri complex. Both categories are defined and the six species comprising the pectinata group, including two new to science, are diagnosed. Review of available facts supports the proposal that L. bipinnata be ranked as a junior synonym of L. rotunda. Phylogenetic relationships within the group based on sexually modified characters are assessed. Two geminate pairs of parapatric species are identified. The geographic ranges of one pair are adjacent in the Andaman Sea, those of the other pair in the vicinity of Cape York, Australia. Each pair appears to be a consequence of a relatively recent speciation event. The apparent phylogenetic intermediacy of L. japonica linking the two tropical species of Asia and the three from Papua-Australia suggests an older sequence of trans-hemisphere spreading and diversification.

γ-Aminobutyric Acid, a Neurotransmitter, Induces Planktonic Abalone Larvae to Settle and Begin Metamorphosis

gamma-Aminobutyric acid (a simple amino acid and potent neurotransmitter in human brain and other tissues of higher animals) and certain of its congeners rapidly and synchronously induce planktonic larvae of the red abalone, Haliotis rufescens, to settle and commence behavioral and developmental metamorphosis. These naturally occurring inducers of algal origin apparently are responsible, in part, for the substrate-specific recruitment, induction of settling, and the onset of metamorphosis of abalone and other planktonic larvae upon specific algae which provide naturally favorable habitats for the young of these species in coastal waters. These observations provide a convenient experimental model for further analysis of the basic molecular mechanisms by which environmental and endogenous factors control the recruitment and development of planktonic larvae. Halogenated organic pesticides significantly interfere with larval settling, as quantified in a new bioassay based upon these findings.