Caller ID for Risso's and Pacific White-Sided Dolphins

Climate change affects the distributions of marine mammals1, and some temperate water species are spreading northward into the Arctic Ocean2, 3. Tracking expanding species is crucial to conservation efforts and using automatic detectors and classifiers to track the locations of their vocalizations could help. Risso’s (Gg) and Pacific white-sided (Lo) dolphins were documented spreading poleward2 and make very similar sounds, making it difficult for both human analysts and classification algorithms to tell them apart. Variational Mode Decomposition (VMD) has provided both an easier visualization tool4 for human analysts and offers promising capabilities in separating call types of similar spectral and temporal properties. Here we show a new visualization tool and feature extraction technique using VMD that achieves 81.3% accuracy, even when using audio files with faint signals and high background noise levels and without context clues. Because not all dolphins whistle5–7, being able to distinguish between just their pulsed signals is important for tracking them using as many files as possible from under-sampled areas of the ocean. Automating the VMD method and expanding it to other dolphin species that have very similar pulsive signals will lead to a faster understanding of ecosystem dynamics under a changing climate than can currently be achieved.

Depth-Dependent Spatiotemporal Dynamics of Overwintering Pelagic Microcystis in a Temperate Water Body

Cyanobacteria in the genus Microcystis are dominant components of many harmful algal blooms worldwide. Their pelagic–benthic life cycle helps them survive periods of adverse conditions and contributes greatly to their ecological success. Many studies on Microcystis overwintering have focused on benthic colonies and suggest that sediment serves as the major inoculum for subsequent summer blooms. However, the contemporaneous overwintering pelagic population may be important as well but is understudied. In this study, we investigated near-surface and near-bottom pelagic population dynamics of both microcystin-producing Microcystis and total Microcystis over six weeks in winter at Dog Lake (South Frontenac, ON, Canada). We quantified relative Microcystis concentrations using real-time PCR. Our results showed that the spatiotemporal distribution of overwintering pelagic Microcystis was depth dependent. The abundance of near-bottom pelagic Microcystis declined with increased depth with no influence of depth on near-surface Microcystis abundance. In the shallow region of the lake (<10 m), most pelagic Microcystis was found near the lake bottom (>90%). However, the proportion of near-surface Microcystis rose sharply to over 60% as the depth increased to approximately 18 m. The depth-dependent distribution pattern was found to be similar in both microcystin-producing Microcystis and total Microcystis. Our results suggest the top of the water column may be a more significant contributor of Microcystis recruitment inoculum than previously thought and merits more attention in early CHAB characterization and remediation.

Patterns and drivers of evapotranspiration in South American wetlands

Evapotranspiration (ET) is a key process linking surface and atmospheric energy budgets, yet its drivers and patterns across wetlandscapes are poorly understood worldwide. Here we assess the ET dynamics in 12 wetlands complexes across South America, revealing major differences under temperate, tropical, and equatorial climates. While net radiation is a dominant driver of ET seasonality in most environments, flooding also contributes strongly to ET in tropical and equatorial wetlands, especially in meeting the evaporative demand. Moreover, significant water losses through wetlands and ET differences between wetlands and uplands occur in temperate, water-limited environments and in highly flooded areas such as the Pantanal, where slow river flood propagation drives the ET dynamics. Finally, floodplain forests produce the greatest ET in all environments except the Central Amazon, where upland forests sustain high rates year round. Our findings highlight the unique hydrological functioning and ecosystem services provided by wetlands on a continental scale.

The genome sequence of the channel bull blenny, Cottoperca gobio (Günther, 1861)

We present a genome assembly for Cottoperca gobio (channel bull blenny, (Günther, 1861)); Chordata; Actinopterygii (ray-finned fishes), a temperate water outgroup for Antarctic Notothenioids. The size of the genome assembly is 609 megabases, with the majority of the assembly scaffolded into 24 chromosomal pseudomolecules. Gene annotation on Ensembl of this assembly has identified 21,662 coding genes.

The latitudinal uniformity of the unique life history of Velia caprai (Heteroptera: Veliidae) and notes to the pre-overwintering period of selected water striders (Heteroptera: Gerridae)

Temperate water striders (Gerridae) overwinter as adults and die after spring reproduction. European water cricket Velia caprai (Veliidae) overwinters concurrently in egg and adult stage in Central Europe. This rare overwintering strategy goes with longevity ofthis species. Adults can survive two winters in Central Europe, unlike other semiaquatic bugs. Scandinavian populations of V. caprai and water striders Gerris lacustris and G. lateralis were examined at the beginning and end of September to determine their life histories. Both gerrids start to overwinter during September, females prior to males and macropterous individuals prior to brachypterous. All females of G. lacustris and G. lateralis enter reproductive diapause before winter. V. caprai overwinters in both adult and egg stage in Norway, and can probably survive two winters. Central European and Scandinavian populations of V. caprai share the same unusual way of overwintering and probably also the whole life history.

Sixteen new generic records of Korean Bryozoa from southern coastal waters and Jeju Island, East China Sea: evidence of tropical affinities

The first records of 16 genera of cheilostome Bryozoa not previously reported for Korea are given here. All are from southern coastal waters, especially Jeju Island, which appears to be Korea’s marine-biodiversity ‘hotspot’. Jodoella koreensis n. gen. et sp. (Robertsonidridae) is new to science. Seven additional new species are described for the genera Copidozoum, Reptadeonella, Schizosmittina, Saevitella, Torquatella, Stephanollona and Plesiocleidochasma. The other genera new to the Korean fauna are Dibunostoma, Corbulella, Onychocella, Stephanotheca, Bryopesanser, Calloporina, Hippaliosina and Pleuromucrum. The Japanese Pleistocene species Calloporina hayamiae Arakawa is newly reported alive from Jeju Island. Four of the species were previously known only from the tropical Indo–West Pacific, three others are found in semitropical/warm-temperate water, and the other known genera have warm-water species, supporting data from other taxa that Korean’s southern waters, especially in the vicinity of Jeju Island, are profoundly influenced by the warm Kuroshio Current and global warming trends. Currently, at least 112 species of Bryozoa are known from Jeju Island, 101 of them Cheilostomata, representing c. 70% of all Korean cheilostome species. Four new combinations are introduced: Copidozoum canui (Sakakura) n. comb., Schizo pedicellata (Soule, Soule & Chaney) n. comb., Torquatella ensenada (Tilbrook) n. comb. and Torquatella longiuscula (Harmer) n. comb. Torquatellidae is subsumed in Celleporidae and Predanophora in Torquatella.