Island Fish Research Articles

Plankton diversity and aquatic ecology of a freshwater lake (L3) at Bharti Island, Larsemann Hills, east Antarctica

The Larsemann Hills range is an ice-free oasis on the Ingrid Christensen Coast of Princess Elizabeth Land, East Antarctica, which includes Bharti Island, Fisher Island, McLeod Island, Broknes Peninsula, Stornes Peninsula, and several other islands, promontories, and nunataks. The Larsemann Hills is an ice-free area of approximately 50 km2, located halfway between the Vestfold Hills and the Amery Ice Shelf on the south-eastern coast of Prydz Bay, Princess Elizabeth Land, East Antarctica. The ice-free area consists of two major peninsulas (Stornes and Broknes), four minor peninsulas, and approximately 130 near shore islands. The Larsemann Hills area contains more than 150 lakes at different Islands and peninsulas. Bharti Island of Larsemann Hills in east Antarctica was selected as a sampling site for the present study. Water sample was collected from a freshwater lake during XXXth Indian Scientific Expedition to Antarctica (ISEA) and analyzed for the physico-chemical parameters, major elements, trace metals and major plankton diversity in surface lake water by following standard methodology. The concentrations of metals Cu, Pb, Cd, Zn and Cr were measured using Inductively Coupled Plasma Optical Emission Spectroscopy (ICP-OES). Phytoplankton and zooplankton were also assessed in the aquatic ecosystem of Lake L3 at Bharti Island, Larsemann Hills over east Antarctica. Psychrophillic bacteria were found 71 cfu in lake water, while total bacterial count was found to be 5.4 × 102cfu.

Distribution and diversity of oligotrich and choreotrich ciliates assessed by morphology and DGGE in temperate coastal waters

We assessed the diversity of coastal planktonic ciliates (Oligotrichia and Cho reo - trichia, Class: Spirotrichea) in Fishers Island Sound off the coast of Connecticut, USA using a com- bination of denaturant gradient gel electrophoresis (DGGE) and morphological analyses. To test the hypothesis that ciliate communities followed water masses, we sampled 3 times at a surface drifter (i.e. floating buoy) and twice at intervening times from points 1 km away. By repeating both PCRs and gel electrophoresis under varying conditions, we confirmed that DGGE is an appropri- ate tool to capture the ciliate community composition, based on the high repeatability of samples. The 2 methods used for assessing ciliate community structure showed similar levels of diversity for tintinnids. However, there was a mismatch in diversity estimates for the aloricate ciliates, espe- cially for the oligotrichs where the estimated diversity was greater by DGGE than by microscopy. This may be attributable to biases in the DGGE (e.g. primer or gene copy number issues) and/or misidentification by morphology. However, the pattern of community structure assessed by cluster analyses is similar for both microscopy and DGGE, suggesting that the mismatch between these methods does not introduce bias in biogeographical analysis. Analyses of both DGGE haplotypes and microscopically observed morphospecies revealed that the ciliate communities were not static within the water mass. Community structure and abundance patterns varied with salinity and cur- rents. These changes could be due to mixing with adjacent estuarine and coastal assemblages, cil- iate behavior, and/or other factors that cause assemblages to be dynamic over short (i.e. ultradian) periods.

Hydrochemistry and sediment characteristics of polar periglacial lacustrine environments on Fisher Island and Broknes Peninsula, East Antarctica

Fisher Island and Broknes Peninsula in the Larsemann Hills constitute part of a polar lowland periglacial environment between marine and glacial ecosystems. The landscape is characterized by gently rolling hills and broad valleys interspersed with lakes formed in glacially scoured basins. We analyzed the physicochemical parameters and the ionic constituents of water samples from 10 lakes in each of these two locations. Our results showed considerable differences between the two regions and demonstrated the influence of lithology and processes including weathering, evaporation, and atmospheric precipitation. All major cations and anions in the lake waters showed positive correlations indicating balanced ionic concentrations. Unconsolidated sediments were sparsely distributed and scattered over glacial deposits, valley fills, and occasional moraine ridges. The type and rate of sedimentation was mainly controlled by surface run-off and aeolian influx. The sediment samples from lake beds and the catchment area on Fisher Island were immature and poorly to very poorly sorted, consisting of gravelly sand with negligible silt and finer fractions. Sediments had a polymodal grain size distribution with the two major populations lying between -2 and -1 phi and between 0 and 1.5 phi. The sediments were lithic arenite to arkosic in composition and the microtextures imprinted over quartz grains were dominated by mechanical textures resulting from several stages of glacial crushing and grinding. The presence of deep dissolution cavities, cryptocrystalline precipitation, and euhedral crystal growth signified the effect of chemical activity after the deposition of grains in the lacustrine environment.

Impacts of fishing and environmental factors driving changes on littoral fish assemblages in a subtropical oceanic island

The structure of demersal fish assemblages of commercial interest was studied at 51 sites on La Palma Island (Canary Islands, northeastern Atlantic). On this island, demersal fish populations are limited and independent from other islands. As deep water separates the islands and the shallow sublittoral platforms are not continuous, adult inter-island migrations are not possible except between the islands of Lanzarote and Fuerteventura. Otherwise, each island functions as a closed system, and the status of an island fish assemblage depends on local environmental conditions and activities performed in situ by the islanders. These circumstances provide a unique opportunity to test the intrainsular variability of fish assemblages. With this background, environmental parameters, fishing pressure and distance to the MPA were considered to identify the main factors explaining the spatial variation of fish assemblages off La Palma Island. Twenty-six fish species were recorded, but 60% of the total fish biomass was represented by only five species (Sparisoma cretense, Pomadasys incisus, Canthidermis sufflamen, Diplodus cervinus cervinus and Bodianus scrofa). However, the structure of assemblages was heterogeneous in response to different variables and showed substantial spatial variation. The assemblages were strongly modified by the presence of upright seaweed cover, fishing activities, and certain environmental variables. Differences were more pronounced in species that occupied the higher trophic levels. The most disturbed assemblages were those located in areas with lower upright seaweed cover and with higher fishing pressure, whereas the best-preserved assemblages corresponded to sites with controlled fishing activities, located within the MPA.

Glaciotectonic deformation associated with the Orient Point–Fishers Island moraine, westernmost Block Island Sound: further evidence of readvance of the Laurentide ice sheet

High-resolution seismic-reflection profiles collected across pro-glacial outwash deposits adjacent to the circa 18 ka b.p. Orient Point–Fishers Island end moraine segment in westernmost Block Island Sound reveal extensive deformation. A rhythmic seismic facies indicates the host outwash deposits are composed of fine-grained glaciolacustrine sediments. The deformation is variably brittle and ductile, but predominantly compressive in nature. Brittle deformation includes reverse faults and thrust faults that strike parallel to the moraine, and thrust sheets that extend from beneath the moraine. Ductile deformation includes folded sediments that overlie undisturbed deposits, showing that they are not drape features. Other seismic evidence for compression along the ice front consists of undisturbed glaciolacustrine strata that dip back toward and underneath the moraine, and angular unconformities on the sea floor where deformed sediments extend above the surrounding undisturbed correlative strata. Together, these ice-marginal glaciotectonic features indicate that the Orient Point–Fishers Island moraine marks a significant readvance of the Laurentide ice sheet, consistent with existing knowledge for neighboring coeval moraines, and not simply a stillstand as previously reported.

A framework to compare theoretical predictions on trait evolution in temporally varying environments under different life cycles

Predicting the evolution of traits such as dispersal or local adaptation, in a variable environment is an important issue in theoretical evolutionary ecology. With concepts such as hard selection vs. soft selection or fine-grained vs. coarse-grained environmental variability, this issue has attracted much attention, and yet different models seldom agree on qualitative predictions about, e.g. the evolution of generalist or specialist strategies, or the occurrence of stabilizing or disruptive selection on studied traits.Here, I investigate the effect of the order of events in the life cycle on trait evolution in a spatially heterogeneous, temporally varying landscape using a Wright–Fisher island model. I first develop a methodological framework allowing for different life cycles. Then I illustrate the importance of life cycles on selection regimes by looking more closely at the evolution of local adaptation.Model results show that the occurrence of disruptive selection and bi- or tristability mainly depends on the life cycle, the convexity of the trade-off behind local adaptation, the immigration rate, and the autocorrelation in patch state. With the same forces driving the evolution of local adaptation, different life cycles induce different evolutionary outcomes. Model results highlight the importance of accounting for life cycle specificities when attempting to predict the effects of the environment on evolutionarily selected trait values, as well as the need to check the robustness of evolutionary model conclusions against modifications of the life cycle.

Biological Characteristics of the Spotcheek Emperor, Lethrinus rubrioperculatus, in the Northern Mariana Islands

As a result of commencement of an incipient commercial fishery in the southern islands (SI) of the Commonwealth of the Northern Mariana Islands (CNMI), biological characteristics for the spotcheek emperor, Lethrinus rubrioperculatus, were estimated from the CNMI SI, including seasonality of spawning, sex ratios, length at sexual maturity (L M ), length at transition (L T ) to male phase, age, and growth. L M and L T estimates corresponded to ages of 1 and 3–4 yr, respectively, and are important in managing hermaphroditic species such as the spotcheek emperor by ensuring that fishery size selection does not significantly reduce effective stock reproduction. Age of the oldest fish was 8 yr, with South Southern Islands (SSI) fish mostly 0–2 yr old and North Southern Islands (NSI) fish 1–4 yr old. Average size of 0-age fish was 22.2 cm fork length (L F ) from the SSI and 18.7 cm L F from the NSI, indicating an initial high growth rate not captured by specimen collection. Growth curves for the NSI and SSI were significantly different at the 5% level. Age and growth parameters were estimated using age- and length-based methods, which resulted in similar values for instantaneous growth coefficient (k) and asymptotic length (L ∞ ). Results support further study into life history characteristics of the spotcheek emperor, in particular maximum age and lengths at maturity and transition, in other locations in the CNMI SI as well as in other Indo-Pacific jurisdictions.

Fine-scale population genetic structure in Alaskan Pacific halibut (Hippoglossus stenolepis)

Pacific halibut collected in the Aleutian Islands, Bering Sea and Gulf of Alaska were used to test the hypothesis of genetic panmixia for this species in Alaskan marine waters. Nine microsatellite loci and sequence data from the mitochondrial (mtDNA) control region were analyzed. Eighteen unique mtDNA haplotypes were found with no evidence of geographic population structure. Using nine microsatellite loci, significant heterogeneity was detected between Aleutian Island Pacific halibut and fish from the other two regions (FST range = 0.007–0.008). Significant FST values represent the first genetic evidence of divergent groups of halibut in the central and western Aleutian Archipelago. No significant genetic differences were found between Pacific halibut in the Gulf of Alaska and the Bering Sea leading to questions about factors contributing to separation of Aleutian halibut. Previous studies have reported Aleutian oceanographic conditions at deep inter-island passes leading to ecological discontinuity and unique community structure east and west of Aleutian passes. Aleutian Pacific halibut genetic structure may result from oceanographic transport mechanisms acting as partial barriers to gene flow with fish from other Alaskan waters.

The Hawaiian Luau

Sweet music drifts on the trade winds, the surf surges upon the shore, and a lavish banquet of island fruit, fish and succulent baked pig is served to men and women seated companionably together beneath the palms … Few meals are as apparently familiar as the Hawaiian luau, one of the iconic repasts of world cuisine. But how much do we really know about this island feast? Using anthropology, ethnohistory and popular art, this paper explores the many narratives, identities and authenticities embedded in the cultural biography and cuisine of the luau.

Austral seabirds: challenges and opportunities for research and conservation

This paper draws together the themes of papers on procellariiform biology contained within this special issue of the Papers and Proceedings ofthe Royal Society ofTasmania which is a tribute to Irynej Skira. The role of these birds as generalised biomonitors of marine ecosystem health as well as their important interactions with commercial fisheries and human societies are major considerations. Seabird conservation faces challenges from introduced pest loss of habitat to urban development, marine pollution and climate and oceanographic changes. Studies are hampered by the difficulties of dealing with birds in remote areas (that are therefore expensive to study), a paucity of funds and problems of overlapping national and international jurisdictions in their individual home ranges or on their migration routes. There is a real need for long-term studies ofseabirds because they have delayed breeding systems, a slow rate ofreproduction, long life-spans and high adult survival. Such knowledge is important in understanding their population dynamics, the effects of changing climate, the impacts of commercial fishing, pollution, breeding habitat loss and the harvesting of chicks. The value of the long-term studies of Shorttailed Shearwaters, Puffinus tenuirostris on Fisher Island, Tasmania, is considered in the light of the importance of research investment in basic curiosity-driven research. Neglect of long-term studies and the diminishing role of local scientific journals in the dissemination of baseline data on which to build generalities are the result of changing priorities of government and other funding agencies towards shortterm output-based assessment models. Our present inability to answer the basic question of what determines seabird population abundance and distribution highlights a lack of fundamental population data in Austral seabird research. This must be addressed so that a mixture of comparative, experimental and modelling studies can be mobilised to complement descriptive studies.

Mercury concentrations in the Patagonian toothfish, Dissostichus eleginoides Smitt 1898, among three distinct stocks

Patagonian toothfish, Dissostichus eleginoides, collections (n = 186) from three distinct stocks (two subantarctic stocks and the stock within the Chilean ZEE) were analyzed for Hg concentration by DMA and comparisons were made by gender, total length (TL), wet weight (WW), and population. There was no difference between TL–WW relationships or Hg concentration by gender within any population across the range examined. The Chilean and Prince Edward Island fish had higher TL-adjusted total Hg concentration than those from the South Georgia and may suggest a possible human health risk. Explanation of these population differences in total Hg may be the actual sample areas and associated hydrogeographic and oceanographic conditions. For example, sampling sites for the Chilean fish lie well outside the Antarctic Convergence whereas the Prince Edward sites straddle the Convergence. The samples obtained from South Georgia lie well within the Antarctic convergence, suggesting that the Polar Front may provide some type of hydrographic barrier as has been shown for this species in terms of larval dispersal and feeding.

How important are intrinsic factors to natal recruitment in Short-tailed Shearwaters Puffinus tenuirostris?

Although many extrinsic factors affecting recruitment in Short-tailed Shearwaters Puffinus tenuirostris have been studied continuously on Fisher Island, Tasmania, since 1947, the need to minimise disturbance in this colony has meant that little is known of the role of intrinsic factors in recruitment for this population of long-lived seabirds. Intensive studies into the intrinsic factors (i.e. parental quality, egg size and the size and weight of chicks prior to fledging) affecting recruitment were initiated in 1994 on nearby Great Dog Island. Herein, we present preliminary data on the recruits from three cohorts from which all were assumed to have returned (i.e. 1993/1994, 1994/1995 and 1995/1996) by the 2004/2005 breeding season. Although the number of recruits was limited, those that did return to breed were from eggs that were 7% larger than those that did not. There were only weak relationships between parental quality, the size and weight of the egg and the chick at 2 months of age. None of these intrinsic factors seemed to explain why some chicks returned to prospect and breed, while others did not. Despite the large number of adults, eggs and chicks used in this study, powerful multivariate statistical analyses were unable to detect which intrinsic factors could be important to recruitment in this species. Hence, we suggest, alternatively, that extrinsic, density-independent factors operating outside the breeding season and away from the Bass Strait islands may determine whether or not a chick survives to return to breed. Clearly, more information is required on the biology of this species whilst at sea, particularly factors that may affect juvenile survival.

Stomach contents and feeding observations of some Easter Island fishes

Stomach contents and feeding observations of some Easter Island fishes

Distinction between Mulloidichthys flavolineatus juveniles from Reunion Island and Mauritius Island (south‐west Indian Ocean) based on otolith morphometrics

Sagittal otoliths of the yellowstripe goatfish Mulloidichthys flavolineatus were analysed in order to compare Reunion Island fish stocks with those of Mauritius (south‐west Indian Ocean). Conventional otolith morphometric variables (area, perimeter, length and width), shape indices (form factor, roundness, circularity, rectangularity, ellipticity and eccentricity) and Fourier shape analysis were compared between three sites; two in Reunion Island and one in Mauritius. Regional and site‐specific differences were found for all the conventional otolith morphometric features. Regarding the shape indices, the differences between sites were best described by form factor, roundness, circularity and rectangularity. A classification by canonical discriminant analysis indicated significant differences between the three sampling sites. The combined use of morphometric variables (size and shape) and external outlines (shape analysis through Fourier series) showed the importance of otolith shape for intraspecific discrimination.

Seafloor character and sedimentary processes in eastern Long Island Sound and western Block Island Sound

Multibeam bathymetric data and seismic-reflection profiles collected in eastern Long Island Sound and western Block Island Sound reveal previously unrecognized glacial features and modern bedforms. Glacial features include an ice-sculptured bedrock surface, a newly identified recessional moraine, exposed glaciolacustrine sediments, and remnants of stagnant-ice-contact deposits. Modern bedforms include fields of transverse sand waves, barchanoid waves, giant scour depressions, and pockmarks. Bedform asymmetry and scour around obstructions indicate that net sediment transport is westward across the northern part of the study area near Fishers Island, and eastward across the southern part near Great Gull Island.

Our History … Mega Projects West Coast … Conferences …

In April of 1961, Engineering News-Record, in its Obituaries column, announced the death of Thomas A. Scott (1877–1961), retired chairman of the board for Merritt-Chapman & Scott. Scott was a renowned constructor who began his career as a blacksmith’s helper in his father’s company. His father, Thomas Albertson Scott (1830–1907), but known to all as Captain Scott, had gone to sea at age 15 and had by 1855 obtained an ownership interest in a schooner. But Captain Scott sold that interest after only a few years and moved his family to Coytesville, New Jersey, where he opened a general store. Within two years he abandoned storekeeping and took a contract to salvage the cargo from a steamer sunk near Fort Lee, New Jersey. After that he was employed by Francis Hopkinson Smith, who had a contract to construct the Race Rock Lighthouse located at the west end of Fishers Island and at the eastern entrance to Long Island Sound. So in the early 1870s the elder Scott moved his family to New London, Connecticut, so they would be with him during the construction of the Lighthouse, a 67-ft-high granite tower. Quoting from the Web site eastendlighthouses.org/rRock, “The construction on the ‘Boulder’ (really a ledge that is 3 to 13 feet below water) required 7 years, thousands of tons of riprap, numerous acts of courage and amazing persistence.” The work was completed in 1878, and the family remained in New London as the Captain continued to be engaged in marine salvage and construction work. As a credit to the quality of the construction, it must be noted that the Race Rock Lighthouse is still in service. The Captain’s firm was incorporated in 1903, under the name of T. A. Scott Company, Inc., and Thomas A. Scott—who had worked as a seaman, ship’s captain, salvage officer, and operations manager—became president. Under his leadership the firm turned increasingly to construction but continued to be extensively involved in marine salvage operations. Design/build is not such a new thing, because in 1904 T. A. Scott Company designed and built a plant to manufacture bichromate of potash and soda for the Mutual Chemical Company in Jersey City, New Jersey. The T. A. Scott Company greatly expanded its salvage operations during World War I but the Navy drew Scott away from the company. He was commissioned a Lieutenant Commander and

Differential recovery of Pacific Island fish remains

The effects of differential recovery have been documented and discussed for almost a century. Screening experiments using comparative collections are one avenue for understanding recovery bias because they develop expectations about what is likely to be recovered. In this study, modern reference specimens of Pacific Island fish were screened through 1/4 inch (6.4 mm) and 1/8 inch (3.2 mm) mesh. Recovery rates are examined across taxa, body size, and element type. The experimental recovery rates are then compared to those from an archaeological fish assemblage from the Moturakau rockshelter, Aitutaki, Cook Islands, to examine how well the data derived from screening experiments are able to predict archaeological recovery patterns. The experimental data is able to accurately predict the taxa recovered in the Moturakau sample. The impact of differential recovery on a variety of interpretations utilizing archaeological fish remains is then discussed.

Sepsis, systemic inflammatory response syndrome, multiple organ dysfunction syndrome, and multiple organ failure: are trauma surgeons lumpers or splitters?

Submitted for publication August 6, 2003. Accepted for publication August 18, 2003. Address for reprints: Arthur E. Baue, MD, P.O. Box 396, Fishers Island, NY 06390.

Similarities in Behavioral Ecology among Amphidromous and Catadromous Fishes on the Oceanic Islands of Hawai'i and Guam

About seven families of fishes occur routinely in fresh water on oceanic high islands of the tropical Pacific; others (sharks, jacks, bonefish, etc.) are occasional visitors. However, amphidromous fishes (freshwater adults, marine larvae) of the families Gobiidae and Eleotridae are predominant in island streams. Hawai'i, representing the northernmost extent of Polynesia, has five species of gobioid fishes whose adults are limited to fresh water, but Guam, in the Mariana Islands of the far Western Pacific, has more than four times that number. Hawaiian stream fishes are strikingly similar to their Guamanian relatives in their distribution, ecology, and behavior. At both localities, these fishes typically exhibit strong species specificity in the section of stream inhabited by adults, in the microhabitat selected, and in their food and feeding. Although incompletely understood, aspects of the life cycles of amphidromous island fishes (spawning, migrations into and from the sea, and others) are cued by seasonal and short-term changes in stream flow. In the Hawaiian Islands, water-use decisions based on the imperatives of allowing no net loss of habitat for aquatic animals and maintaining stream-ocean pathways for migrating animals have facilitated both management and conservation of diversity in island streams.

Measuring density dependence in survival from mark-recapture data

We discuss the analysis of mark-recapture data when the aim is to quantify density dependence between survival rate and abundance. We describe an analysis for a random effects model that includes a linear relationship between abundance and survival using an errors-in-variables regression estimator with analytical adjustment for approximate bias. The analysis is illustrated using data from short-tailed shearwaters banded for 48 consecutive years at Fisher Island, Tasmania, and Hutton's shearwater banded at Kaikoura, New Zealand for nine consecutive years. The Fisher Island data provided no evidence of a density dependence relationship between abundance and survival, and confidence interval widths rule out anything but small density dependent effects. The Hutton's shearwater data were equivocal with the analysis unable to rule out anything but a very strong density dependent relationship between survival and abundance.