Island Bay Research Articles

A World Without Ice

The nearly global retreat of the Earth's ice cover is a matter of concern to people everywhere. The changes are most marked in northern latitudes with accelerated melting of the Greenland ice sheet, widespread thawing of the permafrost, and the rapid decrease of summer sea ice in the Arctic Ocean. Most mountain glaciers and ice caps are wasting away. In high southern latitudes, changes in the ice are more muted except for the land ice of the Antarctic Peninsula and the Pine Island Bay region. In the Southern Ocean, by contrast, the sea ice cover is slowly expanding. Do these large changes represent early warning signs of rapid global warming, recovery from the Little Ice Age, or the natural evolution of the present interglacial period?

Synoptic Assessment of Repletion and Residual Water Dynamics in a Coastal Lagoon by Thermal Remote Sensing: Great Machipongo Lagoon (Hog Island Bay), Virginia, USA

Coastal lagoons are prominent features along many of the worlds sand coasts. Unlike estuaries, a large amount of lagoon volume is exchanged via tidal draining and repletion. We sought to quantify the repletion and residual water volumes in a coastal lagoon using satellite remote sensing. In the Great Machipongo Lagoon approximately 53% of the basin capacity drains out with each ebb tide, leaving a residual volume of about 47%. While the repletion footprint indicates the area of the lagoon that is completely flushed with each tide, residual water flushes at a much slower rate. The footprint of repletion water at full tide covers about 30% of the outer part of the lagoon. A fraction of the residual water is entrained into the repletion water mass along the plume frontal boundary. This allows a relatively small percent of the residual water to be exchanged with the coastal ocean. Thermal responses in ASTER imagery indicate zonation as well as areas of continuous mixing of repletion and residual waters. Comparison of remote sensing data with the tidal volume suggests that about 2-4% of the residual water mass is entrained along the frontal boundary during each tidal cycle and flushing of the residual water mass takes about 25-50 tidal cycles. The overall approach portends further application of thermal satellite remote sensing for monitoring estuarine and lagoon flushing and repletion.

Basement control on past ice sheet dynamics in the Amundsen Sea Embayment, West Antarctica

The development of landscapes and morphologies follows initially the tectonic displacement structures of the basement and sediments. Such fault zones or lineaments are often exploited by surface erosional processes and play, therefore, an important role in reconstructing past ice sheet dynamics. Observations of bathymetric features of the continental shelf of the Amundsen Sea Embayment and identification of tectonic lineaments from geophysical mapping indicate that the erosional processes of paleo-ice stream flows across the continental shelf followed primarily such lineaments inherited from the tectonic history since the Cretaceous break-up between New Zealand and West Antarctica. Three major ice flow trends correspond to different tectonic phases in east–west, northwest–southeast and north–south directions. East–west oriented basement trends correlate with coastline trends and overlay tectonic lineaments caused by former rift activities. Directional trends with northwest–southeast orientation are observed for the glacial troughs of the western embayment outer shelf, the western Pine Island Bay coastal zones, and the inner Pine Island glacial trough and are associated with a distributed southern plate boundary zone of the former Bellingshausen Plate. The north–south trend of the main Pine Island glacial trough and the north–northeast trend of the Abbot Ice Shelf trough on the outer shelf follow the predicted lineation trend of an eastern branch of the West Antarctic Rift System extending from the Thwaites drainage basin northward into Pine Island Bay. An understanding of this context helps better constrain the geometries and sea-bed substrate conditions for regional paleo-ice sheet models.

Religion and Diaspora: Community Creation in Nineteenth-Century New Zealand, the Case of Antoine Garin and the Catholics of Howick and Nelson

Antoine Marie Garin was a Catholic missionary who lived in New Zealand from 1841 until 1889. A member of the Society of Mary, the society to which the Pope had given the task of evangelizing Western Oceania in 1835, Garin worked for seven years with Maori in the Bay of Islands and Mangakahia, Northland, before beginning a lengthy career as a parish priest to the settlers of Howick and Nelson. He is best known for his contribution to Catholic education while parish priest of Nelson.

Movement Patterns and Residence of Adult Winter Flounder within a Long Island Estuary

AbstractWe implanted individually coded acoustic transmitters into 40 adult winter flounderPseudopleuronectes americanus(mean total length = 320 mm; range = 240–423 mm) and monitored them by use of passive acoustic telemetry from September 2007 to April 2009 to classify spatial and temporal movement patterns and quantify residency in Shinnecock Bay, eastern Long Island, New York. Overall, 94,250 valid detections were received. Winter flounder remained inshore, and 89% of the total detections occurred between May and October when bottom water temperature exceeded 15°C. Residency in Shinnecock Bay was dependent on time of release and varied greatly from a few weeks to more than 6 months; total presence (number of days on which individual fish were detected within the bay) averaged 22.0 d (range = 1–132 d). Tracked winter flounder were classified as exhibiting three movement patterns: (1) inner bay movements (short term versus long term), (2) dispersal to offshore waters, and (3) connectivity to other inshore areas. The first two patterns were consistent with historical notions of spatially overlapping resident and migratory individuals, whereas fish that displayed the third pattern may have exhibited a larger home range. These results provide insight into winter flounder movements, residency, and stock structure in a coastal bay of Long Island and provide important information for management. The interaction of exploitation and divergent migration behaviors may be a factor contributing to the winter flounder's decline in Long Island bays; however, more work will be required to obtain a full understanding of the spatial behavior and stock structure of this species.

Numerical Analysis on Effects of Abiki Countermeasures at Ojima fishing port in Kami-Koshiki Island

The previous highest Abiki occurred in the range centering on Kagoshima Prefecture in February, 2009. The damage by the Abiki, such as a fishing boat overthrow and flood under a floor, generated at Ojima fishing port in Urauchi bay of Kamikoshiki island, Kagoshima. Authors (2010) investigated about the propagation characteristic of Abiki by numerical simulation using non-linear long wave theory. However, the problem was in the accuracy of the submarine topography originated in calculation mesh size, and investigation about the magnification of Abiki inside the Urauchi-bay was inadequate. In this research, the numerical simulation using three-step nesting bottom topography data was carried out, and the validity of the calculation technique was checked as compared with local observation data. Furthermore, the effect of Abiki countermearsures was analyzed.

Direct inversion of shallow-water bathymetry from EO-1 hyperspectral remote sensing data

Using the US National Aeronautics and space Administration (NASA) Earth Observing-1 Mission (EO-1) hyperion hyperspectral remote sensing data, we study the shallow-water bathymetry inversion in Smith Island Bay. The fast line-of-sight atmospheric analysis of spectral hypercubes module is applied for atmo-spheric correction, and principal component analysis method combined with scatter diagram and maximum likelihood classification is used for seabed classification. The diffuse attenuation coefficient Kd is derived using quasi-analytical algorithm (QAA), which performs well in optically deep water. Kd obtained from QAA requires correction, particularly those derived in some coastal areas with optically shallow water and calculated by direct inversion based on radiative transfer theory to obtain the bathymetry. The direct inversion method derives the water depth quickly, and matches the results from optimized algorithm.

Conservation status, threats and management options for the Open Bay Island skink (Oligosoma taumakae)

The Open Bay Islands are a Māori-owned Wildlife Refuge located in South Westland (South Island) and support two of the rarest lizard species in New Zealand: the Open Bay Island skink and the Open Bay Island gecko. Both species have been assigned a threat status of Nationally Critical – the highest priority for conservation action. The terrestrial and diurnal habits of the skink make it particularly vulnerable to predation by wēkā, a flightless rail native to New Zealand but introduced to the Open Bay Islands c. 100 years ago. Here, we present results from a 5-day survey of the two main islands (14.7-ha Taumaka and 2.2-ha Popotai) and consider options for reducing the negative impacts of wēkā on skinks and other terrestrial fauna (wēkā removal, exclosure fencing and refuge supplementation; all subject to iwi approval). In total, 19 skinks were caught over 125 trap-days. The majority (16 individuals) were caught on Popotai Island, from which skinks had not been previously recorded. We conclude that removing wēkā from both islands is the only option guaranteed to increase skink abundance, with collateral benefits to other terrestrial fauna on the Open Bay Islands.

Flow and retreat of the Late Quaternary Pine Island‐Thwaites palaeo‐ice stream, West Antarctica

Multibeam swath bathymetry and sub‐bottom profiler data are used to establish constraints on the flow and retreat history of a major palaeo‐ice stream that carried the combined discharge from the parts of the West Antarctic Ice Sheet now occupied by the Pine Island and Thwaites glacier basins. Sets of highly elongated bedforms show that, at the last glacial maximum, the route of the Pine Island‐Thwaites palaeo‐ice stream arced north‐northeast following a prominent cross‐shelf trough. In this area, the grounding line advanced to within ∼68 km of, and probably reached, the shelf edge. Minimum ice thickness is estimated at 715 m on the outer shelf, and we estimate a minimum ice discharge of ∼108 km3 yr−1 assuming velocities similar to today's Pine Island glacier (∼2.5 km yr−1). Additional bed forms observed in a trough northwest of Pine Island Bay likely formed via diachronous ice flows across the outer shelf and demonstrate switching ice stream behavior. The “style” of ice retreat is also evident in five grounding zone wedges, which suggest episodic deglaciation characterized by halts in grounding line migration up‐trough. Stillstands occurred in association with changes in ice bed gradient, and phases of inferred rapid retreat correlate to higher bed slopes, supporting theoretical studies that show bed geometry as a control on ice margin recession. However, estimates that individual wedges could have formed within several centuries still imply a relatively rapid overall retreat. Our findings show that the ice stream channeled a substantial fraction of West Antarctica's discharge in the past, just as the Pine Island and Thwaites glaciers do today.

Stability and bistability of seagrass ecosystems in shallow coastal lagoons: Role of feedbacks with sediment resuspension and light attenuation

Shallow coastal lagoons are environments where a dynamic equilibrium exists between water quality and seagrass cover. Dense seagrass canopies limit the resuspension of bed sediments thereby creating a clearer water column and a positive feedback for seagrass growth. Positive feedbacks are often associated with the existence of bistable dynamics in ecosystems. For example, a bare and a seagrass covered sediment bed could both be stable states of the system. This study describes a one‐dimensional hydrodynamic model of vegetation‐sediment‐water flow interactions and uses it to investigate the strengths of positive feedbacks between seagrass cover, stabilization of bed sediments, turbidity of the water column, and the existence of a favorable light environment for seagrasses. The model is applied to Hog Island Bay, a shallow coastal lagoon on the eastern shore of Virginia. The effects of temperature, eutrophication, and bed grain size on bistability of seagrass ecosystems in the lagoon are explored. The results indicate that under typical conditions, seagrass is stable in water depths < 2.2 m (51% of the bay bottom deep enough for seagrass growth) and bistable conditions exist for depths of 2.2–3.6 m (23% of bay) where the preferred state depends on initial seagrass cover. The remaining 26% of the bay is too deep to sustain seagrass. Decreases in sediment size and increases in water temperature and degree of eutrophication shift the bistable range to shallower depths, with more of the bay bottom unable to sustain seagrass.

First Record of Predation on False Killer Whales (<I>Pseudorca crassidens</I>) by Killer Whales (<I>Orcinus orca</I>)

The first record of killer whale (Orcinus orca) predation on false killer whales (Pseudorca crassidens) is reported here. On 25 March 2010, a group of 50 to 60 false killer whales, including approximately 15 calves and accompanied by three to five bottlenose dolphins (Tursiops sp.), were sighted in the Bay of Islands, New Zealand. Within 30 min, they were approached by a group of approximately eight killer whales. Five false killer whales were attacked, with at least three rammed from below, forcing them out of the water. After 29 min, the killer whales were milling at the surface and feeding on the carcass of a false killer whale calf, possibly the only individual killed. The killer whales had prolific fresh and healed oval wounds, which were attributed to cookie cutter shark (Isistius sp.) bites.

The Advocate ophiolite mantle, Baie Verte, Newfoundland: regional correlations and evidence for metasomatismGeological Survey of Canada, Earth Sciences Sector, Contribution 20090211.

Mantle rocks of the Advocate ophiolite near Flatwater Pond (Baie Verte, Newfoundland) are dominated by harzburgite tectonites, which are extensively converted to listvenite along the Baie Verte Road fault and represent a potential gold exploration target. Most Advocate harzburgites have forsteritic olivine (Fo90.5 to Fo93) and Cr-spinels, with Cr# (= 100Cr/(Cr + Al)) between 52 and 64 and Mg# (= 100Mg/(Mg + Fe2+)) between 56 and 68. These mineral chemical signatures, together with high whole-rock MgO (46%–48%), low Al2O3 (<1%), and TiO2 (<0.003%), imply the Advocate harzburgites are refractory residues after ca. 25%–35% melting. Cr-spinel compositions of Advocate mantle rocks overlap with Cr-spinels from the mantle rocks of the Point Rousse and Betts Cove ophiolites, with Mg# higher than those of Bay of Islands or Thetford Mines mantle Cr-spinels. Although refractory in terms of major elements and mineral chemistry, Advocate harzburgites contain high La–Ce–Pr–Pb–Nd–Sm–Zr contents suggestive of pervasive metasomatism. Similar geochemical signatures occur in all ophiolitic mantle rocks from the Baie Verte Peninsula examined so far. The enrichments are not consistent with supra-subduction zone syn-melting metasomatism as observed in other Appalachian ophiolites. The apparent absence of visible metasomatic channels in most outcrops suggests that metasomatism occurred before obduction by diffuse percolation, but the nature and origin of the metasomatic agent remain speculative. The similarities of mineral and whole-rock geochemistry imply that all mantle rocks from Baie Verte ophiolites are correlative and may represent remnants of a single obducted slab.

A colorful new species of insular rock gecko (Cnemaspis Strauch 1887) from southern Vietnam

A new species of endemic, insular Cnemaspis is described from Hon Khoai Island, Ca Mau Province, Ngoc Hien District, 18 km off the southern tip of the Ca Mu Peninsula in southern Vietnam. Cnemaspis psychedelica sp. nov. is the most uniquely colored of all southeast Asian Cnemaspis in that both sexes and all age classes have bright orange forelimbs, forelegs, hands and feet; a bright orange tail; a dense, yellow reticulum on the neck overlying thick, black, longitudinal lines; and a blue-gray to light purple trunk bearing yellow transverse bars on bright-orange flanks. It also differs from all other species of Cnemaspis in aspects of size and squamation. Cnemaspis psychedelica is the third insular endemic species of Cnemaspis from Vietnam and brings the total number of species in Vietnam to six. Its occurrence on one of the 92 islands in Rach Gia Bay underscores the necessity for continued surveys of these poorly known islands that are beginning to show a surprising degree of endemism and diversity.

Brief communication: Transportation and trauma: Dog‐sledding and vertebral compression in Alaskan Eskimos

Vertebral compression, as evidenced by compression of the centrum, was observed within two Native Alaskan skeletal samples. Information was collected from 1,071 and 656 vertebrae from Golovin Bay and Nunivak Island, Alaska, respectively. In addition, patterns of compression related vertebral change in each collection were characterized by sex and location within the vertebral column. The overall frequencies of vertebral compression were 3.6% (n = 721) at Golovin Bay and 1.7% (n = 403) at Nunivak Island for all observable thoracic and lumbar vertebrae (T1-L5). There was no statistically significant difference in the occurrence of compression among adults between these two collections. When examining the thoracic and lumbar vertebral segments by sex, females at Golovin Bay (4.5%; n = 442) exhibited a significantly higher frequency of vertebral compression than females at Nunivak (1.0%; n = 203). However, this difference in occurrence of compression could be accounted for by the age distributions of the two samples. No difference was noted between the males of the two collections. Compression frequencies in both samples are discussed in relation to the modes of transportation historically utilized by each community.

Revealing the coastal event-history of the Andaman Islands (Bay of Bengal) during the Holocene using radiocarbon and OSL dating

Earthquakes that trigger tsunamis are of great geological, ecological and socio-economic importance. The knowledge of the recurrence interval of these events will give information about the hazard for a region. Coastal sediments on the Andaman Islands located in the eastern Bay of Bengal were investigated to find evidence for palaeotsunamis and palaeoearthquakes. Fieldwork was conducted on Red Skin Island and North Cinque Island, south of South Andaman. Sediment material from event-layers was dated by optically stimulated luminescence and radiocarbon dating method. The results show evidence possibly for one earthquake at about 1,000 or 3,000 years before the present together with deposits from possible tsunamis and storms. The complex pattern of co- and post-seismic uplift and subsidence of the Andaman Islands is reflected in the investigated sections and made it possible to reconstruct an event-history for the last 3,000 years.

Colony Site Dynamics and Habitat Use in Atlantic Coast Seabirds

Colony Site Dynamics and Habitat Use in Atlantic Coast Seabirds

Post-Glacial Isostatic Adjustment and Global Warming in Subarctic Canada: Implications for Islands of the James Bay Region

When Rupert’s Land and the North-Western Territory became a part of Canada as the Northwest Territories in 1870, the islands of James Bay were included within the new territorial boundaries. These same islands became a part of Nunavut in 1999, when the new territory was created from the eastern region of the Northwest Territories. Although the James Bay islands remain part of Nunavut, the western James Bay Cree assert that the western James Bay islands, including Akimiski Island, were part of the Cree traditional territory and that these islands have never been surrendered through treaty. This land-claim issue is further complicated by the fact that glacial isostatic adjustment (GIA) is occurring in the James Bay region and that the islands of James Bay may one day become part of mainland Ontario or Quebec. We used numerical models of the GIA process to predict how shorelines in James Bay will migrate over the next 1000 years as a result of post-glacial sea-level changes. These predictions, which were augmented by an additional contribution associated with sea-level rise due to global warming, were used to determine whether the islands in James Bay will ever become part of the mainland. The predictions for the islands are sensitive to the two primary inputs into the GIA predictions, namely the models for the geometry of the ancient Laurentide ice sheet and the viscoelastic structure adopted for the solid earth, as well as to the amplitude of the projected global warming signal. Nevertheless, it was found that many of the smaller and larger islands of James Bay will likely join the mainland of either Ontario or Quebec. For example, using a global warming scenario of 1.8 mm sea-level rise per year, a plausible range of GIA models suggests that the Strutton Islands and Cape Hope Islands will join mainland Quebec in ~400 years or more, while Akimiski Island will take at least ~700 years to join mainland Ontario. Using the same GIA models, but incorporating the upper boundary of global warming scenarios of 5.9 mm sea-level rise per year, the Strutton Islands and Cape Hope Islands are predicted to join mainland Quebec in ~600 years or more, and Akimiski Island is predicted not to join mainland Ontario. Since Akimiski Island is already being prospected for diamonds and the future ownership of emergent land remains an issue, these findings have great economic importance.

자란만.사량도 패류생산해역의 위생학적 안전성 평가

【Bacteriological examination of a 12,700 ha area within Jaranman Saryangdo area, located in Jaran bay and Saryangdo island, was conducted with 35 fixed (designated areas and adjacent areas) seawater sampling stations between January 2006 and December 2008. According to results, the geometric mean range and the estimated 90th percentile range of fecal coliform counts in sea water samples collected in the designated area were】

Interviews as Experiments: Using Audience Effects to Examine Social Relationships

To explore the ability of audience effects to shed light on social dynamics, the authors contrasted responses given in individual and joint interviews. Interviews were conducted among the English-speaking residents of Utila, one of Honduras’s Bay Islands. Interviewees were older adults with at least one living adult child and younger adults with at least one living parent. Interviews were conducted with individuals alone and with pairs consisting of older adults and their adult children. The topic of the interviews was parenting, but the authors’ particular interest was in a question regarding obligations children have to their elderly parents. Responses to that question and to a control question were coded for length, interviewer behavior, vocalics, and forceful-ness of communicative style. Audience effects were found in children’s responses to the question about obligations to elderly parents: Children interviewed with parents responded more forcefully to that question than children interviewed alone. Responses to the control question showed no audience effect. Involvement in the island’s remittance economy was also associated with a more forceful communicative style, but this effect was not contingent on the audience present or the question asked. Audience effects may be a useful and important new tool for ethnographic research.

Her civilising mission: discovering Hannah King through her textiles

Hannah King occupies a unique place in missionary and colonial history, the history of education, cross‐cultural relations and material culture in New Zealand. She was the only woman from the first 1814 Missionary settlement of the Church Missionary Society (CMS) in New Zealand to remain in New Zealand for the rest of her life, yet she does not have an entry in the Dictionary of New Zealand Biography, and is rarely indexed in either New Zealand’s general historical works or even works more specifically related to the Missionary era. John and Hannah King were one of three artisan missionary couples who sailed with the Revd Samuel Marsden on his ship, the missionary brig ‘Active’, from Port Jackson, Australia to Rangihoua, in the Bay of Islands, in late 1814. Marsden’s 1814 Christmas Day service on the beach at Rangihoua is recognised as the beginning of missionary activity and planned European settlement on New Zealand soil.