Eastern Bay Research Articles

Potential Threat of Microplastics to Zooplanktivores in the Surface Waters of the Southern Sea of Korea.

The potential impact of microplastic to zooplanktivores was assessed by measuring a ratio of neustonic microplastics to zooplankton by abundance in the southern sea of Korea. Neustonic microplastics and zooplankton (0.33-2 mm) were collected using a 330-μm mesh Manta trawl in Geoje eastern Bay and Jinhae Bay before and after the rainy season in 2012 and 2013. The mean microplastic to zooplankton ratios were 0.086 (May) and 0.022 (July) in 2012, and 0.016 (June) and 0.004 (July) in 2013, indicating that zooplanktivores could be more likely to feed on microplastics than natural preys before the rainy season in 2012 and 2013. In particular, the relatively high ratio occurred in a semi-enclosed bay characterized by a shipyard and a beach resort in Geoje Bay, and at stations close to a wastewater treatment plant and an aquaculture facility in Jinhae Bay before the rainy season. Among dominant microplastics and zooplankton before the rainy season, meroplankton of macrobenthos could be confused with paint particles in Geoje Bay, 2012, whereas Styrofoam could be mistaken as immature copepods by predators in Jinhae Bay, 2013. These observations suggest that zooplanktivores could be more likely to feed on microplastics than natural preys around Geoje and Jinhae Bays before the rainy season.

Coastal vulnerability to typhoon inundation in the Bay of Bangkok, Thailand? Evidence from carbonate boulder deposits on Ko Larn island

At the head of the Gulf of Thailand, the subsiding Chao Phraya delta and adjacent low-lying coastlines surrounding the Bay of Bangkok are at risk of coastal flooding. Although a significant marine inundation event has not been experienced in historical times, this work identifies coastal depositional evidence for high-energy waves in the past. On Ko Larn island in eastern Bay of Bangkok, numerous coastal carbonate boulders (CCBs) were discovered at elevations up to 4+ m above sea level, the largest weighing over 1.3 tonnes. For the majority of CCBs, their karstified appearance bears testimony to long periods of immobility since original deposition, whilst their geomorphic settings on coastal slopes of coarse blocky talus is helpful in recognising lifting (saltation) as the probable mode of wave transport. In the absence of local tsunamigenic potential, these CCBs are considered to be prehistoric typhoon deposits, presumably sourced from fringing coral reefs by high-energy wave action. Application of existing hydrodynamic flow transport equations reveals that 4.7 m/s and 7.1 m/s are the minimum flow velocities required to transport 50% and 100% of the measured CCBs, respectively. Such values are consistent with cyclone-impacted coastlines studied elsewhere in the tropical Asia–Pacific region. Overall, the evidence of elevated carbonate boulder deposits on Ko Larn implies that typhoons before the modern record may have entered the Bay of Bangkok. The recurrence of a similar event in future would have the potential to cause damaging marine inundation on surrounding low-lying coastlines.

Impact of river runoff into the ocean on Indian summer monsoon

Rivers of the world discharge about 36000 km3 of freshwater into the ocean every year. To investigate the impact of river discharge on climate, we have carried out two 100 year simulations using the Community Climate System Model (CCSM3), one including the river runoff into the ocean and the other excluding it. When the river discharge is shut off, global average sea surface temperature (SST) rises by about 0.5°C and the Indian Summer Monsoon Rainfall (ISMR) increases by about 10% of the seasonal total with large increase in the eastern Bay of Bengal and along the west coast of India. In addition, the frequency of occurrence of La Niña-like cooling events in the equatorial Pacific increases and the correlation between ISMR and Pacific SST anomalies become stronger. The teleconnection between the SST anomalies in the Pacific and monsoon is effected via upper tropospheric meridional temperature gradient and the North African–Asian Jet axis.

On the eastward shift of winter surface chlorophyll‐a bloom peak in the Bay of Bengal

AbstractAnalysis of satellite‐derived surface layer phytoplankton chlorophyll‐a concentration (Chl‐a) in the Bay of Bengal revealed an eastward shift of peak of Chl‐a bloom during northeast monsoon period (November–March) from western to the eastern Bay. The winter Chl‐a bloom in the western Bay is shorter duration (∼1–2 months) while that in the eastern Bay is longer duration (∼3–4 months). Unlike other oceans, the eastward bloom peak shift found in the Bay of Bengal is opposite to the direction of propagation of Rossby wave and seasonal mean zonal currents. During winter, sufficient light is available in the Bay of Bengal for phytoplankton growth. Herein, we studied the processes controlling the eastward winter bloom peak shift and the zonal depiction of bloom duration in the Bay of Bengal. There is no single dominant process that drives the eastward bloom peak shift everywhere in the Bay of Bengal. Rather, different physical processes operate in different regions. The physical mechanisms governing the eastward winter Chl‐a bloom peak shift reported here include open ocean Ekman pumping, coastal upwelling, upwelling driven by Rossby wave, wind‐induced vertical mixing, nutrients supply from river input, and westward advection through prevailing zonal currents.

English

Experimental gillnetting and setlining provided a detailed account of shark and ray composition at three shallow water sites in Moreton Bay between 2004 and 2007 (n=350 elasmobranchs). The species composition of elasmobranchs significantly differed between sites and shark abundance was highest at the western site (St Helena Island, Waterloo Bay). Juvenile Dusky (Carcharhinus obscurus) and Pigeye Sharks (C. amboinensis) were more abundant at the western site and appear to be rare in the eastern bay. Approximately 8% of the 206 tagged sharks were recaptured, 60% within two kilometres from their release position, with time at liberty ranging from four to 402 days. The results suggest that the documented east-west gradient in teleost diversity in Moreton Bay also extends to the Carcharhinidae. Further research is recommended to determine whether the diversity patterns observed from the three sites are broadly representative of each of these regions. Setlining and rod and line fishing for sharks in a deeper part of the bay between 1978 and 1992 (n=440 elasmobranchs) revealed a different species composition. The Spottail Shark (C. sorrah) and the Spinner Shark (C. brevipinna) comprised 50% and 39% of the catch in this deeper site, respectively, but were rarely caught in shallow regions of the bay, suggesting that the species composition is also partitioned by depth. Western fringes of the bay have been heavily modified by anthropogenic activities and the importance of this area to juvenile whaler sharks needs to be considered. Future sampling at the same fixed locations may provide the opportunity to examine whether recent re-zoning of the Marine Bay Marine Park in 2009, or other factors such as changes in commercial or recreational fishing, have influenced the species composition and abundance of sharks.

Abundance of walruses in Eastern Baffin Bay and Davis Strait

Walruses (Odobenus rosmarus) are exploited for subsistence purposes in West Greenland. However, current information about the abundance of walruses subject to harvest in eastern Baffin Bay subject to harvest has been unavailable despite being critical for maintaining sustainable catch levels. Three visual aerial surveys were conducted in 2006 (21 March to 19 April 2006), 2008 (3 to 12 April) and 2012 (24 March to 14 April) to estimate the number of walruses on the wintering grounds in eastern Baffin Bay and Davis Strait. Data on the fraction of walruses that were submerged below a 2m detection threshold during the surveys were obtained from 24 walruses instrumented with satellite-linked-time-depth-recorders in northern Baffin Bay in May-June 2010-2012. An availability correction factor was estimated at 36.5% (cv=0.08) after filtering of data for an observed drift of the pressure transducer of more than 2.5 m. The surveys resulted in walrus abundance estimates that were corrected for walruses submerged below a detection threshold and for walruses that were missed by the observers. The estimates of abundance were 1,105 (cv=0.31, 95% CI 610-2,002) in 2006, 1,137 (0.48, 468-2,758) in 2008 and 1,408 (0.22, 922-2,150) in 2012.

Inspiring our largest resource – the patient. Outcomes in a chronic care management service that enables greater self-management

Te Whiringa Ora is an evidence-based integrated care service based in the community that facilitates an interdisciplinary web of care around patients (and their whanau) who are identified as having complex, long term health needs and are high users of hospital services. The aim of the service is to improve self management. _“As far as my condition goes, that really hasn’t changed, the condition hasn’t changed, it will never go away. Its just that now I’ve got it more under control, its not so scary. I feel quite confident for the future”[patient]_ The team consists of registered nurses as case managers, and kaitautoko (health coaches) as navigators. Self-management is enabled through patient-centred goal plans, ongoing ‘navigator’ support and in some patients reinforced by the smart use of telemonitor technology. This service was based in the Eastern Bay of Plenty in New Zealand, a predominantly low socioeconomic area where 50% of the population are Maori, a population with a higher burden of chronic disease. An evaluation framework was designed in the development phase. Three years later we are able to report on the outcomes aligned with the Triple Aim framework. As positive as these were, we are now exploring measurement tools that might show improvements in domains such as selfmanagement and self-efficacy, and shared decision making. We discuss the service model, the outcomes, what we believe enabled self-management success, and what measurement tools we are now exploring in the next iteration of the service.

Provenance of the Late Quaternary sediments in the Andaman Sea: Implications for monsoon variability and ocean circulation

We present a geochemical and Sr-Nd isotopic study on a sediment core collected from the Andaman Sea in an attempt to reconstruct the Late Quaternary weathering and erosion patterns in the watersheds of the river systems of Myanmar and understand their controlling factors. Age control is based on nine radiocarbon dates and δ18O stratigraphy. The rate of sedimentation was strongly controlled by fluctuations of the monsoon. We identify three major sediment provenances: (1) the Irrawaddy catchment, (2) the western slopes of the Indo-Burman-Arakan (IBA) mountain ranges and the Andaman Islands, and (3) the catchments of Salween and Sittang and the Bengal shelf, with the first two contributing 30–60% of the material. Enhanced contributions from juvenile sources and corresponding positive shifts of δ18O are observed at seven time periods (11–14, 20–23, 36, 45, 53, 57, and 62 ka) of which five are synchronous with cooling of the northern hemisphere, suggesting a link between the changes in sediment provenances and the shifting of the locus of the summer monsoon, southward from the Himalayas, without substantial reduction in intensity. Our data, and that from other cores in the region suggest that an eastward moving surface current disperses sediments, derived from the Bengal shelf and western margin of Myanmar, from the eastern Bay of Bengal into the western Andaman Sea and that its strength has increased since the LGM. The existence of this current during the LGM implies that the Andaman Sea and the Bay of Bengal were well connected during the last glacial period.

Asian summer monsoon onset barrier and its formation mechanism

The onset process of Asian summer monsoon (ASM) is investigated based on diagnostic analysis of observations of precipitation and synoptic circulation. Results show that after the ASM commences over the eastern Bay of Bengal (BOB) around early May, the onset can propagate eastwards towards the South China Sea and western Pacific but is blocked on its westward propagation along the eastern coast of India. This blocking, termed the “monsoon onset barrier (MOB)”, presents a Gill-type circulation response to the latent heating released by BOB monsoon convection. This convective condensation heating generates summertime (wintertime) vertical easterly (westerly) shear to its east (west) and facilitates air ascent (descent). The convection then propagates eastward but gets trapped on its westward path. To the east of the central BOB, the surface air temperature (SAT) cools faster than the underlying sea surface temperature (SST) due to monsoon onset. Thus more sensible heat flux supports the onset convection to propagate eastward. To the west of the central BOB, however, the land surface sensible heating over the Indian Peninsula is strengthened by the enhanced anticyclone circulation and air descent induced by the BOB monsoon heating. The strengthened upstream warm horizontal advection then produces a warm SAT center over the MOB region, which together with the in situ cooled SST reduces the surface sensible heating and atmospheric available potential energy to prevent the occurrence of free convection. Therefore, it is the change in both large-scale circulation and air–sea interaction due to BOB summer monsoon onset that contributes to the MOB formation.

Mixed layer variability and chlorophyll <i>a</i> biomass in the Bay of Bengal

Abstract. The mixed layer is the most variable and dynamically active part of the marine environment that couples the underlying ocean to the atmosphere and plays an important role in determining the oceanic primary productivity. We examined the basin-scale processes controlling the seasonal variability of mixed layer depth in the Bay of Bengal and its association with chlorophyll using a suite of in situ as well as remote sensing data. A coupling between mixed layer depth and chlorophyll was seen during spring intermonsoon and summer monsoon, but for different reasons. In spring intermonsoon the temperature-dominated stratification and associated shallow mixed layer makes the upper waters of the Bay of Bengal nutrient depleted and oligotrophic. In summer, although the salinity-dominated stratification in the northern Bay of Bengal shallows the mixed layer, the nutrient input from adjoining rivers enhance the surface chlorophyll. This enhancement is confined only to the surface layer and with increase in depth, the chlorophyll biomass decreases rapidly due to reduction in sunlight by suspended sediment. In the south, advection of high salinity waters from the Arabian Sea and westward propagating Rossby waves from the eastern Bay of Bengal led to the formation of deep mixed layer. In contrast, in the Indo–Sri Lanka region, the shallow mixed layer and nutrient enrichment driven by upwelling and Ekman pumping resulted in chlorophyll enhancement. The mismatch between the nitrate and chlorophyll indicated the inadequacy of present data to fully unravel its coupling to mixed layer processes.

Study of the Vulnerability of Coastal Areas of the Algerian Basin with the GIS

The Bay of Algiers is of a strategic, economic, and social, it is located in the heart of the Algerian capital, where the population density is high and many factories and commercial activities making it vulnerable to the pollution. Particularly along the coast, in addition to climate change, all this leads us to study their impact on the coast of Bay of Algiers, and exposure to risks of erosion and seawater intrusion. The aim of the work is the perception of vulnerable coastal areas by determining the coastal vulnerability index (CVI) at Bay of Algiers, based on physical, geomorphological and hydrodynamic factors, coupled a study of groundwater vulnerability to risks bevel saline particular endangered areas. These results obtained enable to project the future maps from the request processing on the state of the coastal system using the Geographical Information System (GIS). Landmark decisive tools to provide preventive and curative solutions to coastal systems for better coastal protection particular to estuarine areas, privileged place for exchange of sediment transport. The results of the study helped to locate areas of high vulnerability to moderate eastern bay of Algiers by the ICV index varying from 8 to 14. These values are still increasing in the medium to long term if no Compensation by protective structures unsupported consideration.

서식지 적합지수를 이용한 진동만 미더덕과 주름미더덕의 어장적지평가

본 연구에서는 미더덕양식장이 밀집되어 있는 남해안의 진동만 10개 정점에 대하여 미더덕과 주름미더덕의 양식순기에 맞추어 계절별(7월, 10월, 1월, 4월)로 실시하였으며, 어장 서식지 적합지수를 위한 어장평가인자로 수온, 클로로필 a, 부유입자물질, 해수유동, 염분, 용존산소 포화도를 이용하였다. 미더덕과 주름미더덕의 성장과 어장환경 상관성을 나타낼 수 있도록 각 인자들에 대한 그래프가 작성되었으며, 서식지 적합지수 산정결과 진동만의 서쪽해역(HSI 0.32~0.41)이 동쪽해역(HSI 0.19~0.27)보다 높은 적합지수를 보였다. 이러한 결과는 미더덕과 주름미더덕의 단위생산량과 유의한 상관성(<TEX>$R^2$</TEX>=0.834, P<0.01)이 있음을 보였다. 본 연구는 과학적 어장적지평가를 통하여 지속적인 생산성을 위한 어장관리에 기여를 할 수 있을 것으로 판단된다. This study was conducted in warty sea squirt farm, Jindong Bay(10 stations; July, October, January, April) for the culture period of Styela clava, Styela plicata. We utilized water temperature, chlorophyll a, suspended particulate matter, hydrodynamics, salinity and dissolved oxygen saturation for the suitability assessment of warty sea squirt farm. Newly, Life Requisite Suitability graphs were made for the correlation between the growth of Styela clava, Styela plicata and farm environment. As a result of the assessment for Habitat Suitability Index, western bay(HSI 0.32~0.41) show values higher than eastern bay(HSI 0.19~0.27). This result shows the high correlation with the unit production of Styela clava, Styela plicata(<TEX>$R^2$</TEX>=0.834, P<0.01). This could be helpful for fishery management for the sustainable productivity through the scientific suitable site assessment.

Medieval Painted Decoration in St Michael’s Church in Mihkli, Estonia

Anneli Randla: Medieval painted decoration in St Michael’sin Mihkli, EstoniaKeywords: medieval murals, church decoration, paint research, technical studies of artSummary:Recent studies in the medieval St Michael’s Church in Mihkli, in western Estonia, have shown that the stone church was constructed in two stages: at first a simple building with wooden ceiling was erected, and at a later date (possibly around 1500) stone vaulting was added over the first chancel and the nave. In August 2013, preliminary investigations were undertaken to study the painted decoration of the inner walls and vaults of the church. The small sample areas uncovered were sufficient to reveal several historical colour schemes. The richest decorationis contemporary with the first plastering of the vaults since the plaster was still moist when the paint was applied. The decoration is vernacular in character and its aim is to enhance the architectural features of the building. Thus the ribs and corbels of the vaults are painted but the decoration is extended to flat surfaces as well. For example painted pendants in grey and red adorn the ends of the ribs of the eight-partite vault of the chancel. The largest composition was discovered in the eastern bay of the nave around the vault boss. An irregular eight-petalled red flower is formed around the boss with a cross on it. These paintings might have been executed by local church builders rather than by professional craftsmen.CV :Anneli Randla earned her PhD in art history at the University ofCambridge in 1999. She has worked for the National Heritage Board of Estonia for ten years. Since 2008 Randla has been an associate professor in the Department of Conservation at the Estonian Academy of Arts and currently she serves as the dean of the Faculty of Art and Culture at the academy. Her main research interests are: medieval ecclesiastical architecture, medieval murals, technical studies of art and the history of conservation.

The Relationship between Interannual Climate Variability and Juvenile Eastern Oyster Abundance at a Regional Scale in Chesapeake Bay

AbstractThe eastern oyster, Crassostrea virginica, is an important ecological and commercial species along the Eastern Seaboard of North America, although its abundance in Chesapeake Bay (Maryland and Virginia) has declined precipitously since the mid‐1800s. Management activities, including efforts to enhance larval settlement, to rebuild the Chesapeake Bay eastern oyster population have met with limited success. Since 1939, juvenile oyster abundance has been measured at oyster bars in the northern portion of Chesapeake Bay. Prior analyses of those data indicate that juvenile oyster abundance is influenced by environmental conditions, which are related to regional climate. We quantified a regional scale (1,000 km2) climate signal using a synoptic climatology approach by identifying predominant weather patterns. We related these weather patterns to Susquehanna River freshwater discharge, a major influencing factor on Chesapeake Bay salinity, and the Palmer Hydrological Drought Index (PHDI), an indicator of the overall wetness or dryness of a given region. We developed path analysis models that linked weather patterns to Susquehanna River discharge and thence to either the PHDI or ambient salinity and water temperature and finally to juvenile oyster abundance in one of four preidentified spatial groupings. The path models indicated that weather patterns that produce wet conditions, leading to a higher PHDI and lower salinity, resulted in reduced juvenile oyster abundance; weather patterns that produce dry conditions that decreased the PHDI and increased salinity resulted in higher juvenile oyster abundance. Our results indicate that regions of higher juvenile oyster abundance may be predicted several months in advance using the path model. These predictions can be used to increase the effectiveness of oyster restoration efforts by indicating where hard substrate added to oyster bars in the four regions is likely to result in greater than average numbers of juvenile oysters.Received January 16, 2013; accepted July 24, 2013Published online December 3, 2013

Shallow-water, nearshore current dynamics in Algoa Bay, South Africa, with notes on the implications for larval fish dispersal

Nearshore currents play a vital role in the transport of eggs and larval stages of fish. However, little is known about their complexity and the implications for dispersal of fish larvae. The study describes the complexity of the shallow nearshore environment in eastern Algoa Bay, on the south-east coast of South Africa, and its effect on larval fish ecology. An ADCP was used to assess short-term spatial current variability across the nearshore (4–20 m depth) during intensive one-day-transect profiling surveys. Data showing long-term temporal variability was collected half-hourly from a bottom-moored (15–20 m depth) ADCP over the course of one year (May 2006–May 2007). The short-term profiling revealed complexity in both current speed and direction with largely wind-driven flow patterns identified. The long-term data showed that the currents were aligned approximately west/east with prevailing winds and local shoreline. Modal speeds of 8 cm s–1 near the surface (4 m) and 6 cm s–1 near the bottom (14 m) of the water column are much lower than the average swimming speeds of postflexion larvae known to occur in the area. Mean current speed decreased with depth from ∼30 cm s–1 (4 m) to ∼10 cm s–1 (14 m), suggesting opportunities for depth refuge from current displacement in older larvae. Potential nett displacements were greater during the spring and summer, coinciding with peak fish breeding with passive eggs and early stage larvae travelling distances of up to 475 km near the surface of the water column. These maximum dispersal distances recorded during the present study differ considerably by half that from other calculations made for the area, highlighting a data error in a previous study. These predictions provide preliminary indications of potential transport from a point source and do not factor in anomalous local oceanography, benthic topographic impediments to transport or the complexities of larval fish behaviour.

Response of mollusc assemblages to climate variability and anthropogenic activities: a 4000‐year record from a shallow bar‐built lagoon system

With their position at the interface between land and ocean and their fragile nature, lagoons are sensitive to environmental change, and it is reasonable to expect these changes would be recorded in well-preserved taxa such as molluscs. To test this, the 4000-year history of molluscs in Great South Bay, a bar-built lagoon, was reconstructed from 24 vibracores. Using x-radiography to identify shell layers, faunal counts, shell condition, organic content, and sediment type were measured in 325 samples. Sample age was estimated by interpolating 40 radiocarbon dates. K-means cluster analysis identified three molluscan assemblages, corresponding to sand-associated and mud-associated groups, and the third associated with inlet areas. Redundancy and regression tree analyses indicated that significant transitions from the sand-associated to mud-associated assemblage occurred over large portions of the bay about 650 and 294 years bp. The first date corresponds to the transition from the Medieval Warm Period to the Little Ice Age; this change in climate reduced the frequency of strong storms, likely leading to reduced barrier island breaching, greater bay enclosure, and fine-grained sediment accumulation. The second date marks the initiation of clear cutting by European settlers, an activity that would have increased runoff of fine-grained material. The occurrence of the inlet assemblage in the western and eastern ends of the bay is consistent with a history of inlets in these areas, even though prior to Hurricane Sandy in 2012, no inlet was present in the eastern bay in almost 200 years. The mud dominant, Mulinia lateralis, is a bivalve often associated with environmental disturbances. Its increased frequency over the past 300 years suggests that disturbances are more common in the bay than in the past. Management activities maintaining the current barrier island state may be contributing to the sand-mud transition and to the bay's susceptibility to disturbances.

Interactions between aggregations and environmental factors explain spatio-temporal patterns of the brittle-star Ophiothrix fragilis in the eastern Bay of Seine

There is a paucity of studies showing long-term changes in the population dynamics of dominant benthic epifaunal species, especially echinoderms, in relation to biological and environmental factors. In the English Channel, the brittle-star Ophiothrix fragilis is a common epifaunal species, mainly found in strong tidal currents characterised by benthic habitats with pebbles. However, in the Bay of Seine, O. fragilis lives on gravel and coarse sandy sediments; more locally, it occurs where there are unexpected amounts of fine particles for such high hydrodynamic areas. This species forms dense aggregations, supporting large populations up to 7450 ind m−2. This paper analyses the long-term spatio-temporal changes of O. fragilis aggregations over the last 25 years in the eastern part of the Bay of Seine through observations obtained from several scientific programmes from 1986 to 2010. This area is characterised as a tidal environment affected by the Seine estuary and is subject to potential sediment supply from the dumping site of the Le Havre harbour dredging operations. During all surveys, there was a similar pattern: persistent patches with high abundances of O. fragilis and sites without O. fragilis, showing that there was a high heterogeneity of the spatial population pattern. Interactions between environmental conditions and ophiurid aggregations (e.g., storm waves, Seine floods and patches) are suggested to explain these patterns.

Influence of continental outflow and ocean biogeochemistry on the distribution of fine and ultrafine particles in the marine atmospheric boundary layer over Arabian Sea and Bay of Bengal

Extensive measurements of aerosol number size distributions (in the size range of 10 to 875 nm) carried out over the oceanic regions of the Bay of Bengal and Arabian Sea during two large cruise experiments (one during pre‐monsoon and the other during winter) are used to investigate the spatial distribution of aerosol size distributions, in general, and that of fine particles, in particular, within the marine atmospheric boundary layer. The size distributions over the northwestern Bay of Bengal, lying downwind of the continental outflow from the Indo‐Gangetic Plain, and over the eastern Bay of Bengal, under the influence of the East Asian outflow, showed a bimodal structure with prominent mode (100–125 nm) in the accumulation regime and weak mode (30–40 nm) in the Aitken regime during both pre‐monsoon and winter seasons. While the Aitken mode was found to be relatively quite weak in the Indo‐Gangetic Plain outflow during both seasons, it was prominent in the East Asian outflow regions, especially during the winter season. The distributions over the northern Arabian Sea, a region quite prone to advection of dust during pre‐monsoon and summer seasons, showed a prominent Aitken mode (~45 nm) followed by a weaker accumulation mode during pre‐monsoon season. Analysis of SeaWiFS data revealed a systematic collocation of Aitken mode aerosols and the high chlorophyll concentration in the northern Arabian Sea, implying the role of ocean biogeochemistry in influencing the aerosol size distributions. Such a feature implying biogeochemical influence was not seen over the eastern and northern Bay of Bengal during pre‐monsoon and winter seasons.

Colorectal cancer presentation in eastern Bay of Plenty, New Zealand.

370 Background: New Zealand has a high incidence of colorectal cancer; the death rate is the highest amongst developed countries. New Zealand does not have a national screening program for colorectal cancer yet. This study was done in a region with a higher proportion Maori ethnicity. We hypothesized that there are differences in presentation and pathology of colorectal cancer between Maori and European people. Methods: A review of new cases of colorectal cancer presenting over a period of three years (2008-2011) at Whakatane Hospital was done. Data was collected from clinical records and entered into SPSS software. Results: 113 new cases of colorectal cancer were identified. Median age was 73 years. Maori patients were younger than the rest (median age 60 vs 74.5; p &lt; 0.05). 95 patients were of European ethnicity and 15 were Maori. The predominant sign/symptom on presentation was PR bleeding (32%). Only 5 cases were asymptomatic and diagnosed on surveillance colonoscopy. The histologic type of tumor was adenocarcinoma in 111 cases. The most common site of the tumors was the rectum (18.6%). 34.5% cases had localized disease (stage 1, 2A) with no significant difference between Maori and the rest.18.6% cases had distant metastasis with no significant difference between Maori and the rest. Curative surgery was not done in 16 patients due to advanced disease, comorbidities or patient refusal. Conclusions: A higher proportion of patients were diagnosed with localized disease at presentation compared to the rest of New Zealand.. Fewer Maori patients had colorectal cancer in view of the higher proportion of Maori in the area (42-61%). The age of Maori was significantly lower than the rest. Colorectal cancer screening in New Zealand will likely detect cancer earlier. [Table: see text]

Episodic phytoplankton bloom events in the Bay of Bengal triggered by multiple forcings

Two episodic phytoplankton bloom events were identified in the southeastern and southwestern Bay of Bengal in January 1998 and December 2005, respectively, from SeaWiFS-derived chlorophyll-a concentration data collected between September 1997 and December 2010. Possible causes were examined using time series datasets of satellite-derived sea surface height anomalies, sea surface temperature, wind stress and Ekman pumping velocity data. It was found that strong cyclonic eddies with long residence time transported cold, nutrient-rich water from the subsurface layer to the euphotic zone, and were responsible for sustaining the continuous growth of phytoplankton that led to the two aforementioned phytoplankton blooms. Moreover, regarding the event in December 2005, three tropical cyclones passed through the region of the phytoplankton bloom and could have been additional factors that enhanced the bloom. Regarding the event in January 1998, transportation from the adjacent Andaman Sea by the geostrophic current and an anomalous zonal easterly wind contributed to the phytoplankton bloom in the southeastern Bay of Bengal. In addition, both blooms occurred during Indian Ocean Dipole (IOD) years. The absence of the second downwelling Kelvin waves in positive IOD year of 1997–1998 favouring the long residence of the strong cyclonic eddy in the eastern bay, and the strong wind-induced mixing in negative IOD year of 2005 might contribute to enhancing productivity.