Taxonomy of Middle Miocene foraminifera from the northern Namibian continental shelf

Middle Miocene foraminifera from the northern Namibian outer continental shelf are indicators of a period prior to the initiation of the Benguela Upwelling System (BUS). This study provides an update to the occurrence and taxonomy of Miocene foraminifera from the continental margin of Namibia. The taxonomy of 51 benthic and 12 planktic foraminiferal species from the northern Namibian shelf are discussed, their stratigraphic significance given, and their ecological preferences and regional distribution summarised within this study. The identification of extinct planktic foraminifera provided key stratigraphic control for the middle Miocene strata of this region. The taxa identified in this study provide a distinct and different assemblage to the overlying younger strata. Many of the species recorded in this study have not been identified in the region and are reported for the first time from the middle Miocene on the southwestern continental shelf of Africa, off Namibia. A total of 47 species are identified and discussed for the first time from this region. Nineteen species recorded in this study are extinct and eleven taxa reported here have previously only been reported on the genus level on the southwestern shelf of South Africa. Seven benthic species (Amphicoryna scalaris, Marginulina obesa, Glandulina laevigata, Globocassidulina subglobosa, Uvigerina peregrina, Sphaeroidina bulloides and Melonis affinis) and two planktic species (Globigerina bulloides and Orbulina universa) did not disappear from the regional stratigraphy and continued to occur in Plio-Pleistocene to Recent sediments along the southwestern continental shelf of Africa.

Estuarine Infauna Within Incidentally Retained Sediment in Artificial Rockpools

Artificial coastal structures (ACSs) are primarily designed to provide services for human use, such as flood defence or shipping, and are generally poor for marine biodiversity. Consequently, there has been significant research effort to enhance these hard structures to increase biodiversity and habitat availability via eco-engineering. On seawalls and breakwaters, this has included the creation of habitats for benthic species found on natural rocky shores, including the provision of cracks, crevices and water retaining features, such as artificial rockpools. When sediment retention in these features has occurred, it has often been deemed detrimental to the overarching aim of the intervention. Yet, it is soft sediment habitat that is impacted the most through coastal construction. As ecological enhancement of a flood defence scheme, nine concrete retrofit rockpools were installed at three different tidal elevations between mean high water neap tide and mean tide level on steel sheet piling on the Arun Estuary in Littlehampton Harbour, United Kingdom, which naturally filled with mud 1 year after installation. To explore how analogous the faunal assemblages and sediment profile of rockpool mud were to two local mudflats, core samples were taken and analysed for species richness, abundance, biomass, assemblage structure, median grain size, and organic matter content. More benthic species were observed in the artificial rockpool than in the local mudflats. Although the rockpools were placed at higher tidal levels than the lower shore mudflat, their assemblage structure and species richness were more similar to the lower shore mudflat at the base of the sheet piling than the upper shore mudflat. This study demonstrates that retained sediment within eco-engineered features on hard ACSs can create habitat for benthic assemblages. Providing sediment-retentive features on ACSs has the potential to provide a novel eco-engineering option that may be appropriate for some heavily modified waterbodies on sheltered, depositional coasts.

Species Sensitivity Distributions of Benthic Macroinvertebrates in Fludioxonil-Spiked Sediment Toxicity Tests

In China, the fungicide fludioxonil, that accumulates and persists in sediments, has a widespread agricultural use to control various fungal diseases. Its residues may cause toxic effects to benthic aquatic fauna, thereby impacting ecosystem service functions of aquatic ecosystems. To assess the potential environmental effects of fludioxonil in the sediment compartment of edge-of-field surface waters, sediment-spiked single-species toxicity tests with benthic macroinvertebrates were performed. In all experiments artificial sediment was used with an organic carbon content of 2.43% on dry weight basis. The single-species tests were conducted with 8 benthic macroinvertebrates covering different taxonomic groups typical for the Yangtze River Delta, China. The 28d-EC10 and 28-LC10 values thus obtained were used to construct species sensitivity distributions (SSDs). In addition, our data were supplemented with similar fludioxonil-spiked sediment toxicity data for benthic invertebrates from the Netherlands. Based on SSDs constructed with 28d-EC10 values of 8 benthic species from our experiments in China, hazardous concentrations to 5% of the species tested (HC5’s) of respectively 0.57 mg fludioxonil/kg dry weight sediment and 5.4 µg fludioxonil/L pore water were obtained. Supplementing our data from China with 8 similar toxicity data for other benthic species from the Netherlands, these HC5 values became respectively 1.2 mg fludioxonil/kg dry weight sediment and 11 µg fludioxonil/L pore water.

Shifts in Estuarine Macroinvertebrate Communities Associated With Water Quality and Climate Change

The present work aims to identify changes in the macroinvertebrate community of the Tagus estuary (Portugal) due to improvements in water quality and to climate change. Data was collected over a period of 16 years (1998–2014) from different sites located along the estuarine gradient. The AZTI Marine Biotic Index (AMBI) was used to assess the ecological quality status based on benthic invertebrate communities and identify possible variations associated with changes in water quality. The overall distribution of each species was examined to detect possible changes associated with climate, based on species’ affinity for more temperate or subtropical climates. Results demonstrate that there was an overall improvement of AMBI scores during the assessment period. The analysis of the geographical distribution of benthic species seems to indicate that there has been an increase of species which prefer subtropical climates in the shallower waters of the estuary, whereas in the deeper estuarine sections the propensity is for species that prefer temperate climates.

Environmental cycles and individual variation in the vertical movements of a benthic elasmobranch

Trends in depth and vertical activity reflect the behaviour, habitat use and habitat preferences of marine organisms. However, among elasmobranchs, research has focused heavily on pelagic sharks, while the vertical movements of benthic elasmobranchs, such as skate (Rajidae), remain understudied. In this study, the vertical movements of the Critically Endangered flapper skate (Dipturus intermedius) were investigated using archival depth data collected at 2 min intervals from 21 individuals off the west coast of Scotland (56.5°N, −5.5°W) in 2016–17. Depth records comprised nearly four million observations and included eight time series longer than 1 year, forming one of the most comprehensive datasets collected on the movement of any skate to date. Additive modelling and functional data analysis were used to investigate vertical movements in relation to environmental cycles and individual characteristics. Vertical movements were dominated by individual variation but included prolonged periods of limited activity and more extensive movements that were associated with tidal, diel, lunar and seasonal cycles. Diel patterns were strongest, with irregular but frequent movements into shallower water at night, especially in autumn and winter. This research strengthens the evidence for vertical movements in relation to environmental cycles in benthic species and demonstrates a widely applicable flexible regression framework for movement research that recognises the importance of both individual-specific and group-level variation.

The Marine Benthic Algal Flora of Puerto Rico, I. Ochrophyta: Phaeophyceae, Pelagophyceae, and Xanthophyceae

This treatment is a taxonomic study of the benthic species of Ochrophyta known from Puerto Rico, Caribbean Sea. In all, 3 classes, 10 orders, 16 families, 33 genera, and 77 species occur in the benthic marine communities in Puerto Rico. Of these, three species of <i>Sargassum </i>are found only as unattached and free-floating. A brief summary of phycological studies in Puerto Rico and ecological descriptions of the most common marine habitats are presented. Along with date, place, and author(s) of valid publication for all genera and species, type locality information and descriptive accounts of vegetative morphological and reproductive anatomy are provided. Distribution of each species is given, and where relevant, comments on their habitat and their taxonomic and nomenclatural status are discussed. A key to the genera and keys to species within genera are included. Either an in situ or other illustration accompanies most species. Two new geographical distribution records for Puerto Rico and a description of one new species, <i>Lobophora brooksii</i> D. L. Ballant. et J. N. Norris, are included. <br>

Improving the Efficiency of Lambari Production and Diet Assimilation Using Integrated Aquaculture with Benthic Species

A single farmed fish species assimilates about 20% of the nutrients in the supplied diet. This study evaluated if the culture of complementary ecological-function species can recover nutrients dispersed into water and transform them into high-valued biomass. A completely randomized experiment was designed with three treatments and four replications of each production system: monoculture of lambari (Astyanax lacustris); integrated aquaculture of lambari and Amazon river prawn (Macrobrachium amazonicum); and integrated aquaculture of lambari, Amazon river prawn, and curimbatá (Prochilodus lineatus). Fingerlings of lambari (0.8 ± 0.8 g) were stocked in twelve earthen-ponds (0.015 ha) at the density of 50 fish m−2. Eight ponds were stocked with juveniles of Amazon river prawn (1.1 ± 0.2 g) at the density of 25 prawn m−2. Four of these eight ponds were stocked with curimbatá fingerlings (0.2 ± 0.1 g) at a density of 13 fish m−2. Only lambari was fed twice a day with an extruded commercial diet. The experiment lasted 60 days when lambari attained commercial size. The inclusion of prawn increased the total species yield from 1.8 to 2.4 t ha−1 cycle−1 and reduced the feed conversion ratio (FCR) from 2.5 to 1.8. The inclusion of prawn and curimbatá increased the total yield to 3.2 t ha−1 cycle−1 and reduced the FCR to 1.4. Therefore, the integrated culture of lambari, prawn, and curimbatá improves the use of space, water, feed, and benthic species to recover the large quantity of nutrients accumulated in the bottom of lambari pond production, converting them into high-nutritional and monetary-valued biomass.

Improving the Efficiency of Lambari Production and Diet Assimilation Using Integrated Aquaculture With Benthic Species

A single farmed fish species assimilates about 20% of the nutrients in the supplied diet. This study evaluated if the culture of complementary ecological-function species can recover nutrients dispersed into the water and transform them into high-valued biomass. A completely randomized experiment was designed with three treatments and four replications of each production system: monoculture of lambari (Astyanax lacustris); integrated aquaculture of lambari and Amazon river prawn (Macrobrachium amazonicum); and integrated aquaculture of lambari, Amazon river prawn, and curimbat&aacute; (Prochilodus lineatus). Fingerlings of lambari (0.8 &plusmn; 0.8 g) were stocked in twelve earthen-ponds (0.015 ha) at the density of 50 fish m-2. Eight ponds, were stocked with juveniles of Amazon river prawn (1.1 &plusmn; 0.2 g) at the density of 25 prawn m&minus;2. Four of these eight ponds were stocked with curimbat&aacute; fingerlings (0.2 &plusmn; 0.1 g) at a density of 13 fish m-&sup2;. Only lambari was fed twice a day with an extruded commercial diet. The experiment lasted 60 days when lambari attained commercial size. The inclusion of prawn increased the total species yield from 1.8 to 2.4 t ha-1 cycle-1 and reduced the feed conversion ratio (FCR) from 2.5 to 1.8. The inclusion of prawn and curimbat&aacute; increased the total yield to 3.2 t ha-1 cycle-1 and reduced the FCR to 1.4. Therefore, the integrated culture of lambari, prawn, and curimbat&aacute; improves the use of space, water, feed, and benthic species can recover the large quantity of nutrients accumulated in the bottom of lambari pond production, converting them into high-nutritional and monetary-valued biomass.