Radium in the Suwannee River and estuary

A two-year study of radium in the Suwannee River has shown that groundwater discharge, via springs, is a very important source of radium both to the river and to offshore Gulf of Mexico waters. Dissolved radium is maintained within relatively narrow limits in the river by uptake into suspended particles. In the estuary, dissolved radium versus salinity profiles show distinctive nonconservative behavior with radium in significant excess of its linear mixing value at mid-salinities. Unlike the situation in many other estuaries, however, desorption of radium from particles cannot account for most of the observed excess. Thus, the anomalously high radium characteristic of much of the west Florida shelf apparently does not have a riverine source. Direct effusion of high-radium groundwater into these coastal waters is thought to be the major supplier of radium, and perhaps other elements as well.     

Phylogenetic characterization of culturable bacterial diversity associated with the mucus and tissue of the coral Acropora digitifera from the Gulf of Mannar

Corals, considered the rainforests of the oceans, harbour an abundance of different bacterial populations throughout the coral structure. In the present study we attempted to characterize the cultivable bacterial population associated within the mucus and tissue of the coral Acropora digitifera from the Gulf of Mannar. 16S rRNA gene was amplified from the cultured mucus and tissue isolates. Amplified ribosomal DNA restriction analysis, performed with a combination of restriction enzymes to determine the polymorphic groups of bacteria, generated 19 distinct groups in the coral mucus and 17 distinct groups in the coral tissue. Phylogenetic analyses based on the full-length sequences of 16S rRNA gene sequences showed that the majority of bacterial isolates belonged to the group Firmicutes , followed by Gammaproteobacteria and Actinobacteria . On investigating their antimicrobial activity, mucus isolates showed about 25% activity and tissue isolates showed 48% activity. This study revealed the presence of actinomycetes in both the coral mucus and the coral tissue, which had high activity against pathogens. This study, for the first time, demonstrates that actinomycetes existing within corals also have potential antibacterial activity. This has been overlooked so far, and indicates that, in addition to mucus, bacteria within the tissue of corals might defend the coral host against pathogens.     

A new genus of Cletopsyllidae (Copepoda,Harpacticoida) from Gulf of Mexico

A new genus and new species of the family Cletopsyllidae Huys & Willems, 1989 from deep-sea sediment in the Gulf of Mexico, are reported and fully described and illustrated. The new genus Pentacletopsyllus (type species: P. montagni sp. n.) can be distinguished from the four known genera of the family by antennule segmentation, length ratio of first and second endopodal segments of P1, and armature pattern on P5 exopod. It also differs from its sister genera by the rostrum being bifid at the tip, third segment of the female antennule having a smooth posterior margin, the baseoendopod of P5 with biarticulate outer setophore bearing basal seta, and female caudal rami without lobate expansion. A revised key to species of the family Cletopsyllidae Huys & Willems, 1989 is provided.     

Seasonal and spatial variation in the reproductive biology of the dwarf seahorse Hippocampus zosterae

Factors associated with the reproductive ecology of the dwarf seahorse Hippocampus zosterae were investigated. Fish from a Tampa Bay (FL, USA) seagrass ecosystem were collected, photographed and returned to the wild, with photos analysed to determine patterns of body size, density, sex ratio and reproductive state across site and season to understand the population dynamics of H. zosterae over time. Animal density did not vary significantly with site and season, indicating there is little evidence of seasonal migration in this species. Densities reported in this study were higher than the mean density for all seahorse species Hippocampus spp. There was no sexual dimorphism in body length and both sexes reached sexual maturity at the same size. The ratio of gravid to non-gravid males was found to shift by season but not by site, with breeding detected year-round in this population compared with populations further north in their range. Peak breeding (70% gravid males) was observed in the late summer–autumn (August–October) in the site furthest from shore. The largest fish for both sexes were recorded during the summer and autumn months in the mid-shore, deepest site. Sex ratio shifted by site with even sex ratios near the shore but significantly female-biased sex ratios detected at sites near open water. Lastly, an increase in marking dates with decreased time intervals between collections did not yield a higher recapture rate, compared with sampling in 2010. However, the Tampa Bay population of dwarf seahorses demonstrated stable densities across 3 years with year-round breeding, indicating that it is a robust population worthy of long-term monitoring for conservation efforts.     

European smelt Osmerus eperlanus in the eastern Gulf of Finland,Baltic Sea: Stock status and fishery

In the eastern Gulf of Finland, European smelt Osmerus eperlanus occurs as an anadromous ecological form that spawns in coastal, low-salinity zones and in several rivers entering the gulf, most importantly in the River Neva. Osmerus eperlanus is a key commercial fish species for the population of St. Petersburg, and the city's fish symbol. However, the state of the smelt stock has considerably deteriorated over the past few decades. Monitoring shows that annual catches during 1965–1992 averaged 2274 t, compared to 292 t in 2002–2017, although some improvement is inidicated by a gradual increase in catches in recent years (e.g., to 595 t in 2017). This paper addresses long-term and recent changes in the fisheries for smelt in the eastern Gulf of Finland, including both commercial and recreational fisheries, and the range of fishing gears used. The commercial smelt fishery is mainly conducted during the spawning period (April–May) on migrating fish, using trap nets of various designs and beach seines. There has been an increase in recreational fisheries for smelt; in years when ice cover on the gulf during winter (December–April) is steady, recreational fishers from St. Petersburg, using hook and line, may catch quantities that are comparable to those of commercial catches. Several factors may account for the stock dynamics and associated changes in catches of smelt: these include a decrease in prey availability in the gulf; loss and degradation of spawning and nursery habitats, partly associated with large-scale hydroengineering operations in Neva Bay; and illegal, unreported and unregulated (IUU) fishing which became widespread in post-Soviet decades. In spite of a gradual increase in smelt abundance in the most recent 15 years, a failure to accurately monitor and manage the extent of IUU and recreational fishing for smelt, to assess the status of the stock, or to forecast catches, increases the risk of overfishing of the spawning stock.     

Ostracoda as bioindicators of anthropogenic impact in salt lakes,saltpans, and a lagoon: A case study from the Gulf of Saros coast (NE Aegean Sea), Turkey

The study area consists of wetlands and semi-wetlands (saltpan and salt lakes) that are separated from the Gulf of Saros in the northeastern Aegean Sea by a littoral cordon. Twenty-four samples were collected from the Enez Salt Lake; Dalyan, Enez Gala, Kuvalak, Isik, and Tasalti Lakes; Vakif and Erikli Saltpans; and Karagol Lagoon. The overall distribution of the sediment sizes reveals that they consist predominantly of mud and sand and a mixture of mud, sand, and gravel. The average proportion of gravel size particles is 8.36%. Feldspar and mica are abundant in sand and gravel-sized materials. Ecological conditions of these coastal areas were assessed on the basis of ostracod assemblages that can be considered as useful bioindicators and depend on water depth, temperature, and salinity. In this context, the effects of physical and chemical properties of the environment, geochemistry of the sediment, and anthropogenic impact on the meiofauna, in particular ostracoda, was here evaluated. Cyprideis torosa Jones, a cosmopolitan species of ostracoda, was found in salt lakes. Other species of ostracoda were shown to be affected by environmental conditions. The toxicity of some heavy metals in the saltpans, salt lakes, and hypersaline lagoons was evaluated. Lake Dalyan and Erikli Saltpan display high toxicity for Cu and Cd levels. The distribution of hydrocarbon pollution of terrestrial origin was determined.     

Maeropsis paphavasitae and Rotomelita longipropoda,two new species (Crustacea,Amphipoda) from?Lower?Gulf of Thailand

Two new species of maerid and melitid Amphipoda, Maeropsis paphavasitae and Rotomelita longipropoda, respectively, collected from a seagrassbed of the Lower Gulf of Thailand, are described. Maeropsis paphavasitae is characterized by it seven teeth on the palm of gnathopod 2 and Rotomelita longipropoda can be recognized by its long gnathopod 1 propodus. Their characters are described and illustrated. All specimens are deposited at Princess Maha Chakri Sirindhorn Natural History Museum, Prince of Songkla University, Thailand and the Museum für Naturkunde, Berlin.     

The biogeography of land snails in the islands of the Gulf of Guinea

Data on land snail diversity in the Gulf of Guinea islands is presented and the biogeography of the Gulf of Guinea fauna is discussed with reference to island snail faunas in the other areas of the world. Although the land snail faunas of the four islands clearly have west and central African affinities, speciation events following rare colonizations have led to high rates of endemism at the species and generic levels. The influence of island size, altitude, isolation and other factors on the development of the land snail faunas is discussed. The effect of land use changes on the land snail fauna over the last 150 years is evaluated. Current threats include recent changes in agricultural practice leading to the destruction of snail habitats in both forest and plantation areas. The potential threat posed by introduced species is also discussed. The Gulf of Guinea snail faunas appear to be in relatively good health in comparison to many other island snail faunas. However, the uniqueness of the faunas makes it imperative that further ecological and taxonomic research is undertaken both to understand the processes by which they developed and to evaluate the current status of many species in terms of distribution and threats.     

Introduced mammals in São Tomé and Príncipe: possible threats to biodiversity

Since São Tomé and Príncipe were colonized by Europeans in the 1470s alien mammal species have been introduced to these islands. The impact of these introduced species (14 to São Tomé Príncipe and 12 to Príncipe) is unknown and though this paper reviews all the available information for each alien species no firm conclusions can be gleaned about their effect on the native biota of the República Democrática de São Tomé e Príncipe. Despite the probable long association of many, if not all, the alien mammals it is clear that the long history of deforestation and habitat modification has had a greater detrimental impact to date. Although all the Red Data Book species are still present it is possible that the introduced mammals could cause future population declines and extinctions. Research and surveys are urgently required to discover the current status, distribution and ecology of both the native Red Data Book species and the alien species. These surveys, in conjunction with the identification of core areas for conservation would allow active management to control any detrimental impacts likely to be caused by the alien mammals. Once identified, regular monitoring programmes should be undertaken to ensure that the conservation aims are being achieved. At present there is a lack of any really suitable institutional organization with the responsibility or skills to undertake the required work. The development of such an organization should be a priority and support should be given both in the short and long terms by international organizations such as Birdlife International and the Gulf of Guinea Conservation Group.     

Phytoplankton Spring Bloom Intensity Index for the Baltic Sea Estimated for the years 1992 to 2004

We introduce an index for estimating the annual phytoplankton spring bloom intensity in the Baltic Sea. It is based on chlorophyll a estimates calculated from automatically sampled fluorescence and chlorophyll a measurements on board cargo ships from 1992 to 2004. The intensity is described by an index including information on the chlorophyll a concentration and duration of the spring bloom period. In all of the years studied, the spring bloom was most intense in the Gulf of Finland. In the Gulf of Finland and the Northern Baltic Proper there was a slight tendency for the bloom to start earlier in the spring.