North Shoreline Research Articles

Lakeshore areas of conservation interest: Characteristics of nursery areas of the threatened lake‐dwelling grayling, Thymallus thymallus

AbstractResearch‐based knowledge is essential for effective conservation and restoration of threatened aquatic species and habitats. Here, our aim was to gather this knowledge on the lake‐dwelling grayling (Thymallus thymallus), typically a riverine fish. Such atypical populations are particularly vulnerable to anthropogenic impacts, including fishing pressure, climate change, eutrophication and waterway construction, some of which affect especially the early life stages. However, there is little information available to guide management and conservation of grayling in lakes. Accordingly, we assessed characteristics of the nursery areas in the threatened grayling population of Lake Puruvesi (eastern Finland). In particular, we used beach seines in two consecutive years to sample lakeshore sites (including islands) that were a priori presumed suitable for grayling. We assessed the occurrence of grayling fry (larvae and post‐larvae <40 mm in length) regarding depth, year, the site's exposure (fetch), bottom shear stress, substrate coarseness and shoreline's north–south orientation. Overall, we found grayling fry in low numbers at every fourth site, with the sites’ exposure and dominant substrate coarseness being most relevant variables. In particular, more exposed sites (i.e. with higher fetch values) and fine‐grained substrates dominated by sand or gravel had more grayling fry. Average depth, bottom shear stress or shoreline orientation along the north–south axis did not have a significant effect. Together, the results suggest that the most important nursery areas for lake‐dwelling grayling are lakeshore zones that are barren and exposed. Hence, the sites share characteristics with those used for reproduction by the more common riverine grayling. We hope that these findings will facilitate lake‐dwelling grayling's management and conservation efforts.

Study on Suitability of Artificially Planted Native Mangroves in Coastal Areas of Guangzhou

At present, the mangrove species planted in the coastal area of Guangzhou is relatively single, and the dominant species is mainly the non-petal Sonneratia caseolaris (alien species). From 2020 to 2021, after the observation of the growth of mangroves on the north shoreline of the Humen Bridge (Guangzhou Section) in Nansha District, Guangzhou, it is shown that the dominant local mangrove species suitable for growth in the coastal area of Guangzhou are Kandelia obovata and Aegiceras corniculatum.

Snowband Characteristics Associated With Lake‐Effect Misovortices During the OWLeS Project

AbstractVortices of diameters 100 m to 10 km have been observed during lake‐effect snowstorms. Lines of misovortices (diameters = 40–4,000 m) have recently been documented forming over Lake Ontario during long lake‐axis‐parallel (LLAP)‐type lake‐effect storms. Using National Weather Service Weather Surveillance Radar—1988 Doppler (WSR‐88D) and Doppler on Wheels radar data from the Ontario Winter Lake‐effect Systems (OWLeS) project, lines of misovortices (also referred to as “misovortex lines” in this study) were investigated for intensive observation period (IOP)7 (7 January 2014) and IOP9 (9 January 2014). Results revealed that the misovortex lines formed on the southern or northern side of the west‐to‐east‐oriented LLAP band, whichever was closest to a low‐level boundary nearest the corresponding south or north shoreline (northern part in IOP7, southern part in IOP9). Examination of these two IOPs in the context of a total of 23 OWLeS IOPs, 11 of which had predominantly LLAP band morphology, showed that, in 4 of the 11 LLAP IOPs, horizontal shear zones/reflectivity bands formed in preferred regions over Lake Ontario and nearby land areas where low‐level boundaries (e.g., land breeze fronts) have been noted to develop near shoreline irregularities. Horizontal shear zones were predominant in approximately half of the OWLeS LLAP IOPs and were associated with storms having a well‐organized, solid banded reflectivity structure. Misovortices occurred when horizontal shear zones were prevalent, supporting the idea that horizontal shearing instability was important to their formation.

Diurnal Wind Pattern and Climate Condition on the Coastal Region of Qatar

Climate pattern in the Persian Gulf is of great interest due to the strategic geographical location of the gulf as a waterway of major oil transportation and its increasing regional economic importance. However, long term and continues climate observations in this region are rare, especially for high resolution data. High resolution wind pattern and climate conditions were measured at 3 heights on a 9 m tower on the shoreline north of Qatar (26.08 N, 51.36 E) from August 2015 to September 2016. In this work, the annual wind and climate patterns (wind velocity, temperature, relative humidity, and air pressure) are first presented. Drag coefficient, turbulent kinetic energy and sensible heat flux are calculated using the high speed measured data to explain the observed climate pattern. The results show the wind in the southern part of the gulf is dominant by a northwest stream with a diurnal average speed of 4.7 m/s. During the test year, the diurnal average temperature and relative humidity were 27°C and 70%, respectively. The drag coefficient is much higher for the wind from 270o-330o, corresponding to the wind coming mainly from northwest. The Turbulent Kinetic Energy (TKE) is strong during the daytime, especially around noon when the diurnal value is at its peak, and weak during the night. The result of this analysis may be used for better understanding of the local climate, allowing for further assessment of wind energy and pollution diffusion in the region.

Nutrient and heavy metal composition in select biotic and abiotic components of Varthur wetlands, Bangalore, India

Lakes or wetlands in urban landscapes provide services such as groundwater recharge, provide fish, fodder and food to the dependent local population, mitigate floods, habitat for fauna, support recreation, etc. Unplanned rapid urbanization with globalization and industrialization has led to the sustained inflow of untreated wastewater from domestic and industrial sectors to water bodies leading to eutrophication and heavy metal contamination. This necessities treatment of sewage and industrial effluents, which needs to be technically feasible and economically viable. This communication investigates the distribution and accumulation of nutrients (carbon and nitrogen) and six heavy metals (cadmium, chromium, copper, nickel, lead and zinc) in the sediment and macrophyte samples of Varthur lake, Bangalore. Higher carbon and nitrogen values in sediment samples of the northwest and northeast shorelines were observed, whereas lower carbon and nitrogen values were observed in the samples of middle and outlets of the lake. Shoots of Colocasia esculenta and Alternanthera philoxeroides accumulated higher amount of carbon and nitrogen. Sediment samples of north shoreline and inlet portion of the Lake had high concentration of heavy metals in Alternanthera philoxeroides and Eichhornia crassipes accumulated heavy metals in higher extent among macrophyte species. Sediment samples had higher concentrations of copper (Cu) followed by zinc (Zn), chromium (Cr), lead (Pb), nickel (Ni) and cadmium (Cd). Compared to this, accumulation of heavy metals in macrophyte samples is in the order Cu > Zn > Cr > Pb > Ni > Cd. Assessment of bioconcentration factor and translocation factor of metals in macrophytes revealed the prospects of select macrophytes in phytoremediation for mitigating metal pollution through phytoextraction and phytostabilization.

Dynamics of Metal Pollution in Sediment and Macrophytes of Varthur Lake, Bangalore.

Eutrophication and metal contamination are the principal pollution problem for almost all inland lakes in world. Phytoremediation is one of the viable solutions for this concern. The present study analysed the concentration and distribution of six metals (cadmium, chromium, copper, nickel, lead and zinc) in sediment and macrophyte samples of Varthur Lake, Bangalore. Higher concentrations of studied metals in sediment were observed at the inlet and north shoreline regions of the lake. Alternanthera philoxeroides and Eichhornia crassipes accumulated higher concentration of metals than other species. Accumulation of metals in the sediment were Cu > Zn > Cr > Ni > Pb > Cd, whereas the order in macrophyte samples was Cu > Zn > Cr > Pb > Ni > Cd. Bioconcentration factor (BCF) and translocation factor (TF) of metals in macrophytes revealed metal pollution could be remediated through phytoextraction and phytostabilization.

Bimodal climate control of shoreline change influenced by Interdecadal Pacific Oscillation variability along the Cooloola Sand Mass, Queensland, Australia

Wave climate in southeast Queensland, Australia has been correlated to changes in the Southern Oscillation Index (SOI), but observations of shoreline change associated with the variable wave climate have been limited due to a paucity of aerial photography, LiDAR, and other beach profiling datasets in this region. A multi-decadal, sub-annual temporal resolution shoreline dataset spanning 1996 to 2017 was produced using satellite imagery collected by Landsat 5, 7, and 8. A total of 147 shoreline positions were delineated using the Modified Normalized Difference Water Index on cloud-free imagery and corrected for horizontal offsets forced by variable tide stages at the satellite flyover time. The relative influence of SOI, the Southern Annular Mode (SAM), Pacific Decadal Oscillation (PDO), and Subtropical Ridge Latitude (STR-L) and Pressure (STR-P) on shoreline dynamics along the Cooloola Sand Mass in Queensland are assessed by performing cross correlations between their respective index values and shoreline change distances calculated by the Digital Shoreline Analysis System. A bimodal climate control of shoreline change is observed dependent upon the phase of the Interdecadal Pacific Oscillation (IPO). IPO modulates the impacts of ENSO on eastern Australia through its control over the position of the South Pacific Convergence Zone and elevating/lowering of tropical Pacific sea surface temperatures. During negative IPO, SOI is negatively correlated to the Cooloola Sand Mass shoreline indicating that the shoreline retreats during negative SOI phases. During positive IPO, the impacts of SOI are weakened and the STR becomes the primary driver of shoreline change with shoreline response being contingent upon its orientation. The SW-NE aligned Noosa North shoreline erodes in response to poleward movement of the STR, likely due to the enhanced cross-shore wave attack as a result of anti-clockwise wave rotation. The opposite response is shown at the SE-NW aligned Rainbow Beach shoreline, which is oriented almost parallel to the incident wave direction and is sheltered by the Double Island Point headland. These results suggest that climate control on shoreline change at Cooloola Sand Mass, and likely other sand islands in the region, is two-tiered, whereby interdecadal variability of the IPO governs the relative influence of SOI and STR under the different IPO phases. The linked climate and shoreline variability correlation shown in this study provides significant insight into how the Cooloola Sand Mass shoreline will respond to future climate changes under a global warming scenario.

Assessing Land Loss from Flooding in the Lake St. Martin Basin in Manitoba, Canada

Floodwaters from the Assiniboine River are typically diverted to Lake Manitoba and then Lake St. Martin to save the City of Winnipeg and Portage la Prairie from flooding. The four Indigenous communities living Lake St. Martin basin experienced many negative impacts, including long-term displacement after the 2011 flood. Data analysis of historical water levels of Lake Manitoba and Lake St. Martin were conducted to understand the impact of control structures and water levels. Satellite imagery allowed geographic information system (GIS) raster analysis of the shoreline change of Lake St. Martin before and after the 2011 super flood. From 1986 to 2010, the Lake St. Martin area increased slightly by approximately 0.63% but in 2011 the lake area increased by 13%. 11,000 acres were lost mainly around Lake St. Martin First Nation (LSMFN) reserve and the Little Saskatchewan First Nation, as a result and many houses and other buildings (churches, band offices, etc.) flooded in these communities. The shoreline change analysis showed that, in particular, the west and north shoreline of Lake St. Martin lost its beaches and lakefront properties, to become swampland after the 2011 flood. Thousands of Indigenous people were displaced for eight years, as the community could only start to rebuild its infrastructure and houses on higher ground after a government settlement was reached.

Local production and imitations of Late Roman pottery from a well in the Roman necropolis of Cuma in Naples, Italy

AbstractArchaeological excavations performed in a funerary complex in Cuma (Campania region, Italy) unearthed excellently preserved common wares dated to the third century A.D. Archaeometric analyses were focused on Campanian pitchers, Aegean‐like cooking pots, and pyriform pitchers, the latter recorded for the first time in an Italian context. The local pitchers were manufactured with a high‐CaO clay (CaO = ca. 12 wt.%) and local volcanic temper, fired at ca. 800–850°C, as suggested by the presence of calcite. The Aegean‐like pots and the pyriform pitchers were made with low‐CaO clay (CaO ≤ 4.0 wt.%) mixed with a calcite‐bearing temper, along with volcanic and siliciclastic grains, and fired at 800–950°C. The comparison with raw materials inferred that local vessels were made with low‐CaO basinal clays which outcrop in the northern Campania region, and sands from the shoreline north of Cuma where carbonate, siliciclastic and volcanic phases mix together. Our results suggest that the Phlegraean Late Roman workshops produced their traditional vases along with imitations of Aegean‐like pottery. Thus, microregional production responded to a market demand requiring shapes and styles similar to imports from the eastern Mediterranean, with which commercial trade was still quite active.

The OWLeS IOP2b Lake-Effect Snowstorm: Shoreline Geometry and the Mesoscale Forcing of Precipitation

Long-lake-axis-parallel (LLAP) lake-effect precipitation systems that form when the flow is parallel to the long axis of an elongated body of water frequently produce intense, highly localized snowfall. Conceptual models of these LLAP systems typically emphasize the role of thermally forced land breezes from the flanking shorelines, with low-level convergence and ascent centered near the lake axis. In reality, other factors such as shoreline geometry and differential surface roughness can strongly influence LLAP systems. Here a WRF Model simulation is used to examine the mesoscale forcing of lake-effect precipitation over Lake Ontario during IOP2b of the Ontario Winter Lake-effect Systems (OWLeS) field campaign. In the simulation, the large-scale flow, shoreline geometry, and differential surface heating and roughness contribute to the development of three major airmass boundaries. The first is a land-breeze front that forms along a bulge in the south shoreline between St. Catharines, Ontario, Canada, and Thirty Mile Point, New York; extends downstream over eastern Lake Ontario; and plays a primary role in the LLAP system development. The second is a land-breeze front that forms along the southeast shoreline near Oswego, New York; extends downstream and obliquely across the LLAP system near Tug Hill; and influences inland precipitation processes. The third is a convergence zone that extends downstream from the north shoreline near Point Petre, Ontario, Canada; and contributes to the intermittent development of lake-effect precipitation north of the primary LLAP system. These results highlight the multifaceted nature of LLAP system development over Lake Ontario, especially the contributions of shoreline geometry and mesoscale airmass boundaries.

Analysis of elevation discrepancies along the Lop Nur ear-shaped stripes observed using GLAS and DGPS data

The Lop Nur is a dried-up salt lake lying in the eastern part of the Tarim Basin in China. The peculiar ear-shaped stripes in Lop Nur observed in satellite images have attracted the interest of investigators. It is believed that these stripes represent former lake shorelines, thus are valuable for studying the lake evolution. Owing to insufficient high-precision elevation data, the elevation along a given stripe was supposed to be constant. In this study, elevation data collected by the Geoscience Laser Altimeter System (GLAS) and the Differential Global Positioning System (DGPS) were carefully analysed. The combined topographic data for the ear-shaped region indicate that the elevations of the south shorelines are approximately 1 m higher than the north shorelines along the same stripe. We analyse the mechanisms of the phenomenon and suggest that the wind-driven water surface tilt at the time the ear-shaped stripes formed is the dominant one. The stripe profiles simulated by this mechanism show an excellent agreement with the measured stripe profiles.

A screening procedure for selecting the most suitable dredged material placement site at the sea. The case of the South Euboean Gulf, Greece

The selection of the best site for the placement of dredged sedimentary material (∼7,000 m(3)) from the Aliveri coastal area in the adjacent South Euboean Gulf (Greece) was accomplished through a screening procedure. The initial stage comprised the determination of physical, chemical, and biological characteristics of the dredged sediment before the commencement of any dredging operation. Grain size measurements, geochemical analyses together with the use of pollution/toxicity indices and empirical sediment quality guidelines, and the conduct of an acute toxicity test showed that the dredged material consisted of "unpolluted to slightly polluted" silty sands and sandy silts. However, the local authorities planned to place this sediment in the neighboring open sea area, i.e., the South Euboean Gulf, due to the absence of any beneficial use or alternative dumping option (i.e., dumping on public lands). Therefore, the next stage of the screening procedure, based on criteria such as the national legislation, seabed and seawater column characteristics, influence of the water mass circulation pattern on the post-placement migration of dredged sediment, impact on living resources and human activities (i.e., aquaculture and fishing), effect on significant marine sites (i.e., sites of scientific, ecological, and historical importance, navigation routes, military zones), and seafloor engineering uses, led to the evaluation of the suitability of the South Euboean Gulf as a potential dumping area. Then, the identification of the appropriate dredged material placement sites in the South Euboean Gulf was based on a cluster analysis, which tested the physicochemical resemblance of the dredged material and the surface sediments of 19 potential placement locations in the gulf. After the statistical process, only four sites situated near the north shoreline of the South Euboean Gulf were qualified as the best dredged material placement locations.

Recent paleorecords document rising mercury contamination in Lake Tanganyika

Abstract Recent Lake Tanganyika Hg deposition records were derived using 14C and excess 210Pb geochronometers in sediment cores collected from two contrasting depositional environments: the Kalya Platform, located mid-lake and more removed from watershed impacts, and the Nyasanga/Kahama River delta region, located close to the lake’s shoreline north of Kigoma. At the Kalya Platform area, pre-industrial Hg concentrations are 23 ± 0.2 ng/g, increasing to 74 ng/g in modern surface sediment, and the Hg accumulation rate has increased from 1.0 to 7.2 μg/m2/a from pre-industrial to present, which overall represents a 6-fold increase in Hg concentration and accumulation. At the Nyasanga/Kahama delta region, pre-industrial Hg concentrations are 20 ± 3 ng/g, increasing to 46 ng/g in surface sediment. Mercury accumulation rate has increased from 30 to 70 μg/m2/a at this site, representing a 2–3-fold increase in Hg concentration and accumulation. There is a lack of correlation between charcoal abundance and Hg accumulation rate in the sediment cores, demonstrating that local biomass burning has little relationship with the observed Hg concentration or Hg accumulation rates. Examined using a sediment focusing-corrected mass accumulation rate approach, the cores have similar anthropogenic atmospheric Hg deposition profiles, suggesting that after accounting for background sediment concentrations the source of accumulating Hg is predominantly atmospheric in origin. In summary, the data document an increase of Hg flux to the Lake Tanganyika ecosystem that is consistent with increasing watershed sediment delivery with background-level Hg contamination, and regional as well as global increases in atmospheric Hg deposition.

Environmental evolution of Xingkai (Khanka) Lake since 200 ka by OSL dating of sand hills

Crossing the Sino-Russian boundary, Xingkai Lake is the largest freshwater lake in Northeast Asia. In addition to the lakeshore, there are four sand hills on the north side of the lake that accumulated during a period of sustainable and stable lacustrine transgression and were preserved after depression. Analysis of well-dated stratigraphic sequences based on 18 OSL datings combined with multiple index analysis of six sites in the sand hills revealed that the north shoreline of Xingkai Lake retreated in a stepwise fashion since the middle Pleistocene, and that at least four transgressions (during 193-183 ka, 136-130 ka, 24-15 ka and since 3 ka) and three depressions occurred during this process. The results of this study confirmed that transgressive stages were concurrent with epochs of climate cooling, whereas the period of regression corresponded to the climatic optima. Transgressions and regressions were primarily caused by variations in the intensity of alluvial accumulation in the Ussuri River Valley and fluctuations in regional temperature and humidity that were controlled by climatic change. Moreover, one obvious transgressive process that occurred in MIS3 may have been related to enhanced precipitation that was reportedly widespread in the west of China, while short-term fluctuations in the lake level might well be a direct response to regional precipitation variations on the millennial scale.

Preferential pathways of phosphorus movement from agricultural land to water bodies in the Canadian Great Lakes basin: A predictive tool

Allaire, S. E., van Bochove, E., Denault, J.-T., Dadfar, H., Thériault, G., Charles, A. and De Jong, R. 2011. Preferential pathways of phosphorus movement from agricultural land to water bodies in the Canadian Great Lakes basin: A predictive tool. Can. J. Soil Sci. 91: 361–374. Preferential flow processes, such as crack flow (CF), burrow flow (BF), finger flow (FF) and lateral flow (LF) are known as factors enhancing phosphorus (P) transport from agricultural soils to water bodies. The objective of this study was to develop a methodology for predicting the likelihood of preferential flow processes in agricultural soils at the landscape scale and their potential occurrence around the Canadian Great Lakes. The methodology considered climate, soil and crop parameters and a water budget that calculated surface runoff and drainage. Crack flow largely depended upon soil clay content, BF on soil texture and climate, FF on layering in sandy soils and LF on the presence of trees, slope and soil restricting layers. Crack flow had a high likelihood to occur southern Lake Ontario and all around Lake Erie. A high likelihood of FF could be found in the area where CF was low (i.e., in the sandy soils north of Lake Huron and Lake Ontario). Burrow flow had a medium likelihood to occur on Manitoulin Island and close to the shoreline north of Lake Ontario. Medium to high likelihood of lateral flow might occur in the area south of Lake Ontario, west of Toronto in a narrow band towards Lake Huron, and to a lesser extend in a large area northeast of Lake Huron. Lateral flow may transport soluble P in areas where P was previously carried downward by FF from inland (in soils) to surface water bodies. In several areas, tile drainage may transport all forms of P carried downward from the soil surface to the subsurface by CF and BF to lake tributaries. Preferential flow distribution maps could be used as tools for supporting the identification of agricultural lands where management might enhance subsurface processes of P transport toward groundwater or surface water bodies.

Catch and Release. Repeat

Catch and Release. Repeat Will Jennings (bio) Spring Training—Evanston, Illinois, 1964 I walk up close as I can to stare at the mortar between the bricks, close enough to pick at the flakes of an old warehouse advertisement that once covered the entire wall. My father and his brother played a sort of toss-and-bounce-back baseball here, back when this wall was the boundary to their yard, back when this ground even was a yard. I can't imagine grass, really, just hard pan and the split tufts of reedy growth, perhaps a clothesline, a pea gravel path to the alley behind. I am nine, my father's age when this was his family's home during the onset of the Great Depression. Above it all looms this four-story wall. ALLIED COLD STORAGE. A mural that once played to a passing opulence: "Ladies! Summer Storage For Your Fine Furs! Bonded! Fire Proof!" Because it is February, and because where their house once stood is now an asphalt lot for a church's overflow of cars, maybe even because there's a fine misting sleet beginning to sting my ears, I have to pretend really hard to hear the thwap and wumple of a rubber Spaldeen, the high running fastballs of my father dimpling the hem of a lady in mink. My dad has taken me along on a service call, a Sunday afternoon in late winter-early spring when an anytime rain along this southern stretch [End Page 55] of Lake Michigan can turn to ice, and the wind from the east off the water lays down an elegant glaze of misery. It's the time of the year when people try to finick and coax their boilers and gravity furnaces through one more season, one last snap of cold. And this is the sort of busy that keeps my dad's shop flush and our home phone a constant interruption most evenings and weekends. I have just watched him wheedle an apartment's aging behemoth back to the living, with what looked like a nimble whispering from where I stood off shyly in the damp against a shuttered flume for coal. My father has brought me here to show me the house where he once lived. Instead, we are walking around this parking lot beside a church and across Chicago Avenue from the raised tracks where the North Shore Line used to run. As my dad paces off steps from the wall, I am slowly tracing a strike zone on the bricks, one mitten off, and I am thinking, this spot, here, back then and now it is now, and now me. We turn and face each other. My father pantomimes a gangly wind up to a pitch, bluffing a tip off to his high-and-tight heater. I place my wrists together, close my eyes, and pretend to wiggle a bat I do not hold. We go on this day to two more lots, all of them former sites of houses where my father used to live. All of them asphalt or gravel now. By the last, even he doesn't seem surprised and we don't even get out of the car. We sit in the stuttering yellow Falcon, the sound of the sleet revealing the tin economy of its make, the vinyl bench seats turning cold and stiff where our bodies cannot warm them. He smokes his Luckies, and I work on a peppermint I've found in the shelf that serves as a glove box. Decades later, now in my fifties, I imagine hovering high above that small plot of Evanston, circling those vacant lots with penciled lines like the at-bats of a scorecard, a constellation to mark the source and direction of his life, maybe even my own. At each stop on that day's circuit of calls, there were things that could be fixed and things that you just had to imagine. Those boilers and burners were real and took well to wrenches. But my father's childhood, tucked in the rhythms of family and trains, the play-ball cadence of one-pitch-two-strike-three was difficult...

Polycyclic aromatic hydrocarbons in water, mussels ( Brachidontes sp., Tagelus sp.) and fish ( Odontesthes sp.) from Bahía Blanca Estuary, Argentina

Polycyclic aromatic hydrocarbons (PAHs), one of the major groups of anthropogenic environmental pollutants, were firstly identified and measured in coastal waters, native mussels and fish of an industrialized South American estuary. The aim of this study was to measure the PAHs concentrations and evaluate distribution and sources in surface seawater, native mussels ( Brachidontes sp. and Tagelus sp.) and fish ( Odontesthes sp.) from various coastal sites of the Bahía Blanca Estuary, in order to put the estuary in a global context and assess it ecotoxicological risk. For this, 40 samples of surface water were collected between August 2004 and February 2006 and analyzed by GC/MS for 17 PAHs, including the 16 EPA priority PAHs. In addition, main physicochemical parameters, nutrients and pigments were simultaneously obtained as key parameters to evaluate possible relationships. Finally, several native mussel communities and fish specimens were also analyzed for PAHs contents. The area of study is located at the Argentinean coast and presents an intensive human and industrial activity at the north shoreline. Total PAHs (Σ17 PAHs) in whole surface waters ranged from undetected to more than 4 μg/l. Seasonal PAHs levels relationship with master parameters suggested a relationship between the phytoplankton microbiological cycling and the dissolved/suspended PAHs occurrence in water. In addition, Cluster Analysis was performed to identify the homogeneous groups of individual PAHs in water and Principal Component Analysis to extract underlying common factors. The result of PCA was similar to that of the cluster analysis; both could differentiate two subsets of pyrogenic sources and a petrogenic origin. PAHs levels in indigenous mussels ( Brachidontes sp. and Tagelus sp.) ranged from 348 to 1597 ng/g (dry weight). Fish specimens ( Odontesthes sp.) showed a mean concentration of 1095 ng/g d.w. in whole tissues. Mussel source ratios and PCA results were in good agreement with the dominant sources assessed for water samples and further enabled the linking of PAHs origins according to the sample location. The Bahía Blanca Estuary wide mean of the PAHs burden in mussels showed that the average PAH contamination level was within the “moderate” category. Levels appeared as ecotoxicologically risk safe for the inner stations; however, they were exceeding various safety criterions at the outer. Results indicate the needing of a systematic monitoring program for the area of study, in order to provide accurately assessment and management of risks for the regional population.

The Sandbar Shark Summer Nursery within Bays and Lagoons of the Eastern Shore of Virginia

AbstractWe sought to examine the spatial use of coastal bays and lagoons associated with the Eastern Shore of Virginia (i.e., the Atlantic shoreline north of the mouth of the Chesapeake Bay) as nursery habitat for sandbar sharks Carcharhinus plumbeus. Generalized linear mixed models were used to examine the relationship between physical factors and the abundance of neonate and juvenile sandbar sharks within the study area. Neonates, small juveniles, and large juveniles were present throughout the sampling area in relatively high abundance throughout the months of June‐September. Abundances of neonates and small juveniles were correlated with sampling distance from the inlet; larger fractions of these groups were captured as distance from the inlet increased. Large‐juvenile abundance was not significantly correlated with any physical factor. The catch rates of neonate and juvenile sandbar sharks within this area were comparable with those observed in nearby Chesapeake Bay, although a larger number of juveniles greater than 100 cm total length were caught within the Eastern Shore lagoons. The bays and lagoons we examined function as an important primary and secondary nursery ground for this species and fit the criteria to be included in future management measures as a habitat area of particular concern.

The age of Late Pleistocene shorelines and tectonic activity of Taranto area, Southern Italy

The results of isoleucine epimerization ratios in pelecypods ( Glycymeris sp., Arca sp. and Cerastoderma sp.) and U-series dating of bivalves and Cladocora caespitosa sampled from different Late Pleistocene units in the Chéradi Islands and in the coastal areas of Mar Piccolo and Mar Grande near Taranto (Apulia region, Italy) are presented. U-series measurements on pelecypods and on corals directly associated with mollusc samples provide an independent calibration of amino acid data. The D/ L ratios of isoleucine show a strong correlation with age, and thus may be considered as a predictive dating technique. This correlation also supports the reliability of U-series ages obtained for molluscs. These results, including the stratigraphic position, the lithological lateral continuity, the morphological evidence and the palaeontological characteristics of the various units, made it possible to attribute them to different marine trangressive phases referable to oxygen isotope stages (OIS) 5e–c, 5a and 3. No evidence of land emersion between OIS 5e and 5c has been found in the area. Pinkish/red sands deposits located above present sea level (∼1 m) have been referred to OIS 3. The Late Pleistocene morphological evolution and uplift of a complex area between the Apulian foreland and the Bradanic foredeep have been reconstructed. Due to the lack of incontestable indicators of past sea level stands the facies analysis has been performed on U-series dated 89.8 ka, OIS 5c shoreline north of Mar Piccolo and an uplift rate ranging from 0.21–0.27 mm/yr has been calculated.

A coastal conservation programme for the chennai sea shore, India —A case study

The Chennai coast, an integral part of the east coast of India, extends over ca. 35 km. Over the past 120 yr the coastline has witnessed both man-made and natural disturbances which led to the destruction of the beach front. The construction of Madras harbour in 1876, was the prime cause of the degradation of this very sensitive coastal region. Continued growth of Madras harbour has helped in the natural formation of the wide ‘Marina Beach’, south of the harbour. But the shoreline north of the harbour suffered the consequences of harbour development activities. The north shore receded by ca. 500 m over the past 120 yr and received attention from the authorities in the past few decades because of the growing awareness of the conservation value of the coast. This paper highlights the effects of Madras harbour development on the adjoining coast and on the shortterm mitigation measures planned and executed by the Government agencies to protect the fragile coastline. In spite of sincere efforts to protect the coastline, the destruction continues unabated due to various reasons. This paper analyses the facts and suggests a long-term solution to protect the coastline and to regain the past glory. Feasible and cost effective permanent measures are identified, construction methods suggested and the advantages that the community can derive from the longterm solutions are discussed.