Patterns of coral damage associated with the 2004 Indian Ocean tsunami at Mu Ko Similan Marine National Park,Thailand

On 26 December 2004, a severe earthquake in Sumatra caused a series of tsunami waves to strike southwestern coastal areas of Thailand. In this study, we investigated the patterns of tsunami‐related damage to coral reefs at Mu Ko Similan Marine National Park. The results showed that the percent of damaged corals ranged from 7.2% to 39.7% of the total live coral cover, and the intensity of the coral damage was high at depths deeper than 10 metres at most study sites. In addition, massive and tabulate coral forms were the most susceptible to tsunami damage. The surveys also revealed that a high degree of coral damage occurred where the reef slope gradually dropped away from the shoreline. Therefore, coral communities and coastal profiles can be major factors influencing the movement of the currents generated by the tsunami and consequently may affect the pattern of coral damage by the tsunami.     

Coral reef tanaidacean assemblages along the SW and SE Gulf of Mexico: biodiversity,geographic distribution and community structure

The biodiversity, geographic distribution, and community parameters of the benthic tanaidaceans associated with three coral reefs along the SW and SE Gulf of Mexico were analysed. A total of 15,525 specimens were grouped in 36 species. The highest value of abundance was found in the PNSAV with 6382 tanaidaceans. The PNSAV presented 30 species, the ANPT-L 16 species, and the SABS 17 species. The species with the widest distribution were Pseudonototanais sp., Condrochelia dubia, Leptochelia forresti, Synapseudes sp., Haplopolemius propinquus, Alloleptochelia longimana, and Paradoxapseudes bermudeus. In the Veracruz System Reef, the highest abundance was recorded for Condrochelia dubia and Pseudonototanais sp. The highest value of diversity was obtained in the SABS (3.08 bits/ind in the reef Bajo Diez), and the lowest value was found in the PNSAV (0.07 bits/ind in the reef Isla de Enmedio). The highest value of abundance was found in coral rubble and macroalgae. A significant relationship between depth and specific richness was found in the three reef systems. Using cluster analysis, three groups were found in each system, mainly related to the proximity to the coast and to urban areas. This is one of the first studies to show the specific substrate and attributes of three communities of tanaidaceans along the SE–SW coast of the Gulf of Mexico.     

The reef and soft-substrate coral fauna of Chagos,Indian Ocean

Summary

A series of collections of the coral fauna from a wide diversity of habitats in the Chagos Archipelago has resulted in nearly a doubling of the species known from the Central Indian Ocean. These are listed and Chagos is shown to be a very diverse part of the Indo-Pacific coral belt, but one lacking in several of the genera that have less widespread distributions such as those which could define a West Indian Ocean subprovince. The free and soft substrate species are poor in diversity, although several of these have an importance greater than their number suggests due to their ability to initiate and extend reefs over previously uncolonized substrate.     

Reef and coral communities of Oman,with a description of a new coral species (Order Scleractinia,genus Acanthastrea)

The coastline of Oman extends 2000 km from 16.5°N to 26.5°N in the north-west Indian Ocean. Most of it is long, exposed sandy beach or mixed sand and shallow rocky areas subject to severe scour, and there is a seasonal, cold-water upwelling whose influence increases towards the equator. Three areas of the mainland support corals, separated by long stretches of shallow sandy or muddy sublittoral. Three categories of coral or reef development are recognized: (A) coral reefs develop with characteristic profiles of reef flat and reef slope; (B) corals provide framework but there is no reef growth and no characteristic reef profile; and (C) no true reef development occurs, but mixed coral/phaeophyte communities are attached directly on to old, often non-limestone substrate. A and B are common in the north and central regions but are rare in the south. Type C is found in the centre and especially the south where the poor reef development is more typical of marginal, high-latitude coral areas. Ninety-one coral species from 47 genera were recorded (77 species from 37 genera being zooxanthellate), although diversity declines towards the equator. Regional comparisons show the Oman fauna to be fairly similar (up to 63% similariy) to that of the Arabian Gulf, but relatively dissimilar to faunas of the Gulf of Kutch (20%) and Lakshadweep (35%), the only other areas known to have significant amounts of corals in the Arabian Sea. A new species of Acanthanstrea with calices 5–8 cm wide is described.     

Marine biodiversity on the Algerian Continental Shelf (Mediterranean Sea)

The Mediterranean Sea is known as a biodiversity hot spot, with 16,848 species reported. Biodiversity is higher in coastal areas and decreases with depth. However, knowledge about the southwestern sector remains scarce. For the last three decades, sampling of soft-bottom communities along the 1180 km of the shallow Algerian coast (0–136 m) has recorded 1642 macrobenthic species. There is a decreasing west–east species-richness gradient, especially for the total species richness and the amphipods. In addition, quantitative sampling in Bou Ismail Bay in summer 1988 (98 sampling sites for a total of 841 species) shows that diversity indices (i.e. species richness, >100 species for 0.2 m^?2; Shannon diversity, >6.0; and ES₅₀, >34) are among the highest for similar sand and muddy-fine sand communities in the Mediterranean Sea and the northeastern Atlantic Ocean. Bou Ismail Bay appears to have the highest species richness among Algerian bays, probably because of its variety of benthic habitats and the absence of significant pollution in this area. Monitoring must be undertaken to survey this high biodiversity, and a national strategy should be proposed to preserve high diversity zones.     

First record of the invasive Asian date mussel Arcuatula senhousia (Benson, 1842) (Mollusca: Bivalvia: Mytilidae) in West Africa

ABSTRACT

Biological invasions can have serious consequences for native communities. The Asian date mussel Arcuatula senhousia is an Asian species that has been accidentally introduced into coastal areas of North America, Oceania and the Mediterranean, with significant impact on local benthic communities. Here, we present the first record of this species in West Africa, after having found one live specimen in a mudflat off the island of Bubaque, in the Bijagós archipelago of Guinea-Bissau. Given the importance of the benthic communities for wintering shorebirds and local fisheries at this key West African wetland, and considering the invasive behaviour of Asian date mussels, we recommend further monitoring to confirm whether a self-maintaining population has settled in the area.     

Exclusion experiments with backwater invertebrate communities of the Green River, Utah

The role of biotic interactions in structuring freshwater invertebrate communities has been extensively studied but with mixed results. For example, fish effects on invertebrates are most pronounced in pelagic and soft-sediment benthic habitats that lack structural complexity, yet appear insignificant in benthic rubble habitats. Backwaters of the Green River, Utah, are shallow, structurally simple, quiet-water embayments adjacent to the river. These habitats form in middle to late summer and are colonized by benthic and epibenthic invertebrates that produce standing crops significantly higher than the river. Backwaters are also utilized by a large number of fish species. We used cages to determine if selective exclusion of backwater organisms could significantly change invertebrate community structure. Results showed that backwater invertebrate community components changed significantly in response to exclusion treatments. Two taxa (both predators), the chironomid genus Tanypus (Diptera: Chironomidae) and the corixid genus Trichocorixa (Hemiptera: Corixidae), increased in density in exclusion cages while cladocerans, immature copepods, the cyclopoid copepod Eucyclops speratus , and the chironomid genus Procladius all decreased in density. Diversity of adult copepods was reduced by exclusion treatments, though density of only a single species changed significantly.     

Macroinvertebrate community structure and related environmental variables in two forks of the Virgin River, Utah

Using multivariate analysis techniques, we analyzed variation in the structure of the benthic macroinvertebrate community in the North Fork and East Fork of the Virgin River in and above Zion National Park in concert with a number of naturally occurring and anthropogenic environmental variables. Correspondence analysis revealed that the community structure in the 2 streams was markedly different despite occurring in areas similar in topography, elevation, and terrestrial vegetation cover. Subsequent analyses of the 2 streams separately using canonical correspondence analysis to test for strength of association of environmental variables with variations in benthic macroinvertebrate community structure revealed that communities in the East Fork of the Virgin River were more associated with nitrogen-related variables influenced by agricultural and urban activities along the river and that communities in the North Fork were most strongly associated with naturally occurring physical variables.     

The influence of habitat features on amphibian distribution in Northeastern Greece

Environmental and isolation variables relating to abundance of breeding amphibians, species richness and community structure at different spatial scales were examined in the Dadia-Lefkimi-Soufli Forest National Park, Evros, Greece. Logistic regression and a generalized linear model were used to relate several habitat characteristics to species occurrence and species richness. The community structure responses to breeding-pond features were examined at four spatial scales using canonical correspondence analysis (CCA). The richest communities live in low-altitude ponds, with stony or clay bottoms, high solar exposure and abundant submerged and floating vegetation. The CCA models were significant (p < 0.005) and revealed the influence of altitude, percentage of field and broadleaf forest coverage, and number of water bodies on amphibian species assemblages at all four spatial scales. There is a specific need for holistic management of amphibians that will consider habitat connectivity, particularly between aquatic and terrestrial habitats, at a larger, more interconnected scale.     

On Paranacypris samambaiensis gen. nov., sp. nov. (Crustacea,Ostracoda), the first South American psychrodromid from the alluvial valley of the Upper Paraná River,Brazil

Paranacypris samambaiensis gen. nov., sp. nov. is here described from closed lakes in the alluvial valley of the Upper Paraná River. The new genus, characterized by a large frontally overlapping left valve, belongs in the Psychrodromini, and is the first representative of this tribe described in South America. Nevertheless, it has some different character states, and the diagnosis of the tribe had to be adapted. The species is rare and restricted to closed lakes (not in contact with the main channels of the river). It mostly occurs in benthic littoral habitats, and far less in the pleuston communities, the most common habitat in this floodplain. The behaviour of P. samambaiensis gen. nov., sp. nov. is enigmatic because it combines long natatory setae on the antennae (swimming behaviour) with a very stout caudal ramus, including the spine‐like posterior seta (crawling behaviour). We present a key to the genera of the Herpetocypridinae.     

The extent of coral bleaching in Rodrigues, 2002

The reefs of Rodrigues were some of the few reef areas in the Indian Ocean to escape the mass coral bleaching event of 1997–1998. However, during the last 2 weeks of February 2002 Rodrigues experienced sea-water temperatures over 30°C, clear skies and calm seas. Rapid assessments of the degree of coral bleaching and coral mortality were carried out at 22 sites around the coast of Rodrigues during March 2002. The surveys showed that the bleaching event in Rodrigues was not widespread, occurring at less than one-third of the sites surveyed and that coral mortality was restricted to sites in the north and west of the island. Where mortality did occur, it was severe, affecting up to 75% of corals at some sites. Coral species most vulnerable were Acropora cytherea and Acropora abrotanoides, which suffered up to 100% mortality. These colonies were still standing and had been very recently overgrown with turf algae. At present the reefs around Rodrigues are in good health, however, they are being impacted by over-fishing and sedimentation, and proposed developments have the potential to cause further damage to the reefs. It is likely that stressed corals will recover from bleaching events more slowly. It is therefore important that the coral reefs in Rodrigues are adequately protected from human impacts in order to increase their chances of surviving future bleaching events.     

Haematozoans,mites and body condition in the oceanic island lizard Gallotia atlantica (Peters and Doria, 1882) (Reptilia: Lacertidae)

We studied relationships among blood haemogregarines (Apicomplexa), ectoparasitic mites (Ophyonissus; Acari: Trombiculidae) and an endemic lizard host (Gallotia atlantica, Lacertidae) on an oceanic islet (Alegranza, Canary Islands). We asked whether blood infection, mite load and body condition were related in lizard subpopulations at two contrasting habitats. Both haemogregarine prevalence (100%) and intensity of parasitism (>1) were strikingly higher than values found for congeneric lizards from the other Canary Islands. There were few differences between habitats in infection levels, suggesting low influence of habitat on parasite performance. Both mite prevalence and intensity were very high, though only prevalence differed between habitats (higher in the richest and climatically more sheltered site). Body condition in lizards did not differ significantly between habitats. We found no association among blood parasite load, mite infection and lizard body condition. Results are discussed in the context of parasite‐host relationships on small islands as compared to larger areas such as continents.     

Biogeography of coastal and anchialine amphipods of Ascension Island,South Atlantic Ocean

Over 8000 amphipods were examined from coastal (primarily intertidal) and anchialine pool habitats of Ascension Is. Twenty-seven species, of which 14 are undescribed, were identified. Comparison of species from Ascension with amphipods found in possible source areas suggests that most colonization of the island by these animals has been via the Benguela Current. Possible western Atlantic faunal contributions are significantly lower than for other marine taxa that have been studied at Ascension, all of which are generally characterized by having dispersive larval stages. The high proportion of apparently endemic species, which exceeds that described for amphipods of other oceanic islands, is probably due to both the island's isolation and incomplete faunal surveys in possible source areas. Amphipod species diversity is low, a probable consequence of the size, isolation, youth and low habitat variability of Ascension Is. Consistent with other Atlantic islands that have been studied, nestlers predominate (56% of the species), with tubicolous species (33%) of secondary importance and inquilines (11%) making only a minor contribution. Three species occur in the anchialine pool habitat. Rather unexpectedly, caprellid amphipods are absent.     

Habitat utilization by juvenile hawksbill turtles (Eretmochelys imbricata,Linnaeus, 1766) around a shallow water coral reef

Contemporary studies of sea turtle diving behaviour are generally based upon sophisticated techniques such as the attachment of time depth recorders. However, if the risks of misinterpretation are to be minimized, it is essential that electronic data are analysed in the light of first-hand observations. To this aim, we set out to make observations of juvenile hawksbill turtles (Eretmochelys imbricata, Linnaeus, 1766) foraging and resting in a shallow water coral reef habitat around the granitic Seychelles (4°'S, 55°'E). Data were collected from six study sites characterized by a shallow reef plateau (<5 m) and a flat sandy area at the base of the reef face (<10 m). Observation data were categorized into the following behaviours: (1) stationary foraging; (2) active foraging; (3) resting; and (4) assisted resting. Central to this investigation was the development of a technique for accurately estimating the size of sea turtles in situ based upon previously tested techniques for reef fishes. This revealed that through calibration, the curved carapace length (CCL) of marine turtles can be consistently estimated to within 10 cm of their actual size. Although rudimentary, this has advantages for assessing the residency or absence of specific life history stages from particular environments. Indeed, our data supported previous claims that following the reproductive season, adult hawksbills in the region may move away from the nesting beaches to alternative foraging grounds whilst immature turtles (following the pelagic juvenile stage) may opt to reside in areas close to their natal beaches. With regards to habitat utilization, juvenile hawksbills displayed an alternating pattern of short, shallow foraging dives followed by deeper, longer resting dives. These findings are consistent with previous electronic studies of free-range diving in this species and suggest that the maximization of resting duration may be an important factor driving this behaviour.     

Benthic community structure in two adjacent streams in Yellowstone National Park five years after the 1988 wildfires

Physical characteristics, benthic macroinvertebrates, and periphyton assemblages in two adjacent headwater streams in Yellowstone National Park were evaluated five years after the 1988 wildfires. The catchment of one stream was burned by wildfire (burned stream) while the other catchment was unburned (unburned stream). Physical measures revealed channel alteration in the burned stream relative to the unburned stream Periphyton biomass was lower in the burned than the unburned stream (29.2 vs. 50.5 g/m 2 AFDM, respectively), further demonstrating the unstable physical conditions of that system. Kendall's coefficient of concordance (an index of similarity) between diatom assemblages was 0.22, indicating distinct assemblage composition between streams. Navicula permitis Hust. was the most abundant diatom in the burned stream while Hannaea arcus (Ehr.) Patr. was dominant in the unburned stream. Macroinvertebrate taxa richness, density, and biomass were all greater in the unburned stream, although Chironomidae was the most abundant taxon in both streams. Results suggest the removal of terrestrial/riparian vegetation by wildfire can directly influence benthic assemblages by altering the inherent disturbance regime of the physical habitat templet.     

Habitat use by the Persian onager,Equus hemionus onager (Perissodactyla: Equidae) in Qatrouyeh National Park,Fars, Iran

Iran’s Persian onager populations are critically endangered. This study of their natural history in Qatrouyeh National Park provides insights for enhancing their conservation. The population as a whole is greatly affected by weather. Wind, rain and cold drive populations from the plains to the valleys of hill-valley habitats. Vegetation features and water also influence habitat use, but differently for different sex and reproductive classes. Females with juveniles use plains with high-quality vegetation, whereas females without young and solitary territorial males choose those of intermediate quality. Females with young foals are also found closest to watering points. Future translocation of Persian onagers will only succeed if prospective habitats have sufficient hill-valley refuges and enough plains with winds to moderately hot conditions. Sufficient plains supporting high-quality vegetation near water for lactating females must co-exist with plains of moderate-quality vegetation that attract females without young, so reducing crowding and competition.     

Environmental characteristics and benthic invertebrate assemblages in Colorado mountain lakes

Twenty-two high-elevation lakes (> 3000 m) in Rocky Mountain National Park and Indian Peaks Wilderness Area, Colorado, were surveyed during summer 1998 to explore relationships among benthic invertebrates, water chemistry (particularly nitrate concentrations), and other environmental variables. Water samples were collected from the deepest portion of each lake and analyzed for ions and other water chemistry parameters. Benthic invertebrates were collected from the littoral zone using both a sweep net and Hess sampler. Physical and geographical measurements were derived from maps. Relationships among benthic invertebrate assemblages and environmental variables were examined using canonical correspondence analysis, and the importance of sampling methodology and taxonomic resolution on these relationships was evaluated. Choice of sampling methodology strongly influenced the outcome of statistical analyses, whereas taxonomic resolution did not. Presence/absence of benthic invertebrate taxa among the study lakes was best explained by elevation and presence of fish. Relative abundance and density of benthic invertebrate taxa were more strongly influenced by sampling date and water chemistry. Nitrate (NO 3- ) concentration, potentially on the rise due to regional nitrogen deposition, was unrelated to benthic invertebrate distribution regardless of sampling method or taxonomic resolution.