Current dynamics and predicted vulnerability to sea‐level rise of a threatened Bittern Botaurus stellaris population

The decline of the Bittern Botaurus stellaris has long been symbolic of wetland habitat loss and fragmentation across western Europe. Wetland restoration and creation activity, targeted at Bittern, has been ongoing in the UK for more than 10 years and the overall numbers of occupied sites has increased five‐fold in that time. The strong recovery, whilst cause for celebration, disguises the continued precariousness of the population. This recovery has predominantly been fuelled by chick productivity from three sites in coastal Suffolk and there is increasing awareness that these sites are in immediate danger from rising sea levels. A key question is whether any loss of these key sites to coastal flooding matters to the UK Bittern population. A cautious approach to mathematical modelling of the sensitivity of the UK Bittern population to sea‐level rise events suggests that we should be concerned about the long‐term future. Our models demonstrate the sensitivity of the UK population to changes in chick survival and suggest that the growth of the UK Bittern population would be negatively affected by the loss of even a proportion of nests from these three key sites. These findings prompt the need for a multi‐layered conservation strategy to meet this dynamic challenge. A potential way forward is discussed.     

DESCRIPTION AND CHARACTERIZATION OF THE ALGAL SPECIES AUREOUMBRA LAGUNENSIS GEN. ET SP. NOV. AND REFERRAL OF AUREOUMBRA AND AUREOCOCCUS TO THE PELAGOPHYCEAE1

The Texas brown tide alga (strain TBA-2) is described as Aureoumbra lagunensis Stockwell, DeYoe, Hargraves, et Johnson, gen. et sp. nov. Pigment composition, chloroplast structure, and 18s ribosomal RNA gene sequence data indicate that A. lagunensis and the east coast brown tide alga Aureococcus anophagefferens (originally placed in the Chrysophyceae) belong in the class Pelagophyceae. The new genus Aureoumbra with A. lagunensis as the type species differs from Aureococcus in 18s ribosomal RNA gene sequence, pyrenoid form, nitrogen physiology, and possession of basal bodies. The genus Aureococcus is placed in the order Pelagomonadates and family Pelagomonadaceae while ordinal placement of Aureoumbra is deferred.     

PILINIA EARLEAE N. SP. (CHLOROPHYCEAE,CHROOLEPIDACEAE) FROM THE FLORIDA WEST COAST1

Pilinia earleae n. sp. family Chroolepidaceae, was found in the Tampa Bay area of the Florida west coast in October, 1976, on the tunic of an ascidian, later on dead mollusc shells, a nylon faking line, plastic strips, and as an epiphyte of Gracilaria foliifera, a red alga. It is described on the basis of abundant material from the natural environment and laboratory cultures. The type locality is the southernmost known for the genus in the western North Atlantic.     

Mapping biodiversity in three-dimensions challenges marine conservation strategies: The example of coralligenous assemblages in North-Western Mediterranean Sea

Multi-facet diversity indices have been increasingly widely used in conservation ecology but congruence analyses both on horizontal and vertical axes have not yet been explored. We investigated the vertical and horizontal distributions of α and β taxonomic (TD), functional (FD) and phylogenetic diversity (PD) in a three-dimensional structured ecosystem. We focused on the Mediterranean coralligenous assemblages which form complex structures both vertically and horizontally, and are considered as the most diverse and threatened communities of the Mediterranean Sea. Although comparable to tropical reef assemblages in terms of richness, biomass and production, coralligenous assemblages are less known and more rarely studied, in particular because of their location in deep waters. Our study covers the entire range of distribution of coralligenous habitats along the French Mediterranean coasts, representing the most complete database so far developed for this important ecosystem. To our knowledge, this is the first analysis of spatial diversity patterns of marine biodiversity on both horizontal and vertical scales.Our study revealed that taxonomic diversity differed from functional and phylogenetic diversity patterns at the station level, the latter two being strongly structured by depth, with shallower stations generally richer than deeper ones. Considering all stations, phylogenetic diversity was less congruent to taxonomic diversity (Pearson's correlation of r = 0.48) but more congruent to functional diversity (r = 0.69) than randomly expected. Similar congruence patterns were revealed for stations deeper than 50 m (r = 0.44 and r = 0.84, respectively) but no significantly different congruence level than randomly expected was revealed among diversity facets for more shallow stations. Mean functional α- and β-diversity were lower than phylogenetic diversity and even lower than taxonomic α- and β-diversity for both vertical and horizontal scales. Low FD and PD values at both α- and β-diversity indicated functional and phylogenetic clustering. Community dissimilarities (β-diversity) increased over depth especially in central and eastern part of the French Mediterranean littoral and in northern Corsica, indicating coralligenous vertical structure within these regions. Overall horizontal β-diversity was higher within the 50–70 m depth belts.We conclude that taxonomic diversity alone is inadequate as a basis for setting conservation goals for this ecosystem and additional information, at least on phylogenetic diversity, is needed to preserve the ecosystem functioning and coralligenous evolutionary history. Our results highlight the necessity of considering different depth belts as a basis for regional scale conservation efforts. Current conservation approaches, such as the existing marine protected areas, are insufficient in preserving coralligenous habitats. The use of multi-facet indices should be considered, focusing on preserving local diversity patterns and compositional dissimilarities, both vertically and horizontally.     

Preliminary observations on the copepods of Tudor Creek,Mombasa, Kenya

The zooplankton of Tudor Creek, a mangrove estuary in Kenya, was investigated from November 1984 to October 1985 at monthly intervals. One hundred and two copepod species were identified of which twelve were abundant. Densities are given for these species and their seasonal fluctuations are discussed.     

Patterns of abundance of exoedicerotid amphipods on sandy beaches near Sydney,Australia

Spatial and temporal patterns of abundance of two species of exoedicerotid amphipod at several sandy beaches near Sydney, Australia are described and related to physicochemical factors. Replicate cores were taken at monthly intervals for one year from the swash zone and data were analysed by two-way (site × month), fixed-factor analysis of variance. Spatial and temporal differences in abundance were usually significant but inconsistent because of significant site × month interactions. Spatial differences in Exoediceroides maculosus sometimes occurred in the absence of obvious corresponding physicochemical differences although the density of stranded seagrass and algae may affect abundance. The abundance of Exoediceros fossor was often greater in lagoons than open beaches. Salinity, temperature and storms had no apparent effect on the temporal patterns of abundance of either species.     

ESTIMATES OF THE NUMBERS OF HUMPBACK WHALES OBSERVED MIGRATING PAST CAPE VIDAL, SOUTH AFRICA, 1988–1991

A recovery-monitoring program of the African east coast humpback whale population was carried out through shore-based visual surveys from Cape Vidal, northern Natal. Surveys of the northward migration were undertaken each winter from 1988 to 1991, and a survey of the southward migration was undertaken in 1990. Independent observer surveys were undertaken during June 1990 and during the entire 1991 survey. Hourly densities of groups sighted each day were adjusted for groups missed by observers with distance from the shore and under different sighting conditions. Densities were multiplied by 24 h and the mean group size of the survey year to give resulting daily densities of individuals, which were summed to provide totals of whales sighted during each year's survey. The best estimate of population size was 1,711 (made during the northward migration of 1990), although this is likely to be biased downwards by a proportion of the population passing outside of observers'view. Bootstrapping of the 1991 daily data resulted in CVs between 11.4% and 12.2%. The numbers sighted show the population to have undergone considerable recovery since protection in October 1963.     

The effect of oocytic atresia on fecundity estimates of the rabbit fishSiganus sutor (Pisces: Siganidae) of Kenyan marine inshore waters

In the strongly group-synchronized oocyte development ofSiganus sutor (Valenciennes, 1835) the group of oocytes to be released in the following spawning, is identified. The smallest size of oocyte belonging to this group was identified by the presence of cytoplasmic vacuoles in oocytes in histological sections. These vacuolated oocytes corresponded to oocytes of 150 µm diameter obtained by treatment with Gilson's fixative. The mean number of such oocytes in stage 4 (late developing) ovaries was found to be 638 000. The proportion of these oocytes removed by atresia before spawning was determined on histological sections to be 5%. The corrected estimate of mean fecundity was thus 606 000 oocytes per spawning.     

What drives the evolution of hunter–gatherer subsistence technology? A reanalysis of the risk hypothesis with data from the Pacific Northwest

Recent studies have suggested that the decisions that hunter-gatherers make about the diversity and complexity of their subsistence toolkits are strongly affected by risk of resource failure. However, the risk proxies and samples employed in these studies are potentially problematic. With this in mind, we retested the risk hypothesis with data from hunter-gatherer populations who lived in the northwest coast and plateau regions of the Pacific Northwest during the early contact period. We focused on these populations partly because the northwest coast and plateau differ in ways that can be expected to lead to differences in risk, and partly because of the availability of data for a wide range of risk-relevant variables. Our analyses suggest that the plateau was a more risky environment than the northwest coast. However, the predicted differences in the number and complexity of the populations' subsistence tools were not observed. The discrepancy between our results and those of previous tests of the risk hypothesis is not due to methodological differences. Rather, it seems to reflect an important but hitherto unappreciated feature of the relationship between risk and toolkit structure, namely that the impact of risk is dependent on the scale of the risk differences among populations.     

广西北部湾近岸生态系统风险评价

根据2009年9月广西北部湾近岸的海洋生态调查资料,利用地理信息系统的空间分析功能,从海水水质、营养水平、生物量和初级生产力水平、生物多样性和生态系统缓冲容量5个方面分析了秋季广西北部湾近岸海域环境现状,并进一步利用生态风险综合指数对广西北部湾海洋生态风险进行了评价.结果表明:2009年秋季,广西北部湾近岸海域生态环境质量较好,大部分生态系统风险指标等级均处于“中低”或“较低”水平,整体处于低风险状态.生态风险综合指数结果显示,广西北部湾海域生态风险分布具有明显的空间异质性,离岸水域生态系统的风险综合指数较低,越靠近港湾内,风险状态等级越高.