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Sediments are habitats and major sources of nutrients for benthic organisms. High concentration of pollutants can impact negatively on the lives of such organisms and ultimately on the lives of human beings who may feed on them. This study was carried out in order to evaluate some environmental pollutants’ load: heavy metals and pesticide residues in Irintan, Omi-Eye and Egbigbu river sediments in Ekiti State, Southwest Nigeria. Sediment samples were taken at upper, middle and lower courses of each river relative to the farm used for the study. The samples were air-dried in the laboratory, disaggregated, sieved and analysed for heavy metals and organochlorine pesticides (OCP) residues using standard methods. The heavy metal range at floodplains (mg/kg) was: Cr (0.25-2.08), Cu (0.19-14.28), Zn (BDL-2.53), Cd (BDL-0.87), Pb (BDL-0.32), Fe (0.38-22.35) while for OCP residues, the range (µg/kg) was α-BHC (0.15-0.33), β-BHC (0.19-14.28), ẟ-BHC (0.25-1.09), lindane (BDL-1.23), chlorothalonil (0.87-1.44), heptachlor (BDL-1.04), heptachlor epoxide (BDL-1.96), endosulfan I (0.20-1.98), endosulfan II (BDL-0.67), aldrin (BDL-1.93), endrin (BDL-0.37), dieldrin (BDL-0.42), p,p-DDE (BDL-0.52), p,p-DDT (BDL-1.20), methoxychlor (0.21-0.88). The pollutants’ concentrations in the sediments were generally low at all the sites when compared with international guidelines for each pollutant. Governments in Nigeria should checkmate indiscriminate dumping of refuse most of which end in our rivers in order to reduce pollutants’ concentration in rivers/sediments so as to protect the lives of benthic organisms.

Abstract It is estimated that up to half of global methane (CH4) emissions are derived from microbial processes in aquatic ecosystems. However, it is not fully understood which factors explain the spatial and temporal variability of these emissions. For example, light has previously been shown to both inhibit and stimulate aerobic methane‐oxidizing bacteria (i.e., methanotrophs) in the water column. These contrasting results indicate that the mechanisms that light has on CH4 oxidation are not yet clearly known, even less so for benthic aerobic methanotrophs. Here, we tested whether light reaching the seafloor can inhibit methanotrophic activity on the sediment surface. We sampled and distributed over 40 intact sediment cores from two coastal sites (illuminated 10 m, and a dark site at 33 m water depth) into 0, 50, and 100 PAR light treatments. After 10 days, we found no difference between treatments for each site in pore‐water CH4 concentrations, relative abundance of aerobic methanotrophs, or the number of RNA transcripts related to methane oxidation. Our results suggest that light attenuation in coastal waters does not significantly affect aerobic methanotrophs in coastal sediments.

Summary: Coral reefs underpin the environmental, social, and economic fabrics of much of the world's tropical coast. Yet, the fine-scale distribution and composition of coral reefs have never been reported consistently across the planet. Here, we present new area estimates enabled by global geomorphic zone and benthic substrate maps at 5 m pixel resolution. We revise global coral reef estimates to 348,361 km2 of shallow coral reefs and 80,213 km2 (46,237–106,319 km2, 95% confidence interval) of coral habitat. The mapping used more than 1.5 million training samples supported by 480+ data contributions to deploy a coral reef classification of over 100 trillion pixels from the Sentinel-2 satellites and the Planet Dove CubeSat constellation. The publicly available maps are accessible via the Allen Coral Atlas and Google Earth Engine and are already being used by thousands of people to improve the conservation, management, and research of coral reef ecosystems. Science for society: Coral reefs possess a quarter of all marine life and contribute to the well-being and livelihoods of a billion people worldwide. Maps of ecosystems underpin many science and conservation activities, but until recently, there were no consistent high-resolution maps of the world’s coral reefs. In this paper, we describe new global coral reef maps from the Allen Coral Atlas, detailing the underlying methodology and our new understanding of the global distribution of coral reefs. The transparent and repeatable nature of our mapping framework allows the maps to be updated based on user feedback, and the ease of access has led to downstream applications such as coral bleaching monitoring and usage in scientific, management, and conservation activities. Hundreds of thousands of people have already accessed the maps, and they are already being used directly around the world for marine spatial planning, marine protected areas, environmental accounting and assessments, restoration, and education.

IntroductionThe Arctic sea ice extent in September (when it is at its lowest) has declined 13% Q10 per decade, and the Arctic Ocean is becoming a more Atlantic-influenced system. Rapid climate-forced changes are taking place in many high-latitude marine ecosystems. The Barents Sea is one such high-latitude shelf ecosystem, between approximately 70° and 80°N in the Norwegian Arctic. The purpose of the current study was to estimate zoobenthic blue carbon across multiple habitats within the Barents Sea (trough, basin, shelf, and shallows), potentially providing values to aid ecosystem-based management of these areas under future climate change scenarios.MethodWe tested this by capture and analysis of 947 high-resolution (each 405.7 × 340.6 mm, 12 MB, 5 megapixels) seabed images at 17 sites with latitudinal cline, linked to a collection of corresponding oceanographic data. Biotas within these images were identified to one of the 14 functional groups and the density was calculated. Mean stored carbon per individual was assigned by ash mass (AM) and ash-free dry mass (AFDM) of individuals caught within Agassiz trawl deployments at the same sites.ResultsTrough sites, except for one site (B16), have a low quantity of zoobenthic blue carbon compared with the shallow, shelf, and basin habitats.DiscussionThe results of a previous study focused entirely on trough habitats and are therefore difficult to scale up as the basis for a meaningful estimate of across-habitat zoobenthic blue carbon in the Barents Sea. Compared with the trough and the basin, the shelf and shallow habitats of the Barents Sea are also subjected to more trawling events through demersal fisheries and showed higher zoobenthic blue carbon stock values.

Abstract Marine biodiversity consists of a complex network of organisms responsible for keeping the ecosystem's balance. Fungi are an understudied group of organisms despite their recognized importance for ecosystem processes and diversity. How fungi respond to environmental change remains poorly understood, especially in marine benthic habitats. The Baltic Sea is a brackish coastal ecosystem with steep environmental gradients in a relatively limited geographical area and is therefore a particularly good system to investigate the impact of different abiotic factors on benthic fungal diversity. This study used environmental DNA (eDNA) metabarcoding to analyze the spatial dynamics of benthic fungal diversity in the Baltic Sea and quantify the environmental drivers that shape these dynamics. Based on 59 stations spreading over 1145 km the results showed that benthic fungal communities were dominated by the phylum Chytridiomycota, and the fungal species Alphamyces chaetifer and Operculomyces laminatus from this phylum were the main drivers of the community structure dissimilarities observed between regions. Water depth and salinity were the main predictors of the benthic fungal community composition. The impact of nutrient availability was also significant, possibly related to the known role of Chytridiomycota species such as A. chaetifer and O. laminatus in nutrient cycling. Our results indicate that the benthic fungal diversity of the Baltic Sea is shaped by salinity gradients and nutrient availability and highlights that the current fungal biodiversity is at risk of species shift or decline with predicted changes in salinity due to climate change and intensified eutrophication.

Holohalaelurus regani and Scyliorhinus capensis are relatively small catsharks, which both occur off the continental shelf around South Africa and are often caught together as by‐catch in demersal trawls. The present study used data collected during annual demersal research surveys conducted between 2009 and 2015 and is a first attempt at modeling the potential intra‐ and interspecific associations, by maturity stage and depth, of H. regani and S. capensis to elucidate species‐specific patterns in their distributions in South African waters. Intraspecifically, both species displayed a wide overlap in distribution between maturity stages, but only H. regani displayed marked changes in distribution with maturity stage, with mature individuals found further eastwards and occupying deeper waters than immature individuals. Interspecifically, the two catsharks displayed an inverse relationship in their distribution, with an increase in the abundance of H. regani and a decrease in the abundance of S. capensis when moving from the south coast to the west coast. Some localized patches of co‐occurrence were, however, evident between species and maturity stages, especially in offshore areas. Overall, our results indicated a stronger co‐occurrence of mature and immature stages within each species and a rather weak co‐occurrence of maturity stages between the two species. The spatial information provided in the present study provides useful information on how sharks with similar morphologies and lifestyles may partition their habitat as a mechanism for potentially reducing competition between them. [ABSTRACT FROM AUTHOR]

The present research is a comparative study on the prevalence of parasites in marine finfish among the two major marine zones; namely the pelagic zone and benthic zone. The objectives of the present study were to investigate the parasite prevalence in both zones, as well as to determine the effect of differing marine zones regarding the presence of parasites in fish. A total of 30 individual fish occurring in pelagic and benthic zones were randomly selected from three different fishmongers at a wet market in Bintulu, Sarawak. Both the gill and stomach content of the samples were examined to detect the presence of parasites. Nematodes and trematodes were observed in the intestinal tract of the fish, Cymothoa exigua was found attached to the fish tongue, and monogenean parasites were also detected on the gills. The prevalence of the parasite was roughly equal in Setipinna breviceps, Ilisha megaloptera, and Selaroides leptolepis. The highest prevalence of parasites (87.50%) from fish in the benthic zone based on fish size was for fish measuring between 20.1 - 30.00 cm in total length (P-value=0.3778), whereas for pelagic fish, the highest prevalence of parasites (100%) in fish measurements of 30.1 - 40.0 cm in total length (P-value=0.0044). A major factor for the diversity of marine fish parasites occurring in the different zones is the difference in feeding behavior of the hosts and depth distribution which resulted in low or high rates of parasite infestation. [ABSTRACT FROM AUTHOR]

Seagrass is the most common ecosystem in Tanjung Berakit waters. Therefore, Tanjung Berakit waters have a very important role as a benthic foraminiferal habitat. This study was conducted to describe the distribution of benthic foraminifera relating to the environmental condition of the waters. The samples were collected from eight stations by handling garb in November 2017. This study collected 18 species of shallow water benthic foraminifera dominated by Amphistegina and Heterostegina. This study recorded a correlation between the sediment texture and foraminiferal assemblages. The most common foraminifera were inhabiting fine-textured sediments, especially very fine sand and silt. Only a few foraminifers are collected from extremely fine sediments such as clay sediments, or extremely coarse including pebbles. [ABSTRACT FROM AUTHOR]

Eoandromeda octobrachiata is a poorly understood Ediacaran organism, with spiral octoradial arms, found in South Australia and South China. The informal Nilpena member of the Rawnsley Quartzite, Flinders Ranges in South Australia preserves more than 200 specimens of Eoandromeda. Here we use the novel application of rotational geometric morphometrics together with palaeoenvironmental information to provide a better insight into their palaeobiology and ecology, and to address conflicting hypotheses regarding mode of life and taxonomic affinity. We find that Eoandromeda probably had a radially symmetrical shape in life, was cone shaped and had a high relief off the microbial mat. Analysis of the symmetric and asymmetric shape components showed that they deform strongly in the direction of palaeocurrent, therefore they are thought to be made of a flexible material. Almost all specimens are compressed flat. Specimens that appear to have not fully collapsed support the idea that Eoandromeda was probably cone shaped and suggest that they possibly collapsed spirally. Our shape analysis, along with observed morphological features, support a benthic rather than pelagic mode of life. Morphological and ecological inconsistencies do not fully support the hypothesis of a Ctenophora taxonomic affinity. [ABSTRACT FROM AUTHOR]

The east basin of Lake Erie continues to suffer from blooms of filamentous green algae (primarily Cladophora). Potential management action through reduced phosphorus loadings have and continue to focus on the dissolved inorganic phosphorus pool but other potentially bioavailable phosphorus pools are not always considered. In this study, we describe the dissolved organic phosphorus pool in eastern Lake Erie, with an extensive sampling of four transects along the north shore of the eastern basin from May to September 2019. The dissolved organic phosphorus pool was characterized and quantified using sequential enzymatic hydrolysis to provide information on the enzymatically hydrolysable phosphorus fraction and component monoester P, diester P and a phytase hydrolysable component. These dissolved organic phosphorus fractions were compared to the soluble reactive phosphorus and total dissolved phosphorus pools. Results from this study revealed that a significant fraction (up to 63%) of the dissolved organic phosphorus pool is potentially bioavailable via enzymatic hydrolysis. Vertical differences in soluble reactive phosphorus, total dissolved phosphorus, and phosphate diester pools were also observed when comparing water column with near lake-bed samples, suggesting that the new benthic ecosystem since dreissenid colonization may be a greater source of dissolved inorganic phosphorus to the east basin than prior to colonization. [ABSTRACT FROM AUTHOR]

Concentrations of mercury in sediment and benthic invertebrate fauna of Nissum Broad, North-western Jutland, Denmark were investigated. The western coast of Nissum Broad is Harboøre Tange, along which heavy mercury contamination - caused by discharge from production of mercury containing seed dressers in the 1950 and 1960s – was documented in the 1980s. Recent investigations showed marked decreases in mercury contamination in the near shore sediments along Harboøre Tange since the 1980s and the present investigation was initiated to learn if the loss of mercury from Harboøre Tange had led to an increased mercury contamination in the neighbouring marine area, Nissum Broad. Mercury concentrations in the surface sediment correlated with the content of organic matter and the slope of the regression is a good indicator for the degree of mercury contamination. Average mercury concentrations in the upper 5 cm of the sediments ranged between 0.9 and 71 ng g− 1 dry weight (dw) with only 1 station exceeding the Background Assessment Concentration of 70 ng g− 1 dw. Average mercury concentrations in blue mussels Mytilus edulis (169–260 ng g− 1 dw) and periwinkles Littorina littorea (66–203 ng g− 1 dw) exceeded those in uncontaminated areas and the Environmental Quality Standard of approximately 100 ng g− 1 dw. Present sediment mercury concentrations in Nissum Broad are approximately half of what they were in the 1980s, rendering it unlikely that mercury lost from Harboøre Tange has been deposited there. Sediment and organism concentrations did not show any correlation. [ABSTRACT FROM AUTHOR]

ABSTRACTAdvances in sonar technology have revolutionized our ability to map the seafloor, however, differences between legacy and modern data pose challenges when analysing multi-source datasets. Acoustic backscatter recorded via multibeam echosounder is commonly used to characterize the seafloor, but a lack of standardized calibration often yields relative rather than absolute backscatter measurements, hindering comparison between surveys. ‘Bulk shift’ methods have been developed for harmonizing legacy backscatter datasets using overlapping survey areas for relative statistical calibration. This becomes increasingly difficult, though, given many datasets collected over extensive time periods. Backscatter data were collected in the Bay of Fundy, Canada, using multiple sonar systems and vessels over an 18-year period. Here, we propose a reproduceable strategy for harmonizing this large volume of disparate backscatter data using the bulk shift method. A final, harmonized map is presented for the entire Bay of Fundy and is validated using in situ observations from seafloor imagery.

Habitat type and grazing are key factors controlling benthic diatom communities. Nonetheless, the strength of grazing may depend on the habitat complexity at fine (substratum roughness) and meso scales (mesohabitat type). The interaction between grazers and physical conditions may thus be an important factor shaping benthic diatom communities. Several investigations have evaluated how habitat type, grazing and substratum roughness separately affect the biomass, species richness and community structure of algal communities. However, how these factors act together remains poorly understood, particularly for sets of common and rare species. The latter is important for understanding whether common and rare species are affected differently by environmental filters at the local scale.We investigated the effects of mesohabitat type, grazer occurrence and substratum roughness as well as their interactions on benthic diatom communities in a split‐split‐plot field experiment consisting of hierarchical treatments: (i) mesohabitat (pools and riffles); (ii) grazer occurrence (presence or absence of grazers >1 cm in size); and (iii) substratum roughness (smooth and rough substrata). We analysed the entire community and also datasets of common and rare species. Here, we define common and rare species based on their abundance–occupancy relationships, with rare species presenting low mean abundance per experimental unit (between 0.025 and 8.2) and low occupancy (between 2.5% and 25%).Substratum roughness was the main factor explaining differences in species richness, with higher species richness found on rough than on smooth substrata for both the complete dataset and for common and rare species. There was evidence that the interactions between mesohabitat and grazer occurrence and between mesohabitat and substratum roughness affected community structure (relative abundances) for the complete dataset and for common species, whereas the three‐way interaction between mesohabitat, grazer and substratum roughness affected community structure of rare species.Our findings emphasise that crevices are important microhabitats that allow the establishment of both common and rare species. Furthermore, our results suggest that physical differences between mesohabitats influenced the effect of grazers on the community structure of common and rare species. For common species, the effects of this interaction were difficult to depict, but we found a change in the second‐most‐common species between mesohabitats and depending on the occurrence of grazers. For rare species, grazers more clearly affected community structure on smooth substrata in riffles than in pools.Our results demonstrate that local patterns of common and rare diatom species resulted from distinct combinations of the evaluated environmental filters. Together, our results highlight how multifactorial field experiments are key to understanding the main environmental filters driving the species richness and community structure of benthic diatom communities. [ABSTRACT FROM AUTHOR]

The frequency of dogs becoming ill or dying from accidental exposure to cyanotoxins, produced by cyanobacteria, is increasing throughout the United States. In January and February of 2021, two dogs died and five dogs became ill after swimming in Lake Travis, central Texas, USA; one deceased dog (C1) was subjected to pathological testing. Algal materials, sediment samples, zebra mussel viscera, periphyton from shells, as well as fluids and tissues from the digestive tract of C1 were investigated for the following cyanotoxins: anatoxin-a, homoanatoxin-a, dihydroanatoxin-a (dhATX), cylindrospermopsin, saxitoxin, and microcystins. Necropsy results of C1 indicated neurotoxicosis with significant levels of dhATX in the duodenum tissues (10.51 ng/g dry weight (DW)), jejunum tissue (6.076 ng/g DW), and stomach contents (974.88 ng/g DW). Algae collected near the site of C1's death contained levels of dhATX, ranging from 13 to 33 µg/g. By comparison, dhATX was detected at much lower concentrations in sediment samples (310.23 ng/g DW) and the periphyton on zebra mussel shells (38.45 ng/g DW). While dhATX was suspected in the deaths of canines from an event in Texas in 2019, this is the first report linking dhATX neurotoxicosis through pathological findings in Texas and potentially in the United States. [ABSTRACT FROM AUTHOR]

Cyanobacteria are favored by climate change and global warming; however, to date, most research and monitoring programs have focused on planktic cyanobacteria. Benthic cyanobacteria blooms also increase and pose a risk to animal and human health; however, there is limited knowledge of their occurrence, distribution and the toxins involved, especially in relation to their planktic conspecifics. Therefore, we analyzed the benthic and planktic life forms of cyanobacterial communities in 34 lakes in Germany, including a monitoring of cyanotoxins. Community analyses were based on microscopic examination and Illumina sequencing of the 16S rRNA gene. The analyses of cyanotoxins were carried out using LC-MS/MS and ELISA. Observed benthic mats containing cyanobacteria consisted mainly of Nostocales and Oscillatoriales, being present in 35% of the lakes. Anatoxin was the most abundant cyanotoxin in the benthic samples, reaching maximum concentrations of 45,000 µg/L, whereas microcystin was the predominate cyanotoxin in the open-water samples, reaching concentrations of up to 18,000 µg/L. Based on the results, specific lakes at risk of toxic cyanobacteria could be identified. Our findings suggest that monitoring of benthic cyanobacteria and their toxins should receive greater attention, ideally complementing existing open-water sampling programs with little additional effort. [ABSTRACT FROM AUTHOR]

Two new marine sand-dwelling dinoflagellate species from subtidal sand collected in Peter the Great Bay, Sea of Japan, were described by morphological and molecular methods. Both species were slightly flattened dorsoventrally or laterally, roughly oval in shape, with small epitheca and large hypotheca, with ascending cingulum, and sulcus covered by a wide list of the first postcingular plate. The species differed in the thecal ornamentation, the number of epithecal plates, the shape of the left sulcal list and the shape of the fifth postcingular plate. Phylogenetic reconstructions based on LSU rDNA sequences of the two new species and their morphological characters confirmed their monophyly and justified the establishment of a new genus, Aliferia gen. nov., with Al. nikselinii sp. nov. and Al. kharlamenkoi sp. nov. The new genus was characterized by dorsoventrally or laterally flattened cells with small epitheca and large hypotheca, ascending cingulum, shifted or not shifted sulcus covered by a wide list on the left side, and with one or two ventral spines. Thecal tabulation: APC 3′ 2a 6–7′′ 2? or 3c 5s 5′′′ 1′′′′. Distance-based analyses indicated Diplopsalidoideae as the closest phylogroup to Aliferia. Seven phylogroups of the Amphidiniopsis complex, Herdmania, the Protoperidinium complex, and Archaeperidinium (Clade 'Y') were grouped with the highest support values, and Aliferia formed an independent branch basal to members of Clade 'Y'. The genus Aliferia showed morphological similarity to both sand-dwelling (Amphidiniopsis and Herdmania) and planktonic (Diplopsalidoideae) species. The morphology and phylogeny of Aliferia suggested complex taxonomic relationships between the planktonic and benthic genera. [ABSTRACT FROM AUTHOR]

In recent decades, monitoring of benthic fauna in Albanian rivers is an important environmental component at a time when their flow and watershed area have been greatly modified by anthropogenic influences. Given the importance of these organisms in aquatic bio-ecological studies defined in the EU (European Union) directive, this study completes the taxonomic panorama of studies in the main rivers of our country. This research was conducted in a period from 2007 to 2019 aimed to give an overall assessment of the EPT group (Ephemeroptera-Plecoptera-Trichoptera) of benthic macro-invertebrates distributed in the seven rivers of Albania, namely: Drin, Mat, Shkumbin, Osum, Devoll, Drinos and the Shushica-Vlora River. The collection of the benthic macro invertebrates was realized by using the Kick-net sampling methodology (rectangular net, 500 micron mesh). A total of 33 stations with different ecological and geophysical typologies have been selected in all rivers. Using the Kick-net sampling a total of 8154 specimens' representatives of 28 families were collected. Caddisflies, or Trichoptera order, were dominant both in number of species (8 species) and in abundance (74.3% of all individuals). Meanwhile Mayflies (Ephemeroptera) and Stoneflies (Plecoptera) contributed much less to species richness and abundance. The presence of 20 EPT families of macro-invertebrates in the the Shushica River study testifies the highest degree of biodiversity. The river with the lowest diversity of EPT species represents (8 families) is the Drini River. Representatives of 28 insect families collected with Kick-net were: Ephemerellidae, Baetidae, Heptagenidae, Caenidae, Oligoneuridae, Potamanthidae, Ephemeridae, Isonychidae, Leptophlebiidae, Siphlonuridae, Leuctridae, Perlodidae, Perlidae, Chloroperlidae, Nemuridae, Capniidae, Brachycentridae, Hydropsychidae, Hydroptilidae, Glossosomatidae, Philopotamidae, Rhyacophilidae, Beraeidae, Leptoceridae, Polycentropidae, Helicopsychidae, Sericostomatidae, and Goeridae. We can conclude that taxonomic panorama of the main rivers of our country is represented by small differences of taxon diversity between the rivers in the northern, middle and southern part of our country. The changes are not only due to the typological conditions of the rivers but also due to the influence of the anthropogenic factor mainly in the urban area. [ABSTRACT FROM AUTHOR]

As global climate change continues and the vegetation period lengthens, the importance of research into cyanobacterial recruitment biomass and associated toxin risks is growing. While most studies focus on planktonic cyanobacteria causing blooms, benthic cyanobacteria have been less explored. This study reports for the first time on the mass proliferation of benthic epilithic macrocolonies of cyanobacteria, Gloeotrichia cf. natans, in water bodies located in a region with continuous permafrost in Yakutia, North-East Russia. The study characterizes the environmental conditions of its habitat, including the chemical composition of the water, which expands our understanding of this species' ecology. Cyanotoxins (microcystins, cylindrospermopsin, saxitoxins, and anatoxin-a) were not detected in the biomass of Gloeotrichia cf. natans using liquid chromatography–mass spectrometry and PCR methods. [ABSTRACT FROM AUTHOR]

While marine top predators can play a critical role in ecosystem structure and dynamics through their effects on prey populations, how the predators function in this role is often not well understood. In the Benguela region of southern Africa, the Cape fur seal (Arctocephalus pusillus pusillus) population constitutes the largest marine top predator biomass, but little is known of its foraging ecology other than its diet and some preliminary dive records. Dive information was obtained from 32 adult females instrumented with dive recorders at the Kleinsee colony (29°34.17' S, 16°59.80' E) in South Africa during 2006-2008. Most dives were in the depth range of epipelagic prey species (less than 50 m deep) and at night, reflecting the reliance of Cape fur seals on small, vertically migrating, schooling prey. However, most females also performed benthic dives, and benthic diving was prevalent in some individuals. Benthic diving was significantly associated with the frequency with which females exceeded their aerobic dive limit. The greater putative costs of benthic diving highlight the potential detrimental effects to Cape fur seals of well-documented changes in the availability of epipelagic prey species in the Benguela.

Microphytobenthos (MPB), typically comprised mainly of diatoms, is a key contributor to nearshore energy flow and nutrient cycles. Deposit‐feeding invertebrates are known to alter the structure and activity of MPB. The eastern mud snail Ilyanassa obsoleta can reach extremely high densities in estuaries of the northwestern Atlantic, and their deposit‐feeding and locomotion strongly influence other invertebrates and microbes. Our objective was to explore quantitative and qualitative effects of this keystone deposit‐feeder on diatoms of intertidal sediments. We gathered snails from mudflat and sandflat habitats and collected their fresh fecal pellets in the laboratory. DNA metabarcoding allowed us to characterize diatom assemblages of ingested sediments and feces. We noted selective feeding such that reduction in MPB biomass with gut passage was difficult to quantify. Diatom α‐diversity was reduced with gut passage in snails from both sedimentary regimes. Mudflat and sandflat diatom assemblages were distinct and differed markedly between feces and sediment in mud‐feeding snails, whereas the difference in sand‐feeding snails was minor. The sandy habitat was dominated by a mix of epipelic and epipsammic diatoms. In contrast, mudflat samples were dominated by epipelic and planktonic diatoms. Compositional differences between sediment and feces reflected preferential removal of planktonic taxa. Our results suggest the importance of phytodetritus to the mud snail diet, particularly in hydrodynamically quiescent environments. Due to the natural spatial patchiness of the snails and the capacity for rapid microbial recolonization, field experiments are recommended to determine whether MPB community changes attributed to gut passage are manifested at the landscape scale. [ABSTRACT FROM AUTHOR]

A new thecate, photosynthetic, sand-dwelling marine dinoflagellate, Coutea sabulosa gen. & sp. nov., observed in various locations from temperate to subtropical areas, is described based on detailed morphological and molecular data of material from Germany and Kuwait. Cells of C. sabulosa are oval, small (14.5–28.3 µm long and 11.1–18.0 µm wide), dorsoventrally compressed, and show a conspicuous apical hook projection pointing to the right. The epitheca is smaller than the hypotheca and the cingulum is ascending, about 3× its width. The thecal plate pattern is unusual and interpreted as APC, 4ʹ, 3a, 7ʹʹ, 5c, 4s, 6ʹʹʹ, 2ʹʹʹʹ. The APC comprises a narrow Po plate with a slit opening, located on the right-dorsal side, and it is covered by a projection of the first apical plate. Morphologically, the plate pattern has some affinities with Amphidiniella sedentaria, a sand-dwelling dinoflagellate species of roughly the same size and gross outline. However, the two taxa differ from each other in shape, size of epitheca and organization of the APC. They possess the same number of apical, precingular, postcingular and antapical plates but their relative sizes, shapes and especially the arrangement differs. Molecular phylogeny inferred from concatenated ribosomal genes reveals that C. sabulosa forms a well supported clade in the core dinoflagellates, but it is not related to any other existing taxa and diverges widely from A. sedentaria. From the present study, this new taxon appears very atypical among dinoflagellates, and further studies will be necessary to resolve its evolutionary position. [ABSTRACT FROM AUTHOR]

The study of the functioning of the high Andean ecosystems is of great importance since any change will influence the entire basin. However, knowledge of these environments is still limited. Therefore, we sought to determine the effect of seasonality on the macrobenthos assemblage of a high Andean River and to determine the limnological, geomorphological, and hydrologicalhydraulic variables that most influence it. In the El Salto River, located 4,500 meters above sea level, in high Andean environments in southern Peru, macrobenthos was collected in 2020 in 11 hydro morphological units, recording limnological variables (dissolved oxygen, saturation percentage, conductivity, TSD, temperature, pH, turbidity and SS), geomorphological (granulometry) and hydrological-hydraulic (flow, velocity, depth, channel width) in dry and wet seasons. The principal component analysis (PCA) of the physicochemical variables showed that the flow rate, conductivity, pH, and total dissolved solids explained the greatest variability of the data (70 %). The predominance of boulders and silt was found. The number of species and density were higher in the dry season than in the wet season. However, the diversity, richness, and equity were higher in the wet season. The ordination analysis (nMDS, stress=0.09) showed a different structure of the macrobenthic assemblage between both seasons. It is concluded that seasonality, given by various factors, mainly flow rate and flow velocity, determine variations in the macrobenthos assemblage, confirming the drastic changes to which these high Andean ecosystems with extreme climates are subjected. [ABSTRACT FROM AUTHOR]

River ecosystems in Himalaya are changing rapidly as glaciers continue to recede at a pace faster than rest of the globe. We delineate riverine ecotones along an elevational gradient in the western Himalaya by examining community turnover of freshwater macroinvertebrates. Using the Threshold Indicator Taxa Analysis (TITAN), we provide a set of indicator macroinvertebrate taxa that represent the altitudinal band of greatest community turnover. Out of a total of 31 taxa, 11 were identified as indicators, responding either positively (n = 2) or negatively (n = 9) to altitude. Further, assessments of community turnover points toward a potential ‘riverine ecotone’ for the western Himalayan streams at an altitudinal band of 1442–2447 m above sea level (asl). As ecotones are transitional bands that harbour communities most sensitive to climate change, we further compared them across different latitudes of Himalaya to ascertain the differences in climate sensitive zones across latitudes. Our comparisons reveal that as we move towards higher latitudes in the Himalaya, the climate sensitivity drops to a lower elevational range of 1442–2447 m above sea level at 31° 33′–31° 43′ N. In contrast, at lower latitudes (27° 51′–28° 23′ N) the riverine ecotones have been recorded at a much higher elevation of 2900–3500 m above sea level. Through our study, we delimit that lower elevations in western Himalaya warrant concentrated long-term monitoring efforts to track species responses to climate change. Our comparisons of riverine ecotones along latitudes unlock new insights to understand the macroecology of community turnovers in riverine ecosystems. [ABSTRACT FROM AUTHOR]

Tropical epibenthic dinoflagellate communities produce a plethora of bioactive secondary metabolites, including the toxins ciguatoxins (CTXs) and potentially gambierones, that can contaminate fishes, leading to ciguatera poisoning (CP) when consumed by humans. Many studies have assessed the cellular toxicity of causative dinoflagellate species to better understand the dynamics of CP outbreaks. However, few studies have explored extracellular toxin pools which may also enter the food web, including through alternative and unanticipated routes of exposure. Additionally, the extracellular exhibition of toxins would suggest an ecological function and may prove important to the ecology of the CP-associated dinoflagellate species. In this study, semi-purified extracts obtained from the media of a Coolia palmyrensis strain (DISL57) isolated from the U.S. Virgin Islands were assessed for bioactivity via a sodium channel specific mouse neuroblastoma cell viability assay and associated metabolites evaluated by targeted and non-targeted liquid chromatography tandem and high-resolution mass spectrometry. We found that extracts of C. palmyrensis media exhibit both veratrine enhancing bioactivity and non-specific bioactivity. LC-HR-MS analysis of the same extract fractions identified gambierone and multiple undescribed peaks with mass spectral characteristics suggestive of structural similarities to polyether compounds. These findings implicate C. palmyrensis as a potential contributor to CP and highlight extracellular toxin pools as a potentially significant source of toxins that may enter the food web through multiple exposure pathways. [ABSTRACT FROM AUTHOR]

Beaver ponds are increasingly promoted as a strategy for physical stream restoration, and more recently recognized as natural solutions for excess nonpoint source pollutants, such as nitrogen (N). Beaver ponds facilitate N transformations on the streamscape by increasing sediment‐water interactions and creating low and high redox conditions in close proximity. Because beaver ponds vary widely in their geomorphology, the spatial extent of morphological units should dictate the degree of biogeochemical processing. We explore the role of beaver pond geomorphic units in facilitating sediment N transformations using a sediment mass balance approach. We quantified input, output, and transformation of N species within the sediments and water of the riffle, backwater, and margin geomorphic units of a beaver pond in Northern Utah. Our interpretations were supplemented using sediment oxygen demand (SOD) and sediment C and N stable isotopes. The backwater performed most of the biogeochemical work, including increased sedimentation (2.1 g N m−2d−1), ammonification (1.3 g N m−2d−1), nitrification (0.07 g N m−2d−1), and denitrification (0.1 g N2 m−2 d−1), the latter facilitated by high sediment OM (14%) and SOD (−0.95 ± 0.2 g O2 m−2 d−1). Backwater sediment isotopes, supported by N flux measurements, indicated increased benthic microbial activity and denitrification. The margin and backwater surface sediments had low C:N ratios, indicating sediment input from autochthonous production. These findings suggest the representation of geomorphic units in a beaver pond may predict whether the pond can facilitate N removal through sediment sequestration and denitrification. Plain Language Summary: Beaver dams may be a natural method for reducing excess N concentrations within streams. Beavers build earthen dams, causing water and sediment to accumulate, creating a pond. Within a pond, the distribution of sediment and water is not uniform, instead forming distinct geomorphic units (e.g., backwater, margin, riffle). A pond is comprised of a mosaic of geomorphic units that containing different levels of sediment oxygen content, temperature, and organic matter, all of which influence how different forms of N are cycled. We hypothesized that N transformations, such as the permanent removal of N through denitrification, will covary with a pond's physical structure. To test this hypothesis, the physical structure of one pond was cataloged using geomorphic unit criteria. Within three units we conducted experiments to quantify different N cycle steps from sedimentation to denitrification. Sediment characteristics related to N cycling such as organic matter concentration and C and N isotope composition were also measured in each unit. Backwater areas facilitated the storage of sediment N and, importantly, denitrification. The inflow riffle facilitated N transport rather than transformation, while nitrification rates were highest in the margin. The geomorphic composition of a beaver pond can inform whether beaver activity can provision water quality remediation. Key Points: Beaver ponds facilitate (N) transformations and N removal from streamscapesDenitrification was highest in areas with high sediment storageNitrification rates were highest near the shore and dam edge [ABSTRACT FROM AUTHOR]

Abstract Background Microorganisms in the seafloor use a wide range of metabolic processes, which are coupled to the presence of functional genes within their genomes. Aquatic environments are heterogenous and often characterized by natural physiochemical gradients that structure these microbial communities potentially changing the diversity of functional genes and its associated metabolic processes. In this study, we investigated spatial variability and how environmental variables structure the diversity and composition of benthic functional genes and metabolic pathways across various fundamental environmental gradients. We analyzed metagenomic data from sediment samples, measured related abiotic data (e.g., salinity, oxygen and carbon content), covering 59 stations spanning 1,145 km across the Baltic Sea. Results The composition of genes and microbial communities were mainly structured by salinity plus oxygen, and the carbon to nitrogen (C:N) ratio for specific metabolic pathways related to nutrient transport and carbon metabolism. Multivariate analyses indicated that the compositional change in functional genes was more prominent across environmental gradients compared to changes in microbial taxonomy even at genus level, and indicate functional diversity adaptation to local environments. Oxygen deficient areas (i.e., dead zones) were more different in gene composition when compared to oxic sediments. Conclusions This study highlights how benthic functional genes are structured over spatial distances and by environmental gradients and resource availability, and suggests that changes in, e.g., oxygenation, salinity, and carbon plus nitrogen content will influence functional metabolic pathways in benthic habitats. Video Abstract

Abstract Turbidity monitoring in shallow coastal waters is fundamental to marine ecosystem research, management and protection. Satellite‐based water turbidity monitoring can be conducted at a greater spatial extent and higher temporal frequency than field measurements. The new Planet Dove satellite constellation has a daily revisit frequency and higher spatial resolution than Sentinel or Landsat satellites, allowing Planet Dove to track water turbidity dynamics in greater detail when suitable atmospheric correction is provided. We developed a new shallow coastal water turbidity estimation algorithm for Planet Dove and similar multi‐spectral satellites. Our algorithm accounts for bottom reflectance in total water‐leaving radiance to derive turbidity values in shallow coastal waters. We tested the algorithm with data from 235 Dove satellite images at five sites with different water conditions (Pelekane Bay, Big Island, Hawai‘i; Hilo Bay, Big Island, Hawai‘i; Kilo Nalu and Ala Wai, O‘ahu, Hawai‘i; Fagatele Bay, American Samoa; Vieques Island, Puerto Rico). We then validated satellite‐derived turbidity results (RMSE = 0.79–1.12 FNU [Formazin Nephelometric Unit]) using 75 days of field‐measured data, ranging in turbidity from 0.1 to 11.6 FNU in the five sites. Results show that our algorithm accurately detects turbidity in critical nearshore environments. In Hawai‘i, we used ~6700 Dove images to support a weekly turbidity monitoring study at a large geographic scale. We found this new, shallow‐water algorithm can be effectively applied to Dove satellite data to monitor water turbidity at high temporal resolution.

Suitable colonization materials are a pursued target in marine restoration programs. Known for making nutrients available while reducing pollutants and the risk of pathogens in terrestrial ecosystems, Biochar and Bioferment materials of organic origin were tested during a two-year experiment. We tested the efficacy of these materials for restoration purposes through experimental concrete tiles treated with Biochar (B) and Bioferment (F) and tiles made of concrete, which were used as controls (Ct) for the colonization of marine organisms in the marine protected area of Porto Cesareo, Southern Italy (20 m depth). Tiles were monitored for photographs from October 2019 to September 2021. Initially, Biochar treatment presented a higher percentage of total benthic cover (81.23 ± 2.76, median ± SE), differing from Bioferment treatment and control tiles (45.65 ± 5.43 and 47.95 ± 3.69, respectively). Significant interaction between treatments and times suggests changes in community structure related to Polychaeta cover increase in Bioferment and control materials from the second monitoring time. Furthermore, the underwater instability of Bioferment on the tiles could explain the similarity with control tiles in marine organisms’ covers. Hence, Biochar is shown to be a material with optimal stability in seawater, demonstrating greater capacity for marine organisms’ colonization in less time compared to the other two materials.

Coral reef rehabilitation in the Caribbean is of major ecological and economic importance in the West Indies. Local organizations in Grenada constructed a cement pyramid artificial reef structure with rugosity (termed “The Pyramid”) and placed a number of these artificial reefs in a shallow marine area fringing two major natural reefs in the southwest coastal region of Grenada. Benthic data for two nearby natural reefs were compared to the benthic evaluation of the artificial reef pyramids. This comparison demonstrated that the artificial reef pyramids were similar in many respects to the natural reefs but were significantly different in macro- and coralline algae cover, two key indicators of reef health. This report is the first benthic evaluation of an artificial reef through comparison to natural reefs in Grenada.

The distribution and abundance of organisms is typically shaped by multiple biotic and abiotic processes. Micropredators are parasite-like organisms that are smaller than their hosts and/or prey and feed on multiple hosts during a given life stage. Unlike typical parasites, however, they spend much or most of their time free-living, associating only temporarily with hosts. In the ocean, micropredators can impact multiple fish species, and in particular can have significant lethal and sub-lethal effects on newly settled fish. Although gnathiid isopods are abundant and primary micropredators in coral reef ecosystems, their impacts are relatively unexplored within sub-tidal temperate rocky reefs. We investigated the distribution of juvenile gnathiid isopods along sub-tidal temperate rocky reefs and tested trap methodology. We also quantified both the sub-lethal and lethal impacts of feeding-stage juvenile gnathiid isopods on juvenile, post-settlement reef fish, Heterostichus rostratus (giant kelpfish). We were most interested in determining the relationship between gnathiid infestation level and fish swimming performance, in particular swimming metrics relevant to predator avoidance maneuvers. We found that Gnathia tridens was present in rocky reefs rather than embayments along the Southern California coastline and that within rocky reefs, gnathiids occurred in the highest densities in lighted traps. Surprisingly, we observed almost no influence of fish size or gnathiid sub-lethal infestation level on ambient or burst swimming performance metrics. However, burst duration was reduced by gnathiid infestation, which is important in predator avoidance. There were significant differences in survivorship among small fish compared to large fish as a result of gnathiid infestation. Larger fish survived higher numbers of gnathiids than smaller fish, indicating that parasite-induced mortality is greater for smaller fish. Investigations of the effects of micropredators on subsequent predator-mediated mortality, including the susceptibility of fishes and their individual responses to micropredators, can further contribute to our understanding of processes affecting recruitment in resident reef fish populations. Further research, especially within temperate sub-tidal ecosystems, is needed to understand and highlight the overlooked importance of micropredation in shaping fish populations within a reefscape.

Benthic macroinvertebrate protocols, in the United States, have been integral in the implementation of the Clean Water Act (33 U.S.C. §1251 et seq. (1972)). The methods in these protocols are designed to describe patterns of biological water quality and ecological condition relevant to legislative oversight, and require a tradeoff between taxonomic precision and protocol simplicity. The global similarity of ecological and evolutionary responses to the challenges of life in flowing waters, by stream organisms, has greatly facilitated the development and implementation of biological data from freshwater mussels, fishes and aquatic insects into streamlined regulatory frameworks. Unfortunately, the factors that expedite the use of benthic data into ecological descriptions sufficient for regulatory processes (taxonomic generalizations, standardization of sampling procedures to focus on a narrow subset of available habitats) also limit the utility of these methods in the conservation of benthic macroinvertebrate species (the large majority of which are insects). Using simple hypothetical simulations, some examples from a taxonomic and ecological database of one state in the USA (Illinois), and data from a large-scale inventory of aquatic insect species in a network of US National Parks, I illustrate how these methods are limited in their ability to effectively describe ecological patterns relevant to the conservation of aquatic insect species. I identify, challenge, and explore three basic assumptions implicit to the genus- and family-level identification methods widely used in freshwater benthic science, then discuss how the failure of these assumptions may create empirical, theoretical and philosophical obstacles to the interpretation of data and certainly hinder the conservation of species. I offer some hopeful suggestions for improving aquatic insect species conservation that are within the reach of all benthic freshwater ecologists.

With climate change and re‐oligotrophication of lakes due to restoration efforts, the relative importance of benthic cyanobacteria is increasing, but they are much less studied than their planktonic counterparts. Following a major water level rise event that inundated massive reed stands in Lake Kinneret, Israel, we discovered the appearance of a vast abundance of Gloeotrichia pisum (cyanobacteria). This provided an opportunity to investigate the biology and ecology of a benthic epiphytic colonial cyanobacterium, proliferating under altered environmental conditions, with possible toxin production potential and as a model for an invasive epiphyte. The species was identified by its typical morphology, and by sequencing its 16S rRNA gene and the intragenic space. We report on the abundance and spatial distribution of the detected colonies, their morphological characteristics, and pigment composition. High phycoerythrin content provides a brownish color and supports growth at low light levels. Genomic community composition analysis revealed that G. pisum colonies host a diverse microbial community of microalgae, cyanobacteria, bacteria, and archaea with a conserved and characteristic taxonomic composition. The Synechococcales order showed high relative abundance in the colony, as well as other prokaryotes producing secondary metabolites, such as the rhodopsin producer Pseudorhodobacter. The microbial consortium in the colonies performed nitrogen fixation. The diazotroph's phylogenetic relations were demonstrated. Tests for the presence of cyanotoxins (microcystin and cylindrospermopsin) proved negative. This study is the first documentation of this genus in Israel, providing insights into the invasive nature of G. pisum and the ecological implications of its appearance in a lake ecosystem. [ABSTRACT FROM AUTHOR]

Two new Uromunna species, Uromunna mundongensis sp. n. and Uromunna jejuensis sp. n., are described from the Korean Peninsula, representing the first record of the genus in Korean waters. Genetic analyses using two mitochondrial (COI, Cytb) and one ribosomal (18S rRNA) gene allowed us to confirm high pair-wise interspecific differences with the establishment of reliable barcoding gaps of COI (19.9%) and 18S (0.4%) between the new species. Finally, the phylogenetic relationship between the Uromunna species as well as the position of the genus within the munnoid groups are reconstructed using 18S. [ABSTRACT FROM AUTHOR]

Two new species of Travisia Johnston, 1840 (Annelida, Travisiidae) are described from the continental shelf of south-eastern Australia: Travisia tribus sp. nov. and Travisia una sp. nov. Travisia olens novaezealandiae Benham, 1927 is raised to species rank as Travisia novaezealandiae Benham, 1927 new status. We describe epidermal structures using scanning electron microscopy, and discuss pygidial morphology of the two new Travisia species and distinguish an additional character. We recognise four species of Travisia recorded from Australia and include a dichotomous key to allow their identification. A separate downloadable resource provides access to an annotated morphological character list for Travisia species, a downloadable interactive key using the Delta (Descriptive Language for Taxonomy) Intkey software, and concise descriptions and minimal diagnoses and descriptions of all currently recognised species of Travisia. [ABSTRACT FROM AUTHOR]

Bacteria drive energy fluxes and geochemical processes in estuarine sediments. Deposit-feeding invertebrates alter the structure and activity of microbial communities through sediment ingestion, gut passage, and defecation. The eastern mud snail, Ilyanassa obsoleta , is native to estuaries of the northwestern Atlantic, ranging from Nova Scotia, Canada, to Florida in the USA. Given extremely high densities, their deposit-feeding and locomotory activities exert ecological influence on other invertebrates and microbes. Our aim was to characterize the bacterial microbiome of this 'keystone species' and determine how its feeding alters the native bacterial microbiota. We gathered snails from both mudflat and sandflat habitats and collected their fresh fecal pellets in the laboratory. Dissection of these same snails allowed us to compare bacterial assemblages of ingested sediments, shell surfaces, gut sections (esophagus, stomach, intestine), and feces using DNA metabarcoding. Our findings indicate a diverse, resident gut microbiota. The stomach and intestines were dominated by bacteria of the genus Mycoplasma. Comparison of ingesta and feces revealed digestion of several bacterial taxa, introduction of gut residents during passage, in addition to unique bacterial taxa within the feces of unknown provenance. Our results demonstrate that I. obsoleta has the potential to modify microbial community structure in estuarine sediments. [ABSTRACT FROM AUTHOR]

Despite an increase in the number of new lumbrinerid descriptions globally and over recent decades, no new lumbrinerid species have been described from southern Africa over the last 40 years. This suggests that species richness in the region is currently underestimated, and that continued research would result in the discovery of more undescribed species. Here, a new species is described from grab samples collected off southern Namibia at >100 m depth. Ninoe namibiensis sp. nov. is characterized by simple multidentate hooded hooks with a long hood that only appears after chaetiger 18, branchiae from chaetiger 1–2 to 38 (with up to 7 filaments) and maxillary apparatus: MX III with one prominent tooth followed by a knob and MX IV unidentate with finely denticulate cutting edge (11 small teeth). A key to the Ninoe from southern Africa is provided. [ABSTRACT FROM AUTHOR]

Advances in sonar technology have revolutionized our ability to map the seafloor, however, differences between legacy and modern data pose challenges when analysing multi-source datasets. Acoustic backscatter recorded via multibeam echosounder is commonly used to characterize the seafloor, but a lack of standardized calibration often yields relative rather than absolute backscatter measurements, hindering comparison between surveys. ‘Bulk shift’ methods have been developed for harmonizing legacy backscatter datasets using overlapping survey areas for relative statistical calibration. This becomes increasingly difficult, though, given many datasets collected over extensive time periods. Backscatter data were collected in the Bay of Fundy, Canada, using multiple sonar systems and vessels over an 18-year period. Here, we propose a reproduceable strategy for harmonizing this large volume of disparate backscatter data using the bulk shift method. A final, harmonized map is presented for the entire Bay of Fundy and is validated using in situ observations from seafloor imagery. [ABSTRACT FROM AUTHOR]

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Cocconeis dapalistriata, first described as a member of the genus Cocconeis, is re-examined due to its unique ultrastructure. Both valvocopulae of this taxon show significant differences compared to those found in the genus Cocconeis. They are expanded and show some similarities with those found in Amphicocconeis. On the other hand, terminal parts of the raphe valve (RV) in C. dapalistriata are simple and the raphe valve (RV) striae are composed of small round areolae with a hymenate occlusion with radial slits, similar to those observed in Cocconeis. Campyloneis and Xenococconeis also have expanded valvocopulae but with numerous morphological differences compared to those found in C. dapalistriata. Furthermore, the areolae of the sternum valve (SV) in C. dapalistriata are occluded by a concave velum with no apparent internal slits, and externally ornamented with irregular silica crystals. Upsilococconeis Riaux-Gobin, Witkowski & Risjani gen. nov. is proposed to accommodate the latter taxon. First described from the Western Indian Ocean (Mascarenes), it was subsequently listed from the Western Pacific Ocean (Guam), the South Pacific Ocean (French Polynesia and New Caledonia) and from the Eastern Indian Ocean (Indonesia), and thus may qualify as pantropical.

This taxonomic account of light micrographs from the coastal Laurentian Great lakes contains taxa from the diatom genera Amphora, Halamphora, Cymbella, Cymbopleura, Delicatophycus, Encyonema, Encyonopsis, Reimeria, Gomphonema, Gomphosphenia, Gomphonella, Gomphosinica, and Gomphoneis. A total of 207 samples of surface sediment and periphyton collected from 106 wetland, high-energy, embayment, and deeper nearshore locales are represented. Light micrographs of 154 taxa are presented. Of these, 76 could not be fully identified as known taxa from the existing literature and so are given tentative names, numbers or conferred assignments. Lake and habitat specificity, modeled autecological optima for phosphorus and chloride, and tolerance to anthropogenic stressors are described for 39 of the more common taxa.

Globally, nations are designating marine protected areas to recover and protect habitats and species. With targets to protect 30% of marine areas by 2030, the effectiveness of MPAs to protect designated space is important. In Lyme Bay (south‐west UK), two co‐located MPAs have each adopted different management styles to exclude mobile demersal fishing: a Special Area of Conservation (SAC) protecting the known extent of sensitive reef habitat and an area including a mosaic of reef and sedimentary habitats where the whole site is protected from mobile demersal fishing under a statutory instrument (SI). Underwater videography, both towed (individuals m−2) and baited (MaxN), was used to enumerate change over time of reef species (number of taxa, total abundance, functional richness and functional redundancy) in the MPAs and nearby control areas (2008–2019). Total abundance and functional redundancy of sessile taxa and functional richness of mobile taxa increased, while the number of sessile or mobile taxa, functional richness of sessile taxa, total abundance of mobile taxa or functional redundancy of mobile taxa did not differ from nearby control sites. Over time, both management styles did result in increases in sessile and sedentary taxa diversity relative to open controls, with increases in total abundance of 15% and 95% in the "feature‐based" and whole‐site MPAs, respectively, alongside increases in the number of sessile taxa of 44% over time in the "feature‐based" MPA. However, the mobile taxa in the whole‐site MPA showed levels of functional redundancy 7% higher than the "feature‐based" MPA, indicative of a higher community resilience inside the whole‐site MPA to perturbations, such as storms or biological invasions. Increases seen in the diversity of sessile taxa were expected only in areas where mobile demersal fishing was excluded (~46.8% of its areas). Therefore, if the whole "feature‐based" MPA was consistently protected, we expected to see similar levels of increase in the functional extent of reef. While the "feature‐based" MPA showed similar results over time to that of the "whole site," the "whole site" showed higher levels of diversity, both taxonomical and functional. [ABSTRACT FROM AUTHOR]

This monograph contains descriptions of taxa from the diatom genera Craticula, Aneumastus, Decussiphycus, Cavinula, Lacustriella, Luticola, Mastogloia, Geissleria, Placoneis, Petroplacus, Navicula, Hippodonta, Sellaphora, Prestauroneis, Fallacia, Stauroneis, Brachysira, Anomoeoneis, Neidium, Diploneis, Caloneis, Pinnularia, Capartogramma, Frustulia, Amphipleura, Krasskella, Gyrosigma and Plagiotropis from periphytic and surface sediment samples in the coastal ecosystems of the Laurentian Great Lakes. Light micrographs are provided for diatom taxa recorded in 207 samples from 106 wetlands, embayments, high-energy and deep, nearshore locales of the five Great Lakes. 148 taxa are characterized, and 2 previously undescribed taxa are named. For 36 of the more common species, lake and habitat specificity, modelled optima for phosphorus and chloride and tolerance to coastal anthropogenic stressors are described. [ABSTRACT FROM AUTHOR]