Lagoon Lake Research Articles

Comparative characteristics of the ichthyoplankton of lagoon lakes of the south-eastern part of Sakhalin

Ichthyoplankton surveys are made in lagoon water bodies of the south-eastern part of Sakhalin (the Vavai-Chibisan system of lakes, Lake Tunaicha, Lake Izmenchivoe) from April until November 2002–2007. Comparative characteristics of ichthyoplankton complexes in the ice-free period is given. In the investigated lagoon lakes, differences in the species composition of the ichthyoplankton by the number and time of appearance of the maxima of abundance of eggs and larvae are noted, and also related to morphological structure and hydrological conditions of water bodies. In lagoon lake Izmenchivoe with a salinity not less than 26‰, the eggs and larvae of marine fishes only takes place while, in Vavai-Chibisan lakes, that of freshwater fishes only takes place. In brackish lake Tunaicha, the lowest number of fish species reproduce. In the Vavai-Chibisan system and in Lake Izmenchivoe, one maximum of abundance of ichthyoplankton in June is recorded and, in Lake Tunaicha, two maxima (the highest in June and less expressed in August) are recorded. Irrespective of the species composition, the ichthyoplankton complexes of lagoon lakes have general traits determined by hydrological conditions of water bodies and by their general origin and geographic situation: prevalence of eggs and larvae of low boreal fish species, the maximum species diversity in the late spring-early summer, and decrease of abundance in cooler years.

Seasonal dynamics of phytoplankton in a lagoon-type lake Izmenchivoye (Southeast Sakhalin)

The seasonal changes in taxonomic structure, dynamics of number, and biomass of phytoplankton in the Izmenchivoye lagoon lake (southeast Sakhalin) were studied. In all, 266 species and intraspecies taxa of microalgae were revealed. The greatest species diversity (according to the Shannon index) was observed in May, August and October (H = 2.76–2.89), the least (H = 0.5–0.86), in April and January of 2006. The monthly average number varied from 997 up to 84 282 cells/l, and biomass from 18.98 up to 878.62 mg/m3. The average annual number of phytoplankton and its biomass were 32 650 cells/l and biomass 172.13 mg/m3 respectively. The maximum number was registered in August, 2005, and maximum biomass was recorded in January, 2006. Winter, spring and summer peaks of number coinciding with those of biomass were registered. For the first time, winter bloom of phytoplankton was registered in inland waters of the Sakhalin Island. In the winter and spring the basic input to formation of the parameters was composed of diatoms; in summer and autumn it was composed of by flagellates (dinophyta and cryptophyta).

The occurrence of epizoic ciliates (Protozoa: Ciliophora) of the juvenile flounder, Platichthys flesus L., 1758, from Sarıkum Lagoon Lake (Sinop, Turkey)

The occurrence of epizoic ciliates on the juvenile flounder, Platichthys flesus L., 1758, collected monthly by fishing net in Sinop's Sarıkum Lagoon Lake during the period from May 2003 to April 2004, was investigated. Five epizoic ciliate species, Trichodina jadranica (Raabe, 1958) Haider, 1964; Trichodina domerguei Wallengren, 1897; Riboscyphidia sp.; Ambiphrya sp.; and Vorticella sp., were found after examination of 296 juvenile flounder. Among these, T. jadranica was the dominant species. The prevalence and mean intensity values of the 5 epizoic ciliates were given as pooled data for 2 groups, namely mobiline ciliates and sessiline ciliates. Mobiline ciliates were commonly found on the gills of juvenile flounders, whereas sessiline ciliates were found only on fins. The highest prevalence and mean intensity levels of mobiline ciliates were recorded in the winter and spring seasons. Sessiline ciliates were absent in winter. The largest-sized juvenile flounder among the established 6 length classes had a higher intensity of mobiline ciliates. This study is the first on the epizoic ciliate fauna present on the juvenile flounder in Turkey. While T. jadranica is a new parasite record, the juvenile flounder is a new host record for T. domerguei in Turkey.

Response of macrozoobenthos of lagoon Lake Izmenchivoye (Sakhalin Island) to the discontinuance of water exchange with the sea

Hydrobiological surveys in lagoonal Izmenchivoye Lake (Sakhalin Island) were carried out in 2004, 2005, and 2007 in order to examine the main changes in the composition and structure of macrozoobenthos after the cessation of its communication with the sea. Changes in the hydrological regime of the lake led to a significant reduction in the species list, a decline in the diversity of benthic communities, as well as a twofold increase in the population density of constituent species. The characteristic communities of the seawater cold spreading layer and tidal littoral communities disappeared after the water exchange with the sea ended. The latter communities were replaced with a lacustrine exposed littoral community dominated by amphipods and isopods. The previously shallow-water community dominated by the bivalve Musculista senhousia became the main benthic community. The number of warm-water elements increased markedly. Water temperature proved to be the main factor affecting the composition and structure of benthos of Sakhalin lagoons at the initial stages of evolution of macrobenthos.

Eucyclops albuferensis sp. nov. (Cyclopida: Copepoda: Crustacea) from Albufera lake, Valencia, Spain

A new species of Eucyclops (Copepoda: Crustacea) is described from the ancient oligosaline lagoon Lake Albufera (Spain). Eucyclops albuferensis sp. nov. belongs to the Eucyclops-serrulatus-group of species and can be clearly separated from other conspecifics by a combination of characters that includes very long setules on distal side of caudal rami, absence of teeth on hyaline membrane on distal segments of antennules, micropatterns of hairs and teeth on both sides of basipodite of antenna and hair reduction on inner coxal spine in P4. This species is suggested to be a local endemic of the Valencia area, which is well known as a Pleistocene refuge during glaciation.

Benthic sediment composition and nutrient cycling in an Intermittently Closed and Open Lake Lagoon

Surfical sediments within Corunna Lake, a moderate size Intermittently Closed and Open Lake Lagoon (ICOLL), were examined for solid phase nutrient concentrations (TN, TP, TOC,) and solute exchange rates between the sediment and water column (O 2, NO 3–N, NH 4–N, FRP, and N 2). The surfical sediments in Corunna Lake contained high concentrations of TN (5 mg/g dry mass), total phosphorus (0.6 mg/g dry mass), and TOC (~ 5% dry mass). The carbon stable isotope ratio ( δ 13C) and TOC:TN ratios ( δ 13C ~ − 24, TOC:TN ~ 11–14) demonstrated that the composition of the organic matter in the sediment was a mixture derived primarily of degraded planktonic matter. The close association between TP and Fe concentrations highlighted the potential role Fe plays in mediating Filterable Reactive Phosphorus (FRP) concentrations in the water column of Corunna Lake. In situ benthic chamber incubations were used to measure benthic fluxes. Solute exchange rates between the sediment and water column in Corunna Lake were similar to other reported studies (O 2 = − 469 to − 1765 µmol m − 2 h − 1, NH 4–N = 0.1–63 µmol m − 2 h − 1, NO 2/NO 3–N = 0 µmol m − 2 h − 1, FRP = − 4–1.6 µmol m − 2 h − 1and N 2 = 12–356 µmol m − 2 h − 1). As more carbon was deposited and mineralized the efficiency of the bacterial population to denitrify nitrogen in the sediment decreases. The linkage between land use and benthic biogeochemistry was also explored. A dairy farm exists in the middle catchment of Corunna Lake, and the receiving bay sediment consistently demonstrated the highest oxygen consumption rates in winter and spring (− 1408 µmol m − 2 h − 1 in winter, − 1691 µmol m − 2 h − 1 in spring) and lowest denitrification efficiencies during summer (~ 3%). Nitrate/nitrite fluxes were not observed during any of the chamber incubations, with the concentrations of nitrate/nitrite being below detection limits (< 10 μg/L). Seasonal changes influenced the rates of solute exchange between the sediment and water column. Critical measures of solute exchange for NH 4–N and biogenic N 2 indicated that seasonal temperature changes play a significant role in mediating the reaction rates of sedimentary based biogeochemical processes. Measurable FRP fluxes were small but greater in the benthic sediments which received higher carbon inputs. Sediments have a high capacity to adsorb P which is released as sediment oxygen demand increases as a result of increases in labile carbon loads.

Parasitic fauna of the flounder, Platichthyes flesus L., 1758 caught in the Sarıkum Lagoon Lake in Sinop (Turkey) and the occurrence of parasites in relation to host factors

Parasitic fauna of the flounder, Platichthyes flesus L., 1758 caught in the Sarıkum Lagoon Lake in Sinop (Turkey) and the occurrence of parasites in relation to host factors

Parasitic fauna of the toothcarp Aphanius danfordii (Boulenger, 1890) (Osteichthyes: Cyprinodontidae), an endemic fish from Sarıkum Lagoon Lake in Sinop (Turkey)

Parasitic fauna of the toothcarp Aphanius danfordii (Boulenger, 1890) (Osteichthyes: Cyprinodontidae), an endemic fish from Sarıkum Lagoon Lake in Sinop (Turkey)

A patch use behaviour approach to model leaf litter breakdown in aquatic environment

1 - We present a mechanistic model of reed leaves decomposition in a Mediterranean coastal lagoon (Lake Alimini Grande, Puglia, Italy). Our aim is to assess the importance of the heterogeneity of leaf detritus and of the different rules of patch colonization by macroinvertebrates on reed detritus processing. 2 - To this end, we propose two versions of the model (homogeneous and heterogeneous detritus model) where the microflora is supposed to complete all the life cycle on a leaf patch, while the macroinvertebrates move towards or left the patch according to patch attractiveness. 3 - The threshold of patch attractiveness and the number of colonizers are the behavioural sources of variation in the model. The effects of the behaviour of invertebrate consumers on detritus mass loss are tested by a multi-factorial ANOVA design. A field study on reed leaf decomposition in Lake Alimini Grande is used as reference to set a number of biological parameters. 4 - Simulated leaf detritus loses weight according to a negative exponential model. The comparison between simulated and experimental data selects the heterogeneous detritus model for describing reed leaf decomposition. Behaviourally–related characteristics of invertebrate consumers also affect decomposition rates, which are directly related to invertebrate abundance and inversely to resource attractiveness threshold. The model results suggest that reed leaf decomposition in Lake Alimini Grande is probably driven by microbial activity.

Metropolitan Development on Drought History of the Tuzla Lake, Istanbul, Turkey

Abstract The coastal environment has changed in the past 25 years relation to the industrial and human settlement around the Tuzla Lake, Istanbul, Turkey. At first, the inlet of the Tuzla Lagoon Lake was filled and isolated from the sea, and changed to a fresh water lake. This was followed by chanelling of dirty creeks and a tunnel construction 8 m below the sea level just behind the lake. These engineering constructions resulted in a 3 m fall of ground water level in 4 years around the lake and, as a result a drought occurred in June, 2001. During this period, salty water encroachment and groundwater saltation occurred and farmlands faced significant irrigation problems. After the drought, two connection pipe lines were constructed between the sea and the lake. However, these pipes were filled by sea originated material, mostly shells, within a year and water exchange between the lake and the sea became impossible. As a result, environmental equilibrium has been disturbed and farming habits have changed....

Temporal and spatial variation in the macrophyte distribution in coastal lagoon Lake Nakaumi and its neighboring waters

During the period May–December 1996, macrophyte distribution and its abundance were investigated for 24 sites in coastal lagoon Lake Nakaumi and its neighboring waters, southwestern Honshu, Japan. More than 21 taxa, including two aquatic angiosperms, were found and the taxa with high frequency of occurrence were Enteromorpha spp. and Sargassum thunbergii. Ruppia maritima, one of the endangered aquatic macrophytes in Japan, was also found making dense meadows in Honjou, an area planned to be reclaimed. Four distinct distributional regions were recognized in the lake by principal component analysis (PCA) using the seasonal maximum cover of each species, and a significant relation was found between PCA axis 1 and electric conductivity. A long-term change in floristic composition is also discussed based on the present results and literature.

Distribution of macrobenthic fauna in Phawong and U‐Taphao canals flowing into a lagoonal lake, Songkhla, Thailand

The macrobenthic fauna of two discharge ecosystems, Phawong Canal and U‐Taphao Canal flowing into Songkhla Lake in Thailand, were studied from August 1994 to August 1995. The salinity of Phawong Canal and U‐Taphao Canal ranged from 0.1 to 27.8 and 0.1 to 17.0 practical salinity units (PSU), respectively. The biochemical oxygen demand (BOD) of Phawong Canal ranged from 2.5 to 33.0 mg L−1, while that of U‐Taphao Canal ranged from 1.1 to 12.6 mg L−1. Temporal changes in the number of species and individuals were determined throughout a year. During the season of heavy rains (November– December), the density and number of most species decreased markedly. Only chironomid larvae increased and these were distributed in the uppermost reaches of the canals during this period. Sixty‐two and 52 species of macrobenthic fauna were found in Phawong Canal and U‐Taphao Canal, respectively; however, the abundance and number of species collected at each sampling was very low in the upper reaches of the canals. The most numerous benthic fauna in the Phawong Canal were polychaetes, followed by amphipods. Pelecypods and gastropods were the dominant groups in U‐Taphao Canal. A distribution pattern of macrobenthic fauna associated with pollution gradients (BOD) was observed only at Phawong Canal. In addition, species diversity according to the Shannon‐Wiener index only was not applicable to the assessment of benthic environmental health when the few individuals found were evenly distributed among the few species present at U‐Taphao Canal. It is recommended that a coastal care project be established by the appropriate government agencies in the study areas.

Seasonal variation of phytoplankton community in Thale Sap Songkhla, a lagoonal lake in southern Thailand

The phytoplankton in Thale Sap Songkhla was investigated at 2–3 month intervals from August 1991 to October 1993. The abundance of phytoplankton ranged from 1.4×106 to 1.3×109 cells m−3. A total of 6 divisions with 103 genera were identified as Bacillariophyta: 49 genera, Chlorophyta: 21 genera, Pyrrhophyta: 15 genera, Cyanophyta: 12 genera, Chrysophyta: 3 genera and Euglenophyta: 3 genera. Although phytoplankton abundance was distinctly greater in the first year of study (August 1991–June 1992) than in the second year (August 1992–October 1993), their patterns are similar: 2 peaks yearly. The peaks of phytoplankton occurred in the heavy rainy season (northeast monsoon) and the light rainy season (southwest monsoon). The main bloom was found during December–January, with a predominance of blue-green algae (e.g. Aphanizomenon andPhormidium) and green algae (e.g. Eudorina). Their species composition also increased, an effect of the large amount of rainfall resulting in low salinity during the northeast monsoon. The minor bloom was produced by diatoms during June–July when water salinity was moderate to seawater. Both phytoplankton numbers and species composition were high. However, unpredictably heavy rainfall during the southwest monsoon period may reduce diatom production due to rapid immediate replacement by blue-green species. Besides salinity concentration, a low total nitrogen: total phosphorus (TN: TP) ratio tended to support the growth of blue-green algae. The diversity of phytoplankton was lowest in the heavy rainy period.

Salinity intrusion into Lake Songkla, a lagoonal lake of Southern Thailand

Salinity intrusion into Lake Songkla, a lagoonal lake of Southern Thailand