Shore Marine Research Articles

A framework for vulnerability assessment of coastal fisheries ecosystems to climate change—Tool for understanding resilience of fisheries (VA–TURF)

Vulnerability assessment (VA) is increasingly developed and utilized in various sectors and fields of society. VA provides a better understanding of the interactions among system, pressures, and threats, which serves as a basis for targeted adaptation strategies. The framework or tool named tool for understanding resilience of fisheries (VA–TURF) was developed to assess the vulnerability of the coastal fisheries ecosystems in the tropics to climate change. VA–TURF has three major components, namely, fisheries, reef ecosystem, and socio-economics. Although each component has intrinsic properties, the three components are strongly interrelated. Indicators associated to sensitivity, exposure, and adaptive capacity were developed for each component of TURF. The exposure variable used was wave. VA–TURF uses information obtained through rapid assessments except for the reef ecosystem component. The analytical approach for integrating scores is straightforward and devoid of highly sophisticated mathematical methods. The utility of VA–TURF primarily considers the fishers of a coastal community (barangay) as the major stakeholder, thereby facilitating familiarization and community ownership of the tool. VA–TURF was demonstrated in all the coastal barangays of two island municipalities (Lubang and Looc, Occidental Mindoro, Philippines) located along the Verde Island Passage, which has the world's highest marine shore fish biodiversity. Local stakeholders such as fishers, barangay leaders, residents, and local executive staff of the two municipalities participated in the process of scoring and determining the vulnerability of the sites during a series of workshops. The local-level fisheries vulnerability assessment framework developed encourages community-level actions and provides opportunities for strategic actions and scaling-up of efforts at various governance levels.

Histopathology of Zinc exposition in Actinia equina L. (Anthozoa, Actiniaria)

Zinc is a trace metal that is regularly found at pollution sites, amongst other metals and pollutants, contributing to the toxicity of marine ecosystems. In this study zinc acute toxicity tests were conducted on the sea anemone Actinia equina. This sea anemone presents a wide geographic distribution on rocky shore marine habitats, is quite resistant to some degree of various forms of contaminants and plays an important ecological key role in the marine environments.After a period of acclimatising on a flow through system, organisms of the same average size were exposed to different concentrations of zinc solution during a period of 96 hours (0 µg/l, 10 µg/l, 50 µg/l, 100 µg/l, and 200µg/l). The histological processing of the specimens was performed using standard procedures, slightly modified due to the peculiar nature of the biological material.The general effects exhibited necrosis of tentacles, mesenterial filaments, and in the gastrodermal regions (Figures 1, 2 and 3). It were observed tentacular cysts, black particulate accumulations in the gastrodermis, hypertrophied cells in the lobes of the mesenteries filaments, and spirocyst and associated necrosis (Fig. 2-3). All anemones exhibited extensive areas of tissue necrosis, degeneration of the epidermis in various stages, with loss of mucous cells, vacuolation, necrosis and ptychocysts from the epidermis, necrosis of retractor muscles and ducts (Figures 2-3). Neoplasms of the gastrointestinal tract and gonads were observed in internal structures. In the former, modifications of the mesenteries such as intensive fragmentation, vacuolization and epithelial thinning and in the latter abnormal gonad development and necrosis were noted (Figures 2-3).The data suggests that Actinia equina may be adversely affected by acute exposures to high levels of zinc as seen during laboratory exposures of other invertebrates and is also probably sensitive to acute exposures to metal’s toxic sediments in the marine environment. The loss of mucous secretory cells and ptychocysts from the epidermis suggest that energy reserves for cell replenishment were adversely affected. Mucus production in benthic cnidarians is necessary to prevent burial by sedimentation and to protect against toxins or invading microorganisms. The serious effects on the gastrodermis integrity indicate that sea water in the coelenteron is no longer circulated. The observed modifications could be considered as a general cnidarians response to stress.Further investigations of bioaccumulation, physiology, and histopathology in this anemone and other anthozoans from polluted environments should prove to be valuable in pollution monitoring studies, as they have for other benthic invertebratesAcknowledgmentsThis work was supported by the Portuguese Foundation for the Science and Technology – Portugal and FEDER funds, through the Projects: PTDC/MAR/464729/2006 and FCT/CNPq (Brazil), Project 6818, Programme 19/ 004.

The Cambrian sedimentary characteristics and their implications for oil and gas exploration in north margin of Middle-Upper Yangtze Plate

Using data from tens of measured and observed outcrop successions, thin rock slices and sample analyses, we comprehensively studied the Cambrian sedimentary environments and evolutionary characteristics in the north margin of the Middle-Upper Yangtze Plate. During the Cambrian, platform, slope, and deep sea basin environments were developed in the study area. On the platform, both clastic rocks and carbonate rocks were deposited. Clastic rocks mainly occur in the Lower Cambrian, and were deposited in marine shore and shelf environments. Carbonate rocks are dominant in the Middle and Upper Cambrian, and were deposited in the open platform, restricted platform, tidal flat, beach, and reef environments. Carbonate gravity flow deposits were developed on the slope. In the basin, mainly black shales and chert beds were deposited. The Cambrian represents one large transgression-regression cycle, and maximum transgression occurred in the Qiongzhusi Age of the Early Cambrian. Tectonics and sea level fluctuations had important impacts on sedimentary environments. The Chengkou-Fangxian-Xiangfan Fracture controlled the position of the platform, slope and basin, as well as the silica supply for chert deposition in basin. Sea level fluctuations controlled types of sediments and sedimentary facies on the platform. In the study area, there are good reservoir rocks, including dolomites, grainstones, debris flow deposits, sandstones, and conglomerates; there are good source rocks, including black shales, dark micrites, and chert beds; and there are also good reservoir-source rock assemblages. The hydrocarbon potential of the study area is great.

Metal Mobilization by Iron- and Sulfur-Oxidizing Bacteria in a Multiple Extreme Mine Tailings in the Atacama Desert, Chile

The marine shore sulfidic mine tailings dump at the Chañaral Bay in the Atacama Desert, northern Chile, is characterized by extreme acidity, high salinity, and high heavy metals concentrations. Due to pyrite oxidation, metals (especially copper) are mobilized under acidic conditions and transported toward the tailings surface and precipitate as secondary minerals (Dold, Environ. Sci. Technol. 2006, 40, 752-758.). Depth profiles of total cell counts in this almost organic-carbon free multiple extreme environment showed variable numbers with up to 10(8) cells g(-1) dry weight for 50 samples at four sites. Real-time PCR quantification and bacterial 16S rRNA gene diversity analysis via clone libraries revealed a dominance of Bacteria over Archaea and the frequent occurrence of the acidophilic iron(II)- and sulfur-oxidizing and iron(III)-reducing genera Acidithiobacillus, Alicyclobacillus, and Sulfobacillus. Acidophilic chemolithoautotrophic iron(II)-oxidizing bacteria were also frequently found via most-probable-number (MPN) cultivation. Halotolerant iron(II)-oxidizers in enrichment cultures were active at NaCl concentrations up to 1 M. Maximal microcalorimetrically determined pyrite oxidation rates coincided with maxima of the pyrite content, total cell counts, and MPN of iron(II)-oxidizers. These findings indicate that microbial pyrite oxidation and metal mobilization preferentially occur in distinct tailings layers at high salinity. Microorganisms for biomining with seawater salt concentrations obviously exist in nature.

Exposure–dose–response of Anadara trapezia to metal contaminated estuarine sediments: 3. Selenium spiked sediments

Selenium enters near shore marine environments from the activities of coal-fired power stations. Although selenium is an essential element, at elevated concentrations it can cause genotoxic damage. The relationship between selenium exposure dose and response was investigated in Anadara trapezia exposed to selenium spiked sediment (5μg/g and 20μg/g dry mass) for 56 days. A. trapezia reached an equilibrium selenium tissue concentration (2μg/g and 10μg/g respectively) by day 42. Gills had significantly more selenium than the hepatopancreas and haemolymph. Between 12 and 21% of accumulated selenium in the gill and hepatopancreas was detoxified and in the metal rich granule. Most of the biologically active selenium in both tissues was in the mitochondrial fraction. Glutathione peroxidase activity and mean total glutathione concentrations for selenium exposed organisms were not significantly different to controls. The ratio of reduced to oxidised glutathione and the total antioxidant capacity were significantly reduced in selenium exposed organisms compared to control organisms. Increased selenium exposure resulted in significant increases in lipid peroxidation, lysosomal destabilisation and an increased frequency of micronuclei. A significant exposure–dose–response relationship for A. trapezia exposed to selenium enriched sediments indicates that elevated sediment selenium concentrations can increased biologically active selenium burdens and cause impairment of cellular processes and cell integrity.

Contrasting habitat use of diurnal and nocturnal fish assemblages in temperate Western Australia

This study examined the diversity and relative abundance of fish species in six coastal habitats during the day and at night. Habitats included seagrass beds, Ecklonia macroalgal beds, other macrophytes, deep reef, rhodolith beds and sand. Surveys were conducted using baited remote underwater stereo-video systems, which at night were equipped with either white or red lights. Three research questions were examined; 1) do fish assemblages sampled during the day differ to those sampled at night across six inshore and near shore marine habitats? 2) Are patterns of habitat associations displayed by diurnal fishes maintained at night? 3) Do stereo-BRUVs sample different fish assemblages when equipped with red versus white lights?Diurnal surveys sampled significantly greater species richness (66% greater) and numbers of individuals (92% more than red lights, 82% than white lights) than nocturnal surveys. Diurnal surveys also showed greater discrimination in the fish assemblages between the six habitats with replicate samples from a habitat clustered together. This clustering of replicate samples was reduced at night where a number of species of fish were seen in multiple habitats. Thirty-one percent of the species viewed at night were seen on multiple habitats, but only a single habitat during the day.Compared to red lights, white lights surveyed a greater number of individuals and species in rhodolith beds (94% more individuals and 63% more species) and over sand (94% more individuals, 83% more species). This was likely due to an attraction of fish to bait fish accumulating near the white light source, but not in the red light source. However, surveys of fish assemblages at night were deemed most effective when red lights were used, because this lighting type had an improved ability to statistically distinguish fish assemblages across the habitats surveyed. By conducting nocturnal survey studies researchers may obtain a more holistic understanding of habitat use by fish species and account for this usage in biodiversity and fisheries management plans.

Nature and Chronology of Prehistoric Settlement on the Vatia Peninsula, Northern Viti Levu Island, Fiji

ABSTRACT Two upland sites from the Vatia Peninsula, northern Viti Levu Island, Fiji, were excavated as part of a larger project investigating the settlement history of this area. These sites represent the first intensive survey and excavation program in this part of Fiji. The sites are a cave (Matanigaga), which acted as a short-term shelter, and a ring-wall mound (Drautana), one of a number of similar sites interpreted as likely precursors to complex ridge-top fortifications. Both sites suggest that occupation in this area began in the last millennium and involved exploitation of near shore marine resources. The number of fortified hilltops on the Vatia Peninsula suggests that conflict may have been endemic in this area of Fiji during the latter part of the last millennium. Site descriptions and the analysis of ceramic, lithic, and mollusk remains are presented here.

Exposure–dose–response of Anadara trapezia to metal contaminated estuarine sediments. 2. Lead spiked sediments

The composition of near shore marine environments is increasingly being altered by contaminants from human activities. The ability of lead, which has no known biological function, to mimic biologically essential metals makes it one of the most toxic to marine biota. The relationship between lead exposure, dose and response was investigated in Anadara trapezia exposed for 56 days to lead spiked sediment (100 and 300μg/g dry mass). Lead tissue concentrations of the 300μg/g exposed A. trapezia doubled in the last 2 weeks of exposure with final lead tissue concentrations of exposed organisms of 1 and 12μg/g, respectively. Tissue lead accumulation of exposed organisms followed the pattern haemolymph>gill>hepatopancreas during much of the 56 day exposure. Between 30 and 69% of accumulated lead in the gill and hepatopancreas was detoxified and fairly evenly distributed between the metal rich granule and the metallothionein like protein fractions. Approximately half of the biologically active lead in both tissues was in the mitochondrial fraction which showed increased cytochrome c oxidase activity in lead exposed organisms. There was a reduction in GPx activity, an associated increase in total glutathione concentrations and reduced GSH:GSSG ratios due to a build up of oxidised glutathione. These changes in the glutathione pathway were reflected in the total antioxidant capacity of lead exposed A. trapezia which were significantly reduced compared to control organisms. Increased lead exposure significantly increased lipid peroxidation, lysosomal destabilisation and frequency of micronuclei. A significant exposure–dose–response relationship for A. trapezia exposed to lead enriched sediments indicates that elevated sediment lead concentrations have the potential to increase biologically active lead burdens and impair the antioxidant reduction capacity leading to a series of associated effects from lipid peroxidation to cellular perturbation and genotoxic damage.

Holocene glacial and climate history of Prince Gustav Channel, northeastern Antarctic Peninsula

The Antarctic Peninsula is one of the most rapidly warming regions on Earth, as evidenced by a recent increase in the intensity and duration of summer melting, the recession of glaciers and the retreat and collapse of ice shelves. Despite this, only a limited number of well-dated near shore marine and lake sediment based palaeoenvironmental records exist from this region; so our understanding of the longer-term context of this rapid climate change is limited. Here we provide new well-dated constraints on the deglaciation history, and changes in sea ice and climate based on analyses of sedimentological proxies, diatoms and fossil pigments in a sediment core collected from an isolation basin on Beak Island in Prince Gustav Channel, NE Antarctic Peninsula (63°36′S, 57°20′W). Twenty two radiocarbon dates provided a chronology for the core including a minimum modelled age for deglaciation of 10,602 cal yr BP, following the onset of marine sedimentation. Conditions remained cold and perennial sea ice persisted in this part of Prince Gustav Channel until c. 9372 cal yr BP. This was followed by a seasonally open marine environment until at least 6988 cal yr BP, corresponding with the early retreat and disintegration of the ice shelf in southern Prince Gustav Channel. Following isolation of the basin from 6988 cal yr BP a relatively cold climate persisted until 3169 cal yr BP. A Mid-late Holocene climate optimum occurred between 3169 and 2120 cal yr BP, inferred from multiple indicators of increased biological production. This postdates the onset of the Mid-late Holocene climate optimum in the South Shetland Islands (4380 cal yr BP) and the South Orkney Islands (3800 cal yr BP) suggesting that cooler climate systems of the Weddell Sea Gyre to the east of the Peninsula may have buffered the onset of warming. Climate deterioration is inferred from c. 2120 cal yr BP until 543 cal yr BP. This was followed by warming. Superimposed on this warming trend, the instrumental record of recent warming at nearby Hope Bay is mirrored by a recent increase in the lake’s primary production and a shift in the diatom communities in the uppermost 3 cm of sediments, suggesting that this is amongst the first records to show an ecological response to recent rapid temperature increase. These new constraints on glaciological and climate events in Prince Gustav Channel are reviewed in the context of wider changes in the Antarctic region.

Variation in community structure across vertical intertidal stress gradients: how does it compare with horizontal variation at different scales?

In rocky intertidal habitats, the pronounced increase in environmental stress from low to high elevations greatly affects community structure, that is, the combined measure of species identity and their relative abundance. Recent studies have shown that ecological variation also occurs along the coastline at a variety of spatial scales. Little is known, however, on how vertical variation compares with horizontal variation measured at increasing spatial scales (in terms of sampling interval). Because broad-scale processes can generate geographical patterns in community structure, we tested the hypothesis that vertical ecological variation is higher than fine-scale horizontal variation but lower than broad-scale horizontal variation. To test this prediction, we compared the variation in community structure across intertidal elevations on rocky shores of Helgoland Island with independent estimates of horizontal variation measured at the scale of patches (quadrats separated by 10s of cm), sites (quadrats separated by a few m), and shores (quadrats separated by 100s to 1000s of m). The multivariate analyses done on community structure supported our prediction. Specifically, vertical variation was significantly higher than patch- and site-scale horizontal variation but lower than shore-scale horizontal variation. Similar patterns were found for the variation in abundance of foundation taxa such as Fucus spp. and Mastocarpus stellatus, suggesting that the effects of these canopy-forming algae, known to function as ecosystem engineers, may explain part of the observed variability in community structure. Our findings suggest that broad-scale processes affecting species performance increase ecological variability relative to the pervasive fine-scale patchiness already described for marine coasts and the well known variation caused by vertical stress gradients. Our results also indicate that experimental research aiming to understand community structure on marine shores should benefit from applying a multi-scale approach.

Impacts and negative feedbacks in community recovery over eight years following removal of habitat-forming macroalgae

The decline or loss of habitat-forming species has affected rocky shore marine communities worldwide. Many short-term studies have documented the initiation of cascading effects due to canopy losses of macroalgae, but relatively few studies have followed recovery dynamics over many years. Here, we show that the experimental removal of a dominant intertidal fucoid in southern New Zealand had numerous community effects up to 8years later. Even though the dominant fucoid returned to a nearly closed canopy, there remained many differences between disturbed and control communities. The disturbed treatments had lower plant density and biomass of the dominant fucoid, fewer species and more turfing coralline algae than controls. Plots with press disturbances were more affected than those with pulse disturbances. The negative feedback of turfing algae on the recovery of fucoid recruitment resulted in effects on cover and diversity in the wider community being evident after 8years. We discuss the feedbacks between fucoids, benthic turfing algae and community recovery and argue that if biodiversity impacts on marine rocky reefs are to be understood, the role of non-trophic interactions in structure, function and dynamics must be better delineated.

Cranial anatomy of middle EoceneRemingtonocetus(Cetacea, Mammalia) from Kutch, India

The family Remingtonocetidae is a basal family of Eocene cetaceans only known from near shore marine environments of India and Pakistan. We describe a new skull forRemingtonocetus harudiensiswhich elucidates the anatomy and functional morphology of the head and provides new details on cranial cavity and nasopharyngeal region. We suggest thatRemingtonocetuswas an ambush predator that hunted from a perch on the ocean floor, and that hearing was its most important sense. We speculate that the greatly elongated rostrum is an adaptation for water retention because these are some of the earliest whales living in seawater.

Remediation of a Marine Shore Tailings Deposit and the Importance of Water–Rock Interaction on Element Cycling in the Coastal Aquifer

We present the study of the geochemical processes associated with the first successful remediation of a marine shore tailings deposit in a coastal desert environment (Bahía de Ite, in the Atacama Desert of Peru). The remediation approach implemented a wetland on top of the oxidized tailings. The site is characterized by a high hydraulic gradient produced by agricultural irrigation on upstream gravel terraces that pushed river water (∼500 mg/L SO(4)) toward the sea and through the tailings deposit. The geochemical and isotopic (δ(2)H(water) and δ(18)O(water), δ(34)S(sulfate), δ(18)O(sulfate)) approach applied here revealed that evaporite horizons (anhydrite and halite) in the gravel terraces are the source of increased concentrations of SO(4), Cl, and Na up to ∼1500 mg/L in the springs at the base of the gravel terraces. Deeper groundwater interacting with underlying marine sequences increased the concentrations of SO(4), Cl, and Na up to 6000 mg/L and increased the alkalinity up to 923 mg/L CaCO(3) eq. in the coastal aquifer. These waters infiltrated into the tailings deposit at the shelf-tailings interface. Nonremediated tailings had a low-pH oxidation zone (pH 1-4) with significant accumulations of efflorescent salts (10-20 cm thick) at the surface because of upward capillary transport of metal cations in the arid climate. Remediated tailings were characterized by neutral pH and reducing conditions (pH ∼7, Eh ∼100 mV). As a result, most bivalent metals such as Cu, Zn, and Ni had very low concentrations (around 0.01 mg/L or below detection limit) because of reduction and sorption processes. In contrast, these reducing conditions increased the mobility of iron from two sources in this system: (1) The originally Fe(III)-rich oxidation zone, where Fe(III) was reduced during the remediation process and formed an Fe(II) plume, and (2) reductive dissolution of Fe(III) oxides present in the original shelf lithology formed an Fe-Mn plume at 10-m depth. These two Fe-rich plumes were pushed toward the shoreline where more oxidizing and higher pH conditions triggered the precipitation of Fe(III)hydroxide coatings on silicates. These coatings acted as a filter for the arsenic, which naturally infiltrated with the river water (∼500 μg/L As natural background) into the tailings deposit.

Genetic population structure of Tectura paleacea: implications for the mechanisms regulating population structure in patchy coastal habitats.

The seagrass limpet Tectura paleacea (Gastropoda; Patellogastropoda) belongs to a seagrass obligate lineage that has shifted from the Caribbean in the late Miocene, across the Isthmus of Panama prior to the closing of the Panamanian seaway, and then northward to its modern Baja California – Oregon distribution. To address whether larval entrainment by seagrass beds contributes to population structuring, populations were sampled at six California/Oregon localities approximately 2 degrees latitude apart during two post-settlement periods in July 2002 and June 2003. Partial cytochrome oxidase b (Cytb) sequences were obtained from 20 individuals (10 per year) from each population in order to determine the levels of population subdivision/connectivity. From the 120 individuals sequenced, there were eighty-one unique haplotypes, with the greatest haplotype diversity occurring in southern populations. The only significant genetic break detected was consistent with a peri-Point Conception (PPC) biogeographic boundary while populations north and south of Point Conception were each panmictic. The data further indicate that populations found south of the PPC biogeographic boundary originated from northern populations. This pattern of population structure suggests that seagrass patches are not entraining the larvae of T. paleacea by altering flow regimes within their environment; a process hypothesized to produce extensive genetic subdivision on fine geographic scales. In contrast to the haplotype data, morphological patterns vary significantly over very fine geographic scales that are inconsistent with the observed patterns of genetic population structure, indicating that morphological variation in T. paleacea might be attributed to differential ecophenotypic expression in response to local habitat variability throughout its distribution. These results suggest that highly localized conservation efforts may not be as effective as large-scale conservation efforts in near shore marine environments.

An Assessment of the Current Status of Bioavailable Metal Contamination Across South Australia Using Translocated Mussels Mytilus Galloprovincalis

This study presents results from the first regional assessment of metal levels in translocated blue mussels (Mytilus galloprovincialis Lamarck, 1819) in the nearshore coastal environment across South Australia. A total of 422 replicate samples of translocated mussels were deployed throughout 11 regions across the South Australian near shore marine environment. Mussels were recovered after approximately 70 days and analysed for total metal load in the flesh of the mussel. Results showed vast differences in metal concentrations between different regions and also compared to the baseline metal concentration. Many of these differences can be attributed to the level of industrial activity in the regions which may have implications for environmental regulation in these regions.

BIOINVASÃO MARINHA: OS BIVALVES EXÓTICOS DE SUBSTRATO CONSOLIDADO E SUAS INTERAÇÕES COM A COMUNIDADE RECEPTORA

Research on invasive species has increased over the past few years, since onus generated by these species can result in economic, ecological and social damage. Rocky shore marine bivalves, introduced in many parts of the world, can influence ecological relationships among native species and modify the structure and development of receiving communities. Therefore, the goal of this study is to summarize the available information in the literature related to rocky shore marine bivalve introductions and their influence on the ecological relations among the receiving community organisms. Among these, the competition by substratum will be analyzed since it is a limiting resource on rocky shores that could create a spatial segregation between native and exotic species. However, some invasive species can function as ecosystem engineers providing secondary space and microhabitats, besides increasing local diversity. In addition, once established in their new environment, exotic bivalves can be incorporated to the local food chain as prey, causing modifications in the diet and patterns of food preference of native predators. The majority of the research studies have examined the records of introduction, distribution, structure and population dynamic of the invasive bivalve species. The interactions established among rocky shore invasive bivalves and the receiving community is poorly studied; however, in the past five years there has been an increasing interest in this subject. Mytilus galloprovincialis is the best studied invasive bivalve. In Brazilian rocky shores five exotic bivalve species have been identified ( Perna perna , Isognomon bicolor, Mytilopsis leucophaeta, Crassostrea gigas e Myoforceps aristatus ). Despite the existence of studies (theses, dissertations and monographs) related to these species ecology in Brazil, few are available as scientific papers. During this review it was observed that the effects of invasive bivalves seem to vary according to the invaded site. Therefore, these studies deserve special attention from the Brazilian scientific community. The research on these invasive species are extremely important to evaluate the possible impacts caused by them and to identify the most sensible and potentially threatened natural resources, in order to develop control plans and, when possible, eradicate the exotic species.

Long-term comparison of the fish community in a Costa Rican rocky shore marine reserve

Despite their role in supporting diverse marine fish communities, tropical rocky shores and reefs have attracted less research and fewer targeted conservation efforts compared to coral reefs. We studied fish community composition in Playa Blanca Marine Reserve (9 degrees 40' N - 84 degrees 40' W), a rocky shore site on the central Pacific coast of Costa Rica. We conducted visual surveys of fishes along six strip transects soon after the area was designated a marine reserve in 1995, then again in 2006 following an eleven-year period of complete protection. We recorded a total of 31 406 sightings of 72 species from 30 families. Pomacentrids (42.5%), labrids (16.6%) and haemulids (14.8%) dominated the community, accounting for > 70% of total fish abundance. In comparison to other sites in the region, the fish community was more similar to one reported from Bahia Honda, Panama (7 degrees 50' N - 81 degrees 35 W) than from the geographically more proximate Culebra Bay, Costa Rica (10 degrees 45' N - 85 degrees 43 W). Sixty-one species from 26 families were recorded in 1995; sixty-nine species from 28 families in 2006. Our results suggest that the Playa Blanca Marine Reserve is fulfilling its conservation role. Average fish abundance, species richness and Shannon's index of community diversity were greater in 2006 than 1995, and fish community composition varied significantly within each transect among years. Much of the change in community composition among years resulted from spatial and temporal variation in the abundance of a few dominant species, including Abudefduf troschelli, Thalassoma lucasanum, Chromis atrilobata, and Stegastes flavilatus/acapulcoensis. Of the 48 species/species groups recorded in both years, 37 (77%) were more abundant in 2006 than 1995, and several species recorded as uncommon or rare in 1995 were more frequent and abundant in 2006. Fish community composition and the abundance of some species changed in the reserve over time, but further study is needed to determine the role of small-scale marine reserves in the conservation of tropical marine biodiversity.

Geochemical and environmental controls on the genesis of soluble efflorescent salts in Coastal Mine Tailings Deposits: A discussion based on reactive transport modeling

Water-soluble efflorescent salts often form on tailings in hyperarid climates. Their high solubility together with the high risk of human exposure to heavy metals such as Cu, Ni, Zn, etc., makes this occurrence a serious environmental problem. Understanding their formation (genesis) is therefore key to designing prevention and remediation strategies. A significant amount of these efflorescences has been described on the coastal area of Chañaral (Chile). There, highly soluble salts such as halite (NaCl) and eriochalcite (CuCl 2·2H 2O) form on 4 km 2 of marine shore tailings. Natural occurrence of eriochalcite is rare: its formation requires extreme environmental and geochemical conditions such as high evaporation rate and low relative air humidity, and continuous Cl and Cu supply from groundwater, etc. Its formation was examined by means of reactive transport modeling. A scenario is proposed involving sea water and subsequently a mixture of sea water/freshwater in the groundwater composition in the formation of these efflorescences. The strong competition from other halides (i.e. halite and silvite (KCl)) for the Cl may inhibit the precipitation of eriochalcite. Therefore, the Cl/Na ratio trend > 1 is a key parameter in its formation. Cation-exchange between Na + and other major ions such as K +, Ca 2+, Mg 2+ and Cu 2+ in the clay fraction of tailings is proposed to account for realistic Cl/Na ratios. With regard to preventing the formation of eriochalcite, a capillary barrier on the tailings surface is proposed as a suitable alternative. Its efficiency as a barrier is also tested by means of reactive transport models.

Measuring the economic effects of sea level rise on shore fishing

In this paper we develop estimates of the economic effects of sea level rise on marine recreational shore fishing in North Carolina, USA. The relationship between angler behavior and spatial differences in beach width is estimated using the Marine Recreational Fishing Statistics Survey and geospatial data. We exploit the empirical relationship between beach width and fishing site choice by simulating the effects of sea level rise on angler site choice. We find that reductions in beach width negatively affect the quality and number of fishing trips even as anglers adapt by using piers and bridges. Welfare losses are potentially substantial, ranging up 39% of the total value of marine shore fishing in North Carolina.

DISTRIBUTION OF ALGAL EPIPHYTES ACROSS ENVIRONMENTAL GRADIENTS AT DIFFERENT SCALES: INTERTIDAL ELEVATION, HOST CANOPIES, AND HOST FRONDS(1).

Understanding epiphyte distribution in coastal communities is important because these organisms affect many others directly or indirectly. Yet, their distribution has been considerably less studied than that of their hosts and other primary-space holders. Identifying major sources of variation in epiphyte abundance is thus still a need. Environmental gradients help predict species distribution and are pervasive on marine shores. In this study, we test the notion that environmental gradients across intertidal elevation, throughout host canopies, and along host fronds explain a large variation in the abundance of sympatric epiphytes. Our model system was the assemblage of Ascophyllum nodosum (L.) Le Jol. and its epiphytes Vertebrata lanosa (L.) T. A. Chr. [= Polysiphonia lanosa (L.) Tandy], Elachista fucicola (Velley) Aresch., and Pylaiella littoralis (L.) Kjellm. On the coast of Nova Scotia (Canada), we found evidence of a spatial segregation among these species at almost all scales. While the red epiphyte V.lanosa was more common at high- and midintertidal elevations (peaking at midelevations) and on middle segments of host fronds, the brown epiphytes E.fucicola and P.littoralis were more common at low elevations and restricted to distal segments of host fronds. Canopy habitat affected abundance only for V.lanosa, which was more common within the host canopy than on its periphery at midelevations. Since the studied gradients are related to predictable changes in abiotic factors, the identification of likely causes behind the observed patterns was facilitated. Our study ends by proposing abiotic and biotic factors that deserve priority in the experimental testing of the forces structuring this assemblage.