Schoolchildren discover hotspots of floating plastic litter in rivers using a large-scale collaborative approach

Rivers are an important transport route of anthropogenic litter from inland sources toward the sea. A collaborative (i.e. citizen science) approach was used to evaluate the litter pollution of rivers in Germany: schoolchildren within the project “Plastic Pirates” investigated rivers across the entire country during the years 2016 and 2017 by surveying floating macrolitter at 282 sites and taking 164 meso−/microplastic samples (i.e. particles 24.99–5 mm, and 4.99–1 mm, respectively). Floating macrolitter was sighted at 54% of sampling sites and floating macrolitter quantities ranged from 0 to 8.25 items m−1 h−1 (average of 0.34 ± 0.89 litter items m−1 h−1). Floating meso−/microplastics were present at 57% of the sampling sites, and floating meso−/microplastic quantities ranged from 0 to 220 particles h−1 (average of 6.86 ± 24.11 items h−1). As only particles >1 mm were sampled and analyzed, the pollution of rivers in Germany by microplastics could be a much more prevalent problem, regardless of the size of the river. We identified six plastic pollution hotspots where 60% of all meso−/microplastics collected in the present study were found. These hotspots were located close to a plastic-producing industry site, a wastewater treatment plant, at and below weirs, or in residential areas. The composition of the particles at these hotspots indicates plastic producers and possibly the construction industry and wastewater treatment plants as point sources. An identification of litter hotspots would enable specific mitigation measures, adjusted to the respective source, and thereby could prevent the release of large quantities of small plastic particles in rivers. The adopted large-scale citizen science approach was especially suitable to detect pollution hotspots by sampling a variety of rivers, large and small, and enabled a national overview of litter pollution in German rivers

Response of subtropical phytoplankton communities to ocean acidification under oligotrophic conditions and during nutrient fertilization

The subtropical oceans are home to the largest phytoplankton biome on the planet. Yet, little is known about potential impacts of ocean acidification (OA) on phytoplankton community composition in the vast oligotrophic ecosystems of the subtropical gyres. To address this question, we conducted an experiment with 9 in situ mesocosms (~35 m3) off the coast of Gran Canaria in the eastern subtropical North Atlantic over a period of 9 weeks. By establishing a gradient of pCO2 ranging from ~350 to 1025 µatm, we simulated carbonate chemistry conditions as projected until the end of the 21st century. Furthermore, we injected nutrient-rich deep water into the mesocosms halfway through the experiment to simulate a natural upwelling event, which regularly leads to patchy nutrient fertilization in the study region. The temporal developments of major taxonomic groups of phytoplankton were analyzed by flow cytometry, pigment composition and microscopy. We observed distinct shifts in phytoplankton community structure in response to high CO2, with markedly different patterns depending on nutrient status of the system. Phytoplankton biomass during the oligotrophic phase was dominated by picocyanobacteria (Synechococcus), which constituted 60-80% of biomass and displayed significantly higher cell abundances at elevated pCO2. The addition of deep water triggered a substantial bloom of large, chain-forming diatoms (mainly Guinardia striata and Leptocylindrus danicus) that dominated the phytoplankton community during the bloom phase (70-80% of biomass) and until the end of the experiment. A CO2 effect on bulk diatom biomass became apparent only in the highest CO2 treatments (>800 µatm), displaying elevated concentrations especially in the stationary phase after nutrient depletion. Notably, these responses were tightly linked to distinct interspecific shifts within the diatom assemblage, particularly favoring the largest species Guinardia striata. Other taxonomic groups contributed less to total phytoplankton biomass, but also displayed distinct responses to OA treatments. For instance, higher CO2 favored the occurrence of prymnesiophyceae (Phaeocystis globosa) and dictyochophyceae, whereas dinoflagellates were negatively affected by increasing CO2. Altogether, our findings revealed considerable shifts in species composition in response to elevated CO2 and indicated that phytoplankton communities in the subtropical oligotrophic oceans might be profoundly altered by ocean acidification

Microplastic-Associated Biofilms: A Comparison of Freshwater and Marine Environments

Microplastics (<5 mm particles) occur within both engineered and natural freshwater ecosystems, including wastewater treatment plants, lakes, rivers, and estuaries. While a significant proportion of microplastic pollution is likely sequestered within freshwater environments, these habitats also constitute an important conduit of microscopic polymer particles to oceans worldwide. The quantity of aquatic microplastic waste is predicted to dramatically increase over the next decade, but the fate and biological implications of this pollution are still poorly understood. A growing body of research has aimed to characterize the formation, composition, and spatiotemporal distribution of microplastic-associated (“plastisphere”) microbial biofilms. Plastisphere microorganisms have been suggested to play significant roles in pathogen transfer, modulation of particle buoyancy, and biodegradation of plastic polymers and co-contaminants, yet investigation of these topics within freshwater environments is at a very early stage. Here, what is known about marine plastisphere assemblages is systematically compared with up-to-date findings from freshwater habitats. Through analysis of key differences and likely commonalities between environments, we discuss how an integrated view of these fields of research will enhance our knowledge of the complex behavior and ecological impacts of microplastic pollutants

Amphithyris comitodentis Nauendorf, Wörheide & Lüter, 2014, n. sp.

&lt;i&gt;Amphithyris comitodentis&lt;/i&gt; n. sp. &lt;p&gt;(Fig. 6; Table 5)&lt;/p&gt; &lt;p&gt; as &lt;i&gt;Amphithyris buckmani&lt;/i&gt; L&uuml;ter 2008: p. 316, fig. 2F&ndash;G (misidentification)&lt;/p&gt; &lt;p&gt; &lt;b&gt;Type material.&lt;/b&gt; Holotype: NIWA 92391, Paratypes: ZMB Bra 2054, ZMB Bra 2145, ZMB Bra 2281, ZMB Bra 2353, ZMB Bra 2354 (20 specimens).&lt;/p&gt; &lt;p&gt; &lt;b&gt;Etymology.&lt;/b&gt; From Latin &lt;i&gt;comitans&lt;/i&gt; (&quot;accompanying, parallel&quot;) and &lt;i&gt;dens&lt;/i&gt; (&quot;tooth&quot;) referring to the fact that this is the only species within &lt;i&gt;Amphithyris&lt;/i&gt; with its teeth parallel to the hinge line.&lt;/p&gt; &lt;p&gt; &lt;b&gt;Type locality.&lt;/b&gt; SW Pacific east of New Zealand; SO168; Stations 13, 96, 97, 99, 105. Depth range: 252&ndash;1865 m.&lt;/p&gt; &lt;p&gt; &lt;b&gt;Diagnosis.&lt;/b&gt; Shell planoconvex, flat dorsal valve, prints of capillae on ventral valve interior. Hinge teeth flat, narrow, parallel to hinge line. Small dorsal septum.&lt;/p&gt; &lt;p&gt; &lt;b&gt;Description.&lt;/b&gt; Shells planoconvex, oval to round. Dorsal valve almost flat (Fig. 6 A) with low median septum, highest point mid-valve (Fig. 6 A). Foramen amphithyrid with pair of short socket ridges at lateral margins that slightly reach over posterior margin (Fig. 6 A). Ventral valve with imprints of capillae on interior (Fig. 6 B and D). Hinge teeth narrow, parallel to hinge line (Fig. 6 C and D), delthyrium triangular. Ventral valve with concentric growth lines on exterior (Fig. 6 E). Protegulum on caudal tip of ventral valve with wrinkled surface (Fig. 6 F).&lt;/p&gt; &lt;p&gt; &lt;b&gt;Remarks.&lt;/b&gt; The specimens erroneously assigned to &lt;i&gt;Amphithyris buckmani&lt;/i&gt; by L&uuml;ter (2008) show a consistent character difference to all other &lt;i&gt;Amphithyris&lt;/i&gt; spp., i.e. the longitudinal axis of their hinge teeth is parallel to the hinge line. We therefore describe it as a new species &lt;i&gt;Amphithyris comitodentis&lt;/i&gt; n. sp. It features similar characteristics to the other &lt;i&gt;Amphithyris&lt;/i&gt; species such as small size, shell convexity, an asymmetrical dorsal valve due to irregular substrate morphology, an amphithyrid foramen and a triangular delthyrium. The specimens feature capillae imprints in the ventral valve interior as in &lt;i&gt;A. hallettensis&lt;/i&gt; and a low dorsal septum as in &lt;i&gt;A. buckmani, A. hallettensis&lt;/i&gt; and &lt;i&gt;A. seminula&lt;/i&gt;.&lt;/p&gt;Published as part of &lt;i&gt;Nauendorf, Alice, Wörheide, Gert &amp; Lüter, Carsten, 2014, Revision of the brachiopod genus Amphithyris (Rhynchonelliformea: Platidiidae) with descriptions of two new species, pp. 221-240 in Zootaxa 3847 (2)&lt;/i&gt; on page 232, DOI: 10.11646/zootaxa.3847.2.3, &lt;a href="http://zenodo.org/record/227230"&gt;http://zenodo.org/record/227230&lt;/a&gt

Amphithyris seminula Philippi 1836

&lt;i&gt;Amphithyris seminula&lt;/i&gt; (Philippi, 1836) &lt;p&gt;(Fig. 5; Table 4)&lt;/p&gt; &lt;p&gt; &lt;i&gt;Terebratula seminulum&lt;/i&gt; Philippi, 1836: p. 97, pl. 6, fig. 15a&ndash;g (original description); 1844: p. 69 (erroneously synonymized with &lt;i&gt;Orthis neapolitana&lt;/i&gt; (Scacchi) (= &lt;i&gt;Joania cordata&lt;/i&gt; (Risso, 1826)) &mdash; Costa, 1852: p. 38 (erroneously synonymized with &lt;i&gt;Orthis neapolitana&lt;/i&gt; (Scacchi) (= &lt;i&gt;Joania cordata&lt;/i&gt; (Risso, 1826)) &mdash; Davidson, 1852a: p. 371 (as &lt;i&gt;Morrisia seminulum&lt;/i&gt;, new combination); 1852b: p. 81 (erroneously synonymized with &lt;i&gt;Argiope neapolitana&lt;/i&gt; (Scacchi) (= &lt;i&gt;Joania cordata&lt;/i&gt; (Risso, 1826)); 1887: p. 152 (erroneously synonymized with &lt;i&gt;Platydia&lt;/i&gt; [sic!] &lt;i&gt;anomioides&lt;/i&gt; (Scacchi &amp; Philippi in Philippi, 1844))&mdash;de Monterosato 1879: p. 307, pl. 13, fig. 3 (as &lt;i&gt;Platidia seminulum&lt;/i&gt;, new combination)&mdash; Fischer &amp; Oehlert 1891: p. 99 (as &lt;i&gt;Platidia seminulum&lt;/i&gt;)&mdash; Thomson 1918: p. 21 (as &lt;i&gt;Amphithyris seminula&lt;/i&gt;, new combination); 1927: p. 216&mdash; Dall 1920: p. 332 (as &lt;i&gt;Platidia seminula&lt;/i&gt;)&mdash; Atkins 1959: p. 125 (suggestion that &lt;i&gt;T. seminulum&lt;/i&gt; is a juvenile &lt;i&gt;Platidia anomioides&lt;/i&gt;, to be left undecided until type material is found)&mdash; Logan 1979: p. 63&mdash; L&uuml;ter &amp; Sieben 2005: p. 185 (identification of possible type material)&mdash; MacKinnon &lt;i&gt;et al.&lt;/i&gt; 2008: p. 324, fig. 4 A&ndash;I (taxonomic status confirmed, investigation of additional historical material)&lt;/p&gt; &lt;p&gt; &lt;i&gt;Orthis anomioides&lt;/i&gt; Scacchi &amp; Philippi in Philippi, 1844: p. 69, pl. 18, fig. 9 (erroneously synonymized with &lt;i&gt;Platidia seminulum&lt;/i&gt;, new combination by Dall 1920: p. 332)&lt;/p&gt; &lt;p&gt; &lt;b&gt;Type material.&lt;/b&gt; Lectotype: ZMB Bra 2146; Paralectotype: ZMB Bra 1675&lt;/p&gt; &lt;p&gt; &lt;b&gt;Type locality.&lt;/b&gt; Trapani, Sicily, Mediterranean Sea.&lt;/p&gt; &lt;p&gt; &lt;b&gt;Material examined.&lt;/b&gt; Lectotype: ZMB Bra 2146; Paralectotype: ZMB Bra 1675&lt;/p&gt; &lt;p&gt; &lt;b&gt;Diagnosis.&lt;/b&gt; Shell planoconvex, flat dorsal valve with low median septum. Capillae absent.&lt;/p&gt; &lt;p&gt; &lt;b&gt;Description.&lt;/b&gt; Shell planoconvex, oval to round. Dorsal valve almost flat, slightly convex from posterior to foramen (Fig. 5 B). Very low median septum, highest point mid-valve or below mid-valve (Fig. 5 A). Two curved, very low ridges on each side of valve underlie the lophophore (Fig. 5 B). Short socket ridges (Fig. 5 C). Ventral valve with hinge teeth beak-like, not parallel to hinge line (Fig. 5 D and E). Valve exterior smooth with growth lines (Fig. 5 F).&lt;/p&gt; &lt;p&gt; &lt;b&gt;Remarks.&lt;/b&gt; Two specimens of &lt;i&gt;A. seminulum&lt;/i&gt; were found in the brachiopod collection of the Museum f&uuml;r Naturkunde Berlin in a glass tube together with an old label (not Philippi&acute;s handwriting) saying &quot; &lt;i&gt;Terebratula seminulum&lt;/i&gt; Ph., Sicilia, Dr. Ph. &quot;. The tube contains a mixture of species with the second species identified as &lt;i&gt;Joania cordata&lt;/i&gt;. L&uuml;ter &amp; Sieben (2005) proposed that Philippi&acute;s figures of &lt;i&gt;T. seminulum&lt;/i&gt; belong to two different species, &lt;i&gt;Platidia anomioides&lt;/i&gt; (Scacchi &amp; Philippi) (Philippi&acute;s fig. 15a&ndash;d) and &lt;i&gt;Joania cordata&lt;/i&gt; (Risso) (Philippi&acute;s fig. 15e&ndash;g). This potential mixture of two species in the original material of Philippi was already discussed by Atkins (1959). Based on a comparison with Fig. 4 of MacKinnon &lt;i&gt;et al.&lt;/i&gt; (2008) (material from the Davidson Collection, NHM, London) demonstrating that &lt;i&gt;T. seminulum&lt;/i&gt; is not an immature stage of &lt;i&gt;P. anomioides&lt;/i&gt;, the two specimens in the Berlin material previously identified as &lt;i&gt;P. anomioides&lt;/i&gt; by L&uuml;ter &amp; Sieben (2005) were assigned to &lt;i&gt;A. seminula.&lt;/i&gt; We further identified this material as the original type series collected by Philippi and therefore designate ZMB Bra 2146 as lectotype and ZMB Bra 1675 as paralectotype of &lt;i&gt;Amphithyris seminula&lt;/i&gt; (Philippi, 1836).&lt;/p&gt;Published as part of &lt;i&gt;Nauendorf, Alice, Wörheide, Gert &amp; Lüter, Carsten, 2014, Revision of the brachiopod genus Amphithyris (Rhynchonelliformea: Platidiidae) with descriptions of two new species, pp. 221-240 in Zootaxa 3847 (2)&lt;/i&gt; on page 230, DOI: 10.11646/zootaxa.3847.2.3, &lt;a href="http://zenodo.org/record/227230"&gt;http://zenodo.org/record/227230&lt;/a&gt

Amphithyris cavernicola Nauendorf, Wörheide & Lüter, 2014, n. sp.

&lt;i&gt;Amphithyris cavernicola&lt;/i&gt; n. sp. &lt;p&gt;(Fig. 7&ndash;9; Table 6)&lt;/p&gt; &lt;p&gt; &lt;b&gt;Etymology.&lt;/b&gt; From Latin &lt;i&gt;caverna&lt;/i&gt; (&quot;cave&quot;) and &lt;i&gt;incolere&lt;/i&gt; (&quot;inhabiting&quot;). The name was chosen for the species as all individuals were found in a reef cave.&lt;/p&gt; &lt;p&gt; &lt;b&gt;Type material.&lt;/b&gt; Holotype: QM G333507, Paratypes: QM G333508; ZMB Bra 2144; ZMB Bra 2175-2180; ZMB Bra 2182-2186; ZMB Bra 2187.&lt;/p&gt; &lt;p&gt; &lt;b&gt;Type locality.&lt;/b&gt; Holmes Reefs, Coral Sea, Australia. Attached to piece of coral substrate removed from cave ceiling, at a depth of 8m.&lt;/p&gt; &lt;p&gt; &lt;b&gt;Diagnosis.&lt;/b&gt; Dorsal septum absent. Ventral valve with low median septum and muscle impressions visible on each side, exterior surface with tubercles and capillae.&lt;/p&gt; &lt;p&gt; &lt;b&gt;Description.&lt;/b&gt; Very small species of &lt;i&gt;Amphithyris&lt;/i&gt; (length 1.2mm; width 1.3mm), oval to round, transparent (Fig. 7 A&ndash;B). Outline and shells often asymmetrical due to substrate, ventribiconvex. Short pedicle, dorsal valve grows very close to substrate (Fig. 7 A). Dorsal valve slightly convex (Fig. 8 A). Exterior surface smooth with growth lines (Fig. 8 B). Dorsal septum absent, interior surface endopunctate, punctae variable in size (Fig. 8 C and D). Interior with U-shaped amphithyrid foramen framed by pair of short socket ridges at lateral margins that slightly extend beyond posterior margin (Fig. 8 E). Oval hinge sockets (Fig. 8 E). Schizolophous lophophore (Fig. 7 B, 8F).&lt;/p&gt; &lt;p&gt;Ventral valve more convex than dorsal valve (Fig. 8 A). Interior with very low median septum extending from anterior edge of V-shaped delthyrium to third of valve length (Fig. 9 A&ndash;C). Oval muscle impressions visible on each side of septum, anterior rounded margin of muscle impressions on the same level as anterior end of septum (Fig. 9 B). Hinge line almost straight, small emergent hinge teeth, not parallel to hinge line (Fig. 9 B). Dental plates absent. Protegulum in all specimens with one wrinkled middle ridge and two very low ridges on each side (Fig. 9 E and F). Weak capillae on exterior side of ventral valve (Fig. 9 I). Brush of endopunctae visible on exterior valve surface (Fig. 9 J), majority of endopunctae accompanied by single tubercle at distal end of brush (Fig. 9 K and L). Tubercles always pointing posteriorly. Distribution and form of tubercles irregular and absent in smooth umbonal area (Fig. 9 D, G and H).&lt;/p&gt; &lt;p&gt; &lt;i&gt;Population density&lt;/i&gt;. Thirty-two individuals of &lt;i&gt;A. cavernicola&lt;/i&gt; n. sp. have been counted on the coral rock (see Fig. 1). The distribution of the specimens across the rock surface is irregular and most of the individuals are concentrated on the bottom area. The highest density found is thirteen individuals in six square centimeters, with no more than two specimens per any square centimeter. The shortest distance between two individuals is approximately 0.4 cm and the longest 5.5 cm. The animals never touch each other nor do they attach to conspecifics. All specimens are attached to the substrate by a short pedicle with some distance to the neighboring individual of the same species.&lt;/p&gt; &lt;p&gt; &lt;b&gt;Remarks.&lt;/b&gt; &lt;i&gt;A. cavernicola&lt;/i&gt; n. sp. is clearly distinguished from the other species within the genus &lt;i&gt;Amphithyris&lt;/i&gt; by the tubercles covering the surface of the ventral valve, the low ventral median septum, and the visible muscle impressions inside the ventral valve. &lt;i&gt;A. cavernicola&lt;/i&gt; n. sp. resembles &lt;i&gt;A. parva&lt;/i&gt; as both share a very small size and the absence of a dorsal median septum. &lt;i&gt;A. cavernicola&lt;/i&gt; n. sp. represents the first record of the genus from the Coral Sea, Australia.&lt;/p&gt; &lt;p&gt;DV length VV length Average Width&lt;/p&gt; &lt;p&gt;Holotype QM G333507 1.3 - 1.4&lt;/p&gt; &lt;p&gt;Paratype ZMB Bra 2144 1.3 - 1.2&lt;/p&gt; &lt;p&gt;Paratype ZMB Bra 2176 - 1.3 1.4&lt;/p&gt; &lt;p&gt;Paratype ZMB Bra 2177 1.0 1.1 1.2&lt;/p&gt; &lt;p&gt;Paratype ZMB Bra 2180 1.3 1.4 1.5&lt;/p&gt; &lt;p&gt;Paratype QM G333508 - 1.3 1.4&lt;/p&gt; &lt;p&gt;Paratype ZMB Bra 2183 1.3 1.4 1.4&lt;/p&gt; &lt;p&gt;Paratype ZMB Bra 2187 1.1 1.2 1.4&lt;/p&gt; &lt;p&gt;Ϭ = 1.2 &plusmn; 0.1 Ϭ = 1.2 &plusmn; 0.1 Ϭ = 1.3 &plusmn; 0.2&lt;/p&gt;Published as part of &lt;i&gt;Nauendorf, Alice, Wörheide, Gert &amp; Lüter, Carsten, 2014, Revision of the brachiopod genus Amphithyris (Rhynchonelliformea: Platidiidae) with descriptions of two new species, pp. 221-240 in Zootaxa 3847 (2)&lt;/i&gt; on pages 233-236, DOI: 10.11646/zootaxa.3847.2.3, &lt;a href="http://zenodo.org/record/227230"&gt;http://zenodo.org/record/227230&lt;/a&gt